Water under Varnish...need advice

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baldpaul

Veteran Member
Joined
Apr 16, 2012
Messages
61
Location
Canada
Vessel Name
Big Tuna
Vessel Make
Defever 49 RPH
Over the course of our typically wet PNW winter, 3-4 spots on my teak cap rails have water intrusion underneath the varnish. This has only happened in the past few weeks, as I do a regular inspection. Last year I had a similar thing happen in a couple spots. To fix last year, I took a heat gun to those spots and re-varnished from bear wood, rebuilding up close to the other varnish. These leaks occur at a couple joints. I typically freshen my varnish each spring. I think this year I will also do a coat in the fall to try and prevent this for next winter.

My question now is how to possibly repair this year without stripping those areas. The wood underneath is good. I was hoping to maybe make a few pin holes to allow the water to escape and maybe apply a vacuum, then let dry for a couple days, sand and apply a few coats of varnish before freshening up all my rails. I read online somewhere this could work....is this crazy....any suggestions?
 
Sorry to tell you this, but in my experience, once moisture gets under varnish it’s toast.

The only cure is light application of a heat gun, and a sharp wood scraper. Like you say, it usually happens near a joint where the wood can move.

But hey, this is the Internet. You might hear of a miracle cure.

Mike
DeFever 40
 
Mike, that is exactly what I did last year. If someone does not affirm my possible miracle solution, I guess I will strip the affected areas and build from scratch.
 
Find where the water is coming from. Do I recall you had water up higher? Maybe it has now migrated to the cap rail via the hurricane boards/side struts. Very common on DeFevers and Europas. I cured mine (largely) by drilling a limber hole into the FRP where the side struts are affixed to the caprail. Another common event is water seeping through a poorly sealed screw or two from railing supports.
 
When i apply pressure with my hand on the varnish, the water seeps out of a couple tiny pinholes around where the joints are on the rails. When I strip those spots, I think I will sand down the joints to smooth them before re-sealing with varnish.
 
One thing that’s cool about this thread is we are all DeFever owners.

My 40 was built in southern Ca, the 48's were built in Ca and TW, the 49 RPH was built in TW and China, and we all have the same problem.

I don't think we're alone though.

Mike
 
Last edited:
I don't think we're alone though.
Mike

In my marina the problem includes Selenes, Grand Alaskans and Flemings. It will be interesting to see how the fake teak caprails hold up on the Flemings and DeFevers.
 
I suspect it's just a matter of stripping dn to bare wood and letting the wood dry out. Then if you use oil based products apply plenty of oil and turpentine ... heavy on the turp .. perhaps 4 or 5 to one. let it sit some and then apply straight varnish. The varnish should adhere very well and there will be no water to give trouble. Of course in time the skin will fail in the form of cracks in the usual places and water will be back in the picture. BUT w the heavy oil base water migration may not occur. This is what I intend to do this summer.

Tom .... FAKE TEAK!
 
recommended refinish to to strip back to the wood. Two coats of solvent thinned epoxy (make your own or ESP 120). This will stabilize and seal the wood. Then several coats of spar varnish to provide the UV protect, mil thickness and gloss.

this may also solve the water problem too.
 
Fixing the varnish is fixing the symptom not the cause. Fixing the cause requires removing the wood or hardware or both and rebedding the wood or rail hardware or whatever is involved in the joint that is allowing the water to get under the finish. We have a lot of this to do on our 40-year old boat.
 
Pauloman,
I agree w you and think the CPES epoxy or what you suggest could easily be better that what I suggested. If I was going to use anything but oil based stuff I' definitely use CPES. Do you really think "solvent thinned epoxy" would be the same as CPES? I like the oil based under coat as it's basically the same stuff as the top coat. If using oil based stuff it would seem to eliminate any or most troubles associated w adhesion between two different coatings.
 
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