Appropriate UV-shield for epoxied deck

[carioca1232001]

I have just finished refurbishing a mahogany deck with inlaid white-wood (marfim /ivory) strips, using epoxy-glue, epoxy resin and two layers of angel hair ( a very fine synthetic fabric as used on surf boards, kayaks and the like).

In doing so I took into account the many helpful tips and invaluable advice obtained on this forum.

The deck is now in show-case form but am now contemplating the (mandatory) UV-shield for the same.

Several coats of 2-part clear polyurethane or several coats of 1-part polyurethane-based varnish, over the epoxied deck ? ?

Which is best for filtering out UV radiation ?

[sdowney717]

Which is best for filtering out UV radiation ?

Keep the boat under cover is best way to prevent sun damage.
or try some of that Nyalic
www.nyalic.com (http://www.nyalic.com)
one gallion covers 1200 sf?

It ought to last on the plastic epoxy surface a long time and it wont yellow, crack or peel.

[Old Bingey]

I keep trying to find the best way to protect epoxy. This "Bristol Finish" two part stuff is the best I have found so far.

http://www.bristolfinish.com/

Good luck.

[carioca1232001]

sdowney,
I note you are ken on Nyalic. Have you used it yourself ? Any idea what it costs ? One factor in its favour is that it does not classify under the hazardous goods tag, so shipping it overseas may be easier.

Old Bingey,
The clear Bristol Finish product is for indoor use while the amber one is for the outdoors, both resilient two-part polyurethanes.
I guess that the amber colouring in the outdoors version is a direct result of the UV filter blended within the brew.
Again both are classified as hazardous products for shipping.......
Any idea as to how a one-part poly-based International brand amber-coloured Varnish would fare in this application ? It is readily avilable here

[sdowney717]

No, but I plan on it in the spring when I get to refinishing the bright wood on the outside.
I just dont like the idea of working hard to get the finish looking so good and then see it go in a few years. And this nyalic looks so easy.
I called them last year and it is not cheap, but supposedly a little goes a long way.
Why dont you blaze the trail here and let us all know how well it works?

[Old Bingey]

I hope you do figure out what to use. The inability of the paint industry to figure out a way to make a long lasting clear coating has perplexed me for a long, long time. I have a clear plastic rain guage that the tractor place gave my mother in 1953 when she bought a new Ford Jubillee. It has been out there in the hot sun ever since and is still as good as new. Airplane windshields hold up pretty good, too, and there is something they call "clear coat" that they spray on cars... what's that?

Anyway the amber Bristol stuff will hold up better than anything I have found so far... as good as the original two part Stoppani that Riva used for so long. When Bruno died, that was the end of that.

Good luck

[GC]

I have had the best results with two part clear Endura, its super glossy, super strong, great UV protection. Its basically an air craft grade clear coat.

[JimD]

I've used Endura as well and am happy with it. Flaked off in a couple spots but that may have been do to poor prepping on my part.

[sdowney717]

found this on interthane clear. And it is expensive.

http://www.oneoceankayaks.com/Wshophtm/Shop28.htm

[carioca1232001]

Old Bingey,
I have a mech engr. friend who retired recently from VW´s R&D Lab at the main São Bernardo do Campo plant.
He suggested to me the final clear coat that VW spray over their auto finishes, an automotive 2-part polyurethane, which soaks in rain and sunshine galore - and survives q ! Much cheaper than any boat stuff ;) The bigger paint shops also carry an additive that you may use to make this clear coat film more flexible

[carioca1232001]

sdowney,
The Interthane product you researched seems to be manufactured by International Paints.
We have a local International 2-part clear-coat polyurethane here called Perfection, which some use as a top coat for underlying 2-part poly paint (tinted).
This Perfection product sells for nearly thrice the price of their clear-coat Interpoly 2-part poly destined for indoor coating of (porous) stone ( ardosia ) tiling material .
In the past, I used Interpoly directly over the raw mahogany deck. Looked grand for a year or two, but then flaked off and crumbled into a mess.
Nyalic seems as good a candidate as any, but how about 2-part clear-coat polyurethane as used by the auto industry ? :rolleyes:

JimD and GC,
Thanks for the Endura suggestion, but like Bristol Finish, it would be a pain to ship overseas - I would be reluctant to ask my pilot friend to bring some down for me :confused:

[pcford]

Just a couple quick notes.

On reflection, you might consider that car finishes have different requirements than wooden boats. Unless of course, VWs are made of wood in Brazil.

2-part polyurethanes came on the runabout market about 15 years ago. The results were stunning as were the catastrophic failures in a year or so. Massive cracks in varnish; varnish came off in great sheets.

People were pretty scared off at that time.

[carioca1232001]

pcford,
Surely, it must be reasonable to expect that generally speaking, 2-part polyurethanes have developed quite a bit (performance-wise) since they were first launched 15 years ago ?

Well, the dash boards on the old Jags were wooden, as also some of the coach-work trim on the older American station-wagons ;)

But as car bodies are metallic, the daily heating/cooling cycle, plus rain and snow, subjects the paint - and topside poly clear-coat - to considerable excesses. This was the point made by my friend from VW.

So after epoxying-and-dynelling a wooden boat deck, which confers a considerable amount of stiffness/firmness to the underlying wooden substrata aside from sealing the same from the vagaries of the elements........ is a 2-part automotive polyurethane clear-coat totally out of the question ? Sherwin-Williams, the manufacturer, also sell an additive that confers greater flexibility to their 2-part auto poly clear-coat.

[carioca1232001]

To add to my last post above...... the UV-filtering properties of automotive 2-part clear-coat polyurethanes is a pertinent concern for the intended application.

[Peter Malcolm Jardine]

2-part clear-coat polyurethane as used by the auto industry ? [Roll Eyes]
I have used two part automotive clear coat, and I have mixed feelings. I used it on a epoxy sealed swim platform that was well above the water, but did get wash when the boat was under way. I added an additional 15% flex agent to the clear coat before spraying, but the compromise took place with slight cracks in the finish, then the clear coat would separate from the platform. I'm going to use a two part varnish on it this time.

http://www.imagestation.com/picture/sraid86/p2f65ad04f911af884c11b645b8df6fb2/faacc1cc.jpg

[pcford]

Having done mahogany runabouts since about '80 I know about clear finishes.

Every few years there is a miracle product. Back in the '70s it was Deks Olje. About 15 years about it was LPUs. Didn't work.

I agree that you do not have a strict wooden deck. And maybe if the boat does not spend any time in sun..an automotive finish might work.

Why are you trying to reinvent the wheel. Traditional varnish is not perfect but you know what it will do.

Refinishing is very time (money) consuming. Why gamble.

Epifanes.

[carioca1232001]

Thanks PMJ for the timely comment. Nothing like hearing from someone who has literally done it !

