Advice needed on primers for covering epoxy

[Norman Bernstein]

I'm wondering if anyone has comments or suggestions on picking an appropriate primer for covering the interior of my strip-planked and epoxy-glassed hull interior (the project is documented here (http://www.marisystems.com/ellipticat))

Not much of the interior will be visible, after the deck is on and the floorboards are in place, but it obviously needs to be primed and painted.

The interior surface is fiberglass set in epoxy. It is 'somewhat' sanded, but not all that perfectly, since the frames and contours and various bits like the floors don't make for easy sanding. I've tried to remove whatever amine blush there is by scrubbing with a ScotchBrite pad and a little water with a tiny bit of detergent in it.

I'd like to avoid using an epoxy primer, due both to cost considerations, as well as the fact that a catalyzd primer will have to be applied all at once, or else there will be significant (and expensive) waste. The exterior of the hull was primed with ordinary Interlux PrimeKote, and it adhered well.

Any suggestions?

[JimD]

IMHO the most important thing is proper prep of the epoxy surface. 'Somewhat' unfortunately just won't do. It's a dreary job but meticulous scuff sanding of all the smooth glossy epoxy surface is a must if you want the paint job to last and not flake off within a year. After that, an ordinary latex primer is probably good enough, or whatever primer is recommended for the type of top coat you intend to use.

[ 10-31-2005, 04:10 PM: Message edited by: JimD ]

[Norman Bernstein]

I had asked more or less the same question to a West Systems rep last year, at the Wodden Boat Show in Portland ME... his advice was to use a 'sticky' primer, like a 2 part epoxy primer... which probably isn't a bad idea.... other than the cost and waste issues. I was just wondering if anyone else had any experience with this. The epoxy is fairly 'old' (i.e., this glassing was done over 18 months ago), so it's really well cured, and except for tiny spots, it's all been scotch-brited to a dull finish.

[JimD]

Originally posted by Norman Bernstein:
I had asked more or less the same question to a West Systems rep last year, at the Wodden Boat Show in Portland ME... his advice was to use a 'sticky' primer, like a 2 part epoxy primer... which probably isn't a bad idea.... other than the cost and waste issues. I was just wondering if anyone else had any experience with this. The epoxy is fairly 'old' (i.e., this glassing was done over 18 months ago), so it's really well cured, and except for tiny spots, it's all been scotch-brited to a dull finish.I've done both - 'sticky' two part primer and garden variety housepaint primer. Both still seem to be holding up fine.

[RodB]

I recommend the fast drying base coat: #1640 Overlay from Parker Paint by Great Northwest Paint (about $20/gal)(interior/exterior Alkyd flat primer finish). . . which sands beautifully, and is thinned with Xylol (Xylene) (is a hot solvent primer in other words) and adheres very well to clean sanded epoxy. This is a very good, tough high build primer to use atop epoxy, fills all those small depressions, etc, and is very easy to apply. Just bursh two coats on..."slather it on liberally"...let it dry and sand it smooth. It is very easy to sand, I use 100 or 120 grit and sanding goes very fast and comes out great. I have had no problems with some shiney areas that weren't sanded but all surfaces were clean from amine blush. You will get good results if you at least rub the surface with scotch bright.

This is a good primer for most paints other than Linear Polyurathanes, especially alkyd enamels and Polyurathanes.

This primer was recommended to me by a professional boatbuilder/designer and he has used it for years with no problems on epoxy stitch and glue boats.

By the way, you need to scotch bright the interior with a 10% solution of ammonia and water, then wipe her down with clean water rags...or better yet, turn her up on her side and rinse her out. The dilute ammonia solution gets rid of the amine blush.

Good luck,

RB

[ 10-31-2005, 10:29 PM: Message edited by: RodB ]

[Dave Hadfield]

The most important thing is to wash the epoxied surface! Sanding doesn't do a good enough job alone. Any amine blush on the surface will prevent adhesion of the next coat. You'll be amazed at the dirty-looking wash water that comes off an apparently clean surface. You don't really need soap, just warm water and mop it all up.

