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Food safe bowl finishes

I

Ira

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Sep 5, 2004
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Location
New Boston, NH
I am fairly new at woodturning and am in search of a durable, high gloss, food safe bowl finish. I have several bowls waiting to be finished the materials range from cherry to beach to maple. I would appreciate any input. Thanks in advance!

Ira
 
Food Safe Finishes - high gloss

I've successfully used both high-gloss tung oil and urethane oil. The urethane oil dries quicker and is less prone to getting dust in it, but does not strengthen wood like tung oil. Both give a great shine and are very clear. I'm also using Fiberall instead of steel wool - it doesn't leave minute metal particles.
 
Welcome to the fold my friend.

You have touched on one of the most controversial subjects in woodturning. I say this because food-safe will split the camps in two.

1)Those who say the finish must be FDA certified (or tested at least) to be food-safe, non-toxic, etc.

2) Those who say that all finishes are food safe once they have been properly cured.

PERSONALLY, I fall into group 1. The main reason for this is that I sell my products and I do not want any leverage against me after the sale.

That said, I have used with some success, Behlens salad bowl finish. It can be a bit finicky to apply, as it it wiped on and required a good 4-6 coats. It dries rather slow, so I only get about 2 coats/day. The coats are thin to avoid sags and drips, so it is buffed through easily. With those caviats, it is glossy, and will protect the wood and is glossy.
Waxs are glossy to start with, but will dull.

I do a good compromise and will put a coat of Behlens on the wood to seal the wood better, let it dry and then use Claphans Salad Bowl Wax over the top of that. It is not glossy, but is a good finish.
 
This issue is something of a mythe that just won't seem to die. It is a leftover from the days of lead paints and such. Lead was never used in wood finishes, so the mythe persists mostly out of a lack of knowledge. The FDA does, indeed, have a standard for "food-safe finishes." However, the last information I have is that there has never been a wood finish (not paint, finish) that has been reviewed by that agency that failed to pass the tests.

Take this one to the bank:

ALL WOOD FINISHES ARE "FOOD-SAFE" WHEN FULLY CURED

With solvent finishes like lacquer or shellac, the film is benign once the solvent is gone. Do you take "timed release" medication? You're eating shellac.

Oil finishes take longer to become "safe" because they take longer to outgas the solvent and then must polymerize to complete the cure. However, after two weeks it's a non-issue.

Yes, there is an arguable issue with the metal-based "driers" used in some varnish-type finishes as well as the danish oil types. However, the minute trace amounts left in a fully cured oil finish have never been shown to be harmful in any test that I have seen or heard about. Someone with detailed knowledge of a particular finish are welcome to jump in here.

I've known several turners who market their bowls, but hold them until the "smell" has disappeared just for the sake of simplifying the sale. Some prospective purchasers think that it's a problem if they can smell the turpentine (real, gum type) used to thin the finish. They forget that they use turpentine to treat that nasty cough (turpenhydrate cough syrup) each winter.

I do hope this helps

Mark Mandell

PS: Guess I'm in Steve's "Camp 2" 😀
 
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Mark,

I'm in group two also. And just to prove how safe they are, I just drank a pint of Tung oil.

I'm
not
feeling
so good

urp!

Dietrich (A.K.A. "ow, that's hot. ow, that's hot. ow, still hot. ow, still hot."

P.S.(I ate lots of lead paint as a child too and it obiously ain't done me no harm!"
 
Mark Mandell said:
This issue is something of a mythe that just won't seem to die. It is a leftover from the days of lead paints and such. Lead was never used in wood finishes, so the mythe persists mostly out of a lack of knowledge. The FDA does, indeed, have a standard for "food-safe finishes." However, the last information I have is that there has never been a wood finish (not paint, finish) that has been reviewed by that agency that failed to pass the tests.
Click to expand...

Mark,

Please direct us to these tests for our own study into this matter.



Mark Mandell said:
Take this one to the bank:

ALL WOOD FINISHES ARE "FOOD-SAFE" WHEN FULLY CURED

With solvent finishes like lacquer or shellac, the film is benign once the solvent is gone. Do you take "timed release" medication? You're eating shellac.

Oil finishes take longer to become "safe" because they take longer to outgas the solvent and then must polymerize to complete the cure. However, after two weeks it's a non-issue.
Click to expand...

Whew. That's good news. Again, please direct us to the test results or at least to the scientific studies supporting this so we can study them ourselves.




Mark Mandell said:
Yes, there is an arguable issue with the metal-based "driers" used in some varnish-type finishes as well as the danish oil types. However, the minute trace amounts left in a fully cured oil finish have never been shown to be harmful in any test that I have seen or heard about. Someone with detailed knowledge of a particular finish are welcome to jump in here.
Click to expand...
I think I'd like to see the studies on this one too, if you please. Just to set my mind at ease.

If you don't have the exact references at hand, could you at least direct me to a location (either on the 'net or a governmental agency or laboratory or university research center, library, etc.) where I can start looking for this information myself? You wouldn't happen to have case study #'s would you? Maybe a federal grant application #? Just simply doing a Google search on this topic doesn't seem to come up with anything but anecdotal and marketing blurbs from book/article writers. I'm very interested in this topic. Any help you can provide would be most appreciated.
 
Old myths die hard.

You have two identical bowls. One is finished with brand X salad bowl finish. The other is finished with tung oil and you have a copy of a report from the FDA that states tung oil is safe after it is completly dry. Which one will sell first?

Mike
 
Research Points

Andrew,

I suggest that you start with the F.D.A. They maintain active outreach offices for all of the information you seek. You may even be able to get actual test results at no charge, provided you make your information requests in writing and pursuant to "The Freedom of Information Act."

You next line of inquiry is in a similar vein with the U.S. Occupational Safety and Health Administration, likewise available through their separate website.

