Thanks! It’s my first bit of welding in a long time. Weird body position compared to the bench top stuff I’m used to. Not beautiful welds, but once ground down, painted and soundproofing applied should do the trick. Thanks again for the guidance. 

t

Looks good!

https://imgur.com/gallery/YUg9d4Z


????

Pictures or it didn't happen. Glad you found a solution. 

Ok, so I ended up ordering a replacement crossmember and using it to patch the bad sections. Pretty pleased with the result. Thanks for the guidance. 

t

When this happens, the front of the crossmember is usually cracked and broken near the nuts.
It is very flimsy even when new.

I have fixed a few of these by drilling a 1/2" hole thru front and back.
Then braze a piece of 1/2" dia steel rod both front and back. Also braze up any crossmember cracks. I use nickel bronze rod.
Front of the rod is previously tapped to 1/4" UNF x 1/2" deep.
This rod is made 2-3mm longer than the crossmember width for good penetration.

I think I'd be tempted to buy a new cross member and use it to make patch panels. 

Thanks for suggestions! To be honest I’ve been looking for a reason to use riv nuts since I saw an ad for them, but fresh metal and captive nut may be the way I go. 

cheers!
t

I’ve become a big fan of riv-nuts for this kind of thing. Unfortinuately, it looks like there’s not enough solid material on the cross member where the holes go. Looks like a little welding is in order first. Then riv-nuts or perhaps captive nuts as long as you’ve got the welder out. 

Riv-nuts: link

Go to or call Grainger or Fastenal and ask for flush mounted or countersunk blind rivet nuts. You'll need to get the tool to install them, but you can either rent one from them or buy a manual version for about 30 bucks.

Edit: I just looked at the picture you posted, and it looks to me like you'll need to weld in some new metal first. You might as well cut out the area and put welded on nuts on the back of the new piece. 

Thanks Doug!

There are several options.  I will list just a few.

You could find some 1/4-28 rivnuts and use them to replace the nut welded in the crossmember.  This would probably require some washers on both sides of the crossmember wall to straddle the existing hole.  It will also leave a raised head (even taller if washers are required).

When I was faced with this I welded a 1/4-28 nut to a fender washer  I fished it into the crossmember while the sills were being replaced. I then drilled a three holes in the crossmember so I could plug weld the washer with nut to the crossmember.  It was involved but did not leave any raised head like rivnuts will.

You could look for some cage nuts and find a way to mount them in new, square holes you make in the crossmember.

Lastly, you could buy a 1/4-20 molly bolt for really thin panels.  Resize the hole in the crossmember to install the molly bolt and drill the necessary clearance holes in the crossmember to accept the spikes on the flange of the molly bolt.  Like the rivnuts this will leave a raised head and you will be changing from 1/4-28 to 1/4-20 threads on that one location.

This is not too uncommon.  I am sure others will have additional suggestions.

https://imgur.com/gallery/z3NcQnI

Hi all,

I have a mk2 and the front passenger seat nuts have pulled out of the sheet metal of the box crossmember. 

Is my best option to weld a new plate and nuts to the face of the crossmember?

thanks in advance for your input. (And sorry for the poor photo )

t