Riveting in deep channel

andrewbirkett

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I had to drill out some rivets in my mast channel where the sliding gooseneck goes up and down (they were obstructing the gooseneck). I now need to re-rivet the channel but it's proving difficult. The channel itself is narrow and 18mm deep. My 'lazy tongs' riveter needs about 20mm of the rivet mandrel inserted inside before it'll grip, but the nose of the tool only manages to go about 4mm into the narrow channel. Consequently, I think I need to find a rivet with a 20+18-4=34mm mandrel but it seems like rivets all generally have ~25mm mandrels.

Is there a supplier of extra-long mandrel rivets out there? Or a rivet tool with a super narrow nose that could get into this narrow channel (15mm wide)?
 

Dan Tribe

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I had to do this recently and had the same problem. There must be a gadget that does this but I couldn't find one. Sparmakers do it all the time.
I got round it by grinding the riveter nose away so it fitted into the track, then making a small aluminium spacer with a hole to take the mandrel which slotted into the track. It was just about do-able but right on the edge. You can sometimes gain a millimetre by adjusting the jaws in the riveter.
 

rszemeti

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The lazy-tong riveters have a very wide nose-piece, try a standard hand riveter, it may fit or can be ground to fit.

Professionally, riveters with long, narrow nose-pieces are used ... often based on the ubiquitous Huck 225 body.
 

andrewbirkett

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Thanks all for the helpful replies. I've emailed rivetwise and will also try to get measurements for hand riveters. I didn't know about pin-drive rivets before, they look like a strong contender. I'll report back once I've found a solution!
 

andrewbirkett

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For posterity, what worked in the end was buying some 50mm long 4.8mm rivets (from Part On Tools), tapping the long mandrel out of them whilst holding them in a vice and transferring it to the correct length rivet, then using a stack of nuts as a spacer so the rivet gun could press against them.

I had bought them a few weeks ago, but hadn't used them initially because I saw their 'break point' was not in the right place and would've left the mandrel stub sticking out by about 10mm. But after testing some I found that a) you can tap the mandrel out the back, and b) there was enough space within the mast to do this even with the extra-long mandrel stub.

I did try grinding down the nose of the rivet gun in an attempt to use regular rivets, to a depth of maybe 10mm - the point at which the innards were starting to be exposed. This allowed the gun to get in deep enough to just grab the very end of the (regular length) mandrel and start to pull. However, the end of the mandrel just deformed and sheared off before doing any useful pulling. It might well be possible to grind away more of the head to get a bit closer, but I switched to the long mandrels before trying.
 
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Dan Tribe

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Final note of the subject of riveting: I wrote an article on my website that's got photos of the various approaches I tried - http://www.sundaysail.com/2019/05/riveting-in-a-deep-channel/. Hopefully the article (and this thread) is helpful to someone else in the future! Thanks again for all the suggestions + tips.

That's a great idea of transplanting the mandrels. I never thought of that and wouldn't have thought it would work. I will try it next time.
Well done.
 
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