Well, pcford, are you suggesting that I spread one-part polyurethane-based marine varnish (amber tint) over the epoxied deck ? Does epoxy take kindly to the stuff ?

It would definitely be much simpler to brush on - and especially, to maintain thereafter - than 2-part clear-coat polyurethane. The amber tint may slightly marr some of the deck´s good looks, but that is the price one has to pay.
:rolleyes:

Do bear in mind that MOST wood varnishes (marine or otherwise) nowadays are one-part polyurethane-based, besides containing all the other standard goodies such as tung oil, solids etc...

[carioca1232001]

pcford,

In time..... I see you have recommended Epifanes.

Could you please tell me exactly which product has provided you with the intended results ?

[Wild Wassa]

I like Aquacote water based two pack marine polyurethane for below and above the water (if it doesn't clash with existing materials and it suits the working surface). I'm still to see a crack in Aquacote and I'm approaching 5 years with my oldest coating on dinghies that take a lot of hard work.

This stuff is superior to varnish for a highly polished finish and a finely faired racing surface.

This stuff is very difficult to apply well and takes a lot of preperation and isn't cheap ... but I find it is worth it. Aquacote is sold in the US. It is manufactured by BoatCraft Pacific.

It is made for the Australian environment that has high UV levels ... even at night.

Warren.

[ 12-20-2005, 02:43 PM: Message edited by: Wild Wassa ]

[sdowney717]

carioca1232001
These polyurthane finishes are not going to be forgiving as the nyalic. If you read the info on nyalic you will see it is a flexible coating. The wood is still going to move a little even sealed up with the epoxy. Wood I think is going to move more than metal. The post about it cracking/crazing on the wood swim platform sounds right as rain to me.
The nyalic is also easy in the extreme to use, no mixing, simply paint it on and simply topcoat more on easily. And you know it is 100% UV PROOF. It can be maintained indefinitely and very easily with no sanding, just clean the surface and put on another coat. It says it will last 10 yrs on metal and 2 years on FG, so setup a maintenance schedule every few years put on another coat.

[sdowney717]

http://www.nyalic.com/techspecs.htm

nyalic has an impressive list of characteristics which are unique compared to varnishes or polyurethanes such as recoating.

' Touch up of Nyalic coated surfaces can be done at any time. Clean the area as required and reapply Nyalic using an aerosol can, sponge brush or spray equipment as necessary. NyalicÓ is self-leveling and self-annealing and will blend into and bond with itself.'

Sounds like a winner, new coats melt into old coats

[carioca1232001]

sdowney717,
You had said earlier that Nyalic costs quite a bit more than what the competitors have on offer, that is, 1-part or 2-part polyurethane clear coats and varnishes.
Can you call Nyalic on their 0800 number - I cannot access them on 0800 from Brasil - and inquire what a litre (or thereabout) costs ?
I might just give it a shot, although they do not seem to have a well developed customer base in the marine market.

Thanks

[sdowney717]

Ok,
I will call and post it. I seem to remember $220 a gallon?
Only saving grace is one gallon covers 1200 sq feet, so a lot ove coverage and the container when closed up lasts indefinitely so it wont go to waste.

You can also email them
HBIinc@BellSouth.net

Newzealand and Australia web site for nyalic and some talk about using it on boats.
http://www.nyalic.co.nz/about.htm

[Wild Wassa]

I've been over the Australian and Kiwi Nyalic sites and have openned may folders and have read much but I'm still to find a reference to use on timber. There are multiple references and testimonials for use on metal.

I also notice that Nyalic recommends the use of preparation solutions including an undiluted acid wash for some jobs.

What have I missed?

Warren.

ps, It is now 8.30 in the morning (Sunday morning) and at 9.00 this morning, I'm going to start painting a hull in Aquacote and the boat is going to race today at 2.00 pm. It won't just be one coat either. The boat will have a light cut and polish as well before the race. It is going to be interesting to see how well the paint holds up.

[ 12-17-2005, 04:35 PM: Message edited by: Wild Wassa ]

[sdowney717]

He is using it on an epoxied fiberglass surface, so it is not wood but plastic.
Only thing mentioned about wood is 2 to 3 coats on plain bare wood since it will soak into the grain.
The stuff dries by solvent evaporation and I think if you took some xylene you could dissolve it off the surface. So it is not a catalyzed coating. This is what lets new coats merge into old coats.
I also think it creates a very shiny surface, since they say it restores oxidized surfaces to like new shiny condition, and they do show this on the newzealand site, a picture of a car and bus surface restored on one side with nyalic.
I dont know about the acid wash but the point is it needs to be put on a clean dry surface with no contaminants present.

[pcford]

pcford,

In time..... I see you have recommended Epifanes.

Could you please tell me exactly which product has provided you with the intended results ? Just plain old gloss Epifanes.

And to the others: If there is a miracle product out there, don't you think _everyone_ would be using it?
Or is it a conspiracy by professional boat refinishers?

[sdowney717]

I just think not too many people know about it, I certainly had never heard of it until 2 years ago.
And they dont like the cost.
And they find it easier to buy something local at the hardware or boat store.
And no, I am not a nyalic salesman.

[carioca1232001]

sdowney717,
Another miracle product out there besides Nyalic - and which in contrast to Nyalic HAS a considerable following at least amongst boaters with deep pockets, a point that Wild Wassa has brought up - is a German product called COELAN.
COELAN´S manufacturer started life by doctoring 2-part polyurethane supplied in bulk by one of the large German chemical outfits (Bayer, I think) and altering its carachteristics for specialist applications.
It is marketed as a water-proofing compound, and is applied straight over wood or wood that has been epoxied over.
I would think that it may also have an in-built UV-shield , but cannot vouch for it.

[Peter Malcolm Jardine]

If Warren recommends something you might better use it. :D ;)

[Wild Wassa]

PMJ, do you mean only for those painters who have a cut and polish fetish?

Warren.

[ 12-20-2005, 02:45 PM: Message edited by: Wild Wassa ]

[sdowney717]

Hi carioca1232001

I called them this am
price for a gallon is $181
price for a quart is $50

They can ship by air to brazil no problem

I have been thinking about colean vs nyalic and I think that nyalic would give you the truer look of what you have right now, I think not sure but I have painted a ton of liquid polyurethane permaflex, dont know how it would compare, but I think the colean might change the optical texture of your epoxied surface. And I think the nyalic would interfer in this least. They do describe it as crystal clear.
The permaflex I use has super glossy look to it, but it also can form drips globs and rivulets just like a thick paint. I think the nyalic is more like water, thinner and will have less surface buildup.

