Hi Creekboater, 

sounds frustrating...

i have some questions and thoughts.

first, just want to confirm that there was no apparent issue with the epoxy before the varnish?  what type of epoxy was it?.  how long before the varnish was the epoxy finished?  we would want to confirm that the epoxy was fully cured and no amine blush which could impact varnish.  we would also want to confirm that you waited long enough to ensure that the denatured alcohol was fully evaporated and that there was no contamination there.   was the rag that you used for the denatured alcohol potentially introduce contaminants onto the surface?

second we want to see if there is anything obvious related to the varnish.  did you mix the varnish thoroughly before applying?  was there any potential contamination?  it sounds like you paid attention to most of the important instructions with respect to thin coats, temp and humidity.

third, i would do a little experiment with the varnish on non-epoxied scrap piece of wood, paying attention to varnish directions and see if that drys properly.  that will at least take varnish off the table if it works and we know that the problem could relate to the epoxy or some other type of contamination.

if you 'bake' the boat - put it somewhere where you can get the temperature 80 degrees for a bit of time and see if you can get the varnish to harden.

all this said, you should not varnish over a tacky coat.   but lets look at the four items above and see if that points us somewhere and we can then see how we could efficiently clean up the tacky varnish if we still have that problem after some more wait time.

h

Thanks for responding, H. 

Ok, let's see...

1. Epoxy. No issues really. I used MAS, slow hardener. Last full coats were days before varnish but I did have some touch ups that were applied 24-48 hours prior to varnish. MAS is not supposed to blush so I did not do a wash down. I can't remember exactly how long after wiping with the alcohol but at least 30 minutes or so. Rag for alcohol was a fresh lint-free shop towel. 

2. It's possible I didn't mix long enough. Varnish was from a freshly opened can but that can had been sitting on my shelf for months. I poured some in a cup, added thinner and stirred for probably a couple of minutes. Contamination very unlikely. Fresh cup, roller, brush, etc. 

3. Varnish on scrap is a good thought. If no hardening soon I'll try that. 

4. I'm cranking up heat in shop for next day or so adn see what I can get out of it. 

Thanks for taking the time to write. I'll keep you posted...

Martin

An update...

Now just over a week out and varnish is still tacky. I've had the shop at 80-85F and 30-35% for about 6 days now. 

Been thinking back to what I might done or not done. I'm quite certain the wipe down had plenty of time to dry. 

I'm hoping i didn't use enough thinner. I had half a solo cup of varnish and used a capful of thinner. Mixed for a couple of minutes.

I have read where varnish could take 30 days to cure properly. It has not been my experience for it to take this long, but again, maybe I simply put too much on. 

Hi Creekboater....

i would try some of the varnish on scrap wood and see if it 'drys' to a no-tack finish.  just do a single, thin coat.   if the thin coat is dry (should only take 8 to 10 hours at 80 degrees)...then at least we know the varnish is ok...

on the 30 day to fully cure, this is really about hardness and up to 30 days for maximum hardness.....but it should not be tacky....after the initial dry/overcoat time on the can ....

h

 Thanks h.  I'll do that and see. 

I thought that 30 day curing seemed strange. This is boat number two and I never had more than an overnight to harden up. 

 What percentage of a "half a solo cup" does a "capful" constitute?  Is it more than 10%?   One should always follow the manufacturers directions when thinning.  

 I am currently using Schooner on a kayak hull and find no need to thin at all.  I am not sure why a spar,  with a much smaller area where you need to maintain a wet edge, would need to be thinned. 

I would suggest at this point that while testing the unthinned varnish on a piece of scrap wood that you take a can of solvent and a clean rag (or perhaps a green 3M stripping pad) and start removing the tacky varnish.  Best to do outdoors or someplace with a lot of ventilation.  Even then an organic vapor mask would be a good idea.  Mineral spirits should be sufficient but you might have to use something stronger such as acetone or solvent based paint stripper.

djdewitt, I'm not sure what that percentage a capful is. On my first boat I just playing around with thinner to my taste so to speak. I never did use much and never did as much as the mfg recommends, which is 50% for first coat. I've never felt like my unthinned coats go on very well, so I always throw in a litte. I'd guess my capful was maybe 10%, probably less.

So...I'm thinking my problem might have been not stirring long enough. Since my last post I have done two things. I have brushed both thinned and unthinned onto scrap and they were dry next day. I also wiped down one spar with mineral spirits and brushed on some thinned varnish on a small section. It was also dry and hard the next day. 

What I DID do different was stir for nearly 5 minutes prior to application. 

Temp, humidity, etc. all the same. 

So...now to completely strip the spars and re-apply. 

Many thanks to all who replied!

   An update...

I never did REALLY figure this one out, but I have something to share that might help someone down the line...

1. Frist, thinning heavily was the only way I was ever able to get the Gold to cure properly on top of epoxy. Curing on bare wood, even unthinned, was never a problem. This certainly implies surface contamination, but I'll be d'md if I could ever find my contamination. Did every test I could think of (washed for amine, got new epoxy pumps, mixed longer, etc, etc, etc.)

2. But what has, in the end, abslutely done away with the problem is adding a little Japan Drier to the varnish. Poof, the stuff hardens in 6-8 hours like it's supposed to. 

moving on...