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http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=3523		 Page 1 of 1
Author:  John Elshaw [ Fri Oct 14, 2005 12:01 am ]
Post subject: 
How long do you all wait before polishing and buffing out a finish? I just completed the French Polish on my old Guarian I'm restoring and am wondering how long to let everything gas out before buffing to a final sheen. I know some people wait a month or so, but is that so the finish is hard, or is it to let all the gasses escape, etc? Any advice would be greatly appreciated.

Thanks!

John
Author:  Michael Dale Payne [ Fri Oct 14, 2005 1:26 am ]
Post subject: 
On a French polish if you are going to buff it I would give it a week or maybe two just to harden a bit, but if you glazed properly you should already have a very high gloss with no need to buff. I have known some go to the buffer in 2 days, but here again the gloss of a true French polish is achieved in the glazing process, not by buffing. If you skipped or did not carry the glazing to mirror reflection point, it is never to late. that is the great thing about French polish it is easy to rework.
Author:  Michael McBroom [ Fri Oct 14, 2005 1:37 am ]
Post subject: 
Being mostly self-taught when it comes to french polishing, I've tried stuff that a lot of y'all would cringe at, I suspect. Like the amount of time I've waited before buffing. I have waited as long as a week, but usually I don't wait more than a few hours.

Yup, hours. I have buffed out instruments within hours of applying the last "coat." I use a fine grade of Meguiars professional buffing polish that can be found at automotive paint stores, and I apply it with a buffing pad attached to my cordless drill. Even though I get a good shine, the finish is still very soft and the guitar has to be treated very delicately for the first couple of weeks or so.

But at least I don't have to wait those two weeks before I get to find out what it sounds like.

Best,

Michael
Author:  Michael Dale Payne [ Fri Oct 14, 2005 1:56 am ]
Post subject: 
a cordless drill and a buffing pad and glazing compound is fine in a few hours better i feel in a few days. My coments were in regard to a power buffer i.e. 12 or 14" buffing wheels.
Author:  John Elshaw [ Fri Oct 14, 2005 2:16 am ]
Post subject: 
I agree with your comment about the glazing. Let me elaborate my problem a little more. The last guitar I FP I gave as a gift to a family member, and I glazed as you mentioned, never needing to buff. I gave the guitar away about a week after I completed the FP. When I went back to visit last week (about 6 months since completing guitar), I noticed it had a very dull haze, almost like a fog around what appeared to be tiny little gas vents in certain spots. I was able to polish the guitar right back with some cotton cloth and hard rubbing, so I assumed the guitar had just gassed a little during the cure. Is there something else that would cause this?

Thanks!

John
Author:  Michael McBroom [ Fri Oct 14, 2005 2:24 am ]
Post subject: 
John,

I would think that, given the way french polish is applied, the finish would be quite uniform in terms of the amount of volatiles it contains. Might it possibly be that the wood itself caused this? Are these spots on the top or back only, for example?

Best,

Michael
Author:  CarltonM [ Fri Oct 14, 2005 5:57 am ]
Post subject: 
[QUOTE=John Elshaw] (about 6 months since completing guitar), I noticed it had a very dull haze, almost like a fog around what appeared to be tiny little gas vents in certain spots. Is there something else that would cause this?[/QUOTE]

This is only a guess, but here 'goes: I'm not sure what you mean by "gas vents," but the haze sounds like oil rising to the surface, especially since you were able to remove it by hand buffing. Alcohol gasses off very quickly, so there shouldn't be any remaining after the first few hours (or even minutes!), if you used freshly mixed denatured alcohol and shellac flakes. If you used canned shellac, it may have slower drying additives that could cause a problem if you build it up quickly. Or, here's a thought: could the guitar have been exposed to a mist of water or alcohol that wasn't wiped off in a timely manner? That might account for the "gas vent" effect!
Author:  John Elshaw [ Fri Oct 14, 2005 8:31 am ]
Post subject: 
The haze is definitely more prominant around the backs and sides (EIRW), and it appears to be spread out around the pores. I pore filled the old fashioned way with pummice, and it seems the haze is almost like a tiny circular shape around where the pores were. I guess it's possible it's oil, but I thought most of that would have been removed when I did the glazing and wipe down with pure DA. Is it possible for oil to get trapped between the shellac (or in pores), and then work it's way to the surface over time?

John
Author:  CarltonM [ Fri Oct 14, 2005 10:49 am ]
Post subject: 
John,

Yep, I bet the pore filling is the problem. The more experienced FP-ers here say to not use any oil during pore filling.
Author:  Robbie O'Brien [ Fri Oct 14, 2005 11:15 am ]
Post subject: 
Try using a latex pore filler and then French Polish to your hearts content.
Author:  John Elshaw [ Fri Oct 14, 2005 2:36 pm ]
Post subject: 
Thanks for the advice guys, I think I'll try a latex pore filler next. Now, what is it and where can I get some?      I haven't ever heard of a latex pore filler. I'm only familiar with epoxy fillers and the more traditional pummice method of filling.

Cheers!

John
Author:  PaulB [ Sun Oct 16, 2005 2:56 pm ]
Post subject: 
I had the same problem on my first (FP over EIR). I used Cyano as a pore filler. I think it's just oil coming to the surface 'cause I used a little too much. It polishes of with a soft cloth.
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