MIMF

Hi.
After watching a few videos i made a serious first attempt at french polishing a guitar.

I went to check on it just now and I have to say I was excited at the result. However it's not like the guys on the videos get.

There is a beautiful shine - more than I expected as a first try - but there are still very fine lines basically running fore 'n aft I guess from when I was padding on the shellac.

So...please advise what I should do from here...keep rubbing with the shellac oil & alcohol till they're gone or I'm dead - or - wait a week lightly sand with 2000 or similar & buff with the Meguairs polishes - or another procedure.

I could send a pic but I'm not sue it would show the lines etc.

I'm pleased, but don't know were to go from here.

Thanks,
Rob.

The end game is that you eventually give up and call it finished <G>. I smile but that is actually how I decide when I'm done. Once could keep going forever but after a while you just kind of know you are done. I make so few instruments that I kind of have to relearn the process each time I do it. It is very much a feel thing and it will eventually just click and start going well. I will say, that I usually relearn that less is more when it comes to how much shellac, alcohol and oil to put on the pad (especially oil).

You say you have fine lines running fore and aft. Are you rubbing on your finish in straight lines or are you finishing by "spiriting off" in straight lines? How many sessions have you done? In the early sessions, I often see very faint lines in the finish (usually swirls from the application). I'm not sure exactly why they are there but they seem to disappear during subsequent sessions. I have always suspected that my technique for loading the pad is rusty when I first start and I get in the zone as the process continues.

My advice:
1) Do a few more sessions and re-evaluate.
2) Answer the above questions and describe your process so far then watch this thread a little while; there are several people here who are actually knowledgeable on the topic (people other than me <g>) and will be along shortly to help.

I've french polished over 80 guitars now. For me, the end game is when I have built a good and reasonably level body. Then I wet sand with a hard rubber block, 800 grit wet and dry paper and mineral spirits. What I want is a very smooth opaque surface and not going through to the wood anywhere. Them I glaze using only one eyedropper of 2 lb shellac, 1 dropper of alcohol and a fresh clean munueca cover. A small amount of oil (I like pressed walnut oil) in the palm of my hand which I spread with my finger and wipe up with my pad. I use straight lines first followed by circles. I alternate these patterns until the pad is dry. I let each surface rest for an hour and repeat four or five times for each surface until it's pretty much perfect. I like to do the neck first, Then one side and top, rest, other side and top, repeating until done. Lastly the back.

If at any time during the process I get any gunk (like lint etc.) I sand it off with fine micro-mesh or 2000 grit wet and dry. When I'm all done I let it set for a couple of days. Then I rub it out using Menzerna SF4000 which will actually remove 2000 grit scratches. I follow this with Menzerna micro polish.

All of this being said, my real end game doesn't come around until at least a year later. By then the shellac has hardened and shrunk revealing pores seams etc including the pixels in end grain rosettes. This is the point at which a light sanding followed by a re-polish can yield a really fine result. Lastly I've seen different approaches taken by folks many of which have yielded some really fine results.

There's nothing wrong with buffing it out, and I've done it many times. Had great success buffing by hand(after leveling to 2000 grit(ANSI) ) with Meguiar's #7 and #9(don't remember which one to use first, but you'll figure it out).

If "they" would have had our modern compounds and equipment 100's of years ago, they would have used them. Give it 2 weeks, though, just to be sure.

I use Meguiar's 'Unigrit' paper to level finishes, both varnish and FP these days. I find that the 2500 grit is enough in most cases, but 1500 can be useful for things that need more persuasion. They sort the particles somehow so that they're more uniform than usual, and don't scratch. I get it at the local auto parts store. After wet sanding level I'll switch to rottenstone, and then Novus plastic polish. It's not as agressive as the Meguiar's polishes, which are made for harder lacquers.

The rule with FP is that you can get halfway from where you are to 'perfect' by putting in as many more hours as you've already spent. If you're halfway there after 10 hours, 20 will get you to 3/4, and another 20 to 7/8, but you'll never reach 'perfect'.

Alan Carruth wrote:<snip>The rule with FP is that you can get halfway from where you are to 'perfect' by putting in as many more hours as you've already spent. If you're halfway there after 10 hours, 20 will get you to 3/4, and another 20 to 7/8, but you'll never reach 'perfect'.

They call that asymptotic French polish, I believe.

Pat Foster wrote:

Alan Carruth wrote:<snip>The rule with FP is that you can get halfway from where you are to 'perfect' by putting in as many more hours as you've already spent. If you're halfway there after 10 hours, 20 will get you to 3/4, and another 20 to 7/8, but you'll never reach 'perfect'.

They call that asymptotic French polish, I believe.

Zeno's Greek polishing.

If you're going to sand, why bother with FP? The whole point of FP is to produce a mirror finish without cheatin' (I still have to resort to plastic scratch remover at the end, but I hope to be able to get past that).

...i understand you question...the idea of lacquer pulling rather than sanding to the lowest point on the whole surface appeals to me since I'm usually dyeing the wood and I manage to sand through from time to time ). That being said - I got to a very nice but not quite perfect shine and being new at this I didn't know whether to keep on rubbin' (Spencer Davis Group 1960 something) . or swap to fine sand & buff. Hence the question. ATM I'm still rubbing. Just for the fun of it )

The key to keeping a French polish finish level is "spiriting off" or "stiffing off" after body sessions. That is, using the muneca/pad with only alcohol added and gliding on and off the surface with long straight strokes with the grain where possible. Starting with relatively heavy pressure and lightening up as you progress. Then, at the end, after developing a build of shellac with bodying sessions, glazing with a light mix of shellac with mostly alcohol, using a similar method to spiriting off. It is the glazing process that really pops the shine on the finish. Properly done, one should need no sanding or leveling with abrasives during a French polish process. Can't say I've ever succeeded at that, but that's the theory!

Sorry: Double post!

Sorry, but the whole point of french polish is to end up with a thin, durable finish that can be applied without special equipment or personal protection.

I've tried brushing and spraying shellac, and leveling and buffing it, but it was never as hard and tough as a rubbed(ie: french polished) shellac finish, so i concluded that the pressure and heat of the process aids in hardening the shellac.

Mario Proulx wrote:Sorry, but the whole point of french polish is to end up with a thin, durable finish that can be applied without special equipment or personal protection.

I've tried brushing and spraying shellac, and leveling and buffing it, but it was never as hard and tough as a rubbed(ie: french polished) shellac finish, so i concluded that the pressure and heat of the process aids in hardening the shellac.

Yep.

You might get arguments from some, but I'd agree with that totally.

Peter Oberg has recently put a video on you tube showing how he does the final stages of French polishing.

https://www.youtube.com/watch?v=dbMKcZMve70

Thanks for all your help guys. Pics when done )