Update on Salad Bowl Finishes

[bfwhitma]

I have been using the commercial salad bowl finishes by General Finishes and Behlen that use a lighter hydrocarbon solvent like alcohol instead of the heavier HC's I suppose to eliminate potential leaching of contaminants in an acidic environment, i.e. vinegar dressing. They produce a harder finish than mineral oil/wax etc. which is an advantage but also need maintenance as I have found. I suspect that a top tung oil formulation like Waterlox would not leach after it is really dry but it has never been ok'd by FDA in a leach test. I also use the finishes on wine goblets where they seem to work well.

Any thoughts/preferences appreciated.

Thks, Brad

 

[allen jay]

slad bowl finishes

try the walnut or nut oils
mike mahoney has one and who would know better than a professional salad bowl maker

 

[Mark Mandell]

I have been using the commercial salad bowl finishes by General Finishes and Behlen that use a lighter hydrocarbon solvent like alcohol instead of the heavier HC's I suppose to eliminate potential leaching of contaminants in an acidic environment, i.e. vinegar dressing. They produce a harder finish than mineral oil/wax etc. which is an advantage but also need maintenance as I have found. I suspect that a top tung oil formulation like Waterlox would not leach after it is really dry but it has never been ok'd by FDA in a leach test. I also use the finishes on wine goblets where they seem to work well.

Any thoughts/preferences appreciated.

Thks, Brad

Brad, Not sure what "leach" test you're thinking about, but last I checked, FDA had not actually tested, let alone "approved", any wood finish. All modern finishes, once cured (rather than just "dried") are food safe. The acid-leaching action of which I think you speak has to do with lead (as in lead crystal) and compounds in certain types of plastic bottles. There is no lead or anything else to leach out of any wood finish.

All that said, for large mixing bowls I use several applications of warmed Waterlox Original sealer followed by a paste made from paraffin and mineral oil. Works for me, and have had no complaints from others. Do the same on cutting boards.

PS: When using nut oils, you must be sure to use the properly refined forms from which all of the proteins which cause nut allergies have been removed. Won't do to present a lovely finished bowl only to hear later that the recipient went to the ER in anaphylactic shock from a nut allergy.

 

[glenkey]

There is no lead or anything else to leach out of any wood finish.

Not been harvesting wood in Oklahoma, have you?
Come across a pecan tree with permission to take as much as I wanted.
Got it home, during the turning, something started to "shine". Stoped the lathe only to find 9 rounds of what looked to be .45's.
They'd been there a while as they were deep in the wood, or maybe they had a hot load.😀

 

[Mark Mandell]

Picked up 400bf of 5/4 fine curly Pennsylvania cherry some years ago, allegedly cut near Carlisle (where the Indian School was located). Before I was done I had picked out 5 or 6 of what appeared to be 50 cal. lead. When I happened to see the guy I bought the wood from, I remarked about all the added weight. He proceeded to relate a story about how some young braves at the school got drunk and the Cavalry came charging in resulting in that particular tree getting shot a number of times. I looked at him sideways a bit and said, "that's all true, eh?" He replied it was his family's story from way back and he was stickin' to it. 😀😀

While I didn't leave the lead, I incorporated the "defects" wherever I could.

 

[bfwhitma]

Salad Bowl Finishes

Mark and others:

I like your idea of using Waterlox and yes it does bond with the wood and cure well, but no, you are not correct that all modern finishes should be assumed to be equal in their resistance to leaching contaminants. I have spent 30 years in the environmental field and much too much time reading the Federal Register for one environmental or health reg. or another (woodturning is more fun). The manufacturers of salad bowl finishes correctly refer to federal approvals for their products. I did not test them and don't know the basis for the approvals but they exist. Leach tests are performed all the time on many different types of materials, for example plastic bottles, to determine whether any of the chemicals--not lead in particular but organics especially today since lead has been banned for years from food containers--will leach out in harmful quantities. Leaching occurs particularly in acidic environments--i.e. vinegar. Putting water in a vessel and testing it is a weak test.

I have not used walnut oil because it darkens the wood greatly over a short period of time. I love my Mahoney bowl but what a shame...

