Sign in to follow this  
Juarnerius

Varnishing with diy lake pigments

Recommended Posts

23 hours ago, Juarnerius said:

Did that include washing linseed oil? I recently read a thread from a french luthier here that washes it with lime water and then cooks it with some more lime. He then uses that oil as a coloring ground on his instruments in the white, and i have to say i was pretty impressed by his results. I cooked my raw linseed oil that was washed with salt water at 280 degrees for 4 hours, and even though it got darker, it did not come even close to what he shows in his pictures. What do you think?

Juarnerius, can you post a link to that thread?  I must have missed it.  Sounds interesting.   

Share this post


Link to post
Share on other sites
18 hours ago, JacksonMaberry said:

Michael,

Sorry to appear dense, but I'm missing something. Why not just air dry the rosinates and then cook them into oil like any other resin? 

Right, but this process stops dried pigment rocks from forming. (Reread Darnton’s post.) I avoid milling and mulling into oil. I go right to mulling the pigment oil into varnish. Voila!

 

Share this post


Link to post
Share on other sites
16 minutes ago, Michael_Molnar said:

Right, but this process stops dried pigment rocks from forming. (Reread Darnton’s post.) I avoid milling and mulling into oil. I go right to mulling the pigment oil into varnish. Voila!

 

Ah, bingo! Thanks. 

Share this post


Link to post
Share on other sites
1 hour ago, Michael_Molnar said:

Right, but this process stops dried pigment rocks from forming. (Reread Darnton’s post.) I avoid milling and mulling into oil. I go right to mulling the pigment oil into varnish. Voila!

 

Right, in the old days, I don't think there was a lot of wasted motion.

Share this post


Link to post
Share on other sites
23 minutes ago, Fossil Ledges said:

Right, in the old days, I don't think there was a lot of wasted motion.

That said, I really disagree with Michelman's premise. I think it very unlikely the ancients were preparing and using rosinates. I use them because their properties suit my aesthetic aims, not because I believe they are historical.

Michael, if I understand correctly, you're using rosinates to color an existing varnish? I don't use them in the same way, if so. After I precipitate them, I dry them. Once dried, I cook them into oil in the same way one would cook raw colophony. No mulling required. Not much wasted motion. Probably not a lot of Pyrex or magnetic stirrers in Old Cremona either, if I had to guess.

Share this post


Link to post
Share on other sites

Apples and Oranges. Today, we have the luxury of time to spend on individual instruments. Back in my museum lab days grinding pigments was worth ZERO if you replicated it once. If you did the molecular to batch triaxials (quite literally a hundred times), and they were consistent, then it was okay.

Share this post


Link to post
Share on other sites
5 minutes ago, Fossil Ledges said:

Apples and Oranges. Today, we have the luxury of time to spend on individual instruments. Back in my museum lab days grinding pigments was worth ZERO if you replicated it once. If you did the molecular to batch triaxials (quite literally a hundred times), and they were consistent, then it was okay.

You've lost me, sorry. What's the apple and what's the orange, here? As to the luxury of time, I sure wish I had it. 

Share this post


Link to post
Share on other sites
9 hours ago, JacksonMaberry said:

That said, I really disagree with Michelman's premise. I think it very unlikely the ancients were preparing and using rosinates. I use them because their properties suit my aesthetic aims, not because I believe they are historical.

Michael, if I understand correctly, you're using rosinates to color an existing varnish? I don't use them in the same way, if so. After I precipitate them, I dry them. Once dried, I cook them into oil in the same way one would cook raw colophony. No mulling required. Not much wasted motion. Probably not a lot of Pyrex or magnetic stirrers in Old Cremona either, if I had to guess.

I no longer use rosinates because as you noted they are not historical with Cremonese techniques. I stick with madder, cochineal, and iron oxide for reds. Nevertheless, modern pigments and techniques beat the old hands down.

Share this post


Link to post
Share on other sites
On 6/4/2020 at 3:19 AM, Fossil Ledges said:

If they are water soluble pigments, I grind them and then dry them. But mostly, I am just lazy and grind them in turp. or linseed oil. I also have a vibratory tumbler and that works pretty well wet or dry, just noisy. Having worked in a materials lab under contract, a lot of wasted motion wasn't tolerated, if the chemistry is the same molecular to batch and batch to molecular, one takes the shortest path to the finished product that is chemically what it needs to be. I choose to believe that the old masters did not waste a lot of time on wasted motion or bizarre rituals either, they were pragmatic, and they consistently turned out some spectacular varnishes.

Fossil you say you worked in a lab. You should probably know that pigments are not water soluble!!

Also Jackson, resinates have been around quite a while though not generally in red colours.  Green copper resinate was used in many old paintings.

Share this post


Link to post
Share on other sites
On 6/3/2020 at 6:32 PM, Michael_Molnar said:

I have had good luck in converting water-based pigments such as Michelman rosinates  into linseed oil by evaporative heating of the water and oil mixture while constantly running a lab stirrer shown below. Just don’t let the linseed oil evaporate or cross-link. I don’t know if this works for all water-borne pigments, but with the right equipment you can try anything.

 

F5637275-7D64-4F5D-9FCA-E53FBFF7BEC9.jpeg.f14f0a85e34f7a6c068784a6680823fc.jpeg

 

 

Michael resinates are not water based pigments,sorry to be technical but you get it right in the 3rd sentence `water borne` pigment, (that is until they are dry.)

