Originally Posted by
oddjob2
Oven cleaner isn't strong enough and is usually a modified ammonia. Lye based draine cleaners can harm paint. For stems, a few days of repeated penetrant like PB Blaster or the WD 40 equivalent, qnd a rap with a mallet or hammer downward are usually enough to free a stem.
Thanks oddjob. I've already gone the PB Blaster route, keeping it full over a weekend, but no success. My next step was to try the same with acetone/ATF mix.