Thanks for your help. Would love to hear more.

Brad

www.bradturnsgreen.com

 

[Mark Mandell]

. . you are not correct that all modern finishes should be assumed to be equal in their resistance to leaching contaminants. . . . The manufacturers of salad bowl finishes correctly refer to federal approvals for their products.

Brad,

Not meaning to argue, but everything I've ever seen on wood finishes, including definite statements from experts such as Michael Dresdner, Bob Flexner, and Jeff Jewitt, have been uniform with regard to the discussion [hype?] over "food safe" wood finishes. Once a solvent finish [lacquer & shellac] fully evaporates its solvent, leaving only the resin, there is nothing to leach. We even use the same shellac and lacquer resins in things like pharmaceuticals [controlled release medications, etc.].

Reactive finishes like the drying oils (linseed, tung, flax] become inert once their carrier and tail solvents and diluents evaporate and the films are fully polymerized (3-6 weeks].

I am, of course aware of the VOC regulations, both state and federal, but those relate to formulations "pre-application" for Clean Air & Water issues rather than standards/tests/approvals for cured finishes.

As I very much want to be both clear and correct when I give information, I'd really appreciate it if you would send me some links to and/or sources for the information you spoke about on tested/approved finishes. The leaching plastics stuff I know about, and I haven't mentioned use of the new acrylic/waterborne finishes which are a whole different world.

You can post the links here, or in a PM. No rush. Thanks. 🙂

 

[Bernie Weishapl]

I talked and e-mailed back and forth with Jeff and Bob. Both told me that all finishes are food safe after cured 72 hrs. Also that those that claim they have salad bowl finish which is food safe is not any different than most other finishes. Ernie Conover says General Finishes so called salad bowl finish is a joke as it generally gets gummy after 2 or 3 years. He says Antique Oil is all he uses. When you can't smell the finish it is cured.

 

[KellyDunn]

Brad, Mark has the drift. The food safe thing is all hype. I forget the issue of the AAW journal, but not long back, the history was laid out of how the whole issue of food safe came up. You have access to experts and fools here. Sometimes the fools are more loud. Bob Flexner and Alan Lacer are experts. I listen when they talk finishes. Bob takes finishing as serious as anyone can. He is the author of the AAW article. Now that I have given Bob and Alan a plug? I hear of zero complaints about Mikes walnut oil finish. He worked with at least Alan to come up with the right process of heat etc to produce a oil that hardens. If you have beens to Mikes place he has a setup to heat and process the oil. 55 gal barrels of walnut oil fill the room. He processes what he needs to fill orders.
As for me as a full time turner who does plenty salad bowls? I did like many and used mineral oil. Messy, and the bowl looked really bad from the first use on. I now dip the bowls in a thinned poly mix with a bit of linseed added to give me a few minutes working time before the mix on the outside begins to harden. I then dry with paper towels and pop them in my kiln overnight. Paying attention to bleeding for about an hour. I then buff all shiny spots and re dip the next day. Koa tends to take two dips before the buffing is all shiny. Other woods as they need. I let the bowls sit and cure out. I then give them a buff and wax. If actually used for food use I reccomend a bit of mineral oil if the piece starts looking a bit dull. I do buff back to wood. My goal is some hard finish in the pores. I have a lot of years under my belt with what I do for a living. Since going to a harder finish if I get a piece back they sure look better than any done with mineral oil. And the owners should hand wash with soap and water and then dry the bowl after use. If not the bits of salad oil will build up and make a black sticky mess over time.

 

[MichaelMouse]

Mark and others:

I like your idea of using Waterlox and yes it does bond with the wood and cure well, but no, you are not correct that all modern finishes should be assumed to be equal in their resistance to leaching contaminants. I have spent 30 years in the environmental field and much too much time reading the Federal Register for one environmental or health reg. or another (woodturning is more fun).

The problem, Brad, is that you are an environmental scientist. You are correct in assuming that none of the turners cited are food or finish scientists. They are turners, and their examples and assertions are at best anecdotal. As Dean Edell, the radio talk doc says "the plural of anecdote is not data."

