older varnish lifting under new varnish

[Tculver]

Hi
I have a 1948 Chris Deluxe that I've owned for 28 years. The boat is stored indoors in the winter and covered in a covered hoist in the summer. In the spring of 2021 I had a local wood boat guy freshen it up with a couple coats of varnish (Epifanes). The varnish on the boat was 10 years old, but in great shape, no peeling or anything. I figured it was time. I put the boat in, in spring of '21 only to find I was having some engine issues. So the boat came out, I pulled the motor and boat went back into storage, Covered with a canvas cover. I pulled the boat out this week to reunite it with the engine and I have some lifting varnish. The guy that did the fresh up said it was the old varnish releasing. Ive never seen this before and the old varnish was very sound before it was freshed. The guy that varnished it said the only way to fix it is to strip the entire boat. Here are some pics. Im open to ideas on how to fix this without taking the whole boat down to wood
Thanks in advancevarn6.jpgVarn1.jpgvarn2.jpgvarn4.jpg

[sp_clark]

Re: older varnish lifting under new varnish

Was that canvas temp cover touching the spots that are now showing lifting?

[Todd Bradshaw]

Re: older varnish lifting under new varnish

I'm not a varnish expert, but I'd be willing to bet that the only real way to fix this properly is to take it back down to bare wood and give it a uniform new varnish finish.

[David Satter]

Re: older varnish lifting under new varnish

Possibly the wood had some moisture in it before he varnished or what ever he wiped it down with lifted some of the old. You may never know an exact answer. But yes weather you do a section at a time or the whole boat, you'll probably have to strip it back to wood

[Tculver]

Re: older varnish lifting under new varnish

It was touching the whole boat. These areas are all engine hatch back. Its a canvas boat cover its been on it for 28 years

[willin woodworks]

Re: older varnish lifting under new varnish

Youll never get a decent finish by spot sanding and patching. You can try it and attempt to tint the bare spots with tinted shellac but its probably less work to strip whats there and start fresh.

I decided to try and spot sand and patch my cabin sole this past weekend. Couple of bare spots and some ratty looking spots where the finish was lifting. Turns out its not varnish but some kind of polyurethane. Spent the last two evenings sanding it all off and got a first coat of Epiphanes on last night.

Miserable crap whatever it was. Thinking it was varnish I started with a sharp scraper and got nowhere. Wound up using 40 grit to get the damn stuff off. Anything finer barely scuffed it. Where it had lifted it came off in big sheets once I got the sharpened edge of a 5 in 1 under it but it was tenacious as all hell where it was still adhered.

[jpatrick]

Re: older varnish lifting under new varnish

How do you know that it isn't the new varnish lifting off of the old?

Jeff

[John Meachen]

Re: older varnish lifting under new varnish

It may not be welcome,but there really isn't any alternative to removing the damaged varnish.You may get away without totally removing all the old varnish,but it will need at least one complete coat or preferably two.The end result will be a big improvement over what is there now.

[Peerie Maa]

Re: older varnish lifting under new varnish

It is noticeable that many of those pictures of damage are around bungs over fastenings. It suggests that whatever the bungs are set in, is giving way, or damp is tracking up the screw hole from below. I would also check the finish on the back side of the planks, it may be internal condensation driving through from inside.
I agree that she probably needs wooded, dried out and redone.

[David G]

Re: older varnish lifting under new varnish

It is noticeable that many of those pictures of damage are around bungs over fastenings. It suggests that whatever the bungs are set in, is giving way, or damp is tracking up the screw hole from below. I would also check the finish on the back side of the planks, it may be internal condensation driving through from inside.
I agree that she probably needs wooded, dried out and redone.

That was the one potential clue I saw also. I've seen other instances where whatever adhesive was used to set bungs, bed fasteners, contaminated the area and eventually caused a failure of adhesion in the affected areas. It hasn't been out in the sun much, otherwise I'd speculate about that adhesive being epoxy, which was now failing from UV, and lifting.

I'd agree... the best way to approach this is to bite the bullet. Wood it. Pay particular attention to cleaning up those problem areas. Re-varnish.

[nedL]

Re: older varnish lifting under new varnish

I agree that it looks like moisture caused the lifting, and sorry to say that there is really only one way to a satisfactory remedy.

[Peerie Maa]

Re: older varnish lifting under new varnish

I agree that it looks like moisture caused the lifting, and sorry to say that there is really only one way to a satisfactory remedy.

Just so, if the canvas cover was so tight that it did not allow for a good airflow, condensation will form, and soak into the structure.

[wizbang 13]

Re: older varnish lifting under new varnish

nature of the beast
thirty grand should do it

[Rod Tait]

Re: older varnish lifting under new varnish

I would agree with other that is most likely moisture that is trying to evaporate out. Seen this a lot in old canvas canoes in which people have put good varnish over bad and once it heats up, the stuff just bubbles up and lifts off. Have had it happen to me a few times as well so old varnish needs to come off and wood left to completely dry.

[jpatrick]

Re: older varnish lifting under new varnish

Since thinking from a distance is easy... I still think that the problem is between the old and the new varnishes. Likely the boat will have to be taken down to wood. But before that, if it were mine or in my shop, I'd carefully use a sharp cabinet scraper to remove the top coats of varnish. If they are well bonded with the old layers, there won't be any real interface. But, if there is a problem between old and and new, the top coats may be removable. The task would be tedious to do over the entire surface of the boat. But it might reveal what's happened.

I would not employ the prior guy who did the work. It's very likely he didn't prepare the surface properly and therein lies the problem.

If you do go to wood... use chemical strippers. You want to preserve the patina of the wood as much as possible. Sand as little as is possible.

Jeff