Varnish Not Drying

[WindHawk]

I coated my transom with 4 coats of West System epoxy, and then let it cure for a week while doing other work. I then washed it down, and sanded everything with 220 before applying a single coat of Interlux Schooner varnish over it on Tuesday morning. It's still not dry (it's tacky, 78 hours later).

I attempted to contact Interlux's tech support line, but they are doing in-house training, and will not be available until Monday July 19th.

Does anyone have any suggestions? The paint guy at West Marine, where I bought it, say's he's never heard of anything like this. The weather here has been in the 80's, but humid; so, I expected it to take a while to dry, but three days seems untenable. West did suggest that I might try another coat, under the theory that that may kick it off. Interlux's web-site says to sand between coats, but that can't happen now.

If another coat doesn't help, how do I get it off? I'd just as soon paint the whole boat at this point. At $80 a gallon, I'd enjoy trying to get my money back, as I'm a bit ticked off, and was operating under advice from West Marine.

[ 07-16-2004, 02:19 PM: Message edited by: WindHawk ]

[Buddy]

Easy there. I do have experience with EXACTLY the same products and problem during high humidity. In fact over five days. BUT, it was still tacky. It does seem that if its too humid during the first bit of drying time, it spoils it for drying fast. It was suggested that another coat be applied on a "good" day, and that the metallic salts used as the dryer would finish off the tacky problem of the previous coat(s) and since the solvents have now long since evaporated, the next coat would dry, nothing would alligator, and it would all be as if nothing alarming ever happened. And that's just how it turned out. Twice now.

[Buddy]

By the by, re reading your post, this most often happens after the first coat. Succeeding coats in the same humid weather will not have the problem. ONE coat in to this, not sanding the first coat is actually more the norm. You're not 7compromising anything. Lots of times you go three or four coats just building up thickness, then sand to level off, and always two coats at the finish with only the barest Scotchbrite or 320 grit before the very last coat.

[WindHawk]

Thanks for the advice, I'm going to give another coat a try. It makes sense.

[Bob Smalser]

Go buy a can of Japan Drier from your local paint store or Home Despot and add some to your varnish.

You could also have a bad lot of varnish. Either way, the drier will help.

[ 07-16-2004, 02:56 PM: Message edited by: Bob Smalser ]

[Paul Pless]

Bob,

I hear the japan drier recommendation often. Are their any drawbacks to using it?

Paul

[ 07-16-2004, 03:42 PM: Message edited by: Paul Pless ]

[WindHawk]

The second coat is setting up nicely after about five hours. Thanks ever so much. Is this something that I can expect over epoxy everytime, or is it just due to the humidity?

[Bob Smalser]

I haven't seen a durability difference 'tween adding drier and not adding drier, Paul....but I suspect using too much might cause a brittleness/delam problem.

I use a lot of it because I'm in the wet most of the year. With the first coat of varnish on any surface, two things have to happen...it has to amalgamate chemically with what it has been asked to adhere to....I think that's why the 2d and subsequent coats dry so much faster....and it has to dry in the atmospheric conditions you provide it.

Varnishing in hyper-humid weather has given me similar problems.

[Steve Miller]

I am thinking differently here. Allowing the epoxy to cure for only a week is very likely to cause the first coat to dry very slowly. I have experienced this several times with Schooner. Don't blame the varnish or humidity. If the epoxy had cured for several more weeks then the varnish would likely have dried normally. I see posts on this for alkyd paints but not normally varnish. Sam Devlin talks about it in his book.

[Buddy]

There is no reason to expect Schooner to do this over WEST epoxy every time. However, don't interpret that to mean every brand of varnish ( or paint- oil and latex) will work reliably over every brand of epoxy practically all the time. Sure they mainly do, but incompatibility pops up often enough to make doing a sample test a wise idea on every new combination the first time. Shoot, there are people who test every new can of the old tried and true products they always use. They won't get surprised. I have seen some real messes with "bad batch" polyester resins and two part urethane foams that completely spoiled plugs for molds or ruined pulled parts.

[Buddy]

Steve, I was recently refinishing the mahogany parts I had pulled from my Boston Whaler. Most I was just sanding overall and appling two new coats of varnish. A few locker top boards which had gotten lots of direct sunlight over the years were in bad enough shape that I decided to sand down their "daylight" sides to bare wood and then seal with epoxy. After maybe three days at the most I started to varnish and when I had the "still tacky" problem, it was just about the same on either side on all the pieces except curiously on a few boards where the edges had enough dings that I sanded them down.to a new radius. I decided to spot "prime " them as it were, and where I had fresh varnish undermeath, the first overall coat had dried in those areas only.

[Scott Rosen]

I can't see how coating with West is worth the expense or the trouble. It's a FINISH we're talking about, not a structural item.

If you feel the need for an epoxy tie coat between the wood and the varnish, then CPES is a better choice. It's designed for the purpose. I've never had any problem using it under varnish, and I've never heard of anyone else having a problem.

[Bob Smalser]

Odd....I use West and Brownell's epoxy routinely under varnish just as soon as the goo cures and I've never had a problem with it interfering with the varnish.

But as I said, I usually add a drop or two of drier routinely to my first coat.

[WindHawk]

The boat is plywood, and was given two coats of epoxy everywhere when she was built, and then painted or varnished. Subsequent neglect, and damage to the hull against docks left the plywood in pretty bad shape in places. I had to take quite a bit of material off in spots to repair the ply, as well as remove water damage, thus leaving bare wood in spots. I felt she needed a new layer (or four) of epoxy to seal her evenly, and avoid trapping water.