Here's where you'll find the rules : http://www.access.gpo.gov/nara/cfr/waisidx_03/21cfrv3_03.html Humans live in a real world with potential contaminants anywhere, and a bit of cobalt or manganese which might leach out of a finish over months in contact with acid foods will never reach the level approved for drinking water. There's not enough available.

The real danger is in the bacteria. You want to be able to get some detergent wash across so they can't shelter and become part of the next serving. There is no minimum recommended dosage for them. One can infect. Give your bowls a bit of water protection so they can be washed.

 

[Mark Mandell]

Michael,

You a bit off the mark here. While Mr. Lacer is a turner, and I haven't looked up Bob Flexner's C-V, Mike Dresdner is a research "finish" chemist who, along with the Zinsser's company, developed the SealCoat shellac products. Jeff Jewitt is a professional restorer and finishing consultant with chemistry degrees who developed and manufactures the Transtint and Transfast lines of dyes.

Flexner and Jewitt are widely recognized and published finishing experts who also lecture. Dresdner consults with a number of finish manufacturers including, I believe, General Finishes. They are Not turners.

I'll take their word over anything a government agency puts out.

 

[MichaelMouse]

Michael,

You a bit off the mark here. While Mr. Lacer is a turner, and I haven't looked up Bob Flexner's C-V, Mike Dresdner is a research "finish" chemist who, along with the Zinsser's company, developed the SealCoat shellac products. Jeff Jewitt is a professional restorer and finishing consultant with chemistry degrees who developed and manufactures the Transtint and Transfast lines of dyes..

I mentioned "turners" specifically, not the other finish manufacturers' "consultants" whose laboratories, dollars to donuts, are their shops, and whose purpose is to pass information on utility, not edibility. They want to make sure it flows, cures and repels well. I value their input on those factors. Though, if they were involved with pharmaceutical research we should certainly doubt their results because the work was paid by a manufacturer's grant.

 

[Wayne Spence]

salad bowl finishes

Michael,

You a bit off the mark here. While Mr. Lacer is a turner, and I haven't looked up Bob Flexner's C-V, Mike Dresdner is a research "finish" chemist who, along with the Zinsser's company, developed the SealCoat shellac products. Jeff Jewitt is a professional restorer and finishing consultant with chemistry degrees who developed and manufactures the Transtint and Transfast lines of dyes.

Flexner and Jewitt are widely recognized and published finishing experts who also lecture. Dresdner consults with a number of finish manufacturers including, I believe, General Finishes. They are Not turners.

I'll take their word over anything a government agency puts out.

Why take anyones word for it? Regardless of expertise, education or affiliation what is needed is published reproducable findings.

 

[Mark Mandell]

Why take anyones word for it? Regardless of expertise, education or affiliation what is needed is published reproducable findings.

Excellent idea.

Now if someone would just post the actual data from the tests that were done for "leachates" of harmful compounds and elements from applied/cured wood finishes perhaps we can all reach agreement here and resolve this perennial issue at last.

Let's also make sure not to confuse "food safe" with "edible", and also be sure that nobody's suggesting making food storage containers out of finishing compounds (Chinese lacquerware excluded, of course). 😀

 

[Wayne Spence]

salad bowl finishes

Excellent idea.

Now if someone would just post the actual data from the tests that were done for "leachates" of harmful compounds and elements from applied/cured wood finishes perhaps we can all reach agreement here and resolve this perennial issue at last.

Let's also make sure not to confuse "food safe" with "edible", and also be sure that nobody's suggesting making food storage containers out of finishing compounds (Chinese lacquerware excluded, of course). 😀

Yes, I did not mean to be flippant but realize that getting any two parties involved to agree on even a testing method or the difference between "food safe" and "edible" is a task bordering on the impossible. Manufacturers want to sell their product and agencies like the EPA exist to show that everyone is a culprit.

 

[Mark Mandell]

Yes, I did not mean to be flippant but realize that getting any two parties involved to agree on even a testing method or the difference between "food safe" and "edible" is a task bordering on the impossible. Manufacturers want to sell their product and agencies like the EPA exist to show that everyone is a culprit.

