View Full Version : Remove Silicon from Gelcoat

02-03-2013, 08:09 PM
I am replacing my exhaust flanges on my 98 prostar 205. I got the old ones off. Now I need to remove the old silicon type stuff from the gelcoat. What is the best method? Also, the old ones had this silicon stuff on the inside diameter of the holes in the transom. How do I reapply new sealant in this area when I get ready to install the new flanges?

02-03-2013, 08:53 PM

02-03-2013, 08:54 PM
I used a plastic putty knife and Goo-Gone to clean up the old RTV stuff behind the flanges.

Was a time consuming job, but got down the gel coat and clean with time.

Used black RTV to seal new flanges, the RTV will ooze everywhere including the bolt holes when the flanges are reinstalled to transom with screws.

Some use 3M 4200 or 5200 to seal flanges. Silicon style product was good enough for MC, so good enough for me. Mine sealed fine.


PS - I was able to reattach exhaust hoses and 2x hose clamps (each) with fuel tank installed. Just some light, laying down and a 1/4 socket wrench.

02-18-2013, 11:29 AM
Single edge razor blade and or a 3M eraser wheel.