Varnish finish

[Rick Crenshaw]

I've finished french polishing my first mandolin. I'm very happy so far. I want a 'distressed' look and this thing looks old with the amber colored Bullseye Shellac. I tried my best to get a super smooth finish, but there is still some very slight padding marks in the finish. I've spirited it off and want to leave it at that right now.

Is there a way to 'polish' the final french polish coat? If not, this will be more than fine. I'm not looking for a nitro'gloss' looking finish. I'll post pics soon.

Lastly, how long should I wait till I final fit the bridge and put on the hardware? I've waited a week and it seems real hard. More patience needed here? How long does one typically wait for the shellac to cure hard enough to start messing with the mandolin?

[David Newton]

There are some really long discussions over on the mimf about FP. I would suggest trying a very thin cut of shellac, a almost dry pad and a dot of olive oil. Work up the speed and pressure in a circular motion, lifting off at speed. I know, it's hard to describe, and I am not an expert.

[buddyellis]

Go to walmart or your auto supply house and grab some 1000, 1500, and 2000 grit wet dry paper and wet sand that puppy till it's smooth, then get some Mcguires #2 and polish it out with a cotton cloth. You can get a very, very smooth and shiny surface with the bullseye stuff, just be careful not to cut though. Did you brush on any coats? If not, you need to be super careful about cut-through. If you didn't brush any, I'd just work real slow with 2000 grit and skip the others. It'l take longer but you're safer that way.

As far as drying, 1 month MINIMUM. Do wait. You will be irked at yourself if you don't. It looks dry, but it takes some time for shellac to gas out fully underneath.

[Rick Crenshaw]

Buddy, I did brush on a coat and sprayed a few coats before that, but I sanded those down very thin each time to get the level finish I now have. There's a good coat, but it is relatively thin. I have some of the 2000 grit paper and have the little micro grit pads that go from 2400 to 12000! After looking at the mandolin again and pulling out the tissue I had in the body, I think the finish is more than thin! Well, I'm going to leave it as is and hope it looks like Bill's mandolin in a few years.

[buddyellis]

If you have Micromesh you can probably polish out with some of the higher grades (say start at 8000) and get the swirlies out without much danger. Otherwise, you might just try the Meguires #2 (although the higher ends of micromesh aren't much larger grit than that) Just take it slow, slow slow. I just put the first coat on my latest, but my base is an oil varnish, over which I'll FP. I need to get a blacklight I think. Fun ain't it

[Michael Lewis]

The traditional method of polishing out shellac is with oil and rotten stone. Put it on a pad and apply elbow grease.

[mandolooter]

not to hijack this, but whats a rotten stone?

[Jim Hilburn]

Very fine pumice.

[ErikAitch]

I do my final padding in straight lines with very thin shellac; it takes a little practice to get the pad on and off without sticking, but one thing's for sure: no swirlies.

[Chris Baird]

I've found that if you pad on enough shellac that you can burnish it out with the palm of your hand. I use this "hand burnishing" technique all the time. It gives a nice old world shine. It does require a somewhat thick layer of fresh shellac.

[amowry]

Rick, I wouldn't worry much about the swirlies. They will shrink away to nothing in a few months. I would wait a week to ten days (a warm room helps), and then polish with 3M Perfect-It II or something similar, followed by McGuire's plastic cleaner (I think it's #9, but I could be wrong). You might want to final fit the bridge before polishing, especially if you are using sandpaper; a stray piece of grit can scratch shellac pretty badly.

[Michael Lewis]

One thing not yet mentioned is that you can achieve a good gloss just from French polishing. The idea is to have a dryer pad as you complete your last coat. You use up the shellac and oil as you rub, and the whole surface begins to take on a gloss as the pad slowly loses it's load. This can take quite a bit of practice but is attainable. The pumice and rotten stone is a reliable method but you risk cutting through layers of finish and leaving witness lines. I use the rotten stone for final levelling just before the last coat of French polishing.

Pumice is volcanic ash, and is available in a couple ranges of coarsness. Rotten stone is powdered mineral of some sort, and is used with a pad and oil. These abrasives seem to be "buffered" in that they tend to break down as you use them, thus becoming finer and finer thus helping the polishing process.

[Hans]

The swirls will shrink down with time. Since French polishing is a learning experience don't expect perfection on the first try. I usually string my instruments after a week or so. Depends on how much finish you have on it and how long between coats or paddings. Sure it leaves marks under the bridge...you could wait months and the bridge would still leave marks.

[Jim Hilburn]

I should have known not to answer. Ask me something about lacquer.
Actually the first finish I ever did was an oil varnish back in the early 70's and I got some rottenstone then and still have a big jar of it. I assume it has a long shelf life.

[Michael Lewis]

Jim, that rotten stone will still be good when we are as old as Antonio Stradivari.

[Rick Turner]

Michael, we'll never be as old as Antonio...he's got a several hundred years' jump on us! Even three thousand years from now, he'll be our elder...

[Michael Lewis]

Yeah Rick, but you know what I mean.

[buddyellis]

Hans:

Not sure if the zinsser/bullseye stuff maybe sets up slower than button shellac, but I wouldn't touch the thing for at least a month. You will not just have 'marks' you will have a stuck bridge and crazing everywhere you touch it (especially under the arm)

Don't ask me how I know this. And yes the can was 'fresh'. It does eventually get real hard though.

[Hans]

Must set up slower Buddy, or is thicker, or slower because of thinning. I use a violin varnish recipe. I do caution folks to keep the instrument out of the case for several months, and to play it only for short periods of time at first, but I believe that it is important to get it vibrating as soon as possible.

[testore]

Jim,that 30 year old oil varnish should be great by now. Unlike spirit varnish, oil varnish gets better with time. It dries better and is easier to use.Spirit varnish has a shelf life of about 6 months.
I too use the palm of my hand after I go through several of the other methods metioned here.It has a way of warming the varnish and it has a nice glossy look without looking polished. Lots of good info here.
Gary

[Rick Crenshaw]

The can of Zinsser Shellac that I used must have been newer. It is less than 8 months old and it dried very quickly. It seems very, very hard now (maybe 9 days since last spirited off). I went ahead and final fit the bridge and will go ahead with the installation of the new Schaller tuners and the simple tailpiece. I wonder if I used a thinner cut than the other users.

I worry only about the thickness of the finish. It is very thin. I'm not sure how to estimate the finish thickness, but it is thin like a violin finish. If it wears, it wears. I'm going to let it distress naturally. It is already amber tinted with the amber shellac and looks like an old mandolin already.

[buddyellis]

GEFool:

Well, I thought the same too. It 'seemed' fine, and was 'real hard'. Then I put the bridge on it, and it got stuck and it started crazing under the arm. I ended up re-frenching the whole top, waiting about 20 days, and it was fine after that.

Personally, I'd wait longer before stringing up and 'using' it, but YMMV. My can was 6 months old. I used a 1.5/lb cut, more or less of the amber.