Hi Wayne,

And I didn't mean to be rude either.😱

It's just that I've gone through this same topic so many times over the last 12 years or so that I've lost count. It just seems to be a beast that won't die. I do appreciate people wanting to make sure that the stuff they make, gift, and sell is safe; that's certainly a responsible attitude that we need more of in general.

I think folks "assume" that because a finish has organic solvents in the can that has various cautions printed on the labeling, that somehow the stuff will remain hazardous for anything other than putting a shine on a piece of wood. Then, when they see some manufacturer put "food safe" on their can, they extrapolate that anyone who doesn't do so must be selling finish that presents some kind of danger, when, in fact, it's all just sales "puffery."🙄

Ah well.

Peace🙂

 

[bfwhitma]

Intelligent Reply from Waterlox

I thank you fellow AAW members for all of your comments. I believe the final word for me at this time is the following:

1. I have not seen nor has Waterlox produced a leach test in which a wooden bowl is filled with some amount of vinegar dressing, allowed for a few hours to stand, and then tested for chemicals. It is not a perfect world and we have to proceed on our best evidence and make our own decisions. I am going to use Waterlox on salad bowls with the caveat that Waterloc provided to me (disclosure of possible nut allergy to tung bean).

2. Yes, I sometimes go with mineral oil etc. and enjoy the natural feel of it but there are times when the figure in the wood in my opinion is just nor given its full beauty that Waterlox gives and mineral oil etc. definitely need more care.

3. Many of you were very close to Waterlox's answer. It is based on chemistry that I understand albeit it is not the absolutely definitive leach test. I agree that the plasticizers used in bottles are different chemicals--actually their toxicity is a lot lower. Mineral spirits is a generic term and has a sort of benign connotation based on the English words. If you want to know what is in the product, look at the MSDS sheet for Waterlox listing the hydrocarbons by chemical name.

4. Here is the reply from Waterlox:

From: Kellie Hawkins
To: Bradford Whitman
Sent: Monday, October 25, 2010 10:43 AM
Subject: RE: Tech/Safety Advice

Brad:

Thank you for your inquiry regarding Waterlox Original Tung oil finishes. Waterlox Original Tung oil finishes are food-safe and non-toxic after they’ve cured for 30-90 days. Here’s why:

Waterlox finishes are non-toxic and food-safe when dry. Special care and attention should be used when applying the finish with regard to spread rate and adequate ventilation.

There are two basic steps to the drying and curing of a Waterlox Original Tung oil finish:

1. The first step is the evaporation of the solvent/"carrier" system. The evaporation of solvent usually occurs in the first 2 - 4 hours with proper cross-ventilation techniques.

2. The second step is the curing of the solids system, which is comprised of the oil and resin. The solids system completes 95% - 98% of it’s complete cure cycle in 7 – 14 days with proper ventilation; full cure, film hardness and chemical resistance properties are achieved in 30 -90 days with continued adequate ventilation.

The only “toxic†portion of the formulation is the mineral spirits, a petroleum distillate, which, as mentioned above, evaporates in order for the finish to dry in the first 2 – 4 hours. A minimum of 7 days should be waited before using the surface. While 95 – 98% of the chemical resistance properties are reached within the first 7 – 14 days, full cure, film hardness and chemical resistance properties are achieved in 30 - 90 days.

If someone has a tree-nut allergy, then they may have a reaction to the finish since Tung oil is a tree-nut. You may wish to include this type of statement on your “disclaimerâ€.

Brad
www.bradturnsgreen.com






Kellie Hawkins Schaffner
Vice President
Waterlox Coatings Corporation
9808 Meech Avenue * Cleveland, OH 44105
216.641.4877 * fx: 216.341.2423
www.waterlox.com * THE Original Tung Oil Finish Since 1910

myself for my own bowls sometimes but they do not either hold up or highlight the wood figure quite they way Waterlox does. Sometimes one doesn't need that extra )

2. You can make your own judgment on walnut oil. I bought my bowl directly from "the guy", have never used it for wet materials, and in short order i, it is a gorgeous figured wood bowl, and in relativle y short order became very darl and lost its beauty.

