Replacing a sailboat hatch

[openseas]

Hi All,
I am changing a 20"x20" sailboat hatch with a used one.The issue is that the hatch that I bought used, still has some hard silicone from the first boat that it was on.
Is there anything that I can use, to be able to remove this material
Thanks,
Andy

[Dave852]

A product called DSR-5 is the best I have found.

[JPA Cate]

I don't know if it really is silicone you have there, but I use a large flat bit screwdriver, and sometimes putty knives to remove old sealant. Eventually, you get it thin enough for chemical mastery, but mostly it's just grunt!

Ann

[a64pilot]

A sharpened piece of plexiglass won't scratch the aluminum, but will remove sealants

[KDH]

Quite a few adhesives, including silicone, can be shifted with denatured alcohol, sometimes known as methylated spirits. As Ann T. Cate suggested, make sure you scrape as much off as you can first.

[Calypso52]

A heat gun, gently.

[openseas]

Hi guys,
Thank you for all your suggestions, I just saw all your replies, but I like to report something that I tried and it worked like magic.
I have a steam iron ( the one that have a 5-6 feet hose that ends with something that looks like a vacuum, all what I did is: I put the end of the hose on the aluminum hatch for 5-8 seconds at the time, then I brush all the adhesive with a kitchen brush, like the one that you you for metal pans, and everything disappear instantly.
Andy