Tom Pistor's Bench

[tpistor]

Trying to make varnish!  Very fun.

 

[tpistor]

Trying to make "linoxin".  Started in March, 2021.  Will this work?

 

[Andreas Preuss]

Looks like fun!

(or if you would put your pictures on a cooking website, the last two pictures look like making curry and raspberry beer. )

[Davide Sora]

On 5/14/2024 at 9:19 AM, tpistor said:

Trying to make "linoxin".  Started in March, 2021.  Will this work?

It works for what? If you want to use it to make a varnish like I use, it has to be soluble in alcohol. I don't think it is at the point you're at, but you can test it by putting a small piece in alcohol to see if it dissolves.
If I were you, I'd grind it up with a meat grinder to break it up and expose more of the surface to the air and any uncured, unoxidized oil trapped inside. But I think you will need a few more years if you want to only use natural oxidation like I do. A clear sign of complete oxidation, in addition to perfect solubility in alcohol, is the color becoming dark brown.

Grinding:

 

Fully cured and oxidized Linoxin:

[Andreas Preuss]

On 5/15/2024 at 10:49 AM, Davide Sora said:

It works for what? If you want to use it to make a varnish like I use, it has to be soluble in alcohol. I don't think it is at the point you're at, but you can test it by putting a small piece in alcohol to see if it dissolves.
If I were you, I'd grind it up with a meat grinder to break it up and expose more of the surface to the air and any uncured, unoxidized oil trapped inside. But I think you will need a few more years if you want to only use natural oxidation like I do. A clear sign of complete oxidation, in addition to perfect solubility in alcohol, is the color becoming dark brown.

Grinding:

 

Fully cured and oxidized Linoxin:

Or you follow the receipe by Lapo Casini who dissolved the ground linoxyn in a solution of natriumcarbinate (or was it natriumhydroxid?)  As a result this red brownish slurry will float up. After letting evaporate the water which adheres to it it can be dissolved in alcohol. However in solution it is not very stable. Therefore Casino advises to blend it in the desired amount with other resins such as shellack and let the alcohol evaporate. Then it can be stored for years.

i made such a ‘Casini varnish block’ long long ago and still use it to imitate fatty oil varnishes in touch up. 
 

note: I might have remembered the procedure not 100% exact. 

[Davide Sora]

1 hour ago, Andreas Preuss said:

Or you follow the receipe by Lapo Casini who dissolved the ground linoxyn in a solution of natriumcarbinate (or was it natriumhydroxid?)  As a result this red brownish slurry will float up. After letting evaporate the water which adheres to it it can be dissolved in alcohol. However in solution it is not very stable. Therefore Casino advises to blend it in the desired amount with other resins such as shellack and let the alcohol evaporate. Then it can be stored for years.

i made such a ‘Casini varnish block’ long long ago and still use it to imitate fatty oil varnishes in touch up. 
 

note: I might have remembered the procedure not 100% exact. 

Remember well, Casini saponifies with sodium hydroxide or sodium carbonate, then "desaponifies" with hydrochloric acid or another acid, to neutralize and recoagulate the linoxin. Then wash it well to remove traces of chemical substances. I prefer the natural oxidation system precisely because it is difficult to get rid of residual traces of chemical substances, which could cause problems. Or maybe not. In doubt, I prefer to have a lot of patience and use the natural method, the result still seems different to me, in the color (darker and redder) and especially in the behavior of the linoxin once dried in the varnish, which remains less soft. But it also works with the chemical system, only you can use less in proportion to the resin because otherwise, the varnish will be decidedly too soft.

This is the Casini book: https://archive.org/details/verniceliutailapocasini

[MikeC]

I made some like that. It is soluble in alcohol but I have not tried to use it in a varnish.  Here is a picture of some I made in Summer of 2021

[Nick Allen]

16 hours ago, Davide Sora said:

Remember well, Casini saponifies with sodium hydroxide or sodium carbonate, then "desaponifies" with hydrochloric acid or another acid, to neutralize and recoagulate the linoxin. Then wash it well to remove traces of chemical substances. I prefer the natural oxidation system precisely because it is difficult to get rid of residual traces of chemical substances, which could cause problems. Or maybe not. In doubt, I prefer to have a lot of patience and use the natural method, the result still seems different to me, in the color (darker and redder) and especially in the behavior of the linoxin once dried in the varnish, which remains less soft. But it also works with the chemical system, only you can use less in proportion to the resin because otherwise, the varnish will be decidedly too soft.