[Dan McCosh]

I would think you have two problems--the vulnerability of epoxy to UV and its low melting point. The standard protection for UV is powdered aluminum mixed in the resin, combined with a solid opaque UV-resistant surface. A white deck also controls the heat buildup, which will be substantial in a dark-finished surfaced. (I have had little luck with epoxy glues in varnished hatches, for the same reason, even in this relatively cold climate.) For UV durability in a clear coat, you can expect about six months before some deterioration sets in. Bristol Finish has good UV resistance, but is very vulnerable to miinor cracks that let water in. It might work on a sealed surface, however.

[sdowney717]

I have heard where epoxy can creep if it gets really hot. Boat hulls painted black, I read stories where people said the hull shows its strips and joints due to epoxy softening up. And you still have some very small wood movement due to moisture cycling.
Then you put a varnish type coating that has no give as it ages and it cracks crazes etc...
So it seesm the colean or nyalic which are flexible coatings are about the only choices if you want it to last more than 1 year. It just seems like a no brainer solution.

[Old Bingey]

We are just finishing up a little boat. It is supposed to be finished bright in a few places which are already epoxified. I am going to try that nyalic. I'll let you know how it turns out.... at least the application part.

[ 12-19-2005, 12:57 PM: Message edited by: Old Bingey ]

[Peter Malcolm Jardine]

Just another small comment as this thread has gone on for a bit..

The problem is not the coating most of the time.... it's the wood underneath. The coating gets compromised because wood moves, and there is two sides... the back and the front. Often varnish starts to lift and crack because the wood underneath has absorbed water from the backside, from drips or whatever. The UV problem is another part of the issue, but I use traditional varnishes, and use ten coats. I get three to five years out of varnish that is exposed to the sun all summer long.

Frankly, I wouldn't be prepared to try a new product for the most part unless I had some experience with something similiar, or because this forum had members that recommended it. There is a lot of varnishing experience here. Personally, the greatest investment I put in my boat is time... and I am not generally prepared to put hours of prep time on an untested or un-testimonialed product.

Just my .02 cents.

[sdowney717]

excerpt from a testimonial nyalic user.

http://www.nyalic.co.nz/newsletters/MOIRA.pdf

And then, wonder of wonders, it was done. I saw a big bug land amidships minutes after we were finished and it happily walked
over the now touch dry surface. Perfection is the only word for the finish and every time I look at it I marvel that it looks so good,
was so easy to apply, and took so little Nyalic to do it. We used 1.25 litres to do it. Did it in less than 2 hours and used two
disposable rollers that cost us a grand total of $4. Since we were slipped to do the bottom anyway the yard bill might be an extra
day (counting the washing time and drying time). All up the paint job cost us less than $350 which is, you can believe, a whole lot
cheaper than repainting the hull.
All in all, I couldn't be happier with Nyalic. Easy to use is an understatement; beautiful finish is a reward.

Richard Chesher
Director, eBusiness Vanuatu Ltd.
PO Box 257 Port Vila, Vanuatu

[sdowney717]

Hi Old Bingey,

Can you also put a little on some bare smoothly sanded oak and mahogany and let us know how it looks.
Supposed to take 2 to 3 coats for bare wood.

[Old Bingey]

PMJ & all

I am going to try it anyway. I have been fighting the varnish problem for a mighty long time and am ready to give any new thing a shot.... particularly on my customer's dime.

I always epoxify and usually fiberglass everything to a fare-thee-well anyway so a bare wood test won't be valid for my situation but I will try it. I bet it won't fill the grain on mahogany with only two or three coats.

Oh, another thing... I have been epoxifying boats since the late sixties and have never had any problem with the reported "creeping" under the paint in the hot sun. Of course I adhere to the N. Herreshoff notion that only a fool would paint a boat black. I have never had any kind of varnish crack until the sun damage had done it in anyway and two part polyurethanes only come off properly prepared epoxy when the coating is shot from the sun (less than three years down here). No regular phenolic varnish will last under all day exposure for longer than a year.

[Old Bingey]

Nyalic:

I ordered two 12 oz. aerosol cans.... $30 a can plus UPS. They are just up the road in Atlanta so I ought to get it in a day or two. I'll follow the instructions and do the experiments and let you all know. I read some of the specs and testimonials on the website. They say it will stick to aluminum better than anything... sort of calls up some other possibilities like maybe it'll preserve an outboard motor in continuous salt water use.

[JormaS]

Nyalic seems like a woderful product, and for many different applications. I have two questions, though:

1. When it is said to be UV resistant, does it mean Nyalic itself is resistant, or does it actually block UV radiation from reaching the substrate? This is crucial when the substrate is wood or epoxy, not so much when applied upon paint.

2. When it is said to last, say, 5 years, what does it mean? Has it hardened then, or has it lost its UV resistance, or is it peeling away? It would be good to know in advance if then only a maintenance coat will be needed, or if it has to be scraped off either partly or completely. If it has to be removed, then also the underlying paint is going to be removed.

I´m going to try it anyway, but I just became curious to know if any of you have an idea.

[sdowney717]

From my previous talking with them.

It blocks the UV 100% with a one coat thickness. Thickness of the coating does not help further for UV because 1 coat does the job. I suppose to give it a longer lifetime more coats could be used.

nyalic wears away from the surface at a very slow rate. It does not disintegrate, it must be abraded away by environmental factors sort of like rocks would wear away by the process of erosion.
That is why you have to maintain the coating. But I dont know why it last 10 years on metal or painted surfaces and 2 on fiberglass, excpet to say this, that the nyalic people are expecting you are putting it on a boat hull which has direct contact with abrasive substances and objects in the water, sand etc... That is why I think they say this.

[JormaS]

Thanks, that was illuminating.

[StevenBauer]

OB, have you ever used Le Tonkinoise? I used it on Spars and oars and have been very happy. Very user friendly (non toxic) and looks beautiful.

http://www.tarsmell.com/isroot/ePages/Images/117991/117991-1065603.jpg

"Le Tonkinois (Lay-TON-kin-wah) is an all natural, environmentally friendly tung oil and linseed oil based varnish oil.

It produces a rich, deep varnish finish that is strong and durable, yet it is very easy to apply and maintain.

Only a light sanding after the first coat is required...between subsequent coats, just wipe down with a water dampened rag. Very user friendly, no complicated thinning or mixing, use right out of the can.

Le tonkinois does not get brittle like synthetic varnishes, it does not crack, peel or blister. Rather, it moves with the wood, while at the same time preserving a durable, waer resistent finish.

Each formula is easy to use, works like a horse, and is stunningly beautiful.

Available in 1 liter cans.
Price: $31.95"

www.tarsmell.com (http://www.tarsmell.com)

Steven

[Todd Bradshaw]

I find one coat of the stuff blocking 100% of UV a bit hard to believe - actually, a LOT hard to believe. A Sunbrella boatcover doesn't even block 100% of UV (high 90% range). Don't you think that if it was anywhere near that good the epoxy manufacturers who invented the technology that you're using would be all over the stuff, and long before a couple guys on an internet forum "discovered it" for use on epoxy coated boats?

