Rosin

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I'm an Engineer. I like hiking, flea markets, and electronics.

Intro: Rosin

This instructable shows how to make rosin out of pine sap / pitch. Rosin can be used for the following:

Electronic Soldering Flux:

Much like burningsuntech's instructable Make your own Eco-friendly soldering flux, you can dissolve the rosin in denatured alcohol for use as a flux.

Alternatively, you can melt the rosin directly with a soldering iron to liquify and then dip in the solder, a lead, or wire.

You can soften the rosin by adding something like vaseline / petroleum jelly to it when molten for rub-on application.

Lastly, you can take an alcohol based mixture of rosin, add water, and evaporate at room temperature to make a water-based emulsion.
 
Stringed Instruments:

Stringed instruments like violins use rosin to create grip between the bow fibers and the instrument strings. You can remelt the solder using a deep fryer and then pour it a c-shaped wooden mold.

Varnish Component:

Rosin can be used as a component in varnish, for example when added to linseed oil.

Grip Enhancement:

Athletes (baseball, gymnastics) use rosin in the form of 'rosin bags' to enhance grip on sports equipment. If available, rosin bags provide the no-fuss source for raw rosin.

Step 1: Collect

In this step, collect pine sap / pitch.

Locate a pine tree with 'wounds' from tree trimming. These contain the pine sap / pitch mixed with wood chips, pollen, bugs, and dirt. Use a butter knife to scoop the sap / pitch into an appropriate container. An appropriate container should be made of glass or of high density polyethylene plastic (HDPE). This type of plastic can withstand strong solvents like acetone and is generally marked with a '2' in the recycling symbol.

Step 2: Dissolve

In this step, liquify the sap / pitch with a solvent.

Add acetone to the collected sap / pitch such that it fills up the container half way. Afterward, shake the container in 15 minute increments to help dissolve large chunks. It's impossible to dissolve all chunks, since some are very thick or are composed of wood chips so check the consistency periodically. When satisfied with the results, continue to the next step.


Step 3: Filter

In this step, filter the sap / pitch solution.

For this step, obtain another HDPE container with a cone-shaped top (such as windshield wiper fluid). Cut the lid-grip off, then cut the upper, cone-shaped portion off and invert it so that it behaves as a funnel into the container. Next, insert two paper coffee filters and then pour in the dissolved sap / pitch solution. If the solution is too viscous, add more acetone. It should flow at least 2-3 drops / second when full. When 1/4 full, using gloves, wring the filter to squeeze out the remaining liquids.

Step 4: Container

In this step, ready the container in which to boil & form the rosin.

For this step, you will need crisco / vegetable shortening, aluminum foil, and a suitable container for heating. Apply a coat of crisco to the inside of the heating container, then cover the inside with a continous sheet of aluminum foil. You can use the outside of the container to preform the foil. Add two more layers of foil and crisco. This will insure that the sap / pitch will be able to easily pop out of the container once the mixture has become rosin.

Step 5: Make Rosin

This step transforms the sap / pitch to rosin.

In this step, you will need vegetable oil, the heating container, and a deep fryer. Place the heating container into the center of the deep fryer and fill it with the filtered sap / pitch solution. Add enough vegetable oil to the deep fryer (but not the solution) so that it comes up to at least half the level of the solution. This will insure adequate heat transfer from the oil to the solution.

In the first stage, set the deepfryer to 'low' about 200 - 250 ºF. At this temperature, the solution will boil off acetone. Do this in a well ventilated location away from open flames to reduce the risk of fire. When the solution stops bubbling like water and becomes more syrup like, proceed to the next stage.

In the second stage, set the deepfryer to 'medium' about 275 - 300 ºF. At this temperature, the acetone disapears completely, and many of the toulenes and miscellaneous compounds that make pine sap permanently stick evaporate as well. When bubbling has receeded / lessened considerably, proceed to the next stage.

In the third stage, set the deepfryer to 'high' about 350 - 400 ºF. At this temperature, you eliminiate most of the non-rosin organic compounds. Bubbling should be miniscule towards the end. To determine whether this stage is complete, use a toothpick to probe the mixture. Check to see that the sample on the toothpick is not sticky, and that it crumbles with pliers into a yellow-brown dust. When finished, turn off the deep fryer and let it cool to the touch.

Step 6: Extraction

In this step, extract and store the cooled rosin.

When the deep fryer has cooled to the touch, extract the rosin. Put it in the freezer for 30 minutes to remove any residual flexibility that it may have. Afterward, remove the aluminum foil and store the rosin.

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11 Discussions

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vreinkymov

6 years ago on Step 3

I forgot to mention, this step is very messy. If it does get on your hands, vegetable oil + alcohol + soap acts as a good sap remover.

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RobinS209vreinkymov

Reply 1 year ago

Hello, very interesting information, I will try it. Question: would I have to remove the wood chips, dirt and pollon to make a perfect rosin? Also I am going to make rosin for the use on bow instruments, so would it be good for any kind of bow instrument, like cello, violin or viola? Thanks

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vreinkymovRobinS209

Reply 1 year ago

You probably would need to. I image things like dirt and sand would be a bit too abrasive and would possibly wear away at the strings of your instrument.

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Tod.Rickey

3 years ago on Step 6

I dissolved the resin from an Austrian White Pine (tar) into pure soybean oil, using slight heating. (This is reminiscent of the fact mentioned in the article that vegetable oil may be used in the cleanup process.) Specifically, 6.0 grams tar was mixed with 100 mL soy oil into a small iron cauldron, heated by a tea lite to approx. 100 degrees C. With a little stirring, it dissolved within just a few minutes. Afterwards, the solution was poured into five (5) amber-glass, 20 mL containers with rubber stoppers. After several weeks, there remains no precipitate. I plan further trials, to ascertain the maximum tar solute load for soy oil. If interested, please email to todd.rickey@gmx.com

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sugarworm

6 years ago on Introduction

I used to do the same thing with alcohol as the solvent! Except I always set the rosin/ solvent solution on fire to get the rosin, and I only used it as a binder for incense. Never knew that there were so many uses :D

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westfw

6 years ago on Introduction

be careful with that acetone near heating elements like a deep fryer (you do mention this, but I think it need emphasized more!) And DON'T substitute some kind of gas stove for the electric fryer! Acetone fumes are infamous for pooling and flowing along the ground to find open flames (ie when stored in a garage near a gas water heater.) At which point you get a fume "explosion" and the source of vapors catches fire...

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rimar2000

6 years ago on Introduction

This is very interesting, thanks for sharing.

A question: can I use regular pine sawdust to obtain rosin?

1 reply