[Norman Bernstein]

Thanks for the tip.. although I'm not sure I can get Parker paint products locally... I'll scan the web to see if it can be ordered online without severe shipping charges as a 'hazardous product'.

[Norman Bernstein]

Hmmm... as I thought, Parker is a northwest regional company with no apparent distribution on the east coast... also, the MSDS indicates that it's got benzene, toluene, and xylene... OK by me, but not cheap to ship.

I'm going to look around locally, and see what analogous primers are available in the northeast... I suppose that having those solvents is a good tip-off as to similarity.

[FSS172]

I asked this very question of the Interlux tech support rep when I glassed the plywood deck of my Friendship with epoxy/glass. After an intitial insistence on the company line of only using their catalyzed primer over epoxy, he did allow as how if the epoxy was well cured, thoroughly washed, and thoroughly sanded that PrimeKote would work just fine. As others have noted, the deal is to get rid of all contamination - amine blush and everything else - and to give the surface enough of a tooth for the primer to grab onto.

[RodB]

Thats the thing about the #1640 Overlay by Northwest Paint...its really tough, and really adheres great to clean epoxy, plus it offers a great barrier between the epoxy and the top coat paint in case any amine solvents are still comming off the epoxy. I got mine from tracyobrien.com where he gets it locally near Chehalis, Washignton. As he recommended it to me...I just asked him to ship it to me.

RB

[ 11-01-2005, 08:41 PM: Message edited by: RodB ]

[Norman Bernstein]

In wandering through the local hardware store, it struck me that the very common and inexpensive 'Killz' stain sealer / primer might be pretty damned close to the Parker product. It's got similar volatiles in it's solvent makeup... covers well, dries quickly, sands well... and is truly cheap: $11.99/gal. There are similar products from Bin and others.

Has anyone tried it as a primer over epoxy / under a finish enamel?

[ 11-02-2005, 09:49 AM: Message edited by: Norman Bernstein ]

[pipefitter]

Killz will work fine.Either way,the primer should be sanded to near transparent and if there is any adhesion problems it will peel off or you wont be able to sand to a feather edge.The 2 part epoxy primer has quite a long pot life and you can use it pretty much all day long. You dont have to mix the whole can at once either.

[Norman Bernstein]

Killz will work fine.Either way,the primer should be sanded to near transparent and if there is any adhesion problems it will peel off or you wont be able to sand to a feather edge.The 2 part epoxy primer has quite a long pot life and you can use it pretty much all day long. You dont have to mix the whole can at once either. Well, in the debate between $11.99 a gallon, and $60+ a gallon, $11.99 a gallon wins hands down if it will work.

This is for the interior of the hull of my catboat, and most of the interior of the hull will not be visible due to the deck, seats, and floorboards. furthermore, it's not a 'finished' surface in the sense that it is really just rough fiberglass/epoxy, sanded enough to remove the blatant bumps and drips, but you can still see the edges of the fiberglass tape used for tabbing to the frames, etc... so it doesn't have to be perfect, just unobtrusive.

I think I'll give 'Killz' or 'Bin' a try up in the bow, which won't be seen at all... and see how it looks after some light sanding.

[ 11-02-2005, 05:23 PM: Message edited by: Norman Bernstein ]

[pipefitter]

I experimented with the killz and white pigmented shellac(alcohol based) and they both are quite sound. I opted for the 2 part primer for the decks.no matter what you use the surface has to be clean. I cleaned it with amonia/water several times and then denatured alcohol and then mineral spirits before paint.If it is clean,the topcoat itself will stick as well as the primer without using any primer at all.

[Steve Hornsby]

Norman,

have a look at the following that I copied from Fritz's Boat Page - really about safer products for boatbuilding with kids. References a study by the Gouge Brothers on primers they tested. I have not been able to find that study. By the way, I used Bull's Eye 1-2-3 over East - worked very well.