Share this post


Link to post
Share on other sites
2 hours ago, fiddlecollector said:

Michael resinates are not water based pigments,sorry to be technical but you get it right in the 3rd sentence `water borne` pigment, (that is until they are dry.)

Right. They are made in water for use in oil.

However, just spitballing here, I wouldn’t be surprised that they can be converted for use in watercolors (spirit varnish) with some gum Arabic and honey. Maybe that would interest @Julian Cossmann Cooke.

Share this post


Link to post
Share on other sites
2 hours ago, avandesande said:

One thing to try is adding some gelatine in your lake this will reduce the size of the crystals

That reminds me of artist Michael Price’s work with azurite.

Share this post


Link to post
Share on other sites
13 hours ago, fiddlecollector said:

Fossil you say you worked in a lab. You should probably know that pigments are not water soluble!!

Also Jackson, resinates have been around quite a while though not generally in red colours.  Green copper resinate was used in many old paintings.

Please re-read the post response, what does water solubility have to do with the molecular to batch formulation? Solubility, (in anything) is part of the multivariable calc.  equation. It must be accounted for in the premix and then again with the oxidation reactions, UV etcetera in the post, ie. what happened? This is basic grad. school chemistry. I don't use water soluble anything. What I grind it in is part of the MECHANICAL process.

Share this post


Link to post
Share on other sites
14 hours ago, fiddlecollector said:

Fossil you say you worked in a lab. You should probably know that pigments are not water soluble!!

Also Jackson, resinates have been around quite a while though not generally in red colours.  Green copper resinate was used in many old paintings.

Cite your sources. I can't be expected to take your word for it. 

Share this post


Link to post
Share on other sites

Remember cooking changes/contributes to your chemistry lots! Mechanical grinding, not so much, other that to increase surface area in preparation for the next chemical change...

Share this post


Link to post
Share on other sites
7 hours ago, Fossil Ledges said:

Please re-read the post response, what does water solubility have to do with the molecular to batch formulation? Solubility, (in anything) is part of the multivariable calc.  equation. It must be accounted for in the premix and then again with the oxidation reactions, UV etcetera in the post, ie. what happened? This is basic grad. school chemistry. I don't use water soluble anything. What I grind it in is part of the MECHANICAL process.

You said ,

``If they are water soluble pigments, I grind them and then dry them. But mostly, I am just lazy and grind them in turp. or linseed oil. ``

Im just correcting you:)

Share this post


Link to post
Share on other sites
7 hours ago, JacksonMaberry said:

Cite your sources. I can't be expected to take your word for it. 

Sources for what?  Copper resinate??  Its a green pigment that was used for ages as a glaze usually.

Share this post


Link to post
Share on other sites
9 hours ago, JacksonMaberry said:

Cite your sources. I can't be expected to take your word for it. 

 

1 hour ago, fiddlecollector said:

Sources for what?  Copper resinate??  Its a green pigment that was used for ages as a glaze usually.

Yep, an italian book that I own that deals with ancient painting materials calls it "Verderame trasparente" (transparent verdigris) and gives it in use from the VIII to the mid-XVI century. Also says that it is sensitive to photo-decomposition and becomes gray-brown, a phenomenon observable in many ancient oil paintings.

Share this post


Link to post
Share on other sites
3 hours ago, fiddlecollector said:

You said ,

``If they are water soluble pigments, I grind them and then dry them. But mostly, I am just lazy and grind them in turp. or linseed oil. ``

Im just correcting you:)

Thank you for the correction, I missed the forest for the trees on that one regarding the language, my apologies! I should have said solubility in the media, regardless of what the media is.

Share this post


Link to post
Share on other sites
13 minutes ago, Fossil Ledges said:

Thank you for the correction, I missed the forest for the trees on that one regarding the language, my apologies! I should have said solubility in the media, regardless of what the media is.

I think of a suspension of particles in a medium as being different from something truly dissolved in a medium.

Share this post


Link to post
Share on other sites

Yes, chemically true, solubility usually implies a chemical bond or reaction somewhere in the process.  So, when I grind my pigments in turp or linseed, they are in a suspension. When I cook the mixture, chemical changes begin to occur, but mostly to the oil in the form of increased oxidation. In chemistry water is the most universal solvent, however, time and lack of reaction become factors, ie; glass is a liquid etcetera. Most of us can't wait a hundred years for our varnish to cook. Lately, I have become increasingly interested in secondary and tertiary oxidation with UV etcetera.

Share this post


Link to post
Share on other sites
4 hours ago, Davide Sora said:

 

Yep, an italian book that I own that deals with ancient painting materials calls it "Verderame trasparente" (transparent verdigris) and gives it in use from the VIII to the mid-XVI century. Also says that it is sensitive to photo-decomposition and becomes gray-brown, a phenomenon observable in many ancient oil paintings.

Thank you, Davide, for this. @fiddlecollector this is what I was asking you for - support for your assertion. That's all. Granted the existence of copper rosinate in that time does t prove Michelman's thesis, I think you'll agree.

Share this post


Link to post
Share on other sites
2 hours ago, JacksonMaberry said:

Thank you, Davide, for this. @fiddlecollector this is what I was asking you for - support for your assertion. That's all. Granted the existence of copper rosinate in that time does t prove Michelman's thesis, I think you'll agree.

In fact, this is the only rosinate that I have ever encountered in the texts on ancient pigments, but my knowledge is not so vast as to exclude others, only to see it unlikely. But the idea of making a pigment more transparent by associating it with a resin was there, although I doubt that they used Michelman's system:)

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.