Next I suggest you contact each manufacturer of the individual products you seek information about. As I haven't gone beyond MSDS Statements with the makers, I can't vouch for how much cooperation you are likely to get from that sector on your search for actual test figures.

I believe the NIH also runs a testing program as do several consumer advocate groups such as Consumers Union. I'm inclined to anticipate, however, that such private groups will expect a "donation" from you for the information.

I'll look forward to your sharing the wealth of informative details you receive back.

Mark Mandell

PS: Please also be sure to post your no-charge No-Gloves! demonstration schedule, especially if you'll be appearing in the metro NY, NJ, Eastern PA, Connecticut area.
 
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Thanks for all of the replys, though I must say sounds like I touched a nerve. Does anybody have specific brand recommendations? Thanks again!

Ira
 
Mark,

You wouldn't happen to remember which agency you saw those test results you mentioned before, would you? Or maybe which month or year that you might have seen them? That'll help me narrow things down in my own search. Any idea on what that FDA test of wood finishes was called?

I'll certainly share whatever I can find, if anything, right here. It's an important issue that, as a producer/wholesaler of kitchenware and certain finishes, I have to have actual hard evidence of what's going on. Far too much liability if I don't. Not to mention that I'd just feel horrible, personally, to not be 100% sure for those that purchase my products. I mean, it shouldn't be their sole responsibility to research this. Their relying on me for that.

Your P.S. response is posted in the appropriate thread.
 
Ira,

I use top grades of dewaxed shellac mixed from dry flakes, as well as Zinsser's Seal Coat which is a proprietary processed bleached shellac, mostly for sanding sealer. I also use Waterlox tung oil original sealer and high gloss finish. I find the tung oil to be a superior choice for bowls and other turnings because the film is more elastic and thus allows for more wood expansion without cracking the coating.

Jeff Jewitt's Homestead Finishing [usual disclaimer] is a good source for dry shellac as well as Waterlox and other finishes and finishing tools.

Mark
 
Just for a completely different input, when I turn salad bowls, I use large amounts of mineral oil and nothing else. I figure that, with all the various liquids going into it, no finish is going to maintain a gloss anyway. This way, I can resand a couple of times when the oil raises the grain and get a nice, consistant texture and look. Washes easy too. Haven't tried oil on just the inside and buff, shellac, and wax on the outside but it's in the works.

Dietrich

(and, yes, I actually did eat paint flakes as a kid. Not too many though (I hope))
 
food safe and stain proof?

I wish to add to Ira's original question. Of these "food safe" finishes which ones have the ability to prevent Balsamic Vinegar from staining a light colored wood. This is a problem I have encountered.
 
Finish experts may be right, but marketing experts win every time. My wife felt much better when I showed her the label that said: “non-toxic when cured†on Salad Bowl Finish by General Finishes.

A high gloss finish can be achieved using this finish, but it depends on how smooth you sand and burnish the bowl before application and it takes many coats.

If you want to keep the hi-gloss, you probably shouldn’t use the bowl. Repeated cleaning, even if never submerged, will eventually doom any gloss finish. So it stands to reason that if you never use the bowl, the finish can be anything, right?

No finish is my preference (except bowls for potato chips that will get exposed to oily residue). Tight grain woods, like cherry and maple can be polished on the lathe to a remarkably high gloss without any finish. Such pieces take on a particular look after use. Sort of a patina’d semi-gloss. Cleaning and maintenance is really simple. Just clean them with water and a common scotch-bright pad (the combo sponge pads). It's not stain-proof, to be sure, but it is hard to beat for "food safeness."

I suggest you turn test samples and try various combinations. This of course also might require a new and bigger lathe and several new gouges and scrapers. But when your health and the safety of others is conerned, the cost should always be a secondary consideration.
BH
 
Eddie Graham said:
I wish to add to Ira's original question. Of these "food safe" finishes which ones have the ability to prevent Balsamic Vinegar from staining a light colored wood. This is a problem I have encountered.
Click to expand...

Eddie,

conventional wisdom says "you can't get there from here" because any finish film that will resist the stain initially will fail (split, flake, reel, etc.) within a rather short period of time. The mineral oil (or oil & wax) that I use will decrease the staining, but not stop it. Seems like you have three choices: 1) give up the balsamic [Boo!], 2) go with the "patina of use" [my choice], or 3) come up with a new process [or just one that I don't know about] that will do what you and many others seek.

Mark
 
Food Safe

Somehow the question begs to be "asked and answered". If people buy expensive wooden bowls to put their food into they surely must be doing it to serve, and to be eaten. Otherwise they would be using plastic containers with sealed lids. So, if a wood finish is really poisionous then we would know that and some of us would be dead, don't you think? Are they the "silent majority?" I think not! Food should be eaten promptly and my guess it that it will spoil a whole lot quicker than the finish on the bowls will poison them. Phil 🙂
 
16 years of use and still glossy

Just to further confuse matters, I have a segmented cherry bowl that I made 16 years ago, finished with many, many layers of "Salad Bowl" finish. It's been used for popcorn and often doesn't get cleaned in a timely fashion. I've used Scotch-Brite more than once to get rid of the congealed oil. It's never been in the dishwasher, but has been washed at least a thousand times. It still has a nice gloss finish -- if you ignore the various dings and scratches that it has acquired through years of use.
 
Brian Hahn said:
It still has a nice gloss finish -- if you ignore the various dings and scratches that it has acquired through years of use.
Click to expand...

Oooh, a real "distressed finish!" Very fashionable, indeed. 😀

And Brian, how many of those dents and dings spark a memory of "Yikes! You dropped Dad's bowl!" or "Gee, it just bounced."

[Another argument for flexible soft oil finishes, they dent but but don't chip.]

M
 
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