Paints
Primers: Its hard to beat good old-fashioned shellac primers (e.g. Zinsser B-I-N) for low toxicity. Shellac is approved as an edible substance, used for candy gloss and oral pharmaceutical coatings. Shellac has a fascinating and ancient history: it's a resin produced by a scale insect and scraped off of trees in India and southeast Asia. Chemically, the shellac resin is laccaic acid (C26H19NO12 and variants). You probably don't want to eat the titanium dioxide pigment added to white shellac primers, but still I think shellac primers are the way to go with kids. Shellac is dissolved in ethyl alcohol, which comes off quickly: dry to recoat in 45 min! No other harmful vapors or solvents. Shellac adheres well to glossy surfaces like epoxy, and makes a good base for bonding topcoats. I've had very good results with white shellac primers on large, traditional boats top coated with marine oil-based paints (I usually use International brand). Shellac primers are supposed work well with latex paints also (but NOT polyurethanes!).
Steve Anderson had this to report about a Gougeon Brothers test of various primers over epoxy:

Okay - I found the West System test results

A top score on their tests was a 5 and the following primers received a score of 5 in all catagories:

Kover - Stain by Zinsser ( oil)
Bulls Eye 1-2-3 Primer sealer by Zinsser (Note: acrylic latex, NOT B-I-N)
ProBlock by Sherwin Williams ( latex)
Flash Bond 400 white - by X-I-M ( solvent based)
Latex Exterior Primer - Benjamin Moore ( latex)
Weather King II Exterior Primer - Fuller O'Brian ( latex)
The following primers tested scored some 5's in some categories but in other categories scores ranged as low as 0:
Moorwhite Alkyd EXT.Primer - Benjamin Moore ( alkyd) Scores ranged from 5 to 0
Ext. Wood and Masonry Primer - Fuller O'Brian ( alkyd) scores ranged from 5 to 0
A-100 Exterior Primer - sherwin Williams ( alkyd) scores ranged from 5 to 0
All of the latex primers did well - they did not test Kilz II.
I used Kilz II on the interior - and did have some problems with it peeling in places that I didn't sand as thoroughly. I called the Kilz people and they were horrified that I was using it over epoxy - and even more horrified that I was using it on a boat. They did say however that their own tests indicated that it was not real good to use over epoxy.
--------
About Kilz, Steve Heil reports:

Kilz (the original) is the only stuff I've used. This stuff really smells bad and if yuo're not careful it can make you dizzy when using it in closed spaces. I think the reason for this is because the volatiles flash-off very quickly. This stuff dries very fast (less than 30 minutes). I have used it on many outdoor and indoor project (however not a boat) and I've never had any problems with it adhereing to anything nor has any top coats failed to stick to it.

With any of these, rough up the epoxy, and make sure the epoxy blush is removed first!

--------------------------------------------------------------------------------
Back to Fritz's Boat Page

[Norman Bernstein]

Steve,

Thanks very much for finding that report for me!

It does look as if I really don't need to spend a fortune on an expensive two part primer... many of these products are pretty inexpensive, and a couple of them are national brands, so I'm sure I can find them. It is interesting that the latex-based products did so well in the tests.

Now that I think about it, the hull interior is a surface that will get little or no wear, with the exception of the top edges of the floors, which bear the weight of the floorboards... but they won't be seen, so some abrasion wouldn't matter.

I was planning to use an ordinary porch-and-floor enamel for the hull interior (light gray or buff colored). I'll save the expensive paints for the hull exterior, which is already primed with Interlux PrimeKote.

[Paul Morris]

Norm;
Please check out the Epifanes line of paint products. They are in Thomaston, ME. They have a nice epoxy/fiberglass prime coat that I use on the interiors and above the waterline of all the boats I build or restore. Have not had any failure yet. If you want I can ship you some or any Epifanes dealer can provide it for you.

Regards, Paul

[Norman Bernstein]

Paul, I'm familiar with Epifanes products.

However, at roughly $76 for 1500 mL, I've got to ask myself: is it worth approximately $200+ per gallon, as opposed to $12.99 for a gallon of Binz or Killz? Especially for a surface that will get no wear?

