Sealers and grounds

[rgwebb6]

The question seems to have gotten lost in the body of another thread, so let me start a new one. When I started to make my first violin, my local luthier, who just retired after 35 years in the business, suggested that I use a heat thickened flour/water mix as a sealer/ground.

I have done that on the 5 I have made and it has seemed to work well on 3 of the 5. The other two (a 3/4 and a 1/4) did not sound as well as the others, but I thought I could pretty much account for that in the size and in known errors I made in the making.

Has anyone else heard of using this mix as a sealer/ground?

And what do you use as a sealer? As a ground?

[gumps]

I have used a wheat sizing before as well. I used a solution of lye and wheat flour to accomplish this. It worked quite well and the ground looked outstanding as well considering the cost for the process was so inexpensive. On top of the ground I used a lite solution of cherry gum to seal it up. I used this primarily for spirit varnishes I should note.

[Craig Tucker]

And what do you use as a sealer? As a ground?

Shellac.

[violins88]

Shellac.

Very thin lime casein.

[Craig Tucker]

Very thin lime casein.

The Shellac is very thin also.

Lots of alcohol - little flake.

Maybe three coats - dry between each coat.

[stradofear]

Tried and rejected for various reasons:

-sandarac/shellac retouch varnish

-linseed oil

-oil varnish

-hide glue/gelatin

-casein

-glass (yup, glass)

-lye

-kerosene (to fill and reject varnish from entering wood)

-turpentine (same)

-terpene resin

-mastic in alcohol

-fresh, wet lake "pigment" without the pigment

-the same, a lake, attempted to be made in the wood, directly

-[there may be others that I'm not remembering. . .]

Settled on (for now):

-shellac

[lvlagneto]

I've started with tea on bare wood... then clean up the raised grain... then shellac... very reflective!

[Nicolas Temino]

What about egg white? Have any of you used it?

[lyndon]

one thing they don't find in the stradivari varnish is shellac, its good for furniture thats about it zulu out

[jezzupe]

one thing they don't find in the stradivari varnish is shellac, its good for furniture thats about it zulu out

Do tell, What do "they" find in it?

[Bassbow40]

Tried and rejected for various reasons:

-sandarac/shellac retouch varnish

-linseed oil

-oil varnish

-hide glue/gelatin

-casein

-glass (yup, glass)

-lye

-kerosene (to fill and reject varnish from entering wood)

-turpentine (same)

-terpene resin

-mastic in alcohol

-fresh, wet lake "pigment" without the pigment

-the same, a lake, attempted to be made in the wood, directly

-[there may be others that I'm not remembering. . .]

Settled on (for now):

-shellac

Hi strado,

could you tell us why have you rejected this, is it an aesthetic or acoustic aspect?

G.

[stradofear]

I chose shellac for both visual and tonal reasons--it beat all the rest in both regards.

[Oded Kishony]

What about egg white? Have any of you used it?

I've been using egg white (glair) but I apply tannin before and after.

~OK

[robertdo]

I've been using egg white (glair) but I apply tannin before and after.

~OK

egg white as part of a vernice bianca or egg white by itself?

[joerobson]

There are several expectations for a good ground.

Does it detract from sound or appearance?

Does it impact structure in any way?

Does is sufficiently seal the wood so that color is not absorbed unevenly?

Are the results repeatable?

If we are interested in the appearance of classic Italian instruments, does it reproduce the physical and optical effects of the Italian ground?

So, it becomes a question of what you want and using the materials that fit. If you like the way your current materials work for you, then it is a good ground.

on we go,

Joe

[CT Dolan]

My own opinion is, shellac was used as a ground in the past (Stradivari, Guarneri, et al), with an added component(s). Don't ask me what was added, but I have a splinter in my brain telling me there was something. This summer I intend to jump on board with all the others and give some ideas a try. One thing's pretty certain though, I'll probably not be attempting anything someone has not already tried before ("nothing new under the sun"...which means I'll likely not discover anything of earth-moving importance). However, if I do (and even if I do not), I'll share what I learn. :-)

Edit - By the way, for what it's worth, I think the variation seen in the quality of the finish on some of these instruments (the quality of the ground) has to do with this added component (whatever it is). After all, simple shellac does not adequately explain the variety of appearance that sometimes exists between instruments from the same maker (at least the variety as has been expressed to me). But, I do believe shellac was the base component, for a variety of reasons (history, availability, applicability, ease, etc). However, if someone has something to add in this regard, please do!!

[CT Dolan]

So, it becomes a question of what you want and using the materials that fit. If you like the way your current materials work for you, then it is a good ground.

on we go,

Joe

Good one, Joe.

[CT Dolan]

I have a question. How well does shellac wear? The old grounds seem to stand up to wear extremely well. Is shellac capable of the same? What about Urushi? Actually, I think I'll search for old threads on Urushi, but if anyone knows about shellac, how well it holds up to wear (or has some experience in this regard), please chime in. Thanks.

[stradofear]

One reason I started testing shellac is because it's one of the few, if only, thing I know that resists wear identlcally to Cremonese ground.

[Don Noon]

I came to settle on shellac through sample testing. Shellac and casein were some of the least disturbing of the wood's properties. Shellac is nice to work with, and has less chance of warping the wood than casein, I think. Plus, you can wipe off excess with alcohol, if necessary.

[CT Dolan]

Thank you. I've known shellac to be durable, but was not sure if it approached the durability of traditional ground.

[joerobson]

Thank you. I've known shellac to be durable, but was not sure if it approached the durability of traditional ground.

In wear resistance it is pretty good. But it is still vulnerable, especially to alcohol.

Joe

[Bill Yacey]

In wear resistance it is pretty good. But it is still vulnerable, especially to alcohol.

Joe

I thought it was reported the Cremonese ground was affected very little by alcohol. Wouldn't this tend to exclude shellac as a major component of their ground?

[Oded Kishony]

I think shellac becomes insoluble in alcohol after some years.

Yes, I use egg white (glair) only, not as an ingredient. However, I believe that the tannin changes some of the properties of the egg white.

Oded

[joerobson]

I think shellac becomes insoluble in alcohol after some years.

Oded

Oded,

Depending on how much wax was in the original shellac it becomes a bit less soluble as it ages...but as far as I can find out it never reaches insolubility.....and it certainly was vulnerable in its youth. Also there is an accompanying rise in water solubility as the film ages....again....not major but the old books call attention to it as it was common as a sealer coat under floor varnish.

IMHO shellac does not have the physical strength we associate with the classic Italian ground.

Joe