Riveting help please

[Vødkäjéllÿ]

David

Try rec.boats.building and uk.rec.sailing

Vj

[Andy Dingley]

Don't use rivets through plastic components - you'll crack them.

Instead I'd rivet a nut insert into the tube, then screw into that. The nuts (rivnuts and many other brands) are basically ready-threaded hollow rivets. You put them in with the same sort of tool.

Watch for corrosion when rivettting, especially involving aluminium and anywhere near boats. Use compatible rivets - talk to a chandlers.

When buying a pop-rivet gun, get a 3 jaw design, not a 2 jaw. There's an extra size increment you can have, just from the grip, let alone the effort needed. Air riveters are nice if you're doing a lot. Lazy tong riveters are not.

[Lobster]

Well, the kids are intermediate level; the elder one is doing inter-club racing for the first time this season, so I've been detailed to fit racing rigging in favour of the OEM stuff (which to answer someone else's query as to why, gives you more control of the sail profile AIUI). At the same time we decided that switching to centre main was a good idea primarily because (a) the local club is currently converting its own Toppers that way, and our kids use them a lot too; and (b) we've found that when on holiday hiring dinghies, most seem to be centre main too.

Thanks David

[Dave]

Yes, I can see why. I wish I had kept all my paperwork on this subject instead of filing it in the round out tray.

What alternatives are there? Could an everyday gunge do the job. How about silicone glue, the type used in making fish tanks? My original worry was that the mast would corrode from inside out, hence to do the job the right way, so that it does not happen.

I would go for the aluminium rivet to fail first :-) As you say, it will only be holding a piece of plastic onto the mast.

Regards

Dave

[Lobster]

Well, thanks very much for all the advice - time to fess up...!

I've just ordered all the bits of string and pulley kits etc over the phone, and I asked about the riveting issue. The nice lady told me that to install the kit I wouldn't need any rivets at all in fact! (just drill out two old ones). Evidently I had misunderstood what the bloke at the sailing club had told me.

Oh well, I learned something about rivets for the future I suppose :-)

David

[Andy Dingley]

Self tappers won't hold in aluminium. Their thread form is too coarse and aluminium is too soft. The "self tappers" for use in aluminium are something like a "Tap-tite" screw that looks more like a normal fine machine screw, until you put it under a microscope and see the sharp-edged thread it uses. Even then you're better with a riveted join, or a riveted thread insert.

[Tony Williams]

I thought Taptites had a non-round profile, being tri-lobed. You can feel it if you spin the thread between your fingers. The idea is that the profile *forms* a thread in soft materials, rather than doing a full cut.

I used to have a set of taps for threading holes in extruded aluminium heatsinks (or other ductile materials. They were tri-lobed profile, with no flutes, producing very little swarf when forming the thread.

[Lobster]

Buggeration - the nice lady lied; the kit which she's finally sent me

*does* > When buying a pop-rivet gun, get a 3 jaw design, not a 2 jaw. > There's an extra size increment you can have, just from the grip, let > alone the effort needed.

Thanks for that advice Andy: now, as a total rivetting numpty, is it obvious whether a river gun has a 3 or 2 jaw design? Never handled one before. What about the Screwfix one which I cited previously?

Thanks David