 

[robo hippy]

I did run into a woman at a show once who was allergic to petroleum distillates. She told me, rather emphatically, that they do not completely cure out, and there are still traces left. I will stick with the Walnut oil.

robo hippy

 

[MichaelMouse]

I did run into a woman at a show once who was allergic to petroleum distillates. She told me, rather emphatically, that they do not completely cure out, and there are still traces left. I will stick with the Walnut oil.

robo hippy

SWMBO is sensitive to shellfish. More people allergic to shellfish than nut oils, BTW. She told me rather emphatically that the mock crab legs (chopped pollock) gave her the same tingle. I choked, said "yes ma'm," and didn't serve her any again. Better part of valor.

She does love Pollock fillets.

 

[Gretch Flo]

Perceived allergy

SWMBO is sensitive to shellfish. More people allergic to shellfish than nut oils, BTW. She told me rather emphatically that the mock crab legs (chopped pollock) gave her the same tingle. I choked, said "yes ma'm," and didn't serve her any again. Better part of valor.

She does love Pollock fillets.

Michael-I have read several times that people in drug testing efficacy or other blinded trials, that 20% of people will respond to a placebo. Is your wife in the 20th percentile??????😀

Gretch

 

[MichaelMouse]

I had occasion to do some research on the testing process for a couple of antidepressant drugs a while back. It was neck and neck between the placebo and the pill, with "effectiveness" barely at the level of statistical significance. The way they are prescribed today ... the modern version of "take two aspirin and call me in the morning."

SWMBO and I just renewed our rolling one-year agreement two weeks ago, so I guess she's stuck with me for at least another 50 weeks.

 

[Jake Debski]

...........................................................................
SWMBO and I just renewed our rolling one-year agreement two weeks ago, so I guess she's stuck with me for at least another 50 weeks.

MM, the LOML recently made her annual trip to the Town Hall in hopes of learning our marriage license needed to be renewed. 😱😀

 

[MichaelMouse]

We married too young, as everyone told us, and I must admit my bride was a bit innocent (gullible?). Couple years after the wedding I pointed out to her that the Michigan marriage license had the phrase "valid for 120 days" printed below the issue date.

 

[Michaels]

... I pointed out to her that the Michigan marriage license had the phrase "valid for 120 days" printed below the issue date.

MM, I just laughed out loud. That's priceless.

michael

 

[Dean Center]

Michael-I have read several times that people in drug testing efficacy or other blinded trials, that 20% of people will respond to a placebo. Is your wife in the 20th percentile??????😀 Gretch

Placebo rates vary, to some extent depending on the problem being studied and the treatment being used. The rate can be anywhere from 10-over 50%, and commonly is 30-35%. The difference between the medicine and the placebo group is often 5-10%. In other words, 35% of placebo people respond and maybe 40-50% of study people respond. It's actually kind of shocking how little real benefit some widely used and very expensive medicines and procedures have demonstrated.
Dean

 

[Gretch Flo]

spouse

We married too young, as everyone told us, and I must admit my bride was a bit innocent (gullible?). Couple years after the wedding I pointed out to her that the Michigan marriage license had the phrase "valid for 120 days" printed below the issue date.

Michael-she's got it good!!!!!!-you do the laundry, cooking and gardening (and????), Now my husband (now ex) would paint the house every 5-7 years and anything that came in front of the brush (bulkhead/wheelbarrel. water pipe, etc!!!), and do the dishes every 3-4 days, babysit as long as the tv was handy. I did everything else. I got tired!!! Gretch

 

[Bill Boehme]

MM, I just laughed out loud. That's priceless.

michael

Don't you need to buy something like a duck stamp annually to keep the license valid?

BTW, I think that Michael hit the most important point that bacteria would be the main concern. There are some wood treatments that I would not want on treenware that could easily leach out such as Pentacryl, Polycryl, (both are smelly) or mineral oil (only because I had to take it occasionally when I was a small child and did not like it then -- I doubt that I would like it now either). Otherwise, something durable and easy to clean seem like the best course of action.

