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Thread: Glueing Teak

  1. #16
    John,I just now saw your question. Lacquer thinner is MOSTLY solvent but has waxes or oils to retard too quick drying .There may be different proprietary formulas but those additives are what makes it "lacquer thinner" and might explain the pushing oil around thing .

  2. #17
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    Quote Originally Posted by Mel Fulks View Post
    I just went and read that again. It says "lacquer thinner, acetone, or other appropriate solvent". They reccommend one inappropriate solvent and don't mention MEK. I find that sloppy. No wonder there is debate and theory!

    Mel, I'm not trying to argue with you - just trying to be clear for the OP - below is the quote from the West System thread detailing specifically how to prepare teak and other oily woods - found down the page from the general comments you quote -

    "Teak/oily woods
    -Wipe with acetone 15 minutes before coating. Solvent removes the oil at the surface and allows epoxy to penetrate. Be sure solvent has evaporated before coating."



    "... for when we become in heart completely poor, we at once are the treasurers & disbursers of enormous riches."
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  3. #18
    Sam, I appreciate your posts and sure all intentions are good . When I find a mistake in something like that ,I stop readin
    And I think most would stop there ,it never occurs to me that the writer might change his mind in another paragraph. As you stated what I wrote was their words. The use of LT is wrong and the recommendation to do so is sloppy.

  4. #19
    Quote Originally Posted by Mel Fulks View Post
    John,I just now saw your question. Lacquer thinner is MOSTLY solvent but has waxes or oils to retard too quick drying .There may be different proprietary formulas but those additives are what makes it "lacquer thinner" and might explain the pushing oil around thing .
    I think lacquer thinner generally contains naphtha and possibly mineral spirits in it. You can get low quality naphtha and spirits that leave behind oily residues, but high quality of the kind you would use in thinner evaporates completely and leaves no residue at all. In fact, mineral spirits are generally considered to be de-greasers and are used industrially to remove oily residues from items. Iit's one of the traditional pre-paint cleaners that you would find in an auto body shop. Hardware store mineral spirits generally won't work well because they're not pure enough, but spirits designed for the task will remove all of the oils and leave nothing behind. Similarly, the VM&P in VM&P Naphtha generally indicates it's appropriateness for use in finishes and lack of oily residue....which would be disastrous in a finish.

    I do believe that you're correct about their being used as retarders. I can't imagine how quickly pure acetone, toulene and MEK would dry in a spray mist....you'd probably just have dry finish hitting the target!
    Last edited by John Coloccia; 11-23-2013 at 1:14 PM.

  5. #20
    I had no idea what was in LT until I did some googling to be sure. This subject first came to my attention by an employer who had some background in chemistry. I was using LT myself at the time I was corrected and told to use MEK. The very type of work you do assures your knowledge and skill. The mistake belongs to someone at the glue plant ,or advertising agency. If I were a steady user of their product I would give them an angry call.

  6. #21
    Quote Originally Posted by Mel Fulks View Post
    I had no idea what was in LT until I did some googling to be sure. This subject first came to my attention by an employer who had some background in chemistry. I was using LT myself at the time I was corrected and told to use MEK. The very type of work you do assures your knowledge and skill. The mistake belongs to someone at the glue plant ,or advertising agency. If I were a steady user of their product I would give them an angry call.
    It's easy to confoozle what goes into these concoctions. I just went out and looked up the MSDS on my thinner. Turns out it's a large part naphtha and spirits...larger than I thought.

  7. #22

  8. #23
    In the "for what it is worth" Category, i'll throw in a couple of cents.

    I have been using epoxy for 30 years for gluing wood. I have used MAS, RAKA, West System, and System 3 throughout those years as their formulas changed, we have changed what we used to best suit our needs. For a glue up, any of them will work fine, though some of these manufacturers still sell epoxy which blushes and you should avoid that if there is any laminating involved. (long discussion not really pertinent here). In general, you want to use the epoxy formula with the best viscosity or flow rate. I have found RAKA and MAS to flow the best.

    The only thing which hasn't changed is what we use for cleaning joints when necessary. As a general rule, when possible, you should always sand away contaminates to get to bare wood. I prefer Denatured Alcohol as a cleaner for epoxy, but will not penetrate deeply and open the pores of the wood. Acetone is just as effective as denatured alcohol for the most part. Just think about how dry your skin gets when denatured alcohol is in regular contact.

    In order for epoxy to be effective, the wood needs to be contaminant free and relatively dry. Air dried is fine, however oily wood which releases to the surface is problematic.

    If you are going to use epoxy then in my experience, there are a few things you need to know. First as this thread implies, the surface and just beneath the surface needs to be clean and dry. Taking a heat gun to the joint for a minute or so before you glue up will help in a couple of ways. First, it will dry oils near the surface, and second it will assist the epoxy to penetrate the joint. Never thin epoxy with thinner when making a structural joint. It can be thinned and used as a penetrating coat, however the thinner will significantly lessen its holding abilities.

    When you glue with epoxy, you always want to spread clear epoxy on the joints and let them set for a couple of minutes before they mate. The clear epoxy will penetrate the surface without starving out any fillers. Then mix some clean wood flour in with the remainder of the mix and spread that on the surfaces as well. Wood flour is more structural than say microballoons or talc though it does take a bit more effort to sand it up.

    When joining the two surfaces, never over clamp. This is the biggest rookie mistake and in general the source of most failed epoxy joints. Epoxy is not like carpenters glue where you need to squeeze the heck out of the joint. You absolutely do not want to squeeze the excess out of the joint with epoxy. Just a firm clamping will do the trick. In most cases, we use spring clamps when using epoxy as a glue. If you are screwing it down, then do not overtighten when doing so.

    After you have glued up your joint, be sure an clean it up as much as possible. NOT with chemicals, just by scraping off the excess with a putty knife or the like. Epoxy dries very hard and when sanding, the surrounding wood gives way much quicker than the epoxy will.

    Now remember that epoxy takes days to cure. It may be dry in 24 hours but is not fully cured for a few days depending on your climate. You should never sand green epoxy unless absolutely necessary and if you do, make sure you have a mask on, good ventilation and you are using a vacuum assisted sander.

    Lastly (AND THIS IS IMPORTANT), remember that epoxy must be protected from UV. Epoxy left unprotected in direct sunlight over a long period of time will break down. There are some epoxies which have a certain amount of UV tolerance, RAKA comes to mind, however even those are UV resistant, not UV protected.

    Remember that there are alternatives such as 3M 5200 which is very popular in decking out topsides of boats, but it won't make a clean invisible glue joint if that is what you are after.

    Hope that helps a little.
    Jackbat

  9. #24
    OK, so one more thing. I have an online video which shows using epoxy as a glue for a set of scarfed gunwales, but I didn't want to post it because I didn't want to appear to be pushing you to another site, however I read the forum rules and I think we are OK with this and if not let me appologize right off the bat to the good people here at Sawmill Creek.

    Anyway, if you go to http://sandypointboatworks.com/wood-.../video-library and look about half way down the page, you will see a video entitled "using epoxy as a glue". I think it may clear up pretty much everything I wrote above. There is also another video there called "Installing Seat Risers" which show you how to attach items to a hull using epoxy which may help as well.

    Happy to answer any questions if I can.
    Jackbat

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