French Polish Over Varnish

[yankees1]

Why french polish over varnish? Isn't it possible to have a beautiful , protective finish using varnish only ?

[Dale Ludewig]

It's a different look. Depending, the varnish under the french polish (shellac) is often more protective.

[Geoff B]

I found it easier to level (without witness lines) with the French polish, and I like the sheen of the shellac vs. the varnishes I've tried. But a oil varnish as the first few coats brings out the color and curl much more as to my liking than shellac. But I only realized that after I heard that's how Gibson did it, so I tried it a few times.

[Andy Morton]

I used a shellac based French Polish on my first mandolin and it worked really well (and has held up well). I understand that the varnish needs more time to cure than the FP...but I have wondered why one would FP (with an less protective finish) over a varnish finish (which is overall more protective).

Andy
Madison, WI

[David Newton]

I'm usually only doing french polished shellac, but I wanted to try out Sherwin Williams Quick Dry Gloss Varnish on a recent ukulele.

I just couldn't get the gloss that I'm used to, so I sanded the varnish back, maybe half way, and french polished over it.
I think, in a way, it may be "the best of both worlds" as it seems tougher underneath, but has the polish on top that I like.
I am concerned that "lean over fat" may lead to cracking over time.

[Marty Jacobson]

Before we got so uppity about the originality of finishes, I think the French polish final coats were intended to be more or less sacrificial. When you get your strings changed, get a new French polish session, and it should stay looking like new forever. I guess we're not likely to do that these days. But it's a great concept... durable, permanent oil varnish with a beautiful, but easily spruced-up FP on top.

[sunburst]

I think the idea was to speed things up in production. Oil varnish is slow to cure, and buffing to a high gloss without witness lines can require weeks or even months of waiting. That's obviously not practical in a production setting. We can have a gloss in a much shorter time by top coating with shellac, and without witness lines.
The look is a little different, but I think that is a byproduct of the "need for speed" in production. Is it any wonder Gibson switched over to lacquer exclusively in the space of a year or two as soon as it was readily available and economical?

As for crazing of a shellac top coat over oil varnish, I've had that happen on the one mandolin that I finished that way. It's about 8 years old and it came in for an f-hole crack repair this past summer so I saw it again. It looks 100 years old! Some think it looks "cool" (including the owner, fortunately) but that was not the intended look! I'll look for before and after pictures and if I can find them I'll post them. That should be fun.

[sunburst]

Found 'em, right there in my external hard drive where they belonged. (Sometimes organization shows up unexpectedly...)
This also shows the red fade that made me abandon aniline dyes.


I remember this picture of the original gloss. I could read the wattage of the light bulb, but I couldn't get it to show up in the picture. Obviously, it's a lot less glossy now!

[jazzman13]

It was an incredible looking instrument to begin with, Mr Hamlett - I really like the way it's aged as well!

[Wilbur Tabacsko]

John, I notice that looking into the f holes of the now picture the back is very dark. What has been done there?

[sunburst]

The photos are just lit differently. The "before" picture was just was a snap shot with a rather poor digital camera, the "after" shot was after I got a much better camera and set up some studio lights. If you light a mandolin from in front, the light shines on the back through the f-holes. If you light it angled from the sides, the back is in shadow and doesn't show up to distract the viewer.
(To me, "snap shot" means just put the camera up and shoot with no particular effort to set up the shot or adjust lighting.)

[Wilbur Tabacsko]

Thanks for the reply John. In my eyes the darker f holes blend in with the colors of the finish as opposed to the lighter, less contrast.