[Old Bingey]

Todd,

Me, too. I just can't help thinking that somebody ought to be able to come up with something and am ready to try anything. I'll let y'all know after about three years.... probably much sooner. I am going to do the one-coat experiment.

[Todd Bradshaw]

I wouldn't test it on anything valuable, like a boat. Try some scrap wood sealed with epoxy. Stick it out in the sun and see how long it lasts before the epoxy turns yellow and starts to get gummy. I'll admit to being one who firmly believes that if something sounds too good to be true - it probably is. Add in the fact that there is almost nothing on the web about the stuff other than company-sponsored hype, plus what good is a testimonial made two days after applying a product that's supposed to last for years? If I'm supposed to be applying it to protect a lot of expensive wood, resin and invested labor, I want to hear from the guy two or three years later, not right after he put it on. And what's the deal with "one coat does it all - but put on two or three if it's going to be around water" as is stated in their info sheets? ...and I didn't get the feeling that they were talking about "underwater". I'd love to be proven wrong, but until the stuff is actually proven to work on bright-finished, epoxy-sealed boats, I'll stick with my old can of Captain's Varnish.

[Gerald]

Scuna products had a bunch of wood samples with several different bright finishes.
Gerald

[Old Bingey]

I am still going to put that stuff on this little skiff. It is just the foredeck, seats, rails and a bright sheerstrake.... all easy to refinish which I'll do for free when it fails. I have had a lot of experience re-epoxifying and re-varnishing. I'll scrape that "Nyalic" and the epoxy off of there in a jiffy. Both I and the customer are very interested in this. I already threatened the company with writing a full report and they were non-plussed. It would be mighty cool if you could spray on one coat with an aerosol can about every two years without any preparation. I'll keep you posted for sure.

As an aside. What sun damaged epoxy does is turn opaque and flake off. On our own little skiff, "Old New" we just let it go for something like five years and almost all of it came off. Then we scraped and refinished the whole boat and she is just as pretty as ever. The only damage to the wood was just a little weathering and wear. We scraped off the gray and the fuzz and re-epoxied and the color came right back. That boat was built with all the strakes fiberglassed on the outside and on the bottom on the inside. The inside above the bilges was finished bright and all that was destroyed by the sun (the boat sits in the sun almost year round). There was no change in the planking. It did not split, check, or warp even though it had intact epoxy and fiberglass on only one side. I think it was a pretty good experiment.

[sdowney717]

Let us know all the details, pictures if you can as well.

I read on the internet that someone put nyalic on their car and it all peeled off. BUT, they put it right on top of the wax.

I was just thinking, if nyalic works as good as they say, it could put the varnish people out of business.

[pcford]

I was just thinking, if nyalic works as good as they say, it could put the varnish people out of business Hmm. Yes, the same thing was said about Deks Olje, clear LPUs and all the rest of the miracle products.

