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Thread: Any Chemists Among Us?

  1. #1
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    Any Chemists Among Us?

    Are there any chemists among us who could answer a question for me about solvents? If so, send me a PM.....thanks
    AKA Young Grasshopper Woodworker
    AKA The Rookie

  2. #2
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    Puyallup, WA
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    I'm a bit of a chemist (BS degree 23 years ago) but don't know how to initiate a private message. Either send me a PM or ask your question here and I'll see what I can do.

  3. #3
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    Quote Originally Posted by Peter Lyon View Post
    I'm a bit of a chemist (BS degree 23 years ago) but don't know how to initiate a private message. Either send me a PM or ask your question here and I'll see what I can do.
    Just click on the persons name above there avy (pic) and a drop-down box will appear.
    "Its only by minute attention to every detail that you will achieve perfection"

  4. #4
    You want to mix up a bomb or desolve a finish? Why not ask your question forum wide.
    More years than want to remember, teaching, schooling, etc. solvents are in my realm, as well as chemical awareness, drs in chemestry are friends and full of knowledge waiting to be asked to use vtheir represses knowledge. If I don't know I can ask around.
    .

  5. #5
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    Quote Originally Posted by Bill Simpson View Post
    ...Why not ask your question forum wide...
    I thought it might be too boring forum wide, but if you insist.....

    There's a lot of controversy about whether Tung Oil is "food safe" or not. I'm hoping for some help making sense of a FDA document.

    I found this document by the FDA which says it is safe after it is cured.

    My first questions concern the part of the document after (ii). My history with chemistry is limited to 1st year univ. gen. chem. during the stone ages, and I can't make heads or tails of it.

    My question is, do those chemicals listed include the use of solvents like "mineral spirits" and turpentine? I did see some terpene something or other....?

    In other words, is it "food safe"--according to them--if Tung Oil is applied with turpentine or mineral spirits as long as it's cured?

    Is it "food safe"--according to them--if Tung Oil had the metal salts added as "drying" agents (after it's cured)?

    Also, is it "food safe"--according to them--if it is applied with a varnish? I think it is because I noticed several references to "resin" and if I understand correctly, a "wiping varnish" is simply oil + solvent/thinner + resin.
    AKA Young Grasshopper Woodworker
    AKA The Rookie

  6. #6
    This is a common concern that appears from time to time, and needs to be addressed by WWers who care about future use of their wares. As it has been discussed repeatedly and needs to be rehashed from time to time, the concensus seems to be that all modern manufactures will claim that their products are food safe , after it cures... after it cures is the question, when is it cured. what is a reasonable amount of time?

    Not a boring question but one many WWers ponder from time to time.

  7. #7
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    You're right, Bill, and that's why I want a chemist to decipher that mumbo-jumbo which is impossible for the lay person to understand. Correct or not, I want to know what the FDA is saying.

    In that document they say Tung Oil is safe after it's cured. But are they saying it's safe after it cured when it's used with thinner? with resin (as a varnish)? with metal salts added for drying?

    And how long does curing take? Well that's anyone's guess....perhaps a chemist can tell us....
    AKA Young Grasshopper Woodworker
    AKA The Rookie

  8. #8
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    Should be food safe after drying. I wonder about this from time -to -time and I figure that I get enough doses of chemicals just from working in the shop and putting finish on. I wonder also about just what kind of chemical compounds are in different woods. I bet there are lots of things to scare you that come out of the wood just when machining it. I really don't worry about it. Ignorance really isn't bliss, just ignorance.

    My son turned a red cedar baseball bat this past week. It is a trophy for the winning team in a tournament he happens to be the commissioner for.

    I opened all the windows and vacated the shop when he was working because I am allergic to cedar. Get flu like symptoms and vertigo real bad.

    At least you are not finishing with peanut oil.
    I'm a certifiable tree hugger. (it's a poor mans way of determining DBH before cutting the tree down)

  9. #9
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    Well, you can go with a mineral ol(food safe) or depending on what it is go with a epoxy fnish.

  10. #10
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    Mar 2011
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    Red Feather Lakes, CO
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    Cynthia,
    This might be a little wordy but all I can say about that is sorry.
    I read this post yesterday and have been thinking about it before I posted. I want to sound half intelligent.
    I am not a chemist but have worked with a lot of real nasty chemicals. The majority of my disability is caused by chemicals. That is another story.
    I think the problem you are running into is the document you linked is really poorly written. The intent is as clear as mud. I think a chemist would even have a hard time understanding what the author was stating.
    I found that even if you get something that has the same name it can be different. I could get two cans of trichloroethylene (nasty stuff). Both cans would come with a MSDS (material safety data sheet). That sheet has a bunch of information on it about the chemical make up, safety precautions, reactions to other chemicals, symptoms of over exposure, blah, blah, blah . The chemical make up of both cans could be different even tho they have the same nomenclature. It depended on the manufacturer. If I had to use them with another chemical to treat a surface for cleaning applying an adhesive I would have to read the sheets on the chemicals to see if they would react to each other and if they would, the chemicals that would have an adverse reaction to if mixed and HOW they would react to each other. If they were mixed wet they might have an explosive reaction, but if one chemical was applied and allowed to dry could I use the other chemical without an adverse reaction?
    I would start with a MSDS for the specific chemicals made by a specific manufacturer. For instance I would look up the MSDS for the tung oil and the MSDS for the thinner you were going to use. This doesn't even come close to answering your question but I hope it can give you a place to start. The cure time should also be on the label for the specific brand of that tung oil. Here is an example of the Tung Oil that Rockler sells.

    http://www.rockler.com/tech/RTD20000304AA.pdf

    If you need help finding the MSDS or reading it holler. I had a book 4 inches thick just for my one man shop. If you have trouble sleeping these are great to have on your night stand.

    Good luck
    Last edited by Mark Rice; 04-29-2011 at 02:39 PM.

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