Reducing hole size for thru hull

[Cadence]

Originally Posted by s/v Jedi

Videos have been posted, West System has a very good Boat Repair guide that shows this exact job in detail as well. A simple Google finds it. If one wants to use polyester (who still uses that, they all switched to vinylester years ago) then do as the polypeople say and get the mats out :-)

I'm guessing the OP's Hunter is poly as are probably what a bunch of contributors have?

[finefurn]

Thanks for all the great advice guys. I'm sort of both a belt and suspenders type. In this case there will only be a 3/8" difference between the original hole size and the new smaller one. ( If the smaller hole is centered in the original cutout.) The width of the deadrise block is exactly the same width as the original hole. SVtiata referenced a link to expoyworks by West Systems that I going to use. The one example shown looks like exactly like my case. Plus I'm going to back up the inside by increasing the size of the deadrise blocks footprint by 1 1/2" all around by epoxying in a 3/16" FRP. I think this should be sufficient, so unless I run into one of the 10's of thousands of rocks along the Maine coast I should be fine.

[ramblinrod]

Originally Posted by finefurn

Thanks for all the great advice guys. I'm sort of both a belt and suspenders type. In this case there will only be a 3/8" difference between the original hole size and the new smaller one. ( If the smaller hole is centered in the original cutout.) The width of the deadrise block is exactly the same width as the original hole. SVtiata referenced a link to expoyworks by West Systems that I going to use. The one example shown looks like exactly like my case. Plus I'm going to back up the inside by increasing the size of the deadrise blocks footprint by 1 1/2" all around by epoxying in a 3/16" FRP. I think this should be sufficient, so unless I run into one of the 10's of thousands of rocks along the Maine coast I should be fine.

Good luck.

This is something that should be communicated to any future purchaser, as their inspection and survey will not detect the installation deficiency, because it will be covered by the transducer flange on the outside and backing plate or transducer mounting nut on the inside.

[pjhagbard]

Originally Posted by SVTatia

This is just bad advice.

Finefurn, check this link, look at Zone 3 - the high risk repair.

WEST SYSTEM | Projects | Fiberglass Boat Repair & Restoration - Repairing machined holes in fiberglass

Why are all repair or grp-boats made with - grp - polyester? This thread is regarding a small "repair" - not glue things together. Inttroducing epoxy will create other problems.. to much to write in a short reply.