Varnish cooking, rosin/resin source

[HighUintas]

Hi. I have been reading about BLO cooking and varnish cooking here. There's an incredible amount of information in older posts from mad monk, Gordo, DPhariss, and others. It has made me interested in the possibility of making my own oil varnish, although I don't know if I will attempt it any time soon. One of the ingredients used is rosin or resin and many different types have been mentioned.

With archery elk season about to start (this weekend!) I am thinking I may collect the dried and hardened resin, which might be properly called rosin but I'm not sure, from the pine trees while I hunt. I often find big globs of it on pine trees from really old elk rubs. I thought it would be fantastic if I made a quality oil varnish using rosin that has been collected from elk rubs where I hunt.

Have any of you varnish cookers that are still here used dried hardened pine tree resin/rosin or know if this would work?

Yes I could just buy some T&T oil varnish, but where's the fun in doing things the easy way?

[flinchrocket]

Have you looked a Diamond G Forest Products. My guess is you would be collecting the same rosin they sell.

[LynnC]

Here we go. Maybe you can entice the Alchemists out of the woodwork 😉 I always enjoy these home brew varnish threads. Good luck!

[HighUintas]

Hopefully!! I really enjoyed reading all those old threads.

I have looked through diamond g products. They're distilling their gum to make the rosin though, which is different than it just drying on the tree.

So I was mainly curious if someone has used it straight from the tree and if any additional processing was needed.

[Eric Kettenburg]

Yes straight from the tree is going to posses many impurities which typically would be driven off in a repetitive heating and straining process.  What it will do using it right off the tree is actually retard drying by gunking up your varnish with raw impurities, including water-based moisture which typically creates a scum that needs to be removed from the oil when boiling.

Most eastern US conifer resins are not the harder resins used for 18th century vanishes other than what were typically cheap common varnishes which frankly relied more on the oil itself than any resin used.

[HighUintas]

Yes straight from the tree is going to posses many impurities which typically would be driven off in a repetitive heating and straining process.  What it will do using it right off the tree is actually retard drying by gunking up your varnish with raw impurities, including water-based moisture which typically creates a scum that needs to be removed from the oil when boiling.

Most eastern US conifer resins are not the harder resins used for 18th century vanishes other than what were typically cheap common varnishes which frankly relied more on the oil itself than any resin used.

Thank, Eric. That's good information. What I meant by using it straight from the tree was to at least dissolve it in turp and then strain out any particulate. But, I was unsure about the other raw components, such as the water based ones you mentioned.

Do you know what the simplest process for incorporating it into a successful varnish is? The only info I could find on people processing the resin or rosin before putting it into the oil was one that involves using wood ash lye and another that used potassium carbonate to make potassium rosinate, which was then altered with the addition of calcium chloride and aluminum chloride. They were essentially saponifying the rosin. I don't know if the sole purpose of that was to be able to bind their alizarin dye or if it was to make the rosin more stable and useful in the varnish. I know part of it was to reduce the acidity of the acids in the rosin. These were luthiers recipes.

I thought that it might be possible to use by putting the rosin straight into the linseed oil and then cooking it for some amount of time at a higher temperature and then straining out the impurities. That might be better than dissolving in turp first and adding it to the oil because you wouldn't be able to cook the oil at as high a temperature to drive off whatever it is you need to drive off from the rosin.

I spent 10 years in the beer brewing industry and taught high school chemistry... So cooking things is right up my alley.

[T*O*F]

I started to do what you are proposing abour 30 years ago.  While elk hunting in CO I noticed these big clumps of rosin on pitch pines, so I started carrying a small ax and collected them.  I filled up a tomato can with them and set it alongside the campfire to concentrate the clumps.  It drove off many of the volatiles and melted into a solid brittle mass when cool.  The stuff is incredibly dirty.  I couldn't figure out a way to strain it while it was molten.  I removed most of the large stuff with a flattened stick.  I've still got it around here somewhere.  The only thing I ever used it for was to mix it with powdered charcoal and use it as a period correct glue and filler.  Also, under international rules, a barrel can only be bedded using natural ingredients and it would serve that purposed.

[Nordnecker]

Years ago, while working with a friend on a construction project, we found a blob of rosin from a cherry or plum tree. It was hard as glass and just as clear, although dark amber in color. We wondered if it could be made into a varnish. We tried to melt it down with solvents. We tried mineral spirits, gas, even xylene. Nothing worked. It wouldn’t soften up so we just left it in a can outside.
One night it rained and filled the can partially with water. Eureka! The rain softened the blob of rosin. We were astounded.

[bob in the woods]

Melt /heat the rosin and then strain/twist the mix in a piece of burlap to strain out the impurities. I have done this, and then added bear fat and ground charcoal to make glue. I  have also mixed the rosin with walnut oil , heated in a sand bath . I used the stuff on a canoe paddle. So far, so good 

[Dphariss]

Hi. I have been reading about BLO cooking and varnish cooking here. There's an incredible amount of information in older posts from mad monk, Gordo, DPhariss, and others. It has made me interested in the possibility of making my own oil varnish, although I don't know if I will attempt it any time soon. One of the ingredients used is rosin or resin and many different types have been mentioned.

With archery elk season about to start (this weekend!) I am thinking I may collect the dried and hardened resin, which might be properly called rosin but I'm not sure, from the pine trees while I hunt. I often find big globs of it on pine trees from really old elk rubs. I thought it would be fantastic if I made a quality oil varnish using rosin that has been collected from elk rubs where I hunt.
I use food grade rosin and food grade Gum Benzoin. I mix the resins in heated real turpentine and then mix oil that I have heat modified into the turpentine mix. Be careful turp has a low flash point compared to LS oil. I use store bought boiled oil as a base then heat it in a deep fat fryer with some calcium carbonate in the pot and add some Japan drier as well. Maybe 3-4 tablespoons to the gallon.

Have any of you varnish cookers that are still here used dried hardened pine tree resin/rosin or know if this would work?

Yes I could just buy some T&T oil varnish, but where's the fun in doing things the easy way?