Locker lid varnishing. Moisture content.

[davidpbo]

It became apparent that water has got under the varnish of an outside locker cover and had blown the varnish and possibly the top layer of veneer off.

I have had it out in the sun drying out, I have a Kamasa timber moisture meter. Current reading is about 10% over most of it, at what level should I consider revarnishing? Would you treat it with thinned epoxy first?

 

[Keith-i]

10% is really quite dry for wood but bear in mind you may only be getting a surface reading and it might still be holding moisture further in. I’d go with some thinned epoxy once it is dry.

 

[Poignard]

I don't have a moisture meter so I work on the basis that if sanding the wood produces dust that can be blown away, it's dry enough to varnish.

Not very scientific but adequate for my standards.

 

[davidpbo]

It's been drying in the sun for over a week. I am hoping that as it's marine ply with presumably a waterproof glue it won't have penetrated too far. It did
not look bad when I was on the boat towards the end of March but I suspect the near constant rain had caused water to penetrate. Then the April sun warm the moisture and lifted the varnish.

 

[BabaYaga]

It's been drying in the sun for over a week. I am hoping that as it's marine ply with presumably a waterproof glue it won't have penetrated too far. It did
not look bad when I was on the boat towards the end of March but I suspect the near constant rain had caused water to penetrate. Then the April sun warm the moisture and lifted the varnish.

I might misunderstand the situation, but if the old, lifted varnish is still on, it will take a long time for the wood to dry. Plus any new rain will risk further penetration of moisture. Would it not be better to take the piece home, strip the varnish and let it dry out indoors?

 

[Stemar]

Would it not be better to take the piece home, strip the varnish and let it dry out indoors?

That's what I would do, but if the veneer has lifted, make a new one. It'll give you something to do during lockdown

 

[davidpbo]

I might misunderstand the situation, but if the old, lifted varnish is still on, it will take a long time for the wood to dry. Plus any new rain will risk further penetration of moisture. Would it not be better to take the piece home, strip the varnish and let it dry out indoors?

Sorry not looked at this thread recently. Locker lid was off, top stripped of varnish and had been put out in the sun repeatedly to dry.

I am now considering varnishing. Would people epoxy first? If yes what mix?

I presume whatever is it says on the tin catalyst/resin? How about if I am to thin it for better penetration using what, Acetone?

What ratio of mix to thinner?

 

[Catalina36]

10% is really quite dry for wood but bear in mind you may only be getting a surface reading and it might still be holding moisture further in. I’d go with some thinned epoxy once it is dry.

For my education, how does one thin epoxy?

 

[Keith-i]

For my education, how does one thin epoxy?

I have to admit I don’t actually know. I guess it’s possible with a solvent or alternatively the warmer it is the better it flows in my experience.

 

[lw395]

For my education, how does one thin epoxy?

Hot air gun.

 

[AntarcticPilot]

For my education, how does one thin epoxy?

One doesn't unless the manufacturer specifies a thinner. Some do, some don't. The epoxy I use, supplied by East Coast Fibreglass, can't be thinned. I think (but don't know) that West can. But you must use the thinner specific to the formulation you're using.