Good luck. You try it first and report back. I won't use it 'til I get plenty of positive feedback. I'm not risking my time and my client's money for a pig in a poke.

~~~~~~~~Wondering.......why are boat owners so eager to take plunge into an untried product? A varnish job on even a small boat is worth thousands of dollars. Why do you risk your time so eagerly? It's a mystery. Something in the American pysche I suppose. There's always something better. Marine related products have improved tremendously over the last 50 years. However, I'd say that it is an evolutionary process. And there are a lot of evolutionary dead-ends.

Sorry if I offended any "intelligent design" people out there. heh.

[Wild Wassa]

There is only one UV shield, a uniform and well coated surface that is well maintained.

It doesn't really matter what you use traditional varnish, poly/oil blend varnish or a clear poly as long as you maintain it.

High quality marine polyurethane seriously kicks boat though and if Nyalic kicks boat better than a quality poly, keep Nyalic well maintained then.

It is not a contest, it is a maintenance issue.

Warren.

[Todd Bradshaw]

...so keep that spray can handy....

[John B]

"There is only one UV shield, a uniform and well coated surface that is well maintained.
It doesn't really matter what you use traditional varnish, poly/oil blend varnish or a clear poly as long as you maintain it."

I don't get it.
What are the "UV inhibitors" that the paint companies cite as the reason for their extraordinary pricing in 'marine varnish'( I'm using the term loosely)I've been told numerous times over the years that the cost difference between a cheap and expensive varnish is "uv inhibitors"
Are you saying there are none?

[Wild Wassa]

John, I was only talking about marine quality materials, I don't talk about anything else.

Traditional varnish if oil rich, is a marine quality material and has been for eons.

Warren.

[Bob Cleek]

Ditto to what pcford is saying. Those of us who have been doing it for a long while know that "miracle cures" are far and few between. Let some other guy take the chance on an untried product. I could fill a swimming pool with the tears I've seen shed over magic finishes that failed to live up to their (often high priced) claims. Good quality varnish (the cost reflects the UV inhibitors in them) like Z Spar or Epiphanes, properly applied in sufficient coats over CPES or a decent sealer (keeps the stuff from lifting as much if the wood gets wet) is the best finish in the long run. Use what the guys who do it for a living use. They've figured out the best cost/benefit analysis through long experience.

[John B]

I see what you mean Wassa.

Merry christmas you guys. I have to go and wear some varnish off as many spars as I can in a week or so.Expose some goldspar to some rays.

[carioca1232001]

I got back last night after a holiday on the island of Fernando de Noronha, some 600 km into the southern atlantic, off the north-eastern Brazilian coast.

So my pace has slowed a bit, although my mind seems to be less foggy than prior to leaving for that destination ;)

So Old Bingey is currently trying out Nyalic. Eagerly awaiting his comments and findings. .

Sdowney, thanks for the pricing info. I sent Nyalic an email but had no response as yet. The cost does not bother me as much as their contention that it blocks UV 100% . Sounds like sales gibberage to me. :rolleyes:

And of course the ensuing hullabaloo, should the Nyalic product fail miserably for the intended application, in comparison to a time-tested solution :mad:

BTW, is it incumbent on paint/coating manufacturers to provide certification from an accredited lab for the claims they make ?

Now Bob Cleek, pcford and some others are sticking to their guns and recommending the traditional UV-blocking route. Fits in with what the chappie below has to say about options for shielding an epoxied surface from UV-degradation:

UV-shield for an epoxied surface (http://www.epoxyproducts.com/clear4u.html)

[Old Bingey]

I got my two cans of Nyalic the day before Christmas. They are high grade 12 oz. aerosol cans. The product looks and smells exactly like nitrocellulose lacquer. The volatile part evaporates as quickly as unretarded lacquer. I haven't tried in in the cold (the extensive instructions say the surface temperature needs to be between five and 55 degrees Celsius) to see if it will blush or not. The hullabaloo yesterday kept me from doing anything but a rudamentary spray test. It does not seal oak worth a flip but they are steadfast in their assertion that one coat will do it.... We'll see.

[Norman Bernstein]

Well, it's fairly obvious that there are many opinions on the subject of just what form of clear UV-protected coating works best... and I suspect that many of these products are probably pretty good...

However, I should think that the more important issue is what one uses to build up the base coat, before applying the various 'miracle' UV-protective coatings.

I'm wondering what the easiest and fastest base coating system might be. Epoxy has been touted, but epoxy is frankly a pain to sand, especially when the surfaces aren't flat enough for an orbital sander, like coamings, gunwales, etc.

Ordinary varnishes take a long time to polymerize, and it takes many coats to get a truly flat result.

I'm thinking about the possibility of using a water-based polyurethane varnish as a way of creating a smooth base coat. I've used Carver Tripp water-based polyurethane varnish on the cabin sole of one of my boats, and was highly impressed with it; it dries VERY rapidly, allowing many coats can be laid down in a single day, is easy to work with (no smell, soapy water cleanup), sands easily, and forms a very flat substrate.

How about a day's worth of water-based polyurethane varnish, as a base coat, followed by any one of these wonder coatings for UV protection? Has anyone tried it?

[carioca1232001]

Old Bingey,
Your initial findings are noteworthy. Keep them coming for the benefit of us all. Bravo !

[Old Bingey]

Norman,

I have tried a lot of ways to build up a base for the varnish job and have gradually evolved down to epoxy. I use the clearest, slowest hardner epoxy I can find. I have also found that if the wood is hot when the epoxy is applied and then the coating is swept with a heat gun after it is on there and re-brushed a little, the viscosity will be reduced so that there will be no runs and the cooling wood will keep any pores from outgassing and making bubbles. It takes a few more coats to get a sufficiency on there but it is easy. I even do spaced rails like that now. I also do not ever sand epoxy. I scrape a little and use a Scotch Brite pad. I have found that epoxy is a much better base for any polyurethane than anything else (even more polyurethane). For the last twenty years I have been using two part polyurethane to protect the epoxy and it seems to last better than anything so far. Regular phenolic varnish is still the prettiest, though, and is actually easier to maintain but you can't neglect it. Down here on the Gulf coast, it has to be sanded and recoated twice a year where two-part will go two years and a Scotch Brite job and another coat will take it another year or two. On my own boats, I let it weather completely off and then start from scratch. It is a running battle. I'll try anything. I'll do one coat of this Nyalic on this boat and then recoat one coat every year and see. No sanding, aerosol can. Kind of incredible sounding but like I said, I'll try anything. I'll let you know.

Edited to add: On my website are some pictures of a boat in the epoxy stage ready for the varnish. It is the little, fat double ended boat still in the shop.

RW

[ 12-26-2005, 09:43 AM: Message edited by: Old Bingey ]

[Norman Bernstein]

RW,

Thanks for the advice. Any particular brand of slow curing, clear epoxy you prefer? Also, where is your website? I'd like to look at what you're working on... mine is at http://www.marisystems.com/ellipticat by the way...

Norm

[ 12-26-2005, 10:53 AM: Message edited by: Norman Bernstein ]

[Gerald]

Carioca1232001
Did you check with Scuna products?
My preference is to always use the local product. However, I am a bit of a nut about that and no one should confuse my nuthood with reality. For example, I would never but never buy a car designed and sold by Japan while living in the US. Where is the profit going?????? Sooo ....... my question is ........... can Scuna provide a product equal to the ones listed in the tread?
Gerald

[pcford]

Just to clarify:
I certainly would consider using other varnishes and coating other than what I am using.