This is the Casini book: https://archive.org/details/verniceliutailapocasini

Hey Davide. Does the linoxin varnish antique well? Does it chip and shade okay? 

Just curious. Thanks. 

[Davide Sora]

31 minutes ago, Nick Allen said:

Hey Davide. Does the linoxin varnish antique well? Does it chip and shade okay? 

Just curious. Thanks. 

If you make the varnish with linoxin and colophony the wear is quite similar to an oil varnish, but it depends on the resin/linoxin percentage, but the same goes for the oil/resin ratio of oil varnish, the wear is different depending on proportions. However, I prefer to use seedlac instead of colophony, to have the varnish more resistant to sweat and therefore the wear will be less and slightly different. I wouldn't recommend it for making copies, faking the wear is more complicated.

[Nick Allen]

23 hours ago, Davide Sora said:

If you make the varnish with linoxin and colophony the wear is quite similar to an oil varnish, but it depends on the resin/linoxin percentage, but the same goes for the oil/resin ratio of oil varnish, the wear is different depending on proportions. However, I prefer to use seedlac instead of colophony, to have the varnish more resistant to sweat and therefore the wear will be less and slightly different. I wouldn't recommend it for making copies, faking the wear is more complicated.

Hmm. Thanks for the concise info. 

I am on the trajectory to make copies/forgeries(not for nefarious purposes) primarily. But having info about all types of varnishes is nice because I can have more tools in my belt when I need them. 

[Davide Sora]

1 hour ago, Nick Allen said:

Hmm. Thanks for the concise info. 

I am on the trajectory to make copies/forgeries(not for nefarious purposes) primarily. But having info about all types of varnishes is nice because I can have more tools in my belt when I need them. 

I'm not saying it's not possible, in fact you can control the percentage of linoxin well and how the chips and cracking behave, but you have less time than with an oil varnish, even if the latter is probably less predictable in its behavior over time. But I am not at all an expert in antiquing, and only for fun on small samples, such as this one with 1:1 linoxin/colophony varnish colored with madder lake, never on whole violins. So please don't take me too seriously...

[tpistor]

Thanks for the replies!  I guess I wasn't expecting anybody to respond.  Sorry for not being specific about "Will this work?"

@Davide Sora Yes, I'm trying to make linoxin like you do.  (love your videos!)  Those photos above where I'm holdup up the skinned-over oil were from Sept. 2022 (about 1.5 years into the aging process).  After taking those photos, I did grind up the skins from 2 of the 8 trays I have in my attic.  You can see the current-day (3 years into the aging) images of these ground-up skins in the photos below.

Out of curiosity, I tried to take some and dissolve it in alcohol, and found it to be completely insoluble.  Not even a little!  I was thinking that maybe some of it is start to get a little bit soluble, but I guess not.

I used "Tried and True Polymerized Linseed Oil".  Does the fact it was "Polymerized" present any problems?  Should I have started with completely unprocessed linseed oil?

Also, should I pile up the ground-up oil skin higher?  I've spread it out sparsely hoping it would oxidize faster.  But, I can't imaging it forming a nice thick brown toffee-like layer like yours.

Next time I'm in my attic, I'll snap a photo of the un-ground (3 year old) skins for comparison.

I'll continue to report the progress of the aging.

I was just looking for some reassurance that I'm on the right track.

[Davide Sora]

5 hours ago, tpistor said:

@Davide Sora Yes, I'm trying to make linoxin like you do.  (love your videos!)  Those photos above where I'm holdup up the skinned-over oil were from Sept. 2022 (about 1.5 years into the aging process).  After taking those photos, I did grind up the skins from 2 of the 8 trays I have in my attic.  You can see the current-day (3 years into the aging) images of these ground-up skins in the photos below.

