Butyl Tape on Acrylic Hatches

Nov 18, 2010
2,441
Catalina 310 Hingham, MA
I have a question about using bed-it butyl tape on acrylic hatches. The large trapezoidal hatch at the bow of our Catalina 310 is leaking at the resistance hinges. I removed the hinges today and found that the foam gaskets around these penetrations were junk. They sell a kit with new foam gaskets but I was thinking I could do better with butyl tape.

My concerns are as follows:
  • Will the butyl tape bond to the acrylic fine? Looks like it would be fine based on other butyl tape literature.
  • The thermal expansion of the acrylic. I have read that acrylic tends to expand more than other materials. I am thinking this would push out the butyl tape through heating and cooling cycles and eventually there would be no butyl tape left.
  • The two pieces that would be screwed together to compress the butyl tape are plastic. There is a coarse thread screw that is used to compress these two pieces. Will this be sufficient to compress the butyl tape? Or will the plastic just break?

Thanks for reading and any advise you might offer.

Fair winds,

Jesse
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
That will work just tighten slowly... Bed-It is fully compatible with acrylic..
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
I am pretty sure that Catalina still uses Dow 795 silcone sealant to adhere their acrylic to frp. http://www.cruisersforum.com/forums...ow-795-still-the-sealant-of-choice-93627.html

I still use Maine-Sail's butyl for just about everything else though.
For acrylic to aluminum frame or acrylic to fiberglass, absolutely. This is to stop a leak where the hinge bolts through the glass..

The large trapezoidal hatch at the bow of our Catalina 310 is leaking at the resistance hinges. I removed the hinges today and found that the foam gaskets around these penetrations were junk. They sell a kit with new foam gaskets but I was thinking I could do better with butyl tape.