I don't think so smile.gif

[Steve Hornsby]

Norman,

Your welcome. A few more thoughts from my experience. The Bull's Eye prime coat was applied to the entire outside of the hull. On the inside I applied it on the floor, extending up the sides about three inches. When dry, it stuck very well.

I used Behr Porch and Floor latex over the primer coat on both surfaces. The outside has held up because the dory does not stay in the water for more than two days at a time. No bubbles, blisters. However, on the inside, the Behr was attacked by the water - mostly from wet feet, rain etc. Anywhere it puddled for more than a day, I could scratch off the paint (and the primer!). I sanded off much of the Behr, reapplied a lite coat of BEye and applied a Para oil on the floor. This worked really well. I will stay with the Behr on the outside as it is not in continual contact with the water.

In conclusion, I would not hesitate to use Bull's Eye again, but like any primer, it needs a good protective top coat suitable to the immediate conditions. I'm sure there is a more robust combination out there in product land, but I don't plan to repaint for a long time if all remains as is.

However you proceed, best of luck.

Steve

[RodB]

Like I said before, Parker Paints alkyd primer 1640 basecoat is one product that will work great, you will just have to get it in Washington state...but still, even after shipping, your cost will be quite reasonable. I would bet Tracy Obrien (360-748-4089) could give you the name of the local dealer and they could ship it to you. I looked into this extensively (primers over epoxy) and decided this was the best choice unless you could find a very similar product locally.

RB

[ 11-03-2005, 05:24 PM: Message edited by: RodB ]

[pipefitter]

I used the alcohol based pigmented shellac on burn damaged home restorations. Was one of the only primers that would totally block heavy smoke damage from bleeding through.Kilz worked ok but still not as well as the shellac. Also,when cleaning the epoxy with alcohol you will notice a slight tackiness. Maybe thats why the shellac adheres well to it.Still no substitute for a clean keyed surface.

Seems that the alkyd based primers are the same as flat alkyd paint. Maybe a higher solids content. I opted to just use the topcoat as a primer to keep from having different hardness/flexibility layers. I actually used the epoxy as the surfacer and sanded the imperfections out of that since it was there anyways and was high build in itself. I doubt I will bother with the primers anymore.

[ 11-03-2005, 10:34 PM: Message edited by: pipefitter ]

[RodB]

I agree that completely cured epoxy that is completely cleaned from amine blush...and sanded...will be fine for applying paint by itself. The only reason I became so enamoured with the primer above was that it is so easily applied and just sands so easy and so beautifully. It just adds a fairly easy to sand top layer that makes it simple to get a really nice finish at the end. I think is also covers up lots you would see with just thinned paint as a primer.

One final note, per Tracy Obrien's recommendataions... as you build your boat obviously most of the epoxy is completely cured with no more solvents (amines) coming off...but if you have done any epoxy work within a few weeks and the weather is not hot, you still could have some solvent venting and thus paint drying problems. The alkyd base coat above (Parker 1640 base coat) which is based on a "hotter solvent (Xylene)" adheres fine to epoxy that is clean of blush...but perhaps was still not absolutely cured...thus provides a good barrier between the epoxy and the final topcoat paint.

I had to paint over some epoxy that was quite recent in the final stages of my skiff, and the primer worked great.

Hey Pipefitter...that damn Simmons Skiff is becomming more and more interesting for a transition boat from my "flats skiff" to the deeper bays and the open water and surf... I especially like the low sides version.

RB

[ 11-03-2005, 11:26 PM: Message edited by: RodB ]

[pipefitter]

I like the low sided version as well. It looks like what people are spending 70k on for a work boat styled bay/flats boat.

Have you used your boat yet? I have been looking for posts of it in the water. I am going to build the 20 next all the while wondering what the hell I am going to do with 2 boats? I just got an awesome deal on a 60 yamaha with approx 100 hrs on it so I had to buy it.
I would rather spend all my time and $ building boats that will rot instead of spending the proud prices they are getting for the glass ones.
Of all the high dollar rigs I work on there is not one that is worth ¼ of what they sell for.

