What compound is "pledge" ?
Silicone oil does not soften rubber. Neither does parrafin.
I guess we’ll see! Here’s why I used it.
1. Pledge was the most common recommendation I found in forums and blogs for softening graflex shutter curtains, and from some experienced folks, so there’s some anecdotal evidence that it’s got a reproducible effect as a softener for graflex curtain “rubber”
2. It did restore some flexibility when I first removed the shutter, so I’ve got some limited first person evidence.
3. And just the fact that whatever the original “rubber” coating was is soluble in hydrocarbons like methanol and acetone and “alkane blend” in the lacquer thinner (It comes off like a paste if you scrape it after soaking in thinner) implies it would be soluble in (therefore absorb) the c7-9 alkanes (aka paraffins) in pledge, so it makes sense in theory as well.
C6 alkanes have a similar boiling point to water so I worry the pledge might evaporate over time. If that happens I’ll probably try other furniture polish like orange glo that use longer-chain paraffins that will maybe last longer since they have a higher boiling point and would stay liquid longer. Or not! The fun is in the experiment