Epoxied table tops anyone?

[John Preston]

I have completed the woodworking part of a 36x36 table for a niece and her unborn sibling.

I wanted to epoxy the top to make the thing easy to clean and give it a darn near indestructible finish.

The top is solid oak.

The problem is, someone mentioned earlier that I should watch out, because epoxy does not allow for expansion or contraction. I didn't think that would make much of a difference, until I saw expansion cracks in a table top at a restaurant.

Their table was made out of pine, and I forgot to check the bottom to see it if was finished. If I put epoxy on both sides of the table, does anyone think it might still crack?

PS. inlaid the table, but wouldn't call it "fine furniture." Will post pix when done.

[Jamie Buxton]

John ---
If the epoxy you're talking about is one of those poured things which forms a layer a quarter inch thick, yes, you'll have a problem. Solid oak 36" wide will want to grow and shrink a good quarter inch in width over the annual humidity cycle. A thick plastic layer isn't going to move at all. You'll get cracks in either the oak or the plastic, or the table will bow.
You'd do much better by varnishing the oak. The varnish forms a thin enough layer that the oak can stretch it as it grows and shrinks. Four coats of good varnish will make a surface durable enough that it can be used as a changing table.
A nice thing about using solid oak for the table is that if the varnish ever gets really scarred up, you can just belt-sand it off and revarnish it. A poured-on thick plastic layer is there forever -- cracks and all.

Jamie

[Richard Allen]

Hi John

My understanding of epoxy is that two coats will make the wood impervious to moisture. That is to say that two coats top and bottom will eliminate any seasonal wood movement.

My understanding is that you don't need a thick finish to acomplish this.

I would warm the wood to about 120 degrees before appling a coat of epoxy top and bottom. That heat will make the epoxy soak deeper into the wood and will also help to elimanate air bubbles. Two hours latter apply a seond coat of epoxy. At that stage the second coat will form a molecular bond with the first coat. If you let the first coat cure then you will need to sand the first coat so the second coat can form a mechancal bond.

Depending on a lot of "stuff" you can warm the piece during the last hour of cure to create the best cure for the epoxy.

A good quality epoxy is not much of a finish. You should plan on sanding and applying a coat of film finish over the epoxy. I have found that the epoxy will give a terrific surface for a top coat that will be very smooth and last for a LONG time.

I typicaly use West System Epoxy for stuff like this using the "slow" hardener. The slow hardener is very nearly gin clear. THe "fast" hardener has a little amber tint to it.

There are some high performance finishes like Cetol or Admiral whichhold up very well and would give many years of hard service.

Please know that these are just my observations. I have not done any scientific studies.

Thanks

[John Piwaron]

I suggest that the original poster should refer to the West System website for additional information. West System is used as a coating, but there are conditions. I am not the expert, but West System is. I'd go to their site and check out what is required.

Personally, I think these things are too plastic for my taste. I think a good Tung oil varnish would do a good job and be refinishable if need be.

[Steve Hepditch]

Not to hijack the thread, but I've recently completed a high chair as a gift to a co-worker and now I have a finishing dilemma. The chair itself is hard maple and I had planned to put a few coats of poly over the entire thing. You're suggestion to use a tung-oil varnish as a durable finish makes me wonder if I could/should do the same. I guess it boils down to two things:

1. Will a tung-oil varnish (or Watco, etc.) give me a "deeper" finish than the poly (in both appearance and durability).

2. For the future owner, is the poly the way to go for general waterproof-ness (especially the tray) and low maintenance.

I lean toward the poly (wiping or non) for durability, but I think the tung or Watco might do the wood better justice.

Opinions?

[Russ Filtz]

Why not do a hybrid Tung/Poly? Just start with thinned "PURE" tung oil, make sure it's 100% tung. You better get it from a woodworking store, not a hardware store. Thin it out a lot with mineral spirits, at least half, and start applying coats. soak in a coat everyday and make sure to dry off the "wet" spots after a while so the tung doesn't get gummy. After you get a few coats on, you can start adding some poly to the mix, up to maybe 1/3 each Tung, spirits, poly. Keep doing the coats until you like it. You can even finish it off with a thin coat of poly if you like. This gives the deeper oil-rub finish, as well as some of the advantages of poly, without getting too plasticy. Still has that close to the wood look if you don't go heavy with the poly at the end. Also, be sure to de-nub between coats.