 

[Jerry Hall]

Bacteria in Wood cutting boards not a hazard to human health...

according to THIS UC Davis research focused on well used plastic cutting boards v. wooden ones. In summary the conclusion is:

"We know of no similar research that has been done anywhere, so we regard it as the best epidemiological evidence available to date that wooden cutting boards are not a hazard to human health, but plastic cutting boards may be."


So, if this is all true, maybe the concerns stated in previous posts about bacteria being a worse problem than finish material falls into the Bill Cosby category of: "NEVER challenge worse!" as in "Things could be worse."

I note too that Chopping Bowls have been used for a few years with a generally accepted safety level. Surely they will have far more nooks and crannies for those pesky critters to hide than our relatively lightly used salad bowls. And how many bowls would we have to eat to become seriously ill? And it wouldn't it be the finish that did us in?

Now, they didn't compare the glass cutting boards. Maybe we should become glass artists and sell knife sharpeners to go with them?

I say wait 30 days after finishing with just about anything, wash them lightly by hand, and keep them in a dry place. Maintain with beeswax, mineral oil, or walnut oil.

 

[Bill Boehme]

according to THIS UC Davis research focused on well used plastic cutting boards v. wooden ones. In summary the conclusion is:

"We know of no similar research that has been done anywhere, so we regard it as the best epidemiological evidence available to date that wooden cutting boards are not a hazard to human health, but plastic cutting boards may be."


So, if this is all true, maybe the concerns stated in previous posts about bacteria being a worse problem than finish material falls into the Bill Cosby category of: "NEVER challenge worse!" as in "Things could be worse."

I note too that Chopping Bowls have been used for a few years with a generally accepted safety level. Surely they will have far more nooks and crannies for those pesky critters to hide than our relatively lightly used salad bowls. And how many bowls would we have to eat to become seriously ill? And it wouldn't it be the finish that did us in?

Now, they didn't compare the glass cutting boards. Maybe we should become glass artists and sell knife sharpeners to go with them?

I say wait 30 days after finishing with just about anything, wash them lightly by hand, and keep them in a dry place. Maintain with beeswax, mineral oil, or walnut oil.

That's interesting, but I believe that you might have missed the gist of Micheal's point which is that proper cleaning in order to prevent the accumulation of bacteria in food residue left on the surface is of greater importance than fretting over the safeness of the finish itself.

As an aside, it does seem somewhat strange that a veterinary medicine school is making a conclusion about human health safety, but perhaps it is being interpreted out of context and refers to safety to food handlers rather than the assumed conclusion that someone will be eating food from the wooden surface. In any case, their list of published papers seem to be focused on what is necessary to clean and/or disinfect wooden and plastic cutting surfaces rather than some intrinsic property of the material itself. Everybody knows that you must keep food handling surfaces properly cleaned -- the question being resolved is the extent of cleaning necessary to accomplish this goal.

Their statement that you quoted seems to be rather pompous and out of character for research conclusions, but maybe not for veterinary researchers. I think that they should have proofread and edited their work better to ensure clarity of meaning.

 

[MichaelMouse]

Couple of thoughts. US military used the veterinary service as its sanitarians. Perhaps other health departments do as well. Cheaper than a cardiologist, and likely more knowledgeable in the matter at hand. Bacterium versus mammal is pretty standard, whether it's Fido or Frieda.

Chopping blocks and bowls made of wood have indeed been used for centuries, and if they were not properly scraped and salted, they passed on a lot of salmonella and other lovelies. Not that the infections would have been as noticeable in an age without high standards for cleanliness and availability of preservatives other than salt. Everybody caught the runs pretty regularly.

Gretch, you divide the duties as able. If she works 8-5, someone has to make dinner. Squash is baking, and I will cook chicken breast in olive oil, wine and shallots for the meat dish. Carbs will have to come from bread. I took care of the granddaughters today. Bet she would have preferred to do that, so dinner had better be good enough to compensate.

She just called. Running 20 minutes late. Fortunately I can turn off the stove and wait for a while. Guys, it's a great thing to pace the cook, especially if you don't want tough meat and the cold shoulder for dinner.