Sign in to follow this  
Norton

Ground (and I'm not talking about dirt here)

Recommended Posts

Hi forum colleagues,

I have a question or two about the ground coat. In the book The Art of Violin Making the authors describe how to make a ground coat using one part hide glue mixed with twenty-five parts of water "to which is added a small amount of alum."

Now this sounds easy enough except: what exactly is a "small amount" of alum -- a teaspoon, a tablespoon, or other?

Has anyone used this recipe and if so, how much alum was used and were you happy with the results? Also, does anyone know if this ground coat is compatible with the oil varnishes offered by the International Violin Company?

Thank you and regards,

Jason

Share this post


Link to post
Share on other sites

I used hide glue on my first instrument , after some time it started to react with the varnish and some very dark patchy sections appeared

Adam

edit : just remembered I had alizarin in the glue

Share this post


Link to post
Share on other sites

Thanks for the replies there Adam and Michael.

I've come to realize that "finishing" a violin is not a straight-forward process and even seems a bit mysterious, to me anyway. What's more, I've found some highly contradictory opinions regarding surface finish. For instance, some luthiers seems to love using shellac while others are dead set against it.

I'm looking for a simple to use, durable surface finish and am rapidly learning that there is nothing "simple" about it.

Looks I need to do additional research into this aspect of violin construction!

Best,

Jason

Share this post


Link to post
Share on other sites

I'm looking for a simple to use, durable surface finish ... Looks I need to do additional research into this aspect of violin construction!

I have used a few different grounds, and shellac is probably one of the simplest.

There are many ideas about grounds; glue, eggs, shellac, short oil/pumice, casein, with and without mineral additives, silicates <_< , and various resins in solvents. So you could spend a long time researching them. If by "aspect" you mean the entire varnishing process, the research task expands exponentially. If you also include antiquing (which I have punished myself with for several weeks now), the research is endless.

Pick something and try it, otherwise you'll be researching forever.

Share this post


Link to post
Share on other sites

I agree that diluted shellac in ethanol is a very simple and effective ground/sealer, and on top of that you can already get some yellow/golden coloration directly. M. Darnton describes his procedure on his web site.

Share this post


Link to post
Share on other sites

Hey Robert, thanks for suggesting that I investigate M. Darton's website regarding the procedure to make a ground/sealer from shellac. However, once at his website, I couldn't find the section on ground coats. Perhaps I overlooked it? I'm no stranger to shellac and would like to learn more about its application on violins. Notably, I'm using sheallac right now to repair a fountain pen.

Ernie, I appreciate the solid advice about trying out a varnish system on a sample.

Best,

Jason

Share this post


Link to post
Share on other sites

Hey Robert, thanks for suggesting that I investigate M. Darton's website regarding the procedure to make a ground/sealer from shellac. However, once at his website, I couldn't find the section on ground coats. Perhaps I overlooked it? I'm no stranger to shellac and would like to learn more about its application on violins. Notably, I'm using sheallac right now to repair a fountain pen.

Ernie, I appreciate the solid advice about trying out a varnish system on a sample.

Best,

Jason

My mistake. the description is not on his website, it's a PDF from him

Share this post


Link to post
Share on other sites

If you dont know the alum makes the glue more water resistant and it feels less sticky/tacky in humid weather.You can also combine the glue with a vegetable dye to give a slightly toned colour and the alum will also fix the dye somewhat!

If you make lake pigments ,you can also add a little glue to the mix which helps to make the pigment particles formed of a small size.

Share this post


Link to post
Share on other sites

I'm looking for a simple to use, durable surface finish and am rapidly learning that there is nothing "simple" about it.

Best,

Jason

Jason,

As you are finding out, there are many more ways to finish a violin than there are violin makers! If you are familiar with shellac, use it.

There LOTS of worse alternatives.

Joe

Share this post


Link to post
Share on other sites

I have a question or two about the ground coat. In the book The Art of Violin Making the authors describe how to make a ground coat using one part hide glue mixed with twenty-five parts of water "to which is added a small amount of alum."

Now this sounds easy enough except: what exactly is a "small amount" of alum -- a teaspoon, a tablespoon, or other?

Has anyone used this recipe and if so, how much alum was used and were you happy with the results? Also, does anyone know if this ground coat is compatible with the oil varnishes offered by the International Violin Company?

If you are still interested in trying this, the weight of alum crystals used can be approximately 10% of the weight of dry glue used. Make up an alum solution using warm water and slowly add this to the warm glue, stirring the glue as you do so.

If the glue starts to coagulate or clot, stop adding the alum solution. From what I recall various recipes refer to this ballpark proportion and it seems to work as long as you are able to avoid clotting. The innate character of the glue (dry strength?) will ultimately dictate how much alum you can get away with adding.

An alternative is to apply the glue wash and then apply an alum wash/size over the top of this.

As fiddlecollector points out, the role of the alum is to tan the glue, creating a more water resistant film.

If you want to use this sort of ground, for a number of reasons I would would suggest that you keep it very thin.

The oil varnish that you are referring to will probably adhere satisfactorily but you will need to try it.

Fiddlecollector's suggestions are well worth adding into the mix.

Good luck!

Share this post


Link to post
Share on other sites

Hi forum colleagues,

I have a question or two about the ground coat. In the book The Art of Violin Making the authors describe how to make a ground coat using one part hide glue mixed with twenty-five parts of water "to which is added a small amount of alum."

