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Best rivnuts?
Ciaran - 13/4/18 at 04:54 AM

About to strip my kit car for a bit of welding and would like the replace every rivet with a rivnut.
Any reccomended type? Best tool?
I have used them before but was very hard to make off the rivnut itself with the tool provided.

Is there any sort of rivnut that is better designed to stop it spinning on removal?


907 - 13/4/18 at 06:43 AM

MEMfast without a doubt.


Some of their rivets have serrations to stop them spinning, and taking the burr of the hole with a badly sharpened drill, we've all got some of them, will also help.
Some de-burring "star" bits leave a vibe edge as well.

Used with copperslip on the tool will leave some in the rivnut thread which will aid removal of the screw in the future.



I think I have 4 pop rivets on my car. I must have had a brainstorm that day.

If I could find them I'd replace them..... but I can't remember where they are.


Paul G


adithorp - 13/4/18 at 08:06 AM

Use knurled rivnuts and they'll very rarely spin (the plain shanked ones are a east of space).
I got mine with s tool similar to a river gun and don't have any issues (sorry don't know make). The memfast tool is well recommended but a bit slower to use.
Remember that rivnuts require bigger holes in you chassis than rivets so that can be a consideration.


nick205 - 13/4/18 at 08:30 AM

Can we ask why you want to replace rivets with rivnuts?

I can see it would make the panels removable, but rivnuts require larger holes than rivets. Surely you'd be weakening the chassis rails by making the holes larger.

Do you need the panels to be removable?


Charlie C - 13/4/18 at 08:49 AM

I've used the tabs for my rivnuts avoiding drilling the chassis eBay Item


nick205 - 13/4/18 at 10:06 AM

quote:
Originally posted by Charlie C
I've used the tabs for my rivnuts avoiding drilling the chassis eBay Item



Seems an OK, but over complicated soluntion. Lots more welding and costly threaded fixings. Certainly for my build (and for many others) rivets seem to do the job. Rivets aren't that expensive either.


Ciaran - 13/4/18 at 10:46 AM

quote:
Originally posted by nick205
Can we ask why you want to replace rivets with rivnuts?

I can see it would make the panels removable, but rivnuts require larger holes than rivets. Surely you'd be weakening the chassis rails by making the holes larger.

Do you need the panels to be removable?


Mostly just so that if I do need to take the floor off the car again itís simple
instead of having to drill out dozens of rivets every time


nick205 - 13/4/18 at 10:55 AM

quote:
Originally posted by Ciaran
quote:
Originally posted by nick205
Can we ask why you want to replace rivets with rivnuts?

I can see it would make the panels removable, but rivnuts require larger holes than rivets. Surely you'd be weakening the chassis rails by making the holes larger.

Do you need the panels to be removable?


Mostly just so that if I do need to take the floor off the car again itís simple
instead of having to drill out dozens of rivets every time




Never had to remove my floor panel, but I guess you may have to.

I fitted my tunnel top with rivnuts for easier removal, but even that only came off once or maybe twice in 3-4 years.


JimSpencer - 13/4/18 at 02:46 PM

quote:
Originally posted by Ciaran
About to strip my kit car for a bit of welding and would like the replace every rivet with a rivnut.
Any reccomended type? Best tool?
I have used them before but was very hard to make off the rivnut itself with the tool provided.

Is there any sort of rivnut that is better designed to stop it spinning on removal?



Hi

Not sure that's a good idea the alloy panels are normally bonded and riveted to the spaceframe to increase its rigidity.

Using just rivnuts will reduce that rigidity and make it porous (the adhesive has the secondary effect of sealing the gap between the panels and the frame so making it less likely to get water in the chassis tubes.)


ReMan - 13/4/18 at 05:46 PM

Agreed of all the places/things to rivnut the floor is probably not it

[Edited on 14/4/18 by ReMan]


J666AYP - 13/4/18 at 05:59 PM

The cheap ones from toolstation have always worked well for me.

Jay


loggyboy - 13/4/18 at 08:12 PM

Agree with the above comments as to is a removable floor much of a benefit. Chassis strength is more important than removal of a part that should only need to be removed on a major refurbishment. Holes for an m3 rivet are 5mm, you wont bet much torque on a m3 bolt, and you wouldnt want holes much bigger than 5mm in the chassis rails.


Ciaran - 13/4/18 at 08:36 PM

Okay point taken will stick with rivets.
Floor coming off to remove the prop and rear diff and the the whole body as all the welds around the rear diff mounting point are cracked


nick205 - 16/4/18 at 02:53 PM

If there are cracked welds on the chassis is it not worth considering rebuilding with a new chassis?


907 - 16/4/18 at 03:25 PM

quote:
Originally posted by nick205
If there are cracked welds on the chassis is it not worth considering rebuilding with a new chassis?



If I may add to your post Nick, check your life insurance is up to date.


Ciaran - 17/4/18 at 04:17 AM

quote:
Originally posted by nick205
If there are cracked welds on the chassis is it not worth considering rebuilding with a new chassis?


MNR changed the chassis to an inboard suspension set up and original chassis no longer available.
Probably my fault to be fair. 13k hitting a damp spot followed by dry road so 7 rpm of momentum has to go somewhere