Over the last thirty years, the preferred varnish has changed from Man O'War to Captains to Epifanes. Others may have other favorite varnishes, but I think as a general rule that has been the evolution 'round Seattle. The point is that I and most other professionals _never_ want to be the first to try a new product. Way too much money on the line. But if the product shows up and has a track record, then I would try out a new varnish or coating.

It always baffles me when owners are so willing to embrace an unproven product.

[samiller]

Originally posted by pcford:
Having done mahogany runabouts since about '80 I know about clear finishes.

Every few years there is a miracle product. Back in the '70s it was Deks Olje. About 15 years about it was LPUs. Didn't work.I am preparing to build skin-on-frame boats using Dacron or Nylon cloth coverings, so the UV issue is key for me. It is disconcerting that those products (Nyalic; Bristol Finish) that advertise UV blocking offer no measurements or other numbers to illustrate their effectivity. Stating that a product offers "10 times" as much protection (Bristol Finish) as an unspecified varnish that isn't quantified for UV doesn't shed much light <sorry> either. Sunblocking lotion and clothing vendors at least manage to assign a relative score... I recall an article years ago (in Car & Driver, perhaps) on automotive polishes (this was when carnauba and paraffin waxes were losing market to newer technology) that concluded that the applied thickness of a product determined the shortest wavelength of radiation that could be attenuated, and that none of the tested products was thick enough to be worth squat against UV.

Scott

[Old Bingey]

I have a sample out in the sun now alongside a similar sample coated with Bristol Finish two part acrylic/polyurethane which is what I have been using lately. Both samples are well epoxified and fiberglassed thin planks of tulip poplar like I have been building boats with for a long time. The epoxy is W.E.S.T. (tm) 105 resin - 209 extra slow hardener. The Nyalic is a single coat wet out about like the top coat on a lacquer finished piece of furniture. Both pieces look good. The Bristol has a slightly more "real varnish" look to it because of that slight amber color but both are very shiny and smooth. The Nyalic aerosol can nozzle is excellent. The Bristol is brushed on and is self leveling at this temperature (63 degrees F). I also have a piece of plain unepoxified oak that I sprayed with Nyalic one coat... did not fill the grain at all and did not make it shiny. I'll see if it prevents the wood from turning gray. I am still going to put Nyalic on the little bit of brightwork on this customer's boat. He lives down in S. Florida and, like me, is always looking for a better way.

Norman, my website is up there on my profile and I think it will work as a link but if not, it's www.robbwhite.com. (http://www.robbwhite.com.) or you can just google "Robb White". That's a neat looking little catboat you are building. I'll keep an eye on it.

[carioca1232001]

Gerald,
Leonardo, CEO of Scuna products, alerted me several times about the need for a UV-shield and actually suggested using International´s Interpoly 2-part clear polyurethane. This was after he very generously put me threw the paces of applying his epoxy-based products on my foredeck.

To be perfectly honest, I felt he was somewhat unsure as to which product he was to recommend for the most effective UV-shield..... :rolleyes:

I shall call up International´s tech assistance line about the suitability of CETOL, an Akzo Nobel/Sikkens product that is now marketed under their umbrella . Supposedly far superior to International´s local marine varnish products, but is required to be applied over virgin wood, no intermediaries tolerated . In the worst case could use their marine varnish Solgard, Schooner etc ....or even their Perfection top-of-the-line ( read deep-pockets ;) ) 2-part clear polyurethane.

pcford,
I am with you on the gullibility of some forumites - I AM NO EXCEPTION - when it comes to the use of novel, untested products. Could it arise from a longing to use something that would free us from the need of frequent maintenance ?
At the same time, we should exercise great caution before committing ourselves into inordinate expenses of both time and money...
As for the post immmediately after yours, it has to be commended for putting into the right perspective, some of the wild - and largely unsubstantiated - claims made by some of the manufacturers of these novel coatings.

[carioca1232001]

Errata:

please read through the paces in lieu of threw the paces

[sdowney717]

yes, As I thought one coat on bare wood wont seal it. It must soak into the wood and then harden inside. It is a thin watery liquid? It would be nice to know if 3 coats on bare wood forms a shiny surface? I also plan on coating my own wood with epoxy before putting on any other coating as well.

[Gerald]

To be perfectly honest, I felt he was somewhat unsure as to which product he was to recommend for the most effective UV-shield.....



Thanks for the info. Good to know because I have some wood to varnish on two boats. I can understand that he might be unsure. There are how many hundreds of lines of text here and everyone is sure and then again not so sure.
Gerald

[carioca1232001]

But do take note that those who are sticking to their guns are pretty sure of themslves.

Again, they do not seem blind to new developments, provided there are volunteers out there to try out the novelties and report the findings.

[Richard Smith]

pcford - "Over the last thirty years, the preferred varnish has changed from Man O'War to Captains to Epifanes."

pcford - 'Not challenging, just curious about the evolution - especially over the last two: Could you pls expand as to your view of which desirable qualities caused the preferences to go from Captains to Epifanes, and then speculate why one might want to stay with Captains? - as some do. For example, is it that Epifanes takes some getting used to for application?

Thanks.

[pcford]

pcford - 'Not challenging, just curious about the evolution - especially over the last two: Could you pls expand as to your view of which desirable qualities caused the preferences to go from Captains to Epifanes, and then speculate why one might want to stay with Captains? - as some do. For example, is it that Epifanes takes some getting used to for application? Nothing wrong with Captain's, in fact, there is nothing wrong with Man O War. It's just that most runabout people think that Epifanes has more gloss and UV resistance. I can't speak to why someone would stay with Captain's...as I said, it's a fine finsih. Some might be put off by Epifances handling...if rather thick in comparison. But that does not take much work to get used to it.

[Puka]

Sikkens is extremely dissapointing, unless you like the look of tinted plastic covered timber.
I prefer it greyed off than covered in sikkens.
Epoxy sealer and spar varnish has my vote if you don't mind doing the 6 coats.

[carioca1232001]

Puka wrote:


Sikkens is extremely dissapointing, unless you like the look of tinted plastic covered timber.
I prefer it greyed off than covered in sikkens.
Epoxy sealer and spar varnish has my vote if you don't mind doing the 6 coats. When you say Sikkens - they are a paint/coating manufacturer, like Epiphanes - are you referring to a specific product, like CETOL for instance ?

And again, was you disappointment based on aesthetics (looks) alone, or did the coating start to flake off, go fut etc. ?

The reason I am asking is that I have used CETOL (matte finish) over bare wood on the fore deck and it held up better than International´s Solgard or Schooner marine varnish.

[J. Blazy]

Please allow me to provide some minor exterior finish Chemistry 101 from back in my days as a polymer scientist developing UV blockers in clear coatings for a 100% solids polymer company:

UV protection in the best modern boat varnishes would a synergistic combination of two additives: Tetratraziole-based UV blockers and Hindered Amine Light Stabilizers (HALS).

The best and largest supplier of these additives are from Ciba-Geigy (Five Year Clear mentions them on their website also), and both additives are deep yellow in color, yet crystal clear liquids, not milky (some will say that the milkiness of the varnish is the UV additives - not true).

These additives are used in a 2 to 1 ratio together, where the overall formula will have at most (very expensive formula loading) 2% by weight Tinuvin (Ciba's brand name) 292 (HALS) and 1% by weight of any of the 400 series of Tinuvin tetratraziole UV blockers. (HALS do not block UV, but "mop-up" the excess free-radicals created from UV oxidation, while the Tetratraziole UV blockers absorb the UV light similar to opaque pigment, but are clear additives)

