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4+2 Tonneau turnbutton replacement
Posted: Sat Sep 26, 2020 10:24 am
by Clive
Hi all. Has anyone knowledge or experience in replacing riveted turnbuttons?
The ones I need to replace are in front of the cockpit screen. Under this in the cabin is a substantial cross member, I assume timber. I can’t see how to drill them out as the body of the rivet will stay in the GRP.
Help welcome!
Cheers Clive
Re: 4+2 Tonneau turnbutton replacement
Posted: Sun Sep 27, 2020 7:18 pm
by Clive
I have the replacements in stainless, what I need to know is how to remove old rivets when they are embedded and don’t appear on the other side without damaging the GRP.
Cheers Clive
Re: 4+2 Tonneau turnbutton replacement
Posted: Mon Sep 28, 2020 7:45 am
by Mdr24uk
Wouldn’t there have been a void behind the GRP skin to allow the rivet to form behind when pulled?
If you drill out the core then the old rivet tail will then fall down behind?
Re: 4+2 Tonneau turnbutton replacement
Posted: Mon Sep 28, 2020 11:30 am
by Freebird19
Could it be possible "blind" rivets were used? These don't need to protrude through to the other side. I did have to drill one rivet, a hook type for elastic loop, as it would not knock through once the head was drilled off. I used a drill bit the same size as the rivet body and only drilled as deep as the new one.
Re: 4+2 Tonneau turnbutton replacement
Posted: Mon Sep 28, 2020 2:08 pm
by Clive
Mark - knowing my luck no, plus they would rattle away when motoring!!
Freebird, you may well have answered it. Pretty careful drilling tho. Did you first drill out the old rivet then enlarge to fit the replacement or do it in one?
For some reason I have quite a lot of anxiety about the drill slipping and gouging the boat. I looks straightforward enough on YouTube!
Thanks for the pointer, Screwfix to the rescue.
Re: 4+2 Tonneau turnbutton replacement
Posted: Mon Sep 28, 2020 2:44 pm
by Freebird19
These might be more suitable. They imply that they are sealed, not leaving the centre hole left by the pop part of the rivet?
Slowly, slowly is the way. Start with a smaller drill, 1.5 ish and build up to the original rivet size. I think mine where 4mm? Being aluminium they might work better on gelcoat and GRP. I've not used them, anyone else have experience with them?
Re: 4+2 Tonneau turnbutton replacement
Posted: Tue Sep 29, 2020 12:59 pm
by Clive
These look good. I think I'll try to track down stainless as any steel is going to rust, but I like the sealed end.
Thanks again, Clive
Re: 4+2 Tonneau turnbutton replacement
Posted: Tue Sep 29, 2020 7:29 pm
by Clive
Or, do you think I could use screws into the void after drilling out the old river? Not convinced so thought I’d ask!