Out of curiosity, I tried to take some and dissolve it in alcohol, and found it to be completely insoluble.  Not even a little!  I was thinking that maybe some of it is start to get a little bit soluble, but I guess not.

I used "Tried and True Polymerized Linseed Oil".  Does the fact it was "Polymerized" present any problems?  Should I have started with completely unprocessed linseed oil?

Also, should I pile up the ground-up oil skin higher?  I've spread it out sparsely hoping it would oxidize faster.  But, I can't imaging it forming a nice thick brown toffee-like layer like yours.

Next time I'm in my attic, I'll snap a photo of the un-ground (3 year old) skins for comparison.

I'll continue to report the progress of the aging.

I was just looking for some reassurance that I'm on the right track.

 

 

At the point you are at it is normal that it is not soluble in alcohol, it takes longer. Using prepolymerized oil shouldn't cause any problems, at most it shortens the oxidation time a little (but not much). With the natural oxidation system it is difficult to establish a time to reach solubility in alcohol because the type of oil and environmental conditions can influence, but I estimate that more or less 5 or 6 years will be necessary. The only way to shorten this time is chemical saponification to eliminate the glycerin content, but as I was saying the final product will not be the same, more pale in color and softer, even if it will be soluble in alcohol and therefore usable to make a varnish.

[tpistor]

Trying to choose color for violin #4.  

Bottom: violin #1

Left: violin #2

Middle: violin #3

Right: scrap violin for varnish practice - this is a candidate varnish for #4 (homemade from tree sap)

Far right... Other test samples

 

[tpistor]

Scroll protector! 

 

[tpistor]

F-Holes shaping up nicely.  Still too small - always afraid to cut to the far edge of my pencil line (removing the line).

[tpistor]

The final touches to the ffs.

[JonnyFW]

Those f-holes look very distinctive. Your own design? They look very different from your violins 1-3 (from the picture above) which are giving me Stainer kind of vibes.

[tpistor]

@JonnyFW

On 9/22/2024 at 3:51 AM, JonnyFW said:

Those f-holes look very distinctive. Your own design? They look very different from your violins 1-3 (from the picture above) which are giving me Stainer kind of vibes.

Yes, for this violin I made my own template based on Guarneri Vieuxtemps poster from "The Strad".  I was not trying to make distinctive f-holes, I was trying to compensate for the curvature of the top plate relative to the flat photo in the poster.  I somehow ended up with this f-hole shape which I kind of liked.  I'm praying that they sound OK!

[Andreas Preuss]

On 7/5/2024 at 10:08 AM, tpistor said:

Still too small - always afraid to cut to the far edge of my pencil line (removing the line).

I always erase the pencil lines to do the final touch. In the end it is about what you see with your eyes and not where is a more or less precise line ‘on the map’.

[tpistor]

My latest in the white.  My best yet I think!  Previous violins were based on templates from makingtheviolin.com.  This one is based on Guarneri Vieuxtemps template (which had strong asymmetry in the body outline and the in the scroll).  I'm still adjusting the sound and will post sample audio once it's settled.

 

[tpistor]

I wish I discovered this earlier - the absolute best surface for thicknessing the ribs.  Cheap (used, $150) lathe from Harbour Freight!  (with tailstock and tool rest removed)

 

[tpistor]

Fairly happy with my homemade oil varnish.  Violin #5 was made from leftover/practice parts from violin#4 build.  This was supposed to be a test run for the varnish.  Turns out violin #5 sounds better than #4!

[MikeC]

Looks good!  What's your homemade oil varnish?   I see you were making linoxin,  did you use that?  

[tpistor]

2 hours ago, MikeC said:

Looks good!  What's your homemade oil varnish?   I see you were making linoxin,  did you use that?  

This was homemade right from tree sap and homemade pigments.  The linoxin is not ready yet.  When it is, I'll try to make varnish like Davide Sora.