waterproofing wood

[fountainman]

I'm building a water fountain out of tile and wood, and am looking for a relatively simple sealant that would waterproof it but remain clear. Is there a marine epoxy or urethane that would do the trick?

Thanks!

[KnottyBuoyz]

Epoxy will be succeptible to UV degradation. You'll have to look at a good marine bright work finish such as Spar varnish or similar.

[Raggi_Thor]

Or epoxy first and then varnish..

[fountainman]

The fountain will actually be inside, so would a liberal coating of Spar Urethane guarantee waterproofing?

[Raggi_Thor]

Several coats of epoxy or varnish is waterproof, that is water can't dissipate through, but wapor can (very slowly).
Another old method is to saturate the wood with a mix of turpentine and (f.ex) decks oil, many layers "wet in wet", more turp in the first layers, more oil in the later ones.

[fountainman]

The fountain is already stained, so would turpentine strip that? Do you think applying just deck oil and then numerous coats of Spar would work well?

[PAR]

No method will "guarantee" water proofing. Clear wood finishes are very high maintenance if used in wet locations. Any breach in the coating (regardless of type used) will eventually lead to problems. This is why the maintenance issue is so important.

If you can insure the coatings will be kept in good shape, then you have several options. The traditional finishes, like wax or oil based sealers are not truly water proof, but can keep the occasional splash or drop from causing problems (if kept clean and in fresh oil).

Epoxy encapsulation is the best method. This requires multiple thin coatings of epoxy be applied to every square inch of wood, inside joints, holes, everywhere. This will embalm the wood in plastic, which will prevent the moisture from getting at it. Indoors, the wood will still need varnish or polyurethane to keep reflected light from eventually darkening the epoxy.

Again, there are no easy, nor cut and dry methods to water proof wood with a clear finish that is water proof. If coatings are maintained, then you can keep them in good looking condition. If you let the coatings go to long and moisture gets in, then you have problems.

This is why many manufactured products have been turning to plastics or other inert materials and using painted or printed wood grain to simulate wood.

[fountainman]

Thanks for the advice. What type of epoxy would you recommend? Would this completely seal the wood? Do you think deck oil under that would just be overkill?

And would you recommend coating Spar urethane or something else over the epoxy?

What's the best way to "maintain" the coatings? Clean it and apply a new one every so often?

Thanks

[Raggi_Thor]

Epoxy is better applied on fresh wood, any kind of oil may give you problems with adhesion.
Any varnish with UV filter will be good.
Yes, a new coat every year or so is a good idea.
Scratches should be fixed immediately.

Remember, I have never built a fountain!

[PAR]

Each manufacture will have a list or recommended stains and oils that are compatible with their brand of epoxy. Check with the manufacture of the epoxy you choose. In most cases you shouldn't have an issue if you use a stain under the epoxy. There may be a slight amount of weakening in the bond, but a compatible mixture will only account for a couple of percent difference, which isn't enough to get excited about.

That said, many if not most of the stains available now are multi purpose products, acting as sealer, stain and finish all in one magic can. These can cause big problems with epoxy adhesive qualities. I personally use dry pigments in the epoxy itself, to color the wood, which eliminates the compatibility issue. These dry pigments are available at the local paint store.

Most deck sealer or water proofers, like Thompson's and the others, are wax based formulations, which will prevent the epoxy from sticking. Don't use any of these type of decking coatings. They're for your back porch, not your fountain (or boat).

Any major brand of epoxy will do a fine job. Pick from what's available locally and then log onto the web site of that manufacture. They'll have application tips and techniques, etc.

After epoxy is applied, it needs to be top coated with something for UV protection. This can be paint (the best) or a clear coat (the worst). Clear coats over epoxy are really falling into two categories, varnish and Polyurethane. Varnish has a rich, warm glow and a pro can tell the difference between it and poly, but 99.5% of everyone else can't. Poly is easier to apply, harder, more durable and clearer. Several coats for each to get a good finish, with 15 or more to get a piano like finish.

Maintaince boils down to keeping it clean and inspected, with repairs to any breaches in the coating as soon as you notice them.

[Bergalia]

Originally Posted by Raggi_Thor

Remember, I have never built a fountain!

Never built a fountain Raggi - then why are you on this forum

But (prepared to be shouted down) I reckon several coatings of boiled linseed oil applied to the timber first (until saturated) should make it pretty waterproof - then add your varnishes (which take well to linseed). Or so I've found in bulding timber hulls.

[VKRUE]

Hey hey...

Just a dumb question that may or may not be of importance.

Is this fountian going to be used in conjunction with a pond that contains fish ?

If so, then I present a second question... will any of these methods pose a threat to the fish in the water ???

[Bergalia]

Originally Posted by VKRUE

Hey hey...

Just a dumb question that may or may not be of importance.

Is this fountian going to be used in conjunction with a pond that contains fish ?

No, no. That's not a dumb question at all. The rest of us are dumb for not asking it.

If it's any help I built a stone fountain and pool for the garden and 'waterproofed' the pool with resin. I allowed a week for it to 'weather', flushed it through a couple of times - then added fish. Apart from the bloody kookaburras most of the fish have survived for the past five years..

[alan white]

Did anyone mention what type of wood? Whether the wood would be submerged or only splashed? If the edges showed?
I had this idea, something that would work with a fountain, but not a boat.
Use plywood with wood facing of choice and pour clear sealant (ideas?) over, lay UV window glass over that, vacuum bag, seal edges.

A.

[VKRUE]

Originally Posted by Bergalia

No, no. That's not a dumb question at all. The rest of us are dumb for not asking it.

Thank you for your recognition... I didn't honestly think that my question was dumb but, only trying to be polite. and suggestive.