[Public-List] Butyl Tape

[John Maliszewski]

It has been about nine years since I bedded all my GulfStar 37 porthole
frames with butyl tape. The butyl tape I used still remains soft and
pliable, although it has formed a slight outer skin at perhaps .005 inches
level. My original logic for choosing butyl was that I
anticipated replacing my inside teak paneling that was installed all the
way to the ports and wanted to make sure that I could remove the port's
frames easily when I got around to replacing the teak. My ports are
mounted from the inside. Well nine years later I have absolutely dry ports
and no new paneling. I can still see the butyl squeeze outs, from under the
port frames and can confirm that they are pliable.
During the original installation I was generous with the butyl and placed a
full ribbon against the port frame before inserting the port into its
opening. The key to good installation  is to make sure that you see butyl
squeezing out as you tighten the mounting screws and then to go back in a
couple of days later and continue with another 1/4 turn on your bolts, I
repeated this process at least two times for three tightening sequences.
The butyl tape I used is marine grade and has low flow characteristics
under pressure. You can buy this tape from  https://marinehowto.com/  look
under the featured products, and that is what I recommend; tapes purchased
from other sources such as RV parts suppliers are not the same.

In general, the https://marinehowto.com/   is a worthwhile website for many
DIY projects.


John Maliszewski

jrmalis at verizon.net

410.353.8115 (M)