If you do build one of the Simmons you will definitely enjoy it.You cant stop looking at the damned thing. Also,the plans are worth buying for GP. At 55.00 it is too reasonable even if just to stare at the lines drawings.

[ 11-04-2005, 12:02 AM: Message edited by: pipefitter ]

[RodB]

Funny you should ask. My boat is at the custom aluminum fabricator now and the poling platform, leaning post with a back rest, and the windshield grabrail are all done. I plan to go to Houston next Friday the 11th, and pick her up and then do the final wiring and installation of the jet pump on my Yamaha 90 two stroke.

BTW, the tests we did went grand. We borrowed a jet pump from a Yamaha 90 and installed it on my motor. The jet pump ghuru told me that he had never seen a jet outake float as high as my boat floats. During the test we estimate my boat ran in about 3-4 inches at full plane. Running in about 7" of water, we noticed no sand sucked up off the bottom by the jet... The flat (14" at the transom that angles up from about 24 " in front of the transom allows the intake of the Jet pump to just barely be below the bottom of my 6 degree bottom. We found her to run very shallow both a full speed (around 32 mph) and slow. I don't thing the jet performance for my hull could have been much better.

The performance with a prop was not as good but can be remedied. Of course a 90 hp with a prop was lots of power...way fast... She began porposing at about 20mph and when turning "slid" a lot. The fix will to be install shims at the motor mount when running a prop plus to install two 3 foot runners on the bottom back by the transom about 6" from the chines. I designed her to run shallow with a jet so I am completely satisfied and if in the future I end up going mostly with a prop I will be able to tune her up for that too.

Change over from prop to jet or back will take about an hour with the mechanical jackplate supplied by the jet pump manufacturer.

More to follow with completion around mid November...lots of photos.

RB

[ 11-04-2005, 12:14 AM: Message edited by: RodB ]

[pipefitter]

I am at a stop for now because of work and a couple trips to NJ.I am hours away from finishing up. Already fit the trailer and weighed the hull.I ended up fixing some loose ends such as hatch fits,etc. The hurricanes were threatening on 2 of the weekends I wasn't away so there is some delay in that.
That is some real shallow running for sure.Figures to get in the water at the roughest part of the year. I have only seen one jet drive here in the last 6 years. I was curious to how well they worked.
I guess I didn't really miss much with the bad red tide we had this year.Stayed around for a long time.Good luck with the rest of it and hope to see the pictures soon. I get to build everyone elses aluminum parts for their boats. Have you seen the power pole flats anchor? We built the prototype for that before he had his own castings and extrusions done.

[ 11-04-2005, 12:39 AM: Message edited by: pipefitter ]

[RodB]

Have you seen the power pole flats anchor? We built the prototype for that before he had his own castings and extrusions done.


No....show a photo please.

Rod

[pipefitter]

They work great. Just push a button and you are stuck .

http://www.power-pole.com/photo_gallery/images/Capt%20Bo%20Johnson_jpg.jpg

They reach down to 6ft if i recall but they now have a deeper reaching one. We have one on the tunnel skiff at our shop.
http://www.power-pole.com/

no more messing with the anchor or staking with a push pole.

[ 11-04-2005, 01:55 AM: Message edited by: pipefitter ]

[RodB]

COOL! but not cheap. The use of such an anchor is interesting.

We normally just stab our Loomis push pole into the bottom and tie off to it while setting up at the edge of a flat.

Rod

[ 11-04-2005, 04:17 PM: Message edited by: RodB ]

[pipefitter]

I dont go for much new fangled gadgets and the likes but after using one of those,it is worth it if you have the green. I can hit the button on the way to grabbing my rod and be on the fish in seconds. I like the way it holds the boat too. It doesn't swing every which way.Same as a push pole. My boss knows the person who makes them and says I can get one if I want. Don't know if I want it on the Simmons but we'll see. I don't really want a push pole on my boat but that can change too.I think the power pole would be better suited when using a trolling motor over the push pole.

