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preventing bleeding? Can i french polish?
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Author:  Robert Lak [ Tue Feb 26, 2019 8:26 pm ]
Post subject:  preventing bleeding? Can i french polish?
my #2 is a padauk body with American holly for the binding. I know, not a well thought out combination, but it looks great! I am now realizing that the paduak will bleed like crazy when i try to french polish, at least i think it will. Anything i can do to protect the blinding white holly from getting ruined by the paduak juice? Will coating in shellac work? or will i need to coat it in an oil based varnish?

or is there a better method?

Will it also bleed with an oil based varnish?
Seal the whole thing with zinsser (sp?) and then oil varnish?

Attachment:
sideview classical.jpg


Thanks!
Rob
Author:  Robert Lak [ Tue Feb 26, 2019 9:16 pm ]
Post subject:  Re: preventing bleeding? Can i french polish?
I just tried rubbing a cutoff with grain alcohol and it bled as expected but also seemed to cause the holly to absorb the orange more so it was harder to scrape it back to white.

I have some old Stewmac rattle-cans of lacquer and they also seemed to dissolve the oils and cause it to bleed, but i am not sure that the holly is not dense enough to withstand a true bleed effect. it may be ok to spray? (I am not much of a woodworker so i have no idea of the best approach). Have to buy some fresh stuff as the cans are too old to use. Nozzles on 4 out of 5 cans seem to be blocked. Or can i get new nozzles?? (looks like home depot has some the might fit.)

So i am now thinking of an alternate finish for the back and sides, maybe blue taping the binding or using a spray of some sort.... and french polishing the top (cedar) only...?
Author:  George L [ Tue Feb 26, 2019 10:30 pm ]
Post subject:  Re: preventing bleeding? Can i french polish?
I've not used your specific combination of woods but have achieved good results in similar situations by spraying a few coats of Zinsser's clear shellac. I followed that with a wiped on varnish finish and all went well; French polishing might give you trouble.

As always, test on scrap.
Author:  Eric Reid [ Tue Feb 26, 2019 11:12 pm ]
Post subject:  Re: preventing bleeding? Can i french polish?
You have certainly made your life more difficult, but it is possible to French polish your guitar without resorting to synthetic materials, spraying, masking, or scraping back. The first step would involve sealing the binding with a muneca indexed on the edge of the guitar--one pass, then let that dry thoroughly. New pad, and do it again. Eventually the holly will be sealed to the extent that the color bleed from pore filling the padauk will not penetrate the holly. You only need the thinnest of spit coats of shellac on padauk for the pore filling with pumice. The resins in the wood will be ample binder for the pumice. As the surface of the pad begins to glaze over with resin, change pads (or pad cover), or you risk smearing over the top of pores, and trapping air in the pores that will later bubble up through the finish. I highly recommend that you practice on your off-cuts of padauk to see how the finish behaves. Do your practice runs all the way through to a high-gloss finished surface. Padauk isn't easy to French polish.
Author:  B. Howard [ Wed Feb 27, 2019 7:19 am ]
Post subject:  Re: preventing bleeding? Can i french polish?
As explained above... With any light colored wood bindings.
Author:  jfmckenna [ Wed Feb 27, 2019 8:53 am ]
Post subject:  Re: preventing bleeding? Can i french polish?
I think the holly looks great. Do what Eric said and you should be fine.
Author:  SnowManSnow [ Wed Feb 27, 2019 10:15 am ]
Post subject:  Re: preventing bleeding? Can i french polish?
Just mask off the body looks line then use shellac to seal the binding. Remove said masking


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Author:  Barry Daniels [ Wed Feb 27, 2019 10:37 am ]
Post subject:  Re: preventing bleeding? Can i french polish?
You will need to seal both the binding and the padauk. The binding needs to be sealed so it doesn't adsorb any padauk juice. And the padauk needs to be sealed so that it doesn't produce said juice. Spraying a sealer of some type would likely be the most successful.
Author:  Robert Lak [ Wed Feb 27, 2019 12:05 pm ]
Post subject:  Re: preventing bleeding? Can i french polish?
OK... Thank you all.. sounds like buried in there is to go slow and be careful. :-)
Author:  Clay S. [ Wed Feb 27, 2019 12:18 pm ]
Post subject:  Re: preventing bleeding? Can i french polish?
Another way to do it might be to "mist on" several coats of spray can shellac, spraying coats so light that the finish stays where it lands. Some people have been known to build a shellac finish by spraying, then level and french polish a few coats on top - the Tweedy method.
Author:  philosofriend [ Wed Feb 27, 2019 1:01 pm ]
Post subject:  Re: preventing bleeding? Can i french polish?
If you mix your own finish, try using less solvent than normal with the shellac. You saw what happened when you rubbed alcohol on it. You want a light and dry spray so the solvent doesn't have enough time on the surface to cause bleeding. If it goes on a bit rough you can smooth that all out after a few dry coats. Glue up some holly/paduak test strips with the same glue as on the guitar, and practice on them.
Author:  Robert Lak [ Thu Feb 28, 2019 11:16 pm ]
Post subject:  Re: preventing bleeding? Can i french polish?
what i decided to do was give the binding a coat of shellac and then go ahead and polish the rest. When done, i'll scrape the bindings clean and hopefully can refinish without too much a mess. The holly doesn't seem too porous so the padauk juice doesn't seem to sink in.
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