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Replaced first Roller Table Impulse Jewel


jdrichard

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Oh my god ! Last night I installed an impulse jewel into a roller table. The hole was round, but I was told by Dave that these would take D shaped jewels and they could not drill D shaped holes :). So I used a lighter as my heat source and a Combination Tool to heat the table and the shellac. The video below shows what I did. The biggest challenge was in applying the shellac to the top of the hole with the jewel loosely in place. I think I need a different technique. All the litterateur on this makes it seem easy, however, it is the hardest job I have done so far.

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Congratulations for losing your roller jewel replacing virginity :)

Did not do such a job myself yet, but already have shellac and need to fix someday that ellipsenstein in the Nachtigall movement.

An old watchmaker told me however that shellac can be dissolved in polar solvents like isopropylalcohol and a small drop on the jewel of this solution will leave shellac there after drying as hard as with melting method. 

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1 hour ago, szbalogh said:

Congratulations for losing your roller jewel replacing virginity :)

Did not do such a job myself yet, but already have shellac and need to fix someday that ellipsenstein in the Nachtigall movement.

An old watchmaker told me however that shellac can be dissolved in polar solvents like isopropylalcohol and a small drop on the jewel of this solution will leave shellac there after drying as hard as with melting method. 

Have you tried the alcohol method? sounds interesting

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20 minutes ago, TimFitz said:

Have you tried the alcohol method? sounds interesting

Yes i have tried it to mount flat glass and ratchet wheel on a wax chuck. I had to wait one day to let it dry. The solution was better than heating for glass since it broke of internal friction coused by the heat difference when i tried mounting on a hot chuck. 

Couldnt try isopropylalcohol since i dont have it, but some other paint solvent with multiple components in it. 

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I recently conducted an experiment to compare the solubility of shellac in isopropyl alcohol and acetone. I put equal size flakes of shellac in small glass beakers containing equal volumes (about 20 ml) of solvent. The shellac did not at all dissolve in the isopropyl alcohol. It did slowly dissolve, albeit incompletely, in the acetone. The acetone was discolored by the shellac. I let the acetone evaporate over a few days. By then, the original flake, somewhat blander in color, was still present. However, the bottom of the glass beaker was coated with hard shellac. I needed to use acetone and vigorous scrubbing to clean the beaker.

If I were a REAL scientist, I would carefully measure the weight of the shellac flake before and after its immersion in the acetone. Then, knowing the volume of the acetone containing the decrement of shellac mass, I could calculate the concentration of shellac in a saturated solution of acetone. From that I could calculate the volume of the saturated solution I would need to fill a hole of known volume with shellac, probably by multiple applications. Fortunately, a microdrop of acetone has a very high surface area to volume ratio, and will evaporate quite quickly. I suspect that heated acetone would contain more dissolved shellac, but heating acetone sounds like a hazardous activity.

I hope that one of you guys will try this approach and report back to us.

—Eric
Ohio. USA


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I recently conducted an experiment to compare the solubility of shellac in isopropyl alcohol and acetone. I put equal size flakes of shellac in small glass beakers containing equal volumes (about 20 ml) of solvent. The shellac did not at all dissolve in the isopropyl alcohol. It did slowly dissolve, albeit incompletely, in the acetone. The acetone was discolored by the shellac. I let the acetone evaporate over a few days. By then, the original flake, somewhat blander in color, was still present. However, the bottom of the glass beaker was coated with hard shellac. I needed to use acetone and vigorous scrubbing to clean the beaker.

If I were a REAL scientist, I would carefully measure the weight of the shellac flake before and after its immersion in the acetone. Then, knowing the volume of the acetone containing the decrement of shellac mass, I could calculate the concentration of shellac in a saturated solution of acetone. From that I could calculate the volume of the saturated solution I would need to fill a hole of known volume with shellac, probably by multiple applications. Fortunately, a microdrop of acetone has a very high surface area to volume ratio, and will evaporate quite quickly. I suspect that heated acetone would contain more dissolved shellac, but heating acetone sounds like a hazardous activity.

I hope that one of you guys will try this approach and report back to us.

—Eric
Ohio. USA


Sent from my iPad using Tapatalk


I may try this technique if I get the time.


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