Hardened Gaskets on a Columbia No. 6 reproducer

[Phonofreak]

I am rebuilding a Columbia No. 6 reproducer. It is the early one with the spring retainer ring instead of the usual type with the 4 hole bezel. I was able to take the ring off with no problem. However, the black gaskets are hard as a rock and it seems to be glued to the reproducer body and mica diaphragm. There is no way I can save the mica diaphragm, so it will have to be replaced. I was able to get a little bit of the gasket, but it was a chore. I used a small jewelers screwdriver as a miniature chisel. Is there an easier way to remove the gaskets? Is there an item that would soften the old gasket so it will come out easier? I'm looking for suggestions.
Harvey Kravitz

[mf77]

I'd try heat. A hair dryer may be enough, but you might have to get heavy duty with it & use a flame and burn the rubber away, or at least soften it enough to remove easily. If the body of the reproducer is pot metal, you'll have to be careful not to melt the metal as it has a very low melting point.
When I've had to resort to using a flame on pot metal reproducers, I apply the flame in very short bursts, and I allow the metal to cool before moving onto the next inch or so.
Mica won't burn so no need to worry about it.
Of course this needs to be done outdoors, and avoid inhaling the smoke

[alang]

I've had some success with soaking in a few drops of brake fluid to soften hard baked on gaskets.
Andreas

[Phonofreak]

Thanks for the replies. I'll try both methods and post the results.
Harvey Kravitz

[Henry]

I've used the brake fluid method to strip paint from styrene plastic in model work. Works great there; shrivels and lifts the paint right off after a couple of hours of soaking, without harming the plastic. Don't know about hardened gaskets, but it's worth a try.