This is the first dead giveaway to me of the effectiveness of any given clear marine varnish - How "yellow" or amber the coating is - the more yellow, the better UV protection. The Ciba additives are also very expensive, so you get what you pay for - i.e. if the varnish is cheap, it'll likely have very little UV protection, and vise versa (hopefully).

This is highly dependent upon the elasticity of the given formula, though. You could have the most expensive, highest loaded UV blocking package in a given formula, but if the urethanes cross-link too tightly, you'll get brittleness and cracks. This is perhaps the advantage of the one-part varnishes that are tried and true, however it is possible to formulate 2 part, elastic varnishes quite well, and thats why they are also high-performance (they spray better, etc).

All this is also dependent upon the mil thickness of the final coating - Too thin, and the sunlight easily penetrates past even the best blockers - too thick and you risk polymer shrinkage cracks.

And one final observation - even the best UV protection in the best aliphatice urethane formula will eventually "extinguish" - which is chemist-speak for the "burning out" of these expensive UV blockers/HALS over the years. This is why you want to apply the maximum safe mil thickness, so that as the surface of the coating extinguishes, the sub layer is going to be "fresh".

Also, as THE final note, I would never do brightwork without a non-blushing epoxy undercoat (WEST 207 hardener, or Paul Oman's non-blushing cycloaliphatic epoxy). You ever wonder why the WEST system 207 "special coatings" hardener is so yellow? Ciba-Geigy's UV additives. And yes, the 207 special hardener works great under varnish like my mahogony deck below:

http://www.imagestation.com/picture/sraid139/pabafcf73e44ee95ed47bc1b820d66e93/f700a261.jpg

[Old Bingey]

It looks like we have fooled around and provoked a good bit of actual knowledge into this discussion. I am impressed. Of course I am easily fooled into trying every new wonderful sounding thing... drove a VW in '54... jumped on the epoxy bandwagon before WB magazine came out... started using two part polyurethane (Stoppani) when Riva did... even tried Deks Olje (which is a good base for pine tar varnish).

I can't help trying to find out if this Nyalic is any good or not. I read all about the expensive additives that block (?) destruction from the sun in varnish of all sorts and I think I understand but what I don't understand is why my mother's old rain guage is still in good shape. It is made out of perfectly clear plastic and was given to her when she bought a new "M" John Deere in 1950... has been sitting on the fence corner post ever since. What's up with that?

I won't be able to communicate in this way for long. When my grandchildren have to go back to school, I am going to quit paying the damned cable people for the use of this little wire and evacuate back to the coast where I belong. When I come back, I'll let you know how my Nyalic experiment looks but it is liable to be a long time. I appreciate that nobody has attacked me on this forum.

Sincerely,

Robb White

[J. Blazy]

Hey Robb,
I've appreciated your posts here - don't go away.
As to your clear plastic rain guage - I'll attempt to answer why its still good after all these years, which will also shed light onto why varnishes don't last.

The rain guage has lasted and the varnishes don't because:

</font> - the rain guage is likely cast acrylic, which being pure PMMA is not degraded by sunlight - vs varnish which is diluted with organics and other diluents to make them liquid at room temp for application
</font> - being cast into shape, and not cast ONTO an expanding/contracting substrate, it is able to move with temp extremes without something (woodgrain) keeping it from doing so
</font> - pure PMMA or other solid thermoplastics are made up almost entirely of long molecular chain molecules. ALL varnishes are made up of multiple oligomers, monomers, and solvents which are neccessary to make it liquid in application, and these ingredients are of very small molecule size, which means that they won't bond to each other as well. Kindof like bricks (large molecular chains) being compared to sand grains (small molecules in monomers and solvents). Bricks can have staggered joints and form great structure, as large molecules overlay each other - not so with small molecular weight urethanes/diluents.
</font> - vitually no solvent entrapment and no unreacted polymer chains in cast acrylic - much more stable when solid AS OPPOSED to liquid varnishes - regardless of whether they are one part or two part cross-linked LPU's. NO varnish on the market is ever 100% "dry" even after a month of drying / curing. There is always trace amounts of non-bonded molecules of unreacted urethane and solvent molecules that migrate to the surface of the film over long periods of time. This is why paint films "curl" when they dry out and crack - the surface shrinks because it is literally losing its body. Exact same principle when a wet sponge is left out to dry - the sponge shrinks, deforms, and gets real hard. Shrinkage is likely the #1 cause of polymer failure. </font>That last point illustrates the need for elastic varnishes, but their problem is lack of surface hardness. Compare the difference between rubber vs window glass. Rubber won't crack and peel, but glass is brittle and will break. Somewhere between is what is out there. This is why the perfect varnish is so elusive - it is theoretically impossible for a varnish to have all the properties one wants.
As for the Nyalic in an aerosol can - you might as well just pee on the finish - at least then you'll know the result right away.
Any finish that is low enough in viscosity to be sprayed through an aerosol can will be about 10% solids and the rest will be solvents - see my point on solvent / monomer entrapment. No build, and high shrinkage. The higher the viscosity of the varnish the better - that is why I and many other pro finishers hot spray. Not too hard to do, and with minimal equipment, but that is another topic - don't get me started. - John Blazy

[carioca1232001]

J. Blazy,
Thanks for shedding light on the subject of UV-shields and the role of varnishes, one (and two) part polyurethanes and other coatings.

A lot of your technical considerations are way over my head - not your fault at all - but some facts have managed to seep in ;)

Like for instance, the (Ciba-Geigy)UV-inhibitors that are added to varnishes and even to some brands of epoxy, the amber colour of the varnish revealing the presence of UV-inhibitors, the practicalities of applying varnishes, the required thickness of coatings etc.

Some years ago there was a forumite on WB who was a high-level chemist and we would make recourse to him to SOS when it came to making choices between products and/or to sift out the men from the boys. ;)

He left us unexpectedly and we all missed him dearly, but all I can say is that it is indeed a pleasure to welcome you on board, to keep on the good work as it were.

2006 ? Promising..... as we seem to be finding our feet again !

[Old Bingey]

It looks like I'll be plugged in until right after the first of the new year. What it is is that down at that little sandbar island where I live there is no phone line and no cable and hardly any electricity.

John's explanation of clear stuff was the most concise, sensible, well written thing I have ever seen. The only trouble is that it inspires more questions.

Not to hijack the theme, but how can you glue polyethylene? Specifically, how can you glue sheet HDPE (high density poly ethylene?) to the bottom of a boat? What is that glue on UHMW (ultra high molecular weight?) tape and how do they get it to stick to the tape, hot melt glue?

I'll give a little advice. Do not try to spray hot two-part anything in a rented airless sprayer.

RW

(edited to add)

P.S. I have added another sample to my experiment. I peed on a little epoxified board and put in the sun (?) with the others. Is that the placebo effect?

[ 12-29-2005, 08:47 AM: Message edited by: Old Bingey ]

[sdowney717]

3M™ Scotch-Weld™ Structural Plastic Adhesive DP8005

Two-part structural acrylic-based adhesive (10:1 mix ratio by volume), that can structurally bond many grades of polyethylene, polypropylene, and thermoplastic elastomers (TPE's) without any surface preparation at room temperature.

Edited, you have to take out the CR's to see it work.

http://products3.3m.com/catalog/us/en001/manufacturing
_industry/engineered_adhesives/node_GSY4QL8V5Lbe/root
_GST1T4S9TCgv/vroot_WHG0MWH6QPge/gvel_GVTSZT9BQQgl/theme
_us_adhesivetape_3_0/command_AbcPageHandler/output_html

[ 12-29-2005, 01:10 PM: Message edited by: sdowney717 ]

[sdowney717]

http://www.gl ueguru.co.nz/content/Guru-Adhesives-Sealants-Fillers-Product.aspx?productId=248&groupId= (http://www.glueguru.co.nz/content/Guru-Adhesives-Sealants-Fillers-Product.aspx?productId=248&groupId=)

