Couple of Questions

[Joe ( Cold Spring on Hudson )]

Went working on the skiff last night. Lightly sanded the varnish and then applied some more varnish. I take varnishing a lot less serious than some people on this forum. I use cheep 'Man-O-War' spar varnish, its like $20 a gallon :D . First I light sand with 200 grit then tack clean with some acetone on a rag. I poor a bit if varnish n a coffee can add a splash of turps. I brush it on with a nylon bush then tip it off with a cheep foam brush. I get very little drips this way. But after 3 coats of varnish I still have glossy spots and matt spots. I know that a coat or two more will fix that. I also may be sanding a bit too much between coats. Also the varnish has a bit of a hazy look in spots? Like I said I don't take it all to serious and the next coat of varnish will be applied without the light sanding just to see. But if anyone has a solution I will be grateful. And YES I did look in WBF FAQ and there doesn't seem to be an answer specifically for my question

The other question is mechanical. Soon I will be reassembling the hardware for the skiff. The centerboard trunk top has been removed and the CB cleaned as well as the CB cap sanded and varnished. What do I use as a seal when I refasten the CB cap? I was thinking a bead of 5200, but will that make it difficult to open the CB if I ever need to work on it again?

[Buddy]

Polysulfide caulk or Dolphinite bedding compound.

[Ian McColgin]

I've never used acetone for tacking in a varnish job. It probably does not hurt, but I'd use whatever thinner you like with your varnish.

The matt spots may be holidays - places where you actually did not get the varnish on. Maybe even pulled the varnish off with the foam brush.

I'm not very fussy myself and regard varnishing as well short of a mystical experience, but even I pass the varnish through a filtre.

I also think that for varnishing, a really good brush is best. Cheap brushes leave hairs in the job. I can't see the virtue in having to go from one brush to another when a good natural bristle brush, while a tad pricy at first, will last a decade or more of happy use.

[Norm Bernstein]

Your 'hazy' spots might be due to the cold... I've had problems like that before. If you're working in an unheated space, try using some form of local warmth, like a small space heater directed at the varnished surface.

[JimD]

I would have thought acetone to be a bit aggressive too, but maybe others swear by it. 5200 is generally considered to be more glue than bedding compound. WB had a good article a while back on different bedding compounds, think it was written by Greg Rossel. Will see if I can dig it up. I'd use almost any brand name marine bedding compound before I'd use 5200 for bedding.

[Bruce Hooke]

I can't imagine how sanding too much could cause matt areas. Sanding way too much just cuts thought to the wood underneath, in which case the varnish in that area might be sligtly rough as a first coat of varnish sometimes is because of picking up the grain, but it should be pretty obvious if that is happening. So, I would continue to sand between coats, if for no other reason than that it is harder to see what you are doing with the new coat if the coat underneath is still shiny.

I think Ian's guess is the most likely answer -- that these are spots you missed, with Norm's answer a close second -- that this is a reaction to the cold or to too much humidity (unlikely this time of year). Close inspection should tell you whether it is a missed spot. If you are varnishing in conditions that are colder or damper than would be ideal you might want to add a very small amount of Japan drier to the varnish. I would try to sand off these dull spots in case they don't go away when you varnish over them (unless you already know that they do).

[Wild Wassa]

Joe, Could you be overstroking the varnish? This will bring the binder to the top, giving different gloss levels. The oil is stroked to the surface.

If the scratch for keying isn't uniform, this can give different gloss levels. The paint draws differently from the brush. More coats will help.


Do you turn your heater off at night? Things don't stop conspiring against the glossy surface.

Warren.

[ 01-23-2004, 11:26 AM: Message edited by: Wild Wassa ]

[Paul Scheuer]

What are you heating the shop with ? Kerosene vapor will upset a perfect varnish job. I've also had problems keeping a wet edge when the humidity is low.

I would also not use acetone to tack as it probably attacks the exisitng varnish and keeps working while you're applying the new finish. A very dilute version of what you putting on is best.

If the sanding is showing through, you should be able to see the marks in the direction that you've sanded. Grandpa had an jeweler's eye loop for that purpose. He was picky, but he did good work.

