To the forum members who have used Wintergreen oil to soften rubber what mixture/ ratio do you use OR do you use straight Wintergreen???

hot water is how i do it
when i was a kid i worked in a small engine shop and we used hot water in a large pan over a totally non-OSHA burner to simmer very hard rubber tires that we then were able to easily stretch over wheels of commercial mowers!

I used about a 3 parts water to one part wintergreen successfully. I soaked it for about 2-3 days. The obsolete rubber intake manifold smelled like wintergreen for a very long time. It was pliable enough to assemble but not as good as new. You are better off if you can find new or reproduction rubber parts, which is not always possible.

yamahahaha,
Just tried procedure this month for my 55 yr old carb boots which were hardened with no flexibility to reinstall. I used 2 oz wintergreen oil to 16 oz 70% isopropyl rubbing alcohol. No magic to my approach as was my first rodeo with this process & only had a 4 oz bottle of wintergreen oil, so split it between each boot which took 16 oz. to cover each one. I soaked 5 days (which was prob too long) but these are unobtainable carb boots and solution did make them soft & flexible again; so easy to install.
The only negative was boot diameter swelled a bit so waiting for some dry time (shrinkage) so clamps can be tightened.
Good luck!!
swm

Have had good luck with 303 Protectant for making old rubber supple again. More UV inhibitor than Armor-all also.

If you had to do it again how many days would you suggest soaking ?????

Hindsight probably 4 days, but rubber was very hardened w/absolutely no flexibility. I was overly cautious to ensure didn't attempt to install until fully soft & pliable.
With yours if rubber has any flexibility then fewer days. Easy solution is simply check progress daily until you've achieved desired results. Wintergreen oil really did work just as the prior threads on YE.com stated!!
Best of luck