[ 12-29-2005, 01:26 PM: Message edited by: sdowney717 ]

[JimConlin]

Try http://cms.3m.com/cms/GB/en/0-131/kkrzcFW/view.jhtml

I think i've seen HDPE sheet with a pressure sensitive stickum on one side. Would that do the trick?

[J. Blazy]

Thanks for the comments Robb and Carioca smile.gif . I will tell you this though - "The Chemist" blows me away by comparison. I only know these things due to a very short period of my life in coatings chemistry - but he seems to know pretty much everything.

Mr. Sdowney717 - Can you do us a favor and edit your long link post to put a space in there somewhere - its expanded the board to about 30 nautical miles wide tongue.gif making it a real pain to read the forum.

HDPE and UHMW are wonder polymers that may stick with the above mentioned adhesive by 3M, but don't count on it surviving on a boat hull. You can only heat weld it otherwise.
I have much experience laminating .030 and .020 polycarbonate film to MDF substrates in art furniture applications using my own formula of 100% solids UV-cured adhesive with 600% elongation, and I can attest that NO adhesive will hold a thick plastic film onto any non-plastic substrate of that size and wear requirements due to the expansion/contraction differences - t'would peel off at the edges and creep away over time (no chemical bond, just mechanical).

[Old Bingey]

I lurked on here for many years before I signed up and I sure do miss "The Chemist." Dave Carnell still posts every now and then. People who are actually expert sure do the rest of us a favor on here. It is altruism in the purest sense.

I have used that sticky UHMW tape on the bunks of trailers for a long time.... just stuck on top of the carpet. Whatever that adhesive is will keep it on there, too. It'll make a good sheathing for the end of an oar. I guess it is thin enough and narrow enough to handle the behavior of the two different substances. I would love to sheathe the bottom of that Rescue Minor (which will google) with it. I am not talking any real thickness... just, say, 1/32".

I have to drag the boat sometimes and I keep running aground and that wears the paint off. Also, the boat stays in the water most of the time and I have done the experiments and barnacles just wipe off with your hand. I was thinking I could use a heat gun and make the thin sheet stuff conform to the shape and do the whole bottom of the boat. I understand that up in Alaska, they nail thick HDPE onto the bottom of those flat bottomed boats so they can drag them over rocks and stuff. Sure would be nice....

As another experiment, I glued a sheet of thin, clear acryllic onto a piece of epoxified wood with epoxy and it is out there in the sun with the others. I'll let you know.

[sdowney717]

Ok, its fixed

[ 12-29-2005, 01:13 PM: Message edited by: sdowney717 ]

[Puka]

carioca1232001


When you say Sikkens - they are a paint/coating manufacturer, like Epiphanes - are you referring to a specific product, like CETOL for instance ? Same product as you mentioned--Akzo Nobel--1 coat Cetol HLS primer followed by three of Cetol Filter 7.


And again, was you disappointment based on aesthetics (looks) alone, or did the coating start to flake off, go fut etc. ? Aesthetics, and it didn't live up to the performance the rep said we could expect. Bearing in mind, our high UV and rapid wet/dry cycles are somewhat harsher than
Northern hemisphere. On resinous timber it weathered off in places. On timber such as WRC, it performed at lot better. With a minimum initial (multicoat) film build
of >250microns and regular (min 9mths) recoats, it comes closer to the performance the manufacturers specify, but aesthetics are out the door.
I would have thought it would have been folly on teak, unless stripped with an approriate organic solvent. (Prep is everything!)

International´s Solgard or Schooner marine varnish.-----Cannot comment on a comparison with these.

Happy and productive new year to all.

[Puka]

BTW.........
Cetol filter 7 pine has been removed from the market here. Whether because it didn't hide the UV blockers sufficiently or it wasn't dark enough so they could use less UVI, who knows.
('cuse the cynicism.)

[Fatso The Bagger]

Originally posted by Puka:
carioca1232001

</font><blockquote>quote:</font><hr /> When you say Sikkens - they are a paint/coating manufacturer, like Epiphanes - are you referring to a specific product, like CETOL for instance ? Same product as you mentioned--Akzo Nobel--1 coat Cetol HLS primer followed by three of Cetol Filter 7.


And again, was you disappointment based on aesthetics (looks) alone, or did the coating start to flake off, go fut etc. ? Aesthetics, and it didn't live up to the performance the rep said we could expect. Bearing in mind, our high UV and rapid wet/dry cycles are somewhat harsher than
Northern hemisphere. On resinous timber it weathered off in places. On timber such as WRC, it performed at lot better. With a minimum initial (multicoat) film build
of >250microns and regular (min 9mths) recoats, it comes closer to the performance the manufacturers specify, but aesthetics are out the door.
I would have thought it would have been folly on teak, unless stripped with an approriate organic solvent. (Prep is everything!)

International´s Solgard or Schooner marine varnish.-----Cannot comment on a comparison with these.

Happy and productive new year to all.</font>[/QUOTE]Ok, stupid question, but aren't akzo nobel car varnishes?

I'm asking because of this:

http://www.akzonobel.dk/03.htm

[carioca1232001]

Akzo Nobel manufactures a considerable variety of paints and coatings.

Much like it's competitors, they manufacture and market this here and that there etc.

I have used Cetol on the exterior woodwork of my boat, on both vinhático and ipê, both very resinous and oily. Have noted that the finish looses it's sheen and lustre before 6 months is up. So sand a little and apply another coat or two !

[Old Bingey]

Well, alright, then. Here are the Nyalic results (so far): All the test samples I made up are still fine out there in the hot sun and the ones in water are, too. The plain epoxy is beginning to look hazy. The sample coated with Bristol Finish two part polyurethane is fine, too. The bare oak sprayed with one coat Nyalic is not as weathered looking as the one that was not sprayed but it does not look brand new anymore. The most interesting experiment was that I cleaned up the propeller on my inboard boat with a Scotch Brite pad and sprayed it with one coat of Nyalic and even though I use the boat all the time and did that back around Christmas, that stuff is still on there. It is extremely tough... real hard to scrape with a knife. Another experiment is a little piece of aluminum they sent with the product which had been dipped half way in the stuff. It has been lying in the bilges of the boat ever since and the coated side is still like new but you can imagine what the other side looks like. I drove a bronze screw in it last week just to see what's what with electrolysis.

As for the customer's boat. I sprayed the brightwork with the aerosol can. It is easily the best spraying stuff I ever used. It wets out wonderfully and stays wet long enough to absorb any overspray. I did not get any sags or runs. The substrate was well epoxified wood Scotch Brited it to a dull sheen. The Nyalic did not try to run... not even on the transom. The fact that I had heated the boat first might have had something to do with it. I tried to spray only one coat on there but the open rails were sort of tricky so I know I have about two or maybe three coats on some places. I followed the instructions including heat treatment. A coated surface not boil as quickly as epoxy does.

It looks good. It doesn't have that 4 mil multi coat varnish look to it but the coating is perfectly clear and the epoxy underneath adds a little depth to it.

I'll let you know.

[JimD]

So far so good. Sounds like it might be a very handy product. Thanks for the update.

[Matt Cohen]

Several coats of 2-part clear polyurethane or several coats of 1-part polyurethane-based varnish, over the epoxied deck ? ?

Which is best for filtering out UV radiation ?

Most 2-Part clear Polys, like Interlux Perfection or Epifanes 2-Part Poly, have a longer lasting and more UV inhibitors than traditional varnishes. You also have the option of sprinkling in Polymeric non-skid particles to make a skid-free clear-coat.

http://www.jamestowndistributors.com/userportal/show_product.do?pid=4245&familyName=Interlux+Perfection+2-Part+Varnish&history=WB
Perfection

http://www.jamestowndistributors.com/userportal/show_product.do?pid=4120&familyName=Epifanes+Clear+Two+Part+Polyurethane+Va rnish&history=WB
Epifanes