Now this sounds easy enough except: what exactly is a "small amount" of alum -- a teaspoon, a tablespoon, or other?

Has anyone used this recipe and if so, how much alum was used and were you happy with the results? Also, does anyone know if this ground coat is compatible with the oil varnishes offered by the International Violin Company?

Thank you and regards,

Jason

I use 1 package knox gelatin to one liter water with a pinch (1/4 teaspoon?) of alum as part of a presealing process to avoid uneven soaking in of coloring agents. This is not a complete ground but just part of a more complex system after several coats of preseal I color the wood then rub on a very thin, hard oil varnish primer. That's the ground and I varnish from there.

Share this post


Link to post
Share on other sites

just came across this posting by fiddlecollector from another thread about making madder lake

No havent tried the strips of cloth method,it was really used back then due to the high price of dyes paticularly madder and carmine ,of which the textile trade tended to have a monopoly on them.So everyone else had to make do with offcuts of cloth unless they had plenty of money. Its supposed to dissolve out some protein in the process and some elements associated with proteins end up in the lake.

So here is another source of protein that could have been found in the ground/sealer/varnish.

Oded

Share this post


Link to post
Share on other sites

Hey all,

 

I thought I would revive this topic to see if anyone has any new experiences regarding a ground comprised of a weak-glue-solution.

 

I am contemplating building the ground with: 0.5oz of hide glue; 12.50z water; and 1/4 teaspoon of alum. Does this sound like a reasonable recipe? I am especially interested in hearing from anyone who has experience with this type of ground.

 

Thanks and regards,

 

Jason

Share this post


Link to post
Share on other sites

Hey all,

 

I thought I would revive this topic to see if anyone has any new experiences regarding a ground comprised of a weak-glue-solution.

 

I am contemplating building the ground with: 0.5oz of hide glue; 12.50z water; and 1/4 teaspoon of alum. Does this sound like a reasonable recipe? I am especially interested in hearing from anyone who has experience with this type of ground.

 

Thanks and regards,

 

Jason

 

Hi Jason,

 

Without measuring the weight of a 1/4 teaspoon of alum, I can't tell whether your proportions are in the ballpark of what has been mentioned earlier in this thread.  (See post #13)

 

I would suggest that you do not add/mix the alum in dry form to the glue but rather make up an alum solution and then add that to the heated glue solution. 

 

Try your recipe and see how it behaves before applying it to any instrument....  (This should include applying varnish over your test sample.)

 

John

Share this post


Link to post
Share on other sites

Hi forum colleagues,

I have a question or two about the ground coat. In the book The Art of Violin Making the authors describe how to make a ground coat using one part hide glue mixed with twenty-five parts of water "to which is added a small amount of alum."

Jason

Jason,

 

Please quote the page, I can't find this recipe.  But it is one of the things that makes violin makers so exasperatingly charming.  I could add to that by suggesting "a small amount" means "a genteel sufficiency." :)  

Share this post


Link to post
Share on other sites

Norton, 

 

The book doesn't really explain how the glue/alum ground is done. I had a friend over from England last summer that does it and she was nice to show me the way. I believe it is a method taught by one the teachers at Newark, one teacher that was not there when I was a student years ago. 

 

The method goes as follows:

 

1-Make your hide glue as you normally would for normal woodwork

2.Make a saturated solution of alum in water. 

3-Drop by drop and stirring constantly, add alum solution into your glue until the mix goes gooey. This is something I look at and actually looks like a flem. Sorry for being bold but can't find a better way to explain. 

4-Add as much water as you have mix glue/alum so you have twice the amount. 

 

 

Ready to go. I have used it to seal spruce and does the job really nice. My favourite is casein but it is worth trying. 

 

Hope it helps. 

 

Jose

Share this post


Link to post
Share on other sites

Christian, your varnish always looks phenomenal.  You get that with hide glue?! 

 

You are using some kind of essential oil varnish that has 10 coats or more, aren't you?  I thought I read that you were doing something like that. 

Share this post


Link to post
Share on other sites

I found this:

 

Hide glue (and casein for that matter) can be made stronger and water resistant with either alum, chrome alum, sodium or potassium dichromate, or tannic acid. Roche (rock) alum and tannin were available to Stradivari.  Modern hardeners include formaldehyde and acetone.

 

Does anyone treat casein with alum? I thought casein was water-proof when dry and does not need any chemical enhancement.

Share this post


Link to post
Share on other sites
 

 

I found this:

 

Hide glue (and casein for that matter) can be made stronger and water resistant with either alum, chrome alum, sodium or potassium dichromate, or tannic acid. Roche (rock) alum and tannin were available to Stradivari.  Modern hardeners include formaldehyde and acetone.

 

Does anyone treat casein with alum? I thought casein was water-proof when dry and does not need any chemical enhancement.

Alum will cause aluminum casienate to precipitate out.  Same as a calcium compound.  Calcium caseinate is the small particles in skim milk.  Also it is found in all kinds of food.   You could put ammonium caseinate on the wood followed by alum. 

 

Or you could make lime-casein which is casein glue.  It remains workable for a while and then dries hard and waterproof.  It was used a lot by old furniture makers on the insides of drawers and backs of cabinets to seal.  It is a very old practice,  and dilute casein glue ought to be tried with hide glue if you are going in a glue direction.

 

And yes,  pure casein stays hard even in high humidity if the pH is reasonably low.  I use a little ammonia casein but with other things.  I never bothered with dilute casein glue because ammonia casein seems fine, as you say.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.