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Removing 'failed' Rivnuts
TimC - 22/9/05 at 07:06 AM

Hi

One of the rivnuts that holds on my mose cone is turning meaning that I can't unbolt the nose.

Does anyone have any better idea than cutting the head of the bolt (cap head socket), removing the bodywork and then butchering the rivnut with pliers and pulling out before replacing with a new one?

Ta in advance.


ditchlewis - 22/9/05 at 07:54 AM

In the past I have used some of that liquid steel glue.

I place it around the rivnut and smooth off, when dry I put a bolt in and tighten it up, in 9 out of 10 attempts I have been able to make the rivnut take and crimp up.

As a matter of course I now mix up some of this glue and put it around the rivnut before I insert and crimp. I was given this advice by a ferrari mechanic who always has problems with this thin in their new cars.

Hope this helps

Ditch


David Jenkins - 22/9/05 at 08:11 AM

On a couple of occasions I have made a tiny tack weld or two between the rivnut and the chassis. Smoothed it out with the angle-grinder - no more problems.

David


TimC - 22/9/05 at 11:33 AM

Thanks - will give the new one the good news with some glue.

TC


Nick Skidmore - 22/9/05 at 05:43 PM

Having used rivnuts on single seaters for years and thinking they were good I have changed my mind to thinking they're best used for nothing better than fridge-freezers for the very reason that they can give out at the very moment you need them most.

what changed my mind was the use of 'nutplates' floating or fixed. They are aeroplanes' answer to captive nuts and can't be allowed to fail.

They are available in imperial and metric and you can even get them with a replaceable nut if you do get in the sh1t.

I've just remembered you can get a proper aviation approved rivnut with a little location tag uder the head to stop them turning , but I still wouldn't use them.

To introduce just a littl commercialism I have large stocks of imperial nut plates all at 5 for a £1 fixed and 4 for a £1 floating.


tks - 22/9/05 at 06:44 PM

yeah basicly it all will depend on how nice was the hole drilled?

but of the fact that the material lose an bit his shape you get movement.

can you post an picture of that nut?

Tks


MikeR - 22/9/05 at 07:13 PM

so nick can you post some pictures of these nuts and how you fit them?


Nick Skidmore - 22/9/05 at 09:21 PM

Have a sqwint at my stock list.

http://www.aems.pwp.blueyonder.co.uk/Stock.html

Pan down it till you find them uder nutplates.

They are attched to the fixing brackets with 2 off 3/32 CSK pop rivets


caber - 25/9/05 at 09:17 PM

Had this problem today on my Range Rover. The solution was to weld a nut to a penny washer, drill the washer for 2 no. 3mm pop rivets and rivet over the hole where the nutsert fell out. If height is a problem drill out the nutsert hole unti it clears the nut and use countersunk pop rivets or self tappers to fix the washer down.

To get the bolt out of a rotating nutsert try putting vicegrips on the head and pull hard while turning, the back edge of the nutsert can bite a bit into the hole so you may get the bolt out or at least far enough to tackle it with a hacksaw I would not be happy anglegrinding against GRP something is bound to get burnt or ge full of nasty black specs!.
Caber

[Edited on 9/25/2005 by caber]


tks - 26/9/05 at 12:57 PM

in fact if you

fix the rivet good..

you are always pulling it faster in the hold shape...

also i use rivets with lillte teeth unther the head.??

Tks


G.Man - 10/10/05 at 09:48 PM

Harder you rivet them the more the nut cuts into the steel.. if the parts move then the hole wears and the rivnut loosens...

JB Weld works nice as an epoxy to help seal a rivnut in place, and its resistant to engine bay heat upto 300 odd degrees c


tks - 10/10/05 at 10:36 PM

i would suggest use more rivnuts, that way the load per rivnut is lower and they wont move!

also use the right drill and i mean to the tenths of the mm of the rivnut...

i always use 1 tenth or 2 smaller then i get the big hammer and it fits..then i wrench it and there ir goes

Tks


JB - 25/10/05 at 08:42 PM

I use Advel splined "Rivnuts" and epoxy them in place, so far non have spun.

John