A finish safe for liquids

Most urethanes. Lacquer. Epoxy. No shellac ... that includes most commercial friction polishes.

- Andrew

How would pure Tung oil be? I know it takes a long time to cure, but it is supposed to be fairly water resistant. Martin

It's better than nothing but it won't stand up to alcohol very well. Any drying oil (Pure Tung, Walnut, Boiled Linseed) will stand up to water to varying degrees but not like the urethanes, lacquers, and epoxies.

- Andrew

I can think of a whole bunch of finishes "safe for liquids", pine-pitch, tar, copper marine bottom paint, just to name a few, but most of them would'nt be safe for "humans" not to mention the flavor they would impart.

disclaimer: this post should be taken with a grain of salt.

James Barley

copper marine bottom paint,

Yum.

Max

Guess by now Kevin has found that bare is best in treen, as elsewhere.

Thanks for all the responses. Yep, plain/bare/nude/raw will be the way to go.

-Kevin

Why? You're not worried about the effects of the liquids on your piece?

- Andrew

Friend likes a little nip of brandy now and then. The turned vessel would hold a bit more than a jigger. I thought it would be kinda cool to have something that could manage the alcohol & from what I read and hear, a wooden container would be far preferable to a leather cup ala SCA.

So (correct me if I'm misunderstanding) you're saying that a "plain/bare/nude/raw" maple wooden "bowls and such" is the way you're going to go even considering the alcohol and water, etc. that might be used with it?

If so, then what brought you to that decision? Why is that preferable, in your opinion, to a finish that will protect your wooden item from these liquids instead?

- Andrew

1) Yes, there is a precedent for unfinished woodenware/kitchenware/treen. However, the links YOU provided to Robins' website does not set nor suggests a precedent for such a thing. Look under the "using woodware" link and you'll see that he oils his pieces. He's using a finish (it just so happens to be a finish that must be continually and frequently reapplied) to help seal and protect his items. You'll also notice (maybe this time at least) that Robin's site is about traditional woodturning. Staying close to the way it was done "back then" (whenever that really is) is what it's about and Robin tries to keep it that way ... for better or worse. This shouldn't preclude advancements in finish technology, uses, and advice for turners wishing the best of this current timeframe. Unfortunately, I assumed (my fault) that Kevin was NOT interested in finishes consistent with the 1400's.

2) There are many precendents, George. Just because there is a precendent given (which was a poor choice .. we'll wait for you to find a better one....) doesn't mean that it is the CORRECT and APPROPRIATE one to be giving advice with.

3) Email Robin (or anyone else that actually makes and sells,especially those that get feedback from their PAYING customers) and ask if a completely unfinished wooden bowl/goblet/cup is going to last long with liquids .... drinking liquids especially ... in frequent contact with it as the original poster, Kevin, said he wanted to find a finish for.

4) Alcohol, unless it's a clear one, will stain unfinished wood and not come out without heavy and deep alterations to the piece. Simple oil finishes will resist this more but is still a poor choice because of the flavor transmitted to the alcoholic liquid and problems with breakdown due to the alcohol. A film building finish (like the urethanes, lacquers, etc. that I mentioned on my first post) will not stain if properly cleaned or, at the very least, will be easily fixed after heavy use (such as the chalices that I make for Catholic churches ... red wine, you know).

- Andrew

What he does versus what they did.

Oh, well, just the musings of an amateur.

Apparently the doctrine of transubstantiation has been repealed?

Hey Andy, Being a relatively new turner as well as wood worker, I ma still somewhat in the dark regarding finishes, in particular those that would be 1. food safe & 2. not impart a taste to the food/liquid being consumed. I may need to turn a small vessel and try some brandy or wine in it to see if there is a significant alteration of the taste. If urethanes (polyurethane?) will do the job of protecting the surface as well as being safe and not significantly altering the taste they may well be the eay to go. If so, any suggestions as to brand names you can offer? Thanks,

-Kevin

preferable,

1) Food Safe: This is a major topic in and of itself. Briefly, there are 2 major theories. One being that every common wood finish (excluding the roofing tar, etc that others have mentioned ) will EVENTUALLY be safe for food contact given enough time for the solvents and other nasties to evaporate/bind/or otherwise become inert enough to not harm. The other theory is that that is a bunch of BS and you can only use immediately natural foodsafe ingredients to be truely safe.

Personally, I'm in the middle. If I'm making something (like my kitchenware) that I'm going to sell or send to my retailers relatively soon, then I'm going to use natural oils, waxes, etc. because I don't want to have to hold on to them for MYSELF feeling safe. If I have something that I can hold onto for awhile (again, long enough for me to feel like it's safe) then I MIGHT use some other finish IF that finish is the best for the piece given what it's going to be used for, etc. For a project like yours (what little I know of what you're doing), I'd feel safe using (in this order for "Food Safe") Epoxy, Lacquer, Polyurethane. I'd leave the item sit for at least 2 months AFTER the last coat of finish, for example. Sometimes more. Sometimes less depending on curing rate, amount of finish, etc.

2) Taste Transfer. Any of the finishes mentioned above, when properly cured, will impart no TASTE to the liquids. However, they will linger in smell for a bit longer. It won't be a whole lot after that 2 months but I wouldn't want to immediately give it to a wine tester. The Epoxy should clear the smell-factor first and then the Lacquer with Polyurethane last. It all depends on the brand and how much you apply too.

Yes, I would highly recommend testing out the finishes you're wanting to try first. That's always the case with any woodworking. Regardless of what anyone says, it's the results YOU get that matters most.

Polyurethane will, indeed, be the easiest route for you to take. I've never seen an epoxy finish on anything that looks good enough for me to sell in kitchenware. Lacquer is kind of nasty stuff to work with and can be finicky to apply. Polyurethane is fairly easy to work and can be easily made nice-looking. Frankly, I'd opt for the Lacquer as my first choice in this situation but it's not that big of a difference between the two for the hassles of dealing with lacquer.

"any suggestions as to brand names you can offer?" I'm glad you asked that. I just so happen to make and sell my own complete line of super duper fantastic polyureth ..... Nah, not really. I wouldn't make the sales pitch here even if I did. That's crass. Seriously though, I really have no brand recommendation (they're all really too close to call anymore) but I do still recommend an oil-based polyurethane for this over a water-based one. Water-based urethanes have come a long long way but for best durability and resistence to water/alcohol I'd still opt for the oil-based.

Remember, many thin coats with some light high-grit sanding and cleaning with a dry clean, lint-free cloth between. Polyurethane bonds to itself mechanically and not chemically like lacquer so it's needs that slightly roughened surface to bind well.

Another thought that you might consider is just finishing the inside surface of your piece. This works well for goblets where I'll use one type of finish in the cup and another on the outside. I still would recommend some kind of finish on the outside, however, but it need not necessarily be the same as the inside. Not all of us are as neat with our drinking/eating as others. You'll still likely get drips and runs of whatever is in the inside of your piece running on the outside so it'll need to be protected too.

I know it's a lot to take in, Kevin. It's a very complicated subject if you're going to do it right and match the finish to the use of your pieces instead of just blindly choosing something like far too many woodworkers/woodturners do.

- Andrew

The use of roofing tar among other things was in response to a post about what finishes were safe for "liquids" not what was safe for humans. In other words what would keep the liquid from harming the turning.

Same disclaimer as my original post, you'll need to find yourself a bit more salt...

Yeah, I got it in the original post. It was funny so that's why I used the reference in mine.

Salt I have ... now I just need the lime!

- Andrew

Salty limes taste better with tequila.

So THAT's why we drink tequila ! It's those salty limes that make us do it.

- Andrew