[Joe ( Cold Spring on Hudson )]

Thanks guys good advice. I will no longer use acetone to tack. Is a little turpentine OK? The shop is heated with 2 large Modine heaters and kept at a minimum temp of 60 deg 75 or so when I'm working in it :D I'm on the 3rd coat of varnish so I'm pretty sure I haven't missed a spot. What about using steel wool to lightly sand between coats. Also thanks for the bedding compound info - I thought 5200 would be a bit too much

[NormMessinger]

Hey, may I come play too? A good bristle brush would be the choice for varnish rather than nylon though I doubt that is the problem.*

3M pads are better that steel wool. They don't leave little metal spicules on you work.*

No need to sand between coats unless you need to cut down a blemish if you put on a coat or so a day. Sand (I prefer wet sanding) between the last couple of coats.*

Set you work lights so you can see the subtle shine of the wet varnish over the old. This will help you avoid widows.*

Man-O-War varnish held up very well on our east facing front door, eight or ten years.*

Thinner does not make a really good tack cloth. Acetone is worse. Better to put a little varnish in the thinner to get a good tack though thinner alone will break the gloss and help key the next coat.*

* Or so I have been lead to believe.

[cs]

Joe I think that 3M makes a product called 4200 (as opposed to 5200) that doesn't have the same sticky power as 5200. Might want to check into that.

Chad

[cs]

Didn't take long.

http://a1672.g.akamai.net/7/1672/116/20031201/www.ritzcamera.com/graphics/boatersworld/products/377870258.jpg


3M manufactures a wide array of maintenance products specifically designed to perform in the harsh marine environment. With 3M quality in every product, you can be sure of getting the results your boat deserves.A polyurethane adhesive/sealant that is very similar to 3M Marine Adhesive/Sealant 5200, but that is about half the strength, which allows for disassembly of parts. 4200 delivers flexible bonds with good adhesion to wood, fiberglass, gelcoat, certain plastics, and metals. It is paintable and sandable, and forms watertight, weather-resistant seals on joints and boat hardware above or below the waterline. 3M 4200 (http://outfittersparadise.com/s/Marine_Sealants/3M_4200_Fast_Cure_Cartridge_Black_303937.htm)

Chad

[Rogue Sailor]

Here's what I do, and it works pretty well.
(Similar to Norm's method).

Apply the varnish with a high quality badger brush working from dry back into wet. Apply the first coat thin. Subsequent coats progressively less thin. Get on about 6 or seven coats to build thickness, then wet sand with 1200. I add a little dish detergent to the water as a lubricant. Here's where you work off any sags/drips or brush brisles. Careful not to sand through, it'll show forever.
For the final coat, apply thin and as dust free as humanly possible. I't'll shine like plastic.

[ 01-23-2004, 01:48 PM: Message edited by: Rogue Sailor ]

[Domesticated_Mr. Know It All]

Pictures Joe, we need pictures. You know you've spoiled us with pictures. :D

[Scott Rosen]

I can think of a few things I'd do differently.

First, I would sand between coats with 220 or 320, not 200. Better yet, a fine ScotchBrite pad. McCloskey's is thin, and you're making it even thinner by adding turps. The 200 grit scratches are probably too aggressive.

Second, lose the nylon brush. Get yourself a good china bristle or badger hair brush. Or, if you must, use the foam.

Next, lose the coffee can. You should never reuse a container for varnishing. For a few pennies, you can get the disposable plasic or paper paint pails.

Strain the varnish, as Ian says. The paper strainers cost pennies apiece.

Don't tack with acetone. It will dissolve the existing varnish a leave it rough and weak. Use high grade mineral spirits. Turps can leave a residue. While you're at it, you should probably thin the varnish with mineral spirits, too. You should use a tack cloth for a final tacking when the solvent has dried, just before applying the varnish.

For your build coats--1 through 5--try using a fine ScotchBrite pad instead of sand paper. After the fifth or sixth coat, you can give it an aggressive sanding with 220 to take down the drips and ridges and get it as smooth as glass. Two more coats, and you're done.

Do your varnishing early in the day. The cooling at night can cause condensation on the surface. Although this time of year there's not a lot of moisture in the air.

[J. Dillon]

Joe,

I guess you like to sand. smile.gif Me thinks you will be doing it all over again soon. :( Spend the bucks and get some good varnish. smile.gif Your time is worth something and to put a 20 bucks a gallon varnish IMHO is a waste of time. :rolleyes: The elements will ruin your work. :(

Sorry I have to be so negative.

JD