Oil ground?

[MikeC]

42 minutes ago, David Burgess said:

In my opinion, that's an excellent paper.

My experimental outcomes have differed from yours.

Maybe because I grind up the dried LO to expose more surface area?   

I once purchased an old muzzle loader rifle from a guy who liked to slather everything with linseed oil.  It took me quite a while to scrape the black goo out of the ramrod channel.  It probably had about 40 years of age on it since the LO was put on it.  

[Michael Darnton]

Worth noting in that context that linseed oil (and some oil varnishes) + skin chemicals = gummy black tar.

Like on the head of this del Gesu that spent 40 or 50 years in a closet:

[Andreas Preuss]

4 hours ago, David Burgess said:

In my opinion, that's an excellent paper.

My experimental outcomes have differed from yours.

Then would you mind to describe what was different and how the experiment was executed?

 

 

[MikeC]

4 hours ago, Michael Darnton said:

Worth noting in that context that linseed oil (and some oil varnishes) + skin chemicals = gummy black tar.

Like on the head of this del Gesu that spent 40 or 50 years in a closet:

I've seen a picture of that scroll before.  Do you have any other pics?  What does the rest of the violin look like?  

Regarding your linseed oil picture earlier,  was it washed?  or did it still have the water soluble gunk in it?  

[Claudio Rampini]

6 hours ago, MikeC said:

Maybe because I grind up the dried LO to expose more surface area?   

I once purchased an old muzzle loader rifle from a guy who liked to slather everything with linseed oil.  It took me quite a while to scrape the black goo out of the ramrod channel.  It probably had about 40 years of age on it since the LO was put on it.  

It was very usual that an original muzzleloader rifle from the XVIII or XIX cent. has linseed oil on the stock, but it was applied with a very good and durable method, like a real varnish. But a violin isn't a rifle, especially if you consider applying the linseed oil before the proteic layer (hide glue, albumine or casein), because generally speaking the glue and similar things don't like greasy surfaces.

But the question on a good violin ground isn't "what" was used, but "why". The european pictorial tradition helps to understand these aspects of the "imprimitura".

6 hours ago, Michael Darnton said:

Worth noting in that context that linseed oil (and some oil varnishes) + skin chemicals = gummy black tar.

Like on the head of this del Gesu that spent 40 or 50 years in a closet:

 

It appears like a lower and cheaper quality colophony/linseed oil varnish, but Guarneri used better varnishes in his best period. I have experienced the same gummy black tar just with colophony/linseed oil varnishes, paradoxically a well applied linseed oil doesn't produce the same black tar on my necks. Could be interesting to see the varnish on the body of that Guarneri.