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  #1  
Old 10-13-2021, 08:59 AM
Neil K Walk Neil K Walk is offline
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Default Reacquainting myself with French polish

In finishing up my second build I've gone back to my first and have taken the opportunity to reacquaint myself with pore filling and French polishing with shellac and pumice. I'd shaved the neck down to bare wood and noticed that the top on #1 was getting scuffed and cloudy. This is after palm sanding it flat and doing one building/spiriting session. I expect that I'll need to do many more.

[IMG][/IMG]
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Old 10-13-2021, 11:52 AM
redir redir is offline
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I don't see any cloudiness in the image, in fact it looks normal to me, but if it's cloudy then something is wrong. I usually end up doing about 20 sessions on a guitar.
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Old 10-13-2021, 01:10 PM
Neil K Walk Neil K Walk is offline
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Quote:
Originally Posted by redir View Post
I don't see any cloudiness in the image, in fact it looks normal to me, but if it's cloudy then something is wrong. I usually end up doing about 20 sessions on a guitar.
Yeah, sorry I should've done a "before" to this "after" picture. There are still some opaque spots around the bridge that I'll likely have to go back over with a smaller pad.

I'm only part joking about reacquainting myself with the process. This is actually my second attempt. On my first I forgot the oil so the pad was taking shellac off instead of blending it in, I was stopping in mid stroke and literally leaving sponge marks in the finish and not following up with a load of alcohol so I was leaving bad scratches in the finish.
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Old 10-13-2021, 08:27 PM
redir redir is offline
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Ah yes if you go to heavy or get stuck it can appear perhaps as cloudy. It's difficult to FP with the bridge in place. You need to use a dry pad and very vigorous motions to get it right. I am a big proponent of using oil. I don't know how some other FP finishers claim they don't use it.
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Old 10-14-2021, 01:36 PM
runamuck runamuck is offline
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When french polishing, cloudiness or blushing is caused by trapped moisture in my experience. Wipe it quickly with alcohol.
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Old 10-28-2021, 04:59 PM
Neil K Walk Neil K Walk is offline
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Quote:
Originally Posted by redir View Post
Ah yes if you go to heavy or get stuck it can appear perhaps as cloudy. It's difficult to FP with the bridge in place. You need to use a dry pad and very vigorous motions to get it right. I am a big proponent of using oil. I don't know how some other FP finishers claim they don't use it.
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When french polishing, cloudiness or blushing is caused by trapped moisture in my experience. Wipe it quickly with alcohol.
Yes, it's really hard to get up against the bridge - even though I've taped over it so that I don't have to worry about bumping it with the pad.

The issue however is the pad itself. It's a couple of cotton balls wadded up inside a piece of t-shirt and is round so there's always a gap around the bridge. I read somewhere that using an eraser or soft piece of rubber can be wrapped in the same cloth to be used as a pad that doesn't have that muffin top problem that is preventing coverage adjacent to the bridge. For something for the solution to actually soak in I can use some makeup application/removal pads.
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Old 10-29-2021, 06:16 AM
Fathand Fathand is offline
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Quote:
Originally Posted by Neil K Walk View Post
Yes, it's really hard to get up against the bridge - even though I've taped over it so that I don't have to worry about bumping it with the pad.

The issue however is the pad itself. It's a couple of cotton balls wadded up inside a piece of t-shirt and is round .
I have only attempted 1 FP but I found bed sheet to work better than T shirt.

Have you considered removing the bridge? Alternately, spray some shellac around the bridge area? A Preval will spray shellac nicely.
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Old 10-29-2021, 06:23 PM
redir redir is offline
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Google up "Michael Thames French Polish"

He is the one I learned the eraser tip from. It works a charm though I only use it for sanding. He uses it to get in the difficult areas around the heel and bridge.
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Old 11-01-2021, 12:00 PM
Neil K Walk Neil K Walk is offline
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It's been a couple of weeks and I've started over a couple of times, get cloudy spots and scratches in the finish. Now I'm at a point where I've let it sit for several days at a time to see if the finish is shrinking at all or if the oil is just sitting on top. I'm still seeing some slight smudging when I touch it and I'm assuming that that's oil rather than finish. It's frustrating so I've come back to re-read your responses so that the advice soaks into my addled brain.

