I was contemplating building my darkroom sink out of corian but found the chemicals to harsh for the acrylic based material. Then I remembered someone built their sink out of plywood and had it sprayed with Line-x.
Will this work? Want to use caulking in the 90 degree corners and inside edges, does it matter what brand of caulking? Any helpful information in regards to plumbing, ie. should I drill the hole first or after spraying for plumbing? The sink itself will be 9'.

I don't know what Line-x is. But if I built a sink of plywood, I would use a couple of layers of marine epoxy like West system on both sides of the panels. I would use their fileting method to glue it togeter too and also paint epoxy in any drilled holes to protect the ends of the plywood. It also might be a good idea to not use the cheapest fir plywood, as it is difficult to get a fair surface. Something like birch or mahogany would be better.
/matti

not sure what line-x is, i caulked my plywood sink then painted it with yacht paint primer, then yacht paint. The stuff is hard as a rock and has held up good..

I think Gordon Hutchings used a plywood sink in his newest darkroom. He had mentioned that the sink would be sprayed with truck bed liner material. Any color available sounds good to me. tim

I've used a bathroom sink/tub paint, which is a two part waterproof paint. The fact that one is mixing two parts indicates a epoxy paint. Any of epoxy outdoor or bathroom tub two part paints will work well. Plan on disposing the brushes afterwards. Once you mix the two parts together be ready to go. Freezing does slow the chemical reaction though.
Jamie

I caulked my corners ,used an oil based primer and 2 finish coats of an oil based paint. I wipe it dry after every use and its holding very well.

We just finished a large sink in wood.
We used West System 105 Epoxy resin part 1 cat 105-b
and West system 2066 Slow Hardener part 2 cat c206-b

It was odourless and worked very well and is holding up. takes a couple of days to do but seems worth it.

Line-X is a tar like truck bed liner if I recall correctly. I would bet it would work well for a sink. If you had some just laying around I'd go for it. If not, I'd buy some of whatever everyone is recommending. Plus doesn't Line-X end up like sandpaper? Scratched knuckles?

I'll second the use of the West System resins painted over exterior grade plywood. Simple and durable. My sinks have been in service for 10+ years now.

Take a look at: http://www.classicbwphoto.com/Darkroom.html

For caulking the corners, I used plain old "Bondo"... the same stuff the body and fender guys used on your wrinkled fenders. Cheap and Easy to work.

For a final coat, I tinted the resin with a light gray pigment.

Reinhold

www.classicBWphoto.com

My plywood sink (actually I used 2x6's for the sides and ends, makes it easy to lean on late at night, and 3/4 for the bottom, size 10' x 32") has two splices in it (didn't want to buy 10' ply). I used cove material to round the inside edges. Did all the gluing with exterior Tite-Bond (regular carpenter's glue) and then coated the whole thing with System three epoxy (do not use the polyester, it will stink up the whole house, and is explosive I think) forget how many coats, used about a 2/3 gallon. It's two years old now, except for stains, it looks like new, and at this point I don't think it could ever leak. I am happy with it. Note the inside corner detail in the photo.
6742 6743

My 19 year old plywood sink is built wit West Systems Epoxy, including their ground carbon in the layer one down from the top. It has never leaked or needed recoating. The cost of this great epoxy has been well worth it.