I'm re-winding an antique coil that was used in the low tension ignition system for a very early internal combustion engine. The original was embedded in a potting compound consisting of tar. It has aged and at room temperature more closely resembles brittle hard coal. There's nothing soft and "tar-ry" about it.
I will be using a plastic bobbin for the new coil. Because the old tar has a fairly high temperature melting point, I'm afraid to re-use it for fear of melting the bobbin.
That brings me to my questions:
1) Where can I obtain for a reasonable price a small quantity of potting compound, say, a pound or two? It can be thermosetting or an epoxy type. I would much prefer something that can be melted and poured our of the cannister, should re-winding ever become necessary, again.
2) Where can I obtain Glyptal, either in quart quantities or in spray cans? I'd like to give each layer of the coil a coat of Glyptal as I'm winding.
Thank you.
Orrin Iseminger Colton, Washington, USA
formatting link
So many projects. So little time.