Bouba
Well-Known Member
What are people’s favourite tips for screwing into fibreglass covered by gelcote ?
Screwing into gelcote covered fibreglass
- Thread starter Bouba
- Start date
stelican
Well-Known Member
Countersink gelcoat to prevent it from cracking. Put sealant in hole and on screw thread.
Do not drill through bottom of boat or concealed wiring.
markc
Well-Known Member
Ensure your pilot hole is not too small, there is not much give if you ram a screw that's too big into it.
Poignard
Well-Known Member
My favourite tip is to suggest you download the WEST System 'Fiberglass Boat Repair & Maintenance' manual and and read the relevant bit of section 7:
https://www.westsystem.com/app/uploads/2022/10/Fiberglass-Manual-2015.pdf
Wandering Star
Well-Known Member
Thanks for this - very useful, just downloaded & saved.
Poignard
Well-Known Member
Refueler
Well-Known Member
Having had a problem to refit stanchion bases on one boat - the interior side is blind and impossible to get to ... I used expander threaded inserts. Similar to Rawlplugs but in metal.
Matched to bolts ... you drill out the GRP so that the expander can be 'screwed' in using a very short bolt that does not expand the item. Once fully home - you then take the longer final bolt to fix your stanchion or whatever item needed.
The strength of the hold they have is phenomenal ....
Over 20yrs later - those stanchions are still rock solid.... with no visible damage to GRP around them.
Matched to bolts ... you drill out the GRP so that the expander can be 'screwed' in using a very short bolt that does not expand the item. Once fully home - you then take the longer final bolt to fix your stanchion or whatever item needed.
The strength of the hold they have is phenomenal ....
Over 20yrs later - those stanchions are still rock solid.... with no visible damage to GRP around them.
