Jump to content
Maestronet Forums

Cooking Colophony Down For Color, Low and Slow?


Berl Mendenhall
 Share

Recommended Posts

  • Replies 628
  • Created
  • Last Reply

Top Posters In This Topic

I have to agree that the Diamond G is a superior product.  I love the turpentine, worth the price as well.   The question at hand however is the rosin's  suitability for low slow transformation to a colorant by Hargrave's Rubification.

 

From Artephius' Secret Book:

 

This white substance, if you will make it red, you must continually decoct it in a dry fire till it be rubified, or become red as blood, which is nothing but water, fire, and true tincture. And so by a continual dry fire, the whiteness is changed, removed, perfected, made citrine, and still digested till it become to a true red and fixed colour.

 

Bob

Link to comment
Share on other sites

After 6 days of continuous cooking at 275F I'm turning the crockpot off. The Diamond G rosin is similar to Woodfinishing Enterprises raw pine gum when cooked low and slow...not much color change. I will say that the Diamond G rosin is the clearest resin (before cooking) that I've seen so far. Hopefully it will make a nice pale varnish.

 

My take on the low and slow method...I think it depends on the resin itself. I have cooked a few different kinds and some had different color and characteristics.

 

I bought five pounds of the Diamond G rosin and have been curious to see how much color change would happen when cooked. Now I know to look elsewhere if I what a red colored rosin. The Abies Alba raw resin turned red quickly when cooked but it makes a too soft varnish on it's own.

 

The resin called Burgundy from Kremer I have cooked several times and it turns a nice yellow/brown, but no red.

 

Perhaps I'll try slow cooking some resin for a month just to satisfy my curiousity...someday

Link to comment
Share on other sites

I'm going to make a batch of varnish later this spring. I'm going to wash the oil and cook the resin down first. My question is how long to cook the colophony and at what temperature. I know it's cooked at a very low temperature, I just not sure how low and how long. Thanks in advance.

Have you made that batch of varnish yet Berl?

Link to comment
Share on other sites

I bought it too, because of your recommendation, it does smell good, have not used it yet, transferred the contents of the aluminum gallon into glass bottles, now will wait a week to see if anything that may have reacted with the aluminum precipitates.

 

Thanks for the tip.

Good thing you transferred it to glass bottles. Turpentine seems to rust in cans and takes on an orange hue. 

Link to comment
Share on other sites

Just for SnG's you should put some in another container and try cooking it hot and fast

After another week if it doesn't darken or get anymore red then I will cook it at 500 degress or more to make some varnish and my guess it will turn brown pretty fast. It would be nice to get some more red in it though.

Link to comment
Share on other sites

I aim to find out what type spruce it is. I collect it in Maine along the coast areas near Brunswick and Portland.

The crockpot works okay but I'm hesitant to leave it on 24/7 since I'm in a residential area. Maybe I need to find an enclosure I can put it in?

I have not weighed anything. I start with a gallon ziplock bag of bark and resin and dissolve about (16 oz ) peanut butter jar about 7/8 ths full of raw resin. That cooks down to about half a jar or a cup or so of cooked resin.

I get a nice color from it but still not dark enough. The samples on the rib stock look good but it is way too thick of a film there.

Hi all,

New to posting here but a longtime viewer!  I am a Maine native and what you typically see in the southern half of the Maine coast is Red Spruce (Picea Rubens) which is eventually replaced by White Spruce (Picea Glauca) further downeast.  Balsam fir is also quite common (Abies Balsamea).  I've never had a particularly positive experience with any native regional woods here for building, but then, I do not have a lifetime of experience at this yet.  Lots of lovely rock maple, and lots of happy mandolin makers.

Did you cook any of that resin into a final varnish?  Results?

Link to comment
Share on other sites

Hi emviolins- if you run it at hi temps why not go to a paint store and get a tube of the pigment  raw umber or burnt umber. Pretty certain you'll get a reddish brown if the rosin is in a condition for coloring. This is a new wrinkle when using rosin that some won't color. I have 5 lbs from City Chemical Co, Conn, that only weakly colors, that's using umber at short hi heat, not slo-cook oxidation. Maybe a list of suppliers with rosin  that hasn't sat on the shelf for enough years (my thinking) to color might help.  fred

Link to comment
Share on other sites

From the Keith Hill website:

 

... free of the acids used in the process of chemically cleaning rosin used to make commercially manufactured varnishes and paints. They remove all the "impurities" from the rosin so that it will never darken--this is a government imposed standard. By removing all the impurities, most of the minerals that give the rosin its color are also removed...

