Author Topic: Riveter question  (Read 576 times)

Riveter question
« on: December 31, 2020, 02:44:07 pm »
I need to replace some rivets on my canoe that hold the end caps on. I've got the correct rivets from the supplier and borrowed a pop rivet gun but I can't get it to pull the rivet through as it's meant to.

I'm wondering if the rivet gun isn't man enough and would a lazy tongue riveter give more purchase?

Re: Riveter question
« Reply #1 on: December 31, 2020, 03:05:38 pm »
Is it gripping the rivet but you can't squeeze it, or failing to grip the rivet?
The former probably needs a better riveter (I have both a lazy tongue and a normal cheap hand riveter - the lazy tongue is definitely easier).

The latter may be because you are using the wrong hole sized adapter thing on the riveter, or the riveter jaws are worn or need cleaning.

robgul

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Re: Riveter question
« Reply #2 on: December 31, 2020, 03:09:59 pm »
How big are the rivets?  - and have you got the correct nipple on the gun for the pin size of the rivet?

Sometimes you need to take 2 bites at the compression - first will start it and part expand the rivet, reduce the clamp on the gun and slide it further down the pin, clamp and squeeze again - and pin should break out.

I have resorted to a couple of bits of steel tube slipped over the gun's handles while trying to fit large-ish steel rivets - to extend them and get more leverage.
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Re: Riveter question
« Reply #3 on: December 31, 2020, 03:10:18 pm »
I find that with my rivet gun (not a lazy tong) I have to squeeze, release, slide the nozzle down the pin so that it abuts the rivet, rinse and repeat - ordinarily the pin will shear on the second or third squeeze.
ETA - crosspost with Robgul.

robgul

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Re: Riveter question
« Reply #4 on: December 31, 2020, 03:13:00 pm »
Here's help - Rosie the riveter
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Re: Riveter question
« Reply #5 on: December 31, 2020, 03:31:05 pm »
worth noting that with 'lazy tongs' there is a reaction force against the work, which might not suit a canoe.

Note also that pop rivets come in more than one flavour; they can be 'blind' or 'open'. Blind rivets are designed so that the shank fails in tension, leaving the hole in the centre of the rivet plugged with the stub of the shank. I'd imagine that you want blind rivets in a canoe since the other sort will let water in?

 If the shank pulls clean through the rivet this can mean that the hole through which the rivet passes is drilled oversize (for that rivet size) and that the joint may not be properly secure.

Anytime you are riveting through something soft (plastic, fibreglass, many non-metals) you need to be mindful of the load on the rivet at the point at which the shank pulls out. If this is too high you can either get failure in the non-metal immediately, or enough stress that it then cracks later over time.  Sometimes you can overcome this by using larger washers/fittings to spread the load, other times you need to use a rivet with a lower pull rating.

   In extremis you can knock the pins out of the rivets, and make the notch in them deeper than normal, so that they pull out at a lower force, more in accord with material properties. Other times you can set the rivet to a given force so that the joint is secure, and then cut the pin off flush with the rivet top, instead of pulling it out (at higher force).

If you use a rubber washer and a steel washer in the back, you can use displacement as a proxy for load in the joint, and this may offer most control when making such joints in materials which might crack or be deformed at high force.

cheers

Re: Riveter question
« Reply #6 on: December 31, 2020, 04:03:29 pm »
I'm not sure of size but the shaft that goes into the gun needs the biggest thread in fitting that comes with the riveter

It's not so much the force to squeeze the rivet gun but more that the gun seems to reach the end of its travel before I have to really squeeze.
I am riveting though quite a lot of material.  It's the end thwart and then the actual canoe material so probably close to 10mm.

Going by the ones in it the rivet shaft breaks off in the rivet but they're only about 5cm below the level of the canoe so by the time any water was going to be going through it I'd probably already be in trouble

Re: Riveter question
« Reply #7 on: December 31, 2020, 05:06:21 pm »
as others have said maybe you need to take 'two bites' at it?  Maybe you can pull on  the protruding part of the shank using pliers (or have an assistant push on the back) whilst resetting the riveter jaws?

cheers

Re: Riveter question
« Reply #8 on: December 31, 2020, 05:07:56 pm »
If  the backside is  not ' blind' and  you  can get  a  spanner / socket in then stainless  nuts  bolts and washers would be my  choice. If  you need some PM me and M5's  could be  smailed in the  New Year

Re: Riveter question
« Reply #9 on: December 31, 2020, 05:51:49 pm »
That's very kind aiden. I'm starting to think the same thing. I may try and borrow a better riveter as won't even pop it when not in anything even with pushing the rivet in each time but if not I'll bolt or screw it. Thankfully I run a parts department so have access to a wall and several cabinets of bolts so will have something there i can use.

Might need one of my children to hold the socket on the inside but hey it's about time they started being useful