Humidity-proof finish.

[Burkhardt]

I posted this in the old showcase thread from 2013 but I am not sure if somebody still goes there so I would like to ask the same question here.

When I did my bamboo bathroom cabinets last Fall I coated the top surface with cast epoxy which is fine so far. But I made a major mistake with the finish for for the fronts, sides and shelves. I thought this is just light internal use and a simple spray lacquer should suffice but I forgot humidity. Especially in the morning when everything is still cold some surfaces get dripping wet with condensation from the shower steam. The nitro lacquer does not like it and actually begins to flake after only a few weeks of use. Bummer.

I am ready to take the cabinets off, sand back to the wood and finish with something else. Any recommendation, like poly or marine spar varnish or acrylic? Preferably something obtainable....and ideally if it does not stink for weeks. I read shellac is actually quite water resistant but that does not sound very durable.

Thanks!

[bobmoore]

You should be able to spray a catalized laquer right over the laquer you have without sanding back to bare wood. Assuming you completely seal all surfaces, catalized laquer will perform very well in humidity.
Bob

[jTr]

Gene,

First point I'll address is "Humidity-proof". Be aware that finishes essentially control / inhibit the moisture exchange between a piece of wood and the atmosphere, but the truth is, the exchange is still taking place.

Epoxy is likely the closest thing to waterproof, but here are some concerns:

1> practicality of application, including expense and successfully spreading an even coat.
2> rigidity of the epoxy coating. An inflexible coating on a piece of wood containing a bit of natural oils that also happens to be expanding and contracting through the seasons = an effect like walking on a thin sheet of ice over soft mud. A bit drastic, but you get the idea.

Best I've used thus far is a marine varnish - epifanes. It is thick, flexible, and unlike many of the modern catalized lacquers, you are encouraged to apply as many coats as your heart desires. Very slow to dry and stinks, but not for weeks. Experience has shown that pre-sealing with an epoxy wood "repair/primer" product that was supposed to optimally "bond" the finish to the wood seemed more prone to cracking/checking under the topcoats than simply using the varnish alone.

In a similar situation at my own home, I found that a water-based finish peeled within a few months. The Sherwin-Williams T77F62 C.A.B. acrylic lacquer I applied to another piece in the same room looks as good as new years after the fact.

Good luck - hope you are successful in reviving those beautiful cabinets!

Jeff

[Ajcoholic]

You should be able to spray a catalized laquer right over the laquer you have without sanding back to bare wood. Assuming you completely seal all surfaces, catalized laquer will perform very well in humidity.
Bob

Yes a post cat lawyer will perform well in a shower ( that's what I used fircyhecwoiswork in my shower and bath which lasts years without issue)

However most if not all brands of catalyzed lacquers and urethane swill NOT go over a non cat base. The cat finish will attack the "weaker" underlying finish and cause blistering and crazing. Do a test before you commit to a new finish over top. And use two in the text as sometimes you'll get away with the first coat but #2 causes all sorts of issues. Been there done that learned my lesson.

[Ajcoholic]

Sorry my phone auto corrected lacquer to lawyer. And they call them smart phones...

[Burkhardt]

.......... what I used fircyhecwoiswork in my shower.....
I understand the problem with phones who are too smart for their owner's good but what was that supposed to mean? :)

I suppose I do not have a choice than sand back to the surface. In some areas the nitro lacquer is already peeling. Then I may try it with the acrylic pre-cat, thanks for the tip.

The epoxy flood coat for all surfaces would anyway be too time consuming. It is in principle very easy to do with only 2 coats within a day and looks interesting with the "wet glass" like surface. But I would need to coat each surface separately because it must be perfectly leveled and everything else masked off.

[bcondon]

Andrew, we were all being too polite to ask why you had a lawyer in the shower....

Thanks for the chuckle!

[Ajcoholic]

I understand the problem with phones who are too smart for their owner's good but what was that supposed to mean? :)

I suppose I do not have a choice than sand back to the surface. In some areas the nitro lacquer is already peeling. Then I may try it with the acrylic pre-cat, thanks for the tip.

The epoxy flood coat for all surfaces would anyway be too time consuming. It is in principle very easy to do with only 2 coats within a day and looks interesting with the "wet glass" like surface. But I would need to coat each surface separately because it must be perfectly leveled and everything else masked off.

That was supposed to read "for the woodwork in my shower"

Sorry guys, that's what I get for trying to type on a tiny phone at 7 am before I left for work.

[phil_o]

Jeff,

I've been following this thread as I have a similar concern on another project. I am a volunteer with Berkshire Carousel. We are building, carving and painting 33 carousel horses that will be on a fully functional carousel. We expect the carousel to be operating at the end of this year.
We have been discussing ways to minimize the very same issues addressed in this thread. One of our members want to coat a carved panel with epoxy. Your response should help with the discussion.
The carousel will be housed in one of the older Crane Paper Co. buildings in Dalton. If you get back to the Berkshires be sure to stop by, I'll get you a free ride.
http://www.berkshirecarousel.com/BerkshireCarousel/Berkshire_Carousel.html Also on Facebook.

Phil (Mr.) O'Rourke

[bobmoore]

Andrew;
Thanks for the heads up. I have sent many projects to my finisher with a coat of spray bomb laquer to stabilize it. Finisher said that was fine. I will do my own testing before doing that again.
Bob

[jTr]

That's quite an ambitious undertaking - be sure and share photos in the show and tell area. If ever I make it out that direction, I'll be sure to look you up - thanks for the invite!

Jeff

[Burkhardt]

Update....

after looking around I picked the Epifanes "Rapidclear" (https://epifanes.com/na/store/varnishes-and-clear-finishes/rapidclear/)finish. I found it quite unique. Very viscous and not much tendency to drip or run, it leaves a pretty thick film. I brushes on evenly but must be done quickly before it starts getting a skin. Since it is made for outdoor use I hope it is good enough for my bathroom. Actually, I may use it for other projects, too. Only satin and semi gloss, though. Oh yes, it is expensive.

[gc3]

in reality there is no true "humidity proof" finish...finishes only slow down the exchange of mc to wood...even epoxy

[Burkhardt]

in reality there is no true "humidity proof" finish...finishes only slow down the exchange of mc to wood...even epoxy
Thanks, I am aware of that. Maybe I should have named the thread differently...
I was not really looking for a hermetic humidity barrier but in the original post I asked for recommendations of a finish that does not self-destruct and flake off like the cheap nitro lacquer when in contact with bathroom dew/condensation. One of the brands mentioned was the Epifanes but not the Rapidclear variety. I took the risk because it promised rather quick drying (and it does). Another advantage is it does not stink as much/badly as the usual polyurethane varnishes.

[kevin]

I've used the product for exterior okay not great

Interior very thick easy build up with a brush also clear good for a bathroom

[mikeb]

best defence for that much moisture is to put in a ventilation fan to get rid of that moisture

[genek]

CAMPBELL MAKES A GREAT LACQUER IT WILL NOT WATER STAIN IF YOU SET A GLASS ON IT IT. VERY HARD AND IS A GOOD MOISTURE PROOFING Lacquer.

easy to spray. I use the gloss version very shinny. will not be back in shop till Monday evening. send me a message to eking1953@yahoo.com will send you part number.

[kevin]

Mike right about ventilation

I forgot one point on the clear coat it will look plastic
As opposed to what I recommend before will look more natural .Its important to know the difference in finishes then reading through the bs