Sticky Varnish

[freedom44]

As any boat owner, I am reasonably proficient at varnishing, but I have come across a problem I have never experienced before and would welcome your wisdom.

I epoxied some plywood which I then put a coat of Epiphanes diluted by about 50% as the base coat before I build up more coats. It is in an outside shed but I put a heater and heat generating spot lights on and left them on for a few days which I reckoned was quite warm , but still the varnish is tacky. What do I do??

Many thanks

 

[sailorman]

Epiphanes take longer than most varnishes to dry.
i have just done the underside of my sole bds
thinned & warmed prior to use done in a spare bedroom they took 3 days to be dry
enough to handle

 

[johnalison]

I'm glad to hear it - the same thing happened to me when I tried it for the first time last week. It was nearly a week before I could re-sand it.

 

[sailorman]

in warm dry weather its ok & no different from other varnishes

 

[tobble]

Was there a reason you thinned it? I was under the impresison that the idea of thinning was to allow the varnish to penetrate into the wood more, but if you've sealed it with epoxy that can't happen...

surely you'll get more build with un-thinned, so that'd be better to begin with (ontop of epoxy). have heard it said that a thinned top coat gives better gloss but not convinced, and in any case that doesn't apply to you if that was the first coat /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

 

[sailorman]

warming to thin the last coats it will "Flow" better & give a full bodied coat

 

[freedom44]

Thanks for the input. I thinned it as I thought it might be easier to spread and dry hard. I got that wrong. I was always going to put on uncut coats later.
It looks like perserverance with the heaters.

 

[ccscott49]

Summer, put it in the fridge, winter, put it in a bucket of hot water.
Make sure the substrate you are varnishing is dry and warmish.

Works for me.

 

[earlybird]

AFAIK, this happens with conventional varnish over epoxy, due, I believe to a surface effect of the epoxy, ( amine blush ??? ). The remedy is to either thoroughly abrade or wash the epoxy surface with water prior to varnishing.
Add; I think the effect is worse if the epoxy cures under cool conditions. I found polyurethane varnish, ( 1 pot ), was less affected than traditional oil based type.

 

[davidfox]

Im pretty sure this is 'amine blush' i had a problem with a dinghy I built and varnished 2 years ago, i had to strip it off, it was in the summer and nice and warm etc but the varnish would not harden.

 

[tobble]

will take that as confirmation that I haven't got the wrong end of the stick!

 

[matelot]

had a foreman painter once who got thoroughly fed up of having part used cand of paint knicked from work. so he decided to dose one can with hydraulic oil. it disappeared and he had no more than a week to wait before one of the cleaners approached him to ask if he ever had paint that wouldnt dry.

bingo! /forums/images/graemlins/grin.gif

just a story incidentally - not suggesting anything, before anyone gets excited!