You didnt have a stakeout holster put on your pole platform?

[ 11-04-2005, 09:19 PM: Message edited by: pipefitter ]

[RodB]

I checked out the website on the anchor and found it quite interesting. Its nice the weight is not very much. I'd like to try it on a boat for grins.

Haven't decided on the stakeout holster yet...but may have it installed later on.

When fishing the really shallow water the push pole is king. Of course the larger the craft, the more difficult to control with a push pole. You can control the boat so well and move ever so slowly, which is important when site casting to reds and specs...and even more important with Bonefish and Tarpin. Sometimes on calm days, I sit on the poling platform with the pushpole across my thighs,(when its not my turn to fish on the foredeck) and I just let the tip of the pole swing down on either side to control our drift...very relaxing and allows you to drink your beer while poling with one hand.

I pretty much will forego the trolling motor for coastal fishing ...but will still have that choice for freshwater bass fishing. You should see the fish run when you move along with a trolling motor in the shallows on the coast. Its like a school of Piranha are moving in front of you and all the fish are racing like mad to get away.

I like the shallow draft of your skiff, which is very versatile...but with the wind we have here, you would be fighting to control her with the higher freeboard. The possibilities of the Simmons are running through my mind.

RB

[ 11-04-2005, 09:44 PM: Message edited by: RodB ]

[pipefitter]

We have high winds here from now until April it seems but all the places I fish are in the shelter of mangroves. I have 4 select areas to fish for the different seasons. I agree with the pushpole. I used to run a gill net for mullet with one on a net skiff. The bigger boat with the outboard would let us off in the skiff and we would make smaller strikes encircling a school of mullet with nothing more than a push pole.He would make the larger strikes with the power boat.I have poled up to 11 miles(with the tide) with nothing more than a pole.Fish a whole 6 hr tide and just steer the boat with the pole then ride it back. Thats how we used to fish.I can really move a boat with a pole and pretty much steer it without issue. The Simmons isn't really all that high.Mostly we just park it and get out of the boat so everyone has open casting position. Reds come right up to you. I squat down and then fire up under the mangroves for snook.Still scares the hell out of me when they hit. Now you got me all in fishing mode. Last time I went fishing I caught a jet ski with a zara spook tongue.gif

[RodB]

Chrome and especially clear Zara spooks work great on the flats here....

RB

[pipefitter]

Red/wht....silv/blue...clear...and chrome/blue or black works here. My favorites are the mirro lures for just about everything and bomber long A's. The chrome/black bomber with the rattles and the red eyes is deadly on snook. I shouldbe totally done with the boat this weekend. Hang the motor and controls next week. Had to get the trailer ready and start driving the truck again.

Hope to start on the other Simmons in a couple months.

[RodB]

Favorite mirror lure ....blue back, white belly, silver sides... great for Reds ans Specks.

Favorite Zara Spook: Clear... anywhere in clear water.

Why the 2nd Simmons...? What will it offer you that your present boat doesn't have besides space?

RB

[ 11-05-2005, 01:36 PM: Message edited by: RodB ]

[pipefitter]

It is just something to do,RodB. I have had this boat to build in my spare time and I dont feel like turning back to furniture. And I got so much experience on this 18 and would love to try one without as much 2nd guessing.The 18 I would love to give to my son as he is a fishing nut as well.

[RodB]

No sail boat???

Perhaps a Herreshoff Alerion?

or a sharpie.

RB

[pipefitter]

I thought about sail boats and alot of them I like alot. Especially the double enders and the open versions.I like the cat boats and the likes too. Just not real practical for my schedule.I do good enough just to get out and fish.Maybe someday. Never can tell though.I am satisfied with admiring other's sailboats.I might would build a model of one. smile.gif

[RodB]

One thing about one of the classics...if you build a desirable design you could always get a decent amount of money for it if you decided to sell it later on.

Besides , once you get into sailing you will be hooked!

RB