Quote:
Originally Posted by redir View Post
Google up "Michael Thames French Polish"

He is the one I learned the eraser tip from. It works a charm though I only use it for sanding. He uses it to get in the difficult areas around the heel and bridge.
I've been watching his videos and several interesting things have caught my attention:

1) he doesn't use oil while building up the many coats. I'm assuming that's why it's not clouding up on him.

2) when he wet sands he uses soap to cut through any oil left in the finish. Again, no oil is left on the guitar.

3) he only uses a drop of oil on the guitar, NOT on the phad. I've been doing it the latter way and I think that may be contributing to the cloudiness.

4) I haven't seen him "shock" the finish with just alcohol yet - but admit that I'm only part way through the video series.

So next up is to procure an eraser and build a hard phad and see if I can emulate his procedure. If I have to sand back down to a smooth surface yet again so be it.
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  #10  
Old 11-01-2021, 01:12 PM
Neil K Walk Neil K Walk is offline
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Here are some pics. I let it sit for 3 days so that things would shrink a little more before I go back at it. I tried to show the scratches and swirl marks but iPhones have this frustrating feature where they edit it out apparently.





Headstock:



I haven't touched the back and sides but the neck is now a nice semi-gloss with the end grains filled in by adding pumice to the shellac.





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  #11  
Old 11-01-2021, 02:07 PM
BEJ BEJ is offline
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Looks like it is getting there. Looks like a lot of work went into that back, came out pretty good.
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  #12  
Old 11-01-2021, 08:24 PM
Neil K Walk Neil K Walk is offline
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Quote:
Originally Posted by BEJ View Post
Looks like it is getting there. Looks like a lot of work went into that back, came out pretty good.
Thank you. I put a lot of effort into pore filling but in all honesty there's a LOT of buckle rash.
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  #13  
Old 11-01-2021, 11:00 PM
BEJ BEJ is offline
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There is a great article on French Polishing by George Frank in Fine Woodworking issue #58, it's listed on their website, available to members to read. He was a master refinisher and also one hell of a story teller on learning his trade. Good info on setting up tools used and use of oil, goes into detail on what and why he does it his way.
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  #14  
Old 11-02-2021, 09:52 AM
SColumbusSt SColumbusSt is offline
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That guitar looks great Neil!

I'm by no means an expert but am on my fourth french polish job (two ukes and two guitars). For my last three I've followed the LMI directions:

https://www.lmii.com/blog/2017/10/07...polish-finish/

All have ended up with the cloudiness you describe on your guitar when I finished the last step (well almost the last step, I have not tried polishing with rottenstone yet as I've been satisfied with the glossiness I've achieved with just the shellac). Fortunately I'm in no rush so I let the finish cure for about a week and then vigorously wipe it down with an old 100% cotton t-shirt. This initially removes the surface oil but after two days more has surfaced so I wipe it down again. I keep doing this every other day until the finish cloudiness is for the most part gone.

The waiting for the finish to cure is an important step. On my current build I went after the cloudiness with my t-shirt a day after my last french polishing session and scratched the heck out of the finish. The nice thing about shellac is no error is terminal. I sanded the scratches out and started building shellac layers again and it looks good as new.
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  #15  
Old 11-04-2021, 04:00 PM
Neil K Walk Neil K Walk is offline
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Yea, the waiting is hard but worth it. I wasn’t a big fan of spiriting off the oil with alcohol on the phad; I was just tearing the finish off and causing flaws and the haziness. I was having better success getting rid of the oil by spritzing slightly soapy water on the finish then wet sanding with 3000 grit going along the grain. It’s also minimized the hairline scratches. Now I can feel that the surface is approaching that smooth as glass feeling so i feel like I’m getting close. I’m just afraid of tearing off the finish with alcohol though.

That being said, as pretty as that back looks it is seriously chewed up. I’m going to have to take it down to bare wood, steam out some big fissures and start over from scratch - no pun intended. The sides could use a little wet sanding too but not nearly as bad.
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