Ferminj,
You can use heat on the casts, but take your time. Any tapping/hammering you do should not be directly to the casts. Use hardwood between the hammer and the casts. The corrosion you are dealing with is tenacious, but with lots of tapping and patience you`ll eventually get it free. I was able to remove the casts from my boom without heat by thoroughly and firmly tapping all the way around the extrusion where it contacts the cast (many times around). After that, I tapped the cast out itself with a soft, but heavy, rubber mallet.
Also, if there is even a very tiny space left between the flange/lip of the cast and extrusion, you may be able to break the adhesion by trying to hammer the cast further on/into the extrusion. This is a good angle to get the job going but may not be an option.
Also keep in mind that I do not have any experience with Prindles, just Hobies and other boats.
Dave
Thanks Dave,
I was hoping for a 'miracle' product/method. I guess it's more of a patience and tenacity issue.
Loved what you did to your boat.
Fermin