Turned wood sinks

[Jeff Brody]

I have turned two large maple bowls that I hope to use as matching sinks in a new house. I have been trying to determine what finish I can use to make them waterproof for this purpose as they will be installed like countertop porcelain sinks.

I have heard that I should start by brushing on a low viscosity epoxy resin and let it soak into the wood and cure. I've also heard that there is a two-part polyurethane that can be applied over the top, but has to be sprayed on by a painting expert.

I would appreciate any suggestions on specific products to use for this project and for ideas on the specific steps for finishing these bowls.

[JohnC Lucas]

Epoxy applied by the slow turn method. lots of guys in the Chattanooga club are using this method. They use a Rotisserie motor to turn the lathe or make a thier own chuck mounting system. I think you can find youtube videos on it. I found this one but if you do a search for slow turn epoxy application you will find a bunch.
https://www.youtube.com/watch?v=C9g_GRTobUg&t=108s

[John Keeton]

The inherent movement of wood caused by time and changes in ambient conditions - temperature, humidity, etc., make any film finish subject to failure. The larger the vessel, the more movement, and some woods move more than others. Using wood as a sink has built in issues - intermittent exposure to temperature and humidity changes, as well as wear from use of soap, etc.

I would think elasticity would be a very close second to moisture resistance when choosing a finish. Durability would rank high, as well. I wish you the best on your project, but long term I think you will have to maintain/repair whatever finish you use.

[Rob Price]

I agree with John- it'll look cool and different but I think it will be troublesome. I wonder how movement will affect the plumbing fixtures?

I would use two part marine epoxy- they make wooden boats out of the stuff. It'll be your best bet for moisture resistance (not proof) and flexibility.

[Steve Doerr]

Jeff, I just recently finished a wooden bathroom sink for a customer. I did a lot of research before even saying I would do it. I found a product at either Lowes or Home Depot that is manufactured by Famowood called Glaze Coat. It is a two part epoxy and is the type of finish you find on some bars and tables. It has a high gloss finish to it but can be flattened out with steel wool or the 3M stuff. I found this video by Carl Jacobson to be very helpful https://www.youtube.com/watch?v=y3wt13z4lH0

[Mike Cutler]

Jeff

I don't really know very much about turning, but working with wood, in a marine environment, I know how to seal it against the elements to the extent possible.
If I had to do as close to waterproof as possible for a boat application, it would be a thixotropic marine epoxy coating over .5oz S-glass. West systems, or Pro marine make some really nice products. West Marine and Defender have good online websites for these types of products.
The entire bowl, inside and out, would have to be done. Any holes for drains, or scuppers, would have to be treated also.
If you plan to do multiple epoxy coatings, make sure you pick a product that supports that method. Not all will, and some require an additional treatment in between coats.

I know that everyone likes to do an entire project themselves, but if you're not that familiar with epoxies, I would definitely either buy enough to experiment and get the technique down, or find a fiberglass repair shop near you to do the work.

[Alex Zeller]

I think you would be better off asking this question in the boat building section. If it was me I would use fiberglass and epoxy. Done right the fiberglass will disappear.

[Mike Cutler]

I think you would be better off asking this question in the boat building section. If it was me I would use fiberglass and epoxy. Done right the fiberglass will disappear.

Absolutely! The correct glass will virtually disappear.
One more advantage is that like stains, gel coats, or top coats, can be clear tints that could really enhance he hue of a piece of wood.
Most fiberglass boats are built from the outside in. Aircraft are built from the inside out.

[John K Jordan]

I found this video by Carl Jacobson to be very helpful https://www.youtube.com/watch?v=y3wt13z4lH0

That video and another I watched showed applying thin CA glue to the bare wood under the drain flange. He did say there was a rubber gasket under the flange but does an application of CA glue waterproof wood enough to protect it from years of water contact around the outside of the gasket? Any experience with this? Seems to me the drain area should have the same treatment as the rest of the bowl.

JKJ

[John Keeton]

I think the fiberglass idea is the way to go. While thousands of wooden hull boats are in use and well sealed they often need maintenance as well.

But, one thing to consider is there is usually very little endgrain involved in boat construction and any movement is across the grain. With proper construction and sealing, that can be minimized. With bowls, just consider all of them you have seen turned from dry wood that ultimately become oval. I just yesterday handled a very large bowl (18-20”) that was turned from spalted curly maple in 2012. It was about 3/8” thick and very well done with a nice finish that appeared to be lacquer. It was gifted to the owner and he indicated it seemed dry and remained stable for awhile, but is now very oval and the rim is warped with the end grain being 1/2” high. This happened as it was sitting in a conditioned environment in his home.

I think the bowl sinks is a neat idea and I hope the project goes well.

[Steve Doerr]

I'm going to have to disagree with the camp that says you need to use fiberglass. That in my opinion is over kill. If you think about it for awhile you will realize that a boat and a bathroom sink operate in two completely different environments and thus have different requirements as it relates to keeping the wood dry. A boat sits in water all day long, runs thru water at a high speed and is exposed to UV rays all the time. In a boat, the fiberglass helps strengthen the wood and provides an extra protection against the water as the water wears off the marine varnish.

A bathroom sink does not have water sitting in it all day, is not exposed to UV rays (more than likely), and has water running in it for a very short period of time. Plus, the water that is running in it does not have the force, or speed, that the boat has as it is running thru the water.

Also, think about how many of us make utilitarian bowl, platters and plates. They are used for food and get washed with soap and water. Most of the time the finish is basically walnut oil or mineral oil. I do not know of anyone that has used fiberglass, or even two part epoxy, to seal the wood from food, oil or even water.

I agree, that a bathroom sink, much like a bar or tables in a pub, needs to have a finish that is more durable than poly or lacquer. That is why you find most people that make a wooden sinks, seal it with a two part epoxy.

That's my story and I'm sticking to it!