Finishing a Wooden Sink

Suggestions for an extreme case: a finish to protect a sink made from Mahogany. August 31, 2009

Question
I have to finish an Arican mahogony farmhouse sink. Obviously it has to be non toxic and water proof. I saw African mahogony finished with teak oil and liked it quite a bit. Perhaps a Schlack over the top of it would work?

Forum Responses
(Finishing Forum)
From contributor G:
Why does it have to be non toxic? Are they going to be eating off of it? Most finishes are non toxic when the solvents have gassed off. If this is going to be near the sink I would suggest a conversion varnish or a 2K poly. Even standard brush on polyurethane would work well. Schlack or as we like to call it, Shellac will not handle water at all. It is a very poor finish to use in a sink area.



From the original questioner:
Itís not the "sink area" but actually the sink itself.Non toxic would be nice since silverware and plates will be in direct contact and soaking in it with water.


From contributor S:
All coatings are non toxic after solvent release and full cure with the exception of the nut oils and those who are allergic to nuts. That said, I would think that your best options include the oils and the maintenance that goes with them or a marine grade polyester.


From contributor O:
Unless you use a heavy pour on finish anything else will scratch through from the pots and pans etc. Once scratched through, the water will get under and either lift the finish or rot/discolor the wood under the finish, and warp like crazy. The heavy pour finishes are polyester and scratch up easy.

Two thoughts - first go look at West Systems for thin fiberglass embedded in epoxy finish. They use it on strip canoes. The wood shows through but is fully encapsulated. The other thought is to leave the wood naked, but switch to teak, or something that handles wet and dry cycles with some grace. Epoxy the joints. Either way it sounds like something my old friend Phil (the Mad Designer) would have loved. He used to paint everything white and put in white carpets - it guarantees that they will be calling you back in a year.



From contributor A:
I would go with contributor Oís approach. Saturate the completed bowl with epoxy reduced 20% (denatured alcohol or acetone). Bond 6oz fiberglass cloth to the wood with epoxy. Itís kind of tricky cutting the glass unless you have experience. Then as many coats of epoxy that you can stand to apply.


From contributor O:
You have been offered two, and I would suggest they are the only two. Encapsulate it so it never sees water, or leave it naked so that it will air dry between uses, reaching some more or less stable average moisture content and having no finish to get under. Is it that you don't like either way? What is the perfect result that you seek?

No other finish provides the mechanical strength to prevent water penetration, and if water gets below a finish it will fail. Oiling either hardens producing a film that would lift or a non-hardening oil would be removed by the detergent used in the sink. Please specify what you don't like about the answers you have received.

To expand the epoxy solution, if you want the last possibility, you could vacuum impregnate the sink with a resin either as a complete unit or building it up of laminate and in effect turn the wood to a big plastic chunk, but finding the vacuum chamber, the right resin, buying sufficient volume of resin and keeping the sink from floating would take some doing and thinking. No matter what the sink will in all probability have a very short life. I think Woodpecker said it well.