 

AsaBB, Don Leister... I'm in Maine for a few months, I have collected some beautiful Canada balsam,  spruce resin sounds interesting, is it clear? Gold, orange or white?

 

Thanks

Link to comment
Share on other sites

Hi emviolins- if you run it at hi temps why not go to a paint store and get a tube of the pigment  raw umber or burnt umber. Pretty certain you'll get a reddish brown if the rosin is in a condition for coloring. This is a new wrinkle when using rosin that some won't color. I have 5 lbs from City Chemical Co, Conn, that only weakly colors, that's using umber at short hi heat, not slo-cook oxidation. Maybe a list of suppliers with rosin  that hasn't sat on the shelf for enough years (my thinking) to color might help.  fred

I have a tube of burnt umber and enough resin to give your method a try. Now I need to find your recipe again...Thanks
Link to comment
Share on other sites

From the varnish section in the bass thread (Roger Hargrave):

 

"The method(s) I used for combining these ingredients was based on two or three further snippets of information. The first of these concerned the length of the colophony molecules. These were not found to have been significantly altered. Accordingly, White had concluded that the colophony had not been cooked at a high temperature. He suggested that it had probably been heated just hot enough and long enough to blend it with the oil and mastic. (His conclusion about the mastic was that it had probably been added as plasticizer.)

 

"In addition to this important observation about the cooking process, at a later date Professor White was asked to examine a particularly red and rather typical Venetian varnish on a violin by Sanctus Seraphin. White was specifically asked to identify the colouring agent. His reply was illuminating. Having examined the instrument he concluded that the redness in the varnish was simply the result of oxidisation, rather that any additional colouring agent. For me personally this was a revelation."

If the colophony is just cooked hot and long enough to blend with the oil and mastic, and the red is due to oxidization rather than any additional coloring agent then it is possible that the redness was from cooking and oxidizing linseed oil?  

Link to comment
Share on other sites

Hi Asabb, thanks for the tree info. Comes from Harpswell, Maine, I was thinking red spruce too.

I have not made a varnish from the 2 resins that I cooked ( re: post #160 ). While they appear dark after cooking, they are quite thick and would not give enough color solely to make a suitable varnish.

Carlo, the resin on the tree ranges from clear to brown and is semi-hard usually and gets stuck to the bark and dirt and what ever, so what I collect is more bark than resin until I separate it with solvent.

It seems there are so many variables in getting the resin to a state that is good for making a varnish, that anything I say will not be that helpful. It is fun to poke around with it and see what I come up with though.

Link to comment
Share on other sites

Coloring agents have been found in red violins by Strad, etc.

 

Lots of Amati's are not red, and the Sanctus Seraphin violin I held was not red either. Maybe professor white was not talking about red, but about some darkening, the Seraphin I saw was not dark IMHO but had some color, orangy perhaps?. And it is a venetian instrument, have any of his been scientifically analyzed? Perhaps in the varnish recipe there are resins that darken more naturally, like Sandarac for example which is notorious for getting red as it ages.

Link to comment
Share on other sites

if you run it at hi temps why not go to a paint store and get a tube of the pigment  raw umber or burnt umber. Pretty certain you'll get a reddish brown if the rosin is in a condition for coloring.

 

Hi FredN,

 

is there any particular reason to use raw umber from tube oil color?

I tried the pigment (the earth) in the dry form and it seems to work, but it's just the first time I've done this test.

Do you think I might have missed something in the end result?

 

Davide

Link to comment
Share on other sites

Have you made that batch of varnish yet Berl?

em, sorry for the late reply I just found your question. The short answer is no. I started this thread you would think I'd keep up with it, but twelve pages of questions and answers. These varnish threads can take on a life of their own. I've been busy with other projects and haven't got to making varnish. I'm not a great multi-tasker. As I said earlier I've got plenty of varnish, I just wanted to make some. From what I've read the red color thing isn't working as well as expected.
Link to comment
Share on other sites

em, sorry for the late reply I just found your question. The short answer is no. I started this thread you would think I'd keep up with it, but twelve pages of questions and answers. These varnish threads can take on a life of their own. I've been busy with other projects and haven't got to making varnish. I'm not a great multi-tasker. As I said earlier I've got plenty of varnish, I just wanted to make some. From what I've read the red color thing isn't working as well as expected.

OK, I was just wondering if you had any luck getting a red rosin. If you had I would have inquired which type/brand of colophony you used. Thanks for the reply.

Link to comment
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...
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.




×
×
  • Create New...