The transom is solid spruce, and although taking it all the way down to bare wood (as I did), might have let her survive on her trailer with varnish only; since she's spruce, and everything else is epoxyed, I gave it four coats.

I'd never used epoxy before, and am now sold on it for plywood boats. I will likely never attempt to refinish a plywood boat again, since the material is too thin to work very much, and then finish clear. Believe me, I'm going to put more paint on her than I wanted to, but the water damage especially, forced my hand. Her entire deck was clear, and those water spots are everywhere. Although I'm tempted to try varnish on the deck, and give her the "distressed" look; I don't think it look too good.

[Steve Miller]

Interesting Bob. I'll have to try some of the dryer next time. I have had this first coat issue on several brands of paint. The worst was the West Marine brand 1 part poly - mostly alkyd I guess. Brightsides seems to not be too bad. But I usually use a primer under paint, mostly to help the paint cover not for the bond to the epoxy. Recently I tried some Zinser 123 water base primer on a test rudder over 2 day old epoxy. Dried fine and I could do the two coats of primer in a morning since it dries to recoat in an hour. Like the stuff so far. Sands like its a tough coating. Time will tell how it holds up on the rudder.

[Todd Bradshaw]

There were problems mentioned somewhere about 20-25 years ago with Schooner Varnish over WEST Epoxy that, as I remember, sounded similar to those you're having. Must have been either in WB or in "Boatworks", the Gougeon Brothers newsletter/magazine thingy (more likely in Boatworks). Sorry, I don't remember the details or whether anyone had a fix for them but I got the feeling that it was some sort of chemical reaction between the two substances which was preventing the varnish from drying in a reasonable amount of time. The other Interlux varnishes were not affected similarly and dried fine. You might call the Gougeon tech staff and see if anybody there has any advice or whether they suggest using something other than Schooner.

[Wild Wassa]

Originally posted by Paul Pless:
"I hear the japan drier recommendation often. Are their any drawbacks to using it?"

The major drawback is that Japan dryer slowly brings on yellowing when used with all oil based materials. If you are pulling the boat on a regular basis, you just keep stripping or painting over the subtle yellowing, so it is not even a problem.

On painting projects other than boats, you will need to paint more ofter than one might normally if the yellowing is a problem. I like varnish to look like varnish. Varnish will yellow soon enough, without being a sublte version of Cetol.

When using Japan dryer it can cause an increase in brittleness or it can make the paint more flexible (layer by layer). I pressume this is an oil quantity thing, right from the start.

If the painting is to be of a high quality and last a long time, avoid Japan dryer. I view a slow drying time as a plus not an inconvenience.

Get Japan dryer wrong over your underlying coats, you can watch your top coat split, years ahead of time. Using a Japan dryer negates the real reason for selecting an oil based medium ... for me anyway.

I'm sure if I didn't stir my varnish for a long time to blend the solvents and oils well, it would take a long time to set, don't just stir varnish until it feels right, stir it until you know it is right. I buy and replace my stiring rods by the handfull, they are only a dollar each. Don't stir varnish with a stick or your wooden leg pirates.

Warren.

[ 07-22-2004, 10:19 PM: Message edited by: Wild Wassa ]

[Keith Wilson]

I'd bet the problem's in the epoxy, not the varnish. I had a similar problem where Interlux standard marine enamel took forever to dry over System 3 epoxy, but only intermittently. One location would dry normally, another would not, seemingly at random. The epoxy was well cured, with no amine blush. According to a very knowledgeable fellow at System 3, unreacted hardener interferes with the drying chemistry. Because the mix varied a bit at random, the batches that had a little too much resin were fine, while those that had too much hardener caused trouble. I now always make sure that there’s a slight excess of resin in the epoxy mix (excess resin will eventually self-polymerize, they say) and I haven’t had the problem since.

If it doesn’t dry soon, and it’s not too hard to get off, you might try another coat of epoxy with a little extra resin.

[ 07-23-2004, 02:46 PM: Message edited by: Keith Wilson ]

[True Love]

Can someone quantify a bit as to what "adding a little Japan drier" means? I can't help it, I'm a bit anal retentive.

[Bob Smalser]

Originally posted by True Love:
Can someone quantify a bit as to what "adding a little Japan drier" means? I can't help it, I'm a bit anal retentive.One dollop per 2qt paint bucket for the first coat.

[ 07-25-2004, 06:40 PM: Message edited by: Bob Smalser ]

[TimH]

Originally posted by True Love:
Can someone quantify a bit as to what "adding a little Japan drier" means? I can't help it, I'm a bit anal retentive.Hows the Dark Harbor coming? Any new pix? :D

[michaelpetrozzi]

Thanks for the info above. I had a problem where I repaired a mast, scraped back, sanded and applied thinned epoxy which i sanded after washing down and leaving for a week. The first coat of varnish (Feast Watson Spar Varnish) was still tacky after 24 hours. I called Feast Watson and they said the varnish was still curing - helpful?

I applied another coat over the tacky varnish and it had hardened by morning over most of the mast. I then applied another coat and it is hard all over although in a couple of sections the last coat reacted with the one underneath and the varnish is wrinkled. I plan to now let the whole lot dry for a couple more days, sand and apply more varnish (I'll change to either Goldspar or awlgrip) as i think there may also be a problem with the initial varnish i used.

Frustrating but i seem to have gotten through it ok.