PDA

View Full Version : Welding in pans



vpogv
26-08-2008, 12:04 AM
I do have a question as to the best way to put in new pans - read everything from continuous welds to short beads to spot welding to rosette welding. What have you all done? Seems as though spot welds or rosette welds would be the best. The second part would be that doing everything but a constant bead you would need to seal it up somehow, what did you use for the water tight seal?

letterman7
26-08-2008, 02:13 AM
Traditionally, VW pans are spot-welded in place. The factory undercoating took care of the weather infiltration if there was any. I prefer to spot weld my stuff in place to make sure it's where it needs to be. If changes needed to be made, it's easy to cut the welds. Once everything is in place, I'll pull a continuous bead around the perimeter. A caveat here: do the continuous bead in sections, say 6-8 inches working one side of the pan then the other. That will help keep the heat distortion to a minimum. I made the mistake of welding the tunnel side of a pan in one shot once, and by the time I hit the outer rail, the pan had twisted almost a half inch!

vpogv
26-08-2008, 03:00 AM
But you still recommend doing a bead around it all - just over several passes to keep the heat down?

bobbybrown
26-08-2008, 03:06 AM
Yeah thats the best way.
Spot weld it in place first so thats its where it needs to be.
Then put a bead around the pan but in lenghts of 6 to 8 inches as Rick said, do a bit on one side of the pan then a bit on the other.
Stops one side getting too hot and bending.

letterman7
26-08-2008, 12:07 PM
But you still recommend doing a bead around it all - just over several passes to keep the heat down?

Personally, I feel better (safer) with full welds rather than just spot welds. Factory welds were/are almost always spot welds, so if you're confident in your abilities, then spots will be fine. Seal the seam with any seam sealer, I use this: http://www.eastwoodco.com/jump.jsp?itemID=1595&itemType=PRODUCT from time to time depending on what I'm working on.

To test your pan welds, stand in the middle of the pan and pump your legs a few times to see if anything breaks....don't jump - you'll bend them!

MicksRedNova
26-08-2008, 08:43 PM
Factory welds were/are almost always spot welds, so if you're confident in your abilities, then spots will be fine. Did that.


Seal the seam with any seam sealer Did that too


To test your pan welds, stand in the middle of the pan and pump your legs a few times to see if anything breaks....don't jump - you'll bend them! Did that too (the testing not the bending).

I spot welded the lip of the drop to the flange along the tunnel using the 'drill a hole in the top and fill with weld' technique, whatever it's called. The front and rear of the pan were seam welded to the existing chassis. The joins in the floorpan drop fabrication were seam welded and the outside edge of the drop was tacked then seam welded in short runs, as mentioned above.

I've jumped in and out of the car quite a few times and (accidentally) jacked it up under the pan drops a couple of times and it's still in one piece.

Mick

jimcub
26-08-2008, 11:14 PM
Most MOT men will olly accept weld runs not spot welds, it adds strengh and makes one feel that bit safer also fills gaps to stop Mr rust getting in

vpogv
16-02-2009, 04:34 PM
To update I tried spot welding but didn't feel the best about them. Ended up putting 1-2" beads around on the top and bottom. The good is they are nice and strong - the bad is that the pans are now welded to the tunnel. I will kick myself for doing this if I ever have to replace the full pans again. :dunce:

letterman7
16-02-2009, 04:42 PM
Don't feel bad - you'll have greater confidence in the chassis when you hit those ally-oops on the highway. And the pans and chassis will probably outlast you once they are done!

vpogv
16-02-2009, 05:16 PM
Very true Rick. I do feel a lot better with the additional welds. Pans didn't warp much so no issues. As always, thank you everybody for the input.