23 replies to this topic

[Cooperman]

When I've done this I have cut a hole about 3" x 2" in the outer sill, fitted a new 5/16" UNF nut, welded it on, then made a flush patch repair welded in place, linished back, given the lightest skim of filler as necessary and re-painted locally.

That's the proper and most straightforward way to do it.

[tiger99]

Exactly! I did that once, in about 1970, in my MK 1 van, as it was the least intrusive possibility. I would do it again if necessary. Anything else is either unsafe or a depressingly large amount of work.

[jonjosar]

Rivinuts are for fitting non stress bearing items. I honestly wouldnt use one for a subframe and definitely not to bolt my seats to. God forbid the car is involved in a collision. I'd prefer that my fat derriere is firmly planted into a seat that is absolutely secured by something other than an alloy insert.

[tiger99]

I was thinking of steel rivnuts for the seats. Also they come in several basic types, one of which is adequate for a seat. The genuine Rivnut manufacturer has sufficient data on their web site to work it out. But beware of other brands, some may be better, or worse. It is vital to check the strength data on the actual items that you propose to use. That is unlike, for example, a bolt, where the most common size, 5/16" UNF grade S (or SAE grade 5) has the same strength if it is a genuine part from any manufacturer. In other words, bolts conform to international standards, but Rivnut, Nutserts and similar products are manufacturer specific.

[Aridgerunner]

Crap! Just today I welded on the new left side outer sill and now I read this. Oh well, at least I'll know what to do if the nuts break loose.

[Cooperman]

All you need is an angle-grinder with a 1mm cutting disc, a MIG-welder, a magnet and some paint and filler, plus the usual tools.

It takes around two hours.

[mini13]

similar to above, but what Ive done in the past is weld a nut to a thick penny washer, then dril the hole to size with a step cutter ( I love step cutters!!). drill a hole in a bit of flat bar or somthing thats not as wide as the washer, then you can bolt it to the washer, hold it in position and tack it top and bottom, un bolt it and seam round it and skim over with agrinder/ flap disc.

 

the step  cutters good as it take she hole out evenly and is pretty good at keeping it all lined up, do check its in the right place before you seam it up though!

[Cooperman]

similar to above, but what Ive done in the past is weld a nut to a thick penny washer, then dril the hole to size with a step cutter ( I love step cutters!!). drill a hole in a bit of flat bar or somthing thats not as wide as the washer, then you can bolt it to the washer, hold it in position and tack it top and bottom, un bolt it and seam round it and skim over with agrinder/ flap disc.

 

the step  cutters good as it take she hole out evenly and is pretty good at keeping it all lined up, do check its in the right place before you seam it up though!

By gum, that's a great idea!

[tiger99]

I agree! I will remember that in case it happens to me one day.