Violin Forum/Message Board

JWH · Member Joined: 26 Mar 2007 Posts: 72

For those of you who have made pine resin varnish and in more particular the Baese linseed/colophony/mastic formula, what's the true need for mastic? Is it there only to lend flexibility and why wouldn't a fatter formulation with more oil do the same thing?

MANFIO · Posted: Mon May 28, 2007 8:16 pm Post subject:

Mastic is a natural drier. I would stick to the recipe, it's an old recipe, dated 1550 circa, the original is on the Biblioteca Marciana, Venezia.
_________________
www.manfio.com

http://www.flickr.com/photos/7875988@N02/with/464604020/

DonLeister · Posted: Mon May 28, 2007 10:41 pm Post subject:

I don't understand how mastic could add flexibility. Having used mastic tears to make varnish, I have observed them to be hard a rather brittle. Maybe the colophony dissolved in turpentine or the turpentine itself.
I'm no expert at making varnishes but can I ask you if you have tried this recipe yet? Is it cooked?
Don

MANFIO · Posted: Tue May 29, 2007 7:41 am Post subject:

Yes, I've made it and use it as a ground in a paste with fine white tripoli that I burnish into the wood.

The varnish is simple: 2 parts oil, 1 part crushed colophony, 1 part crushed mastic. Cook the oil, add the colophony, let it dissolve, and then the mastic, filter while hot.
_________________
www.manfio.com

http://www.flickr.com/photos/7875988@N02/with/464604020/

JWH · Member Joined: 26 Mar 2007 Posts: 72

Manfio:

Let's discuss this further. The Baese formula and process seems simple enough. Do you find that you need to thin with turpentine before applying? Do you apply several thins coats or just a few thicker ones?

I believe I have some white powdered tripoli from a telescope lens polishing project years ago but never thought the refractive indexes were close between it and an oil varnish. So, your fill work is with this paste initially, let it dry, and then burnish the entire instrument? What are your oil to tripoli measurements and are they different for filler and ground?

Your instruments look great. Do you you work with any stains or glazing, or is the colorant strictly limited to the varnish?

Also, as far as ground purposes, have you ever tried montmorillonite (bentonite) and varnish? Both I believe are volcanic.