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Thread: French Polish getting cloudy

  1. #1
    Join Date
    Apr 2016
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    Default French Polish getting cloudy

    Seems the top of a Padauk Uke is getting cloudy as the polish is being applied.
    The alcohol spirits off as the rubber moves in circles and overlaps on the uke but their seems to be a cloudiness to the finish now.Not like it was in the beginning, Not sure what is being done wrong. Im not applying the the polish but if I were the same thing may be happening.
    Any suggestions would be appreciated..
    Thanks
    Bud
    Spokane WA

  2. #2
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    Little River, California
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    This is usually caused by a humidity/moisture problem. Water and shellac do not mix = cloudiness. Seeing where you live, not surprising. Fixable. Don't despair.

  3. #3

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    Is your alcohol pure enough. It can pick up water if exposed to air.
    Michael Smith
    Goat Rock Ukulele
    www.goatrockukulele.com

  4. #4
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    The alcohol is 190 proof....kept in a mason jar.. I believe my friend has kept the top of the jar on it... Ive been away for the last two weeks and hes been working
    on the uke during that time. I know that the shellac has a shelf life too so I wasnt sure if that maybe that was the problem as its over 3 weeks since we mixed it.
    Im just going by what hes told me.. He was thinking it could be that hes used too much oil..
    I will see him today and can ask him about the cut being exposed to the air.
    That totally makes sense now that I think about it.. the same thing happens to nitro... it gets cloudy with too much moisture..
    Thanks Sequoia and Michael for your responses...
    Bud
    Spokane WA

  5. #5
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    Quote Originally Posted by sequoia View Post
    Fixable. Don't despair.
    Heh... ok... what would be the fix for this?
    Sanding? wiping down with straight alcohol? Im not sure how to go about getting it on the right path.
    Despair hasnt set in yet.. but.. Im sure its right around the corner..

    Also I was wondering about finishing the polish... Level sanding Im thinking with 600 grit sand paper and then applying another coat of shellac and letting dry then spiriting it off..
    that would be finishing it wouldnt it?
    Or would it be more of what is done with Nitro.............. 600, 800,1000, 1200 or 1500 then 2000 and buffing...
    Really.. Im going to get a book or something on this... watching videos online and reading bits here and there arent cutting it..
    Thanks for any help..
    Last edited by UkulelesRcooL; 05-29-2016 at 12:44 PM.
    Bud
    Spokane WA

  6. #6
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    If moisture (from very high humidity) is a problem clouding the finish, you can try using a hair dryer to gently try and drive off the water. Gently. Try a small area and then wait... wait.
    See if it starts to clear.

    I've used shellac that is a year old and never had a problem... Here is the thing though, you didn't do the finish and your friend did and you were not there so who knows what happened. And then there is the issue with the too much oil. This could be the problem and that is not good. The whole issue is becoming cloudy. Of course you can just take the finish off and start over. Sometimes that is the best way to go. Just sand it off and try again.

  7. #7

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    If you are starting at 190 proof you still have 5% water. I suggest going to a product that is close to 100%. You can buy isopropyl that is 99% or shellac thinner that is close to 100% alcohol. The only advantage of using Everclear 190 proof grain alchohol is that you can pour a little in your orange juice to make the french polishing chore go a little easier. But you can do that anyway and use the water free products for your finish.
    Michael Smith
    Goat Rock Ukulele
    www.goatrockukulele.com

  8. #8
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    The thing with French Polishing is that it's very thin as far as finishes go. If you start out sanding P600 and working your way through the grits, I'll bet the farm that you cut through to the timber, and then you're back to square one.

    If you don't know how much oil was added to the mix, and was a bit more added for subsequent sessions? How much was used on the rubber when applying......well then you really are better off to suck it up and strip that finish off and start again.

  9. #9
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    It's impossible to get 100% alcohol and it's probably difficult to get 99% alcohol too. I know that they sell it as 99% Iso (I buy the stuff) but I suspect that it's a little less than 99% by the time that we use it. I doubt that it's the strength of the original alcohol that is causing the issue but it could be that polishing in a rather high humidity could be trapping moisture, coupled with the oil and it will form an emulsion. I'd try the gentle heat advice, often it will drive off the moisture.
    Even a non drying oil will form a gummy deposit if (a) too much is used (b) the oil isn't removed between polishing sessions. If that happens you usually see witness lines when trying to rub it out, similar to using an oil varnish. That's why it's always important to remove as much oil as you can. You can gently mop it up with kitchen absorbent paper or even baking flour, then spirit it off in the normal way. If you use very little oil there really isn't a need to use the paper or the flour.
    The highly processed shellacs (dewaxed blonde/platina) have a relatively short shelf life in the dry state. Waxy types seem to last decades. Once mixed you might get 4 months or so out of the dewaxed, bleached varieties. They slowly lose their drying/hardening ability. Again, waxy types have a shelf life a little longer, maybe 6 months or more. A lot depends on local conditions and how fresh the dry shellac was in the first place. I've never seen old shellac cause the cloudiness issue though, usually old shellac is difficult to dissolve in alcohol or it doesn't dry/harden very well.
    Last edited by Michael N.; 05-30-2016 at 01:49 AM.

  10. #10
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    Quote Originally Posted by Michael Smith View Post
    The only advantage of using Everclear 190 proof grain alchohol is that you can pour a little in your orange juice to make the french polishing chore go a little easier. But you can do that anyway and use the water free products for your finish.
    Too funny... and thanks for the info.. my friend got this stuff from a friend of his that made it.. so I think its has a bit more kick than everclear and I got the opportunity to taste it.. Very nice.. but I dont think I want to make a habit of it even if it was some of the smoothest stuff Ive ever had..
    Bud
    Spokane WA

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