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Wed Jan 14, 2015 5:26 pm

Like it says, my welds aren't sticking. I have welded a ton of stuff and never had a problem, but I went to weld my floor pans in and every single one of them looked fine on the top (floor pan side), but didn't stick to the tunnel lip side. I had it set at low heat, slow speed, and the metal was clean and shiny and clamped pretty tight together. I punched the holes (1/8" or so with the HF punch) and it will fill the hole, but just not sticking. Is my set up wrong or what would cause this? I don't want to tack more in until I figure it out. I still have 1/2 a drivers side and a whole passenger side to go.

Wed Jan 14, 2015 7:32 pm

I had to go to a 5/16" hole with my pans so that I could make sure I started my weld bead on the bottom lip metal. I always weld as hot as I can without burning through. If you start your weld in the center of the hole on the thicker lip metal on the bottom, you can go hotter and let the puddle pool up until it flows into the thinner pan metal.

Wed Jan 14, 2015 8:33 pm

X2
Like beetle says

Sounds like you need to crank the voltage up to penetrate the thicker tunnel material first.

Wed Jan 14, 2015 8:54 pm

Yea, I think a rosette weld you probably want the hole 2x thickness of the metal at a bare minimum. Bigger would be preferable.

Turn it up too! and use pauses to control heat. You know, go 3 sec then stop for 1.5, repeat utill hole filled.

Thu Jan 15, 2015 6:23 am

X# what beetle said. I will add you do not want a "polished" metal. It should be rough & clean. You do not mention what type of welding machine you are using. Post a picture of what you are doing before you weld & what it looks like after.

Fri Jan 16, 2015 11:00 pm

1 . . . Punch holes in new pan.
2 . . . Place new pan on chassis.
3 . . . Use a "Sharpie" in the pan holes to mark the tunnel flange.
4 . . . Remove pans and drill only the top layer of the tunnel flange at marked locations using 1/4" drill.
5 . . . Re-install pan.
6 . . . Weld with medium heat and wire speed. Start with wire in center of hole and do not go "round and round", but rather weld in the middle until the puddle fills up to hole in pan.

Try it . . . works great!

BTW . . . your punch makes a 3/16" hole.

Also . . . if we are talking about pans for yer Oval Window, and you are using generic pans, don't forget to add the support bracket for the clutch shaft bracket. You can see it on my pan . . . the plate with two tapped holes.

Sun Jan 18, 2015 3:26 pm

57Blitz, your method worked GREAT. I upped the heat and put it right in the middle and could actually see it "weld up" if that makes sense to get to the pan. As it went on, I was almost TRYING to blow holes through it (if that makes sense) until it got to the pan sheet metal and all I can say is that now those babys are in and they aren't going anywhere. Just a few more loose ends and it's off to powdercoat! Thanks a ton to everybody. I'm tired as hell and by back hurts but so stoked to have come this far!

Sun Jan 18, 2015 9:29 pm

Here is a thread on the same topic a few months back.

It seems that the 'fill the hole method' has disbelievers.

http://www.thesamba.com/vw/forum/viewtopic.php?t=608976&highlight=

Sun Jan 18, 2015 11:24 pm

ratpanel61 wrote: 57Blitz, your method worked GREAT. I upped the heat and put it right in the middle and could actually see it "weld up" if that makes sense to get to the pan. As it went on, I was almost TRYING to blow holes through it (if that makes sense) until it got to the pan sheet metal and all I can say is that now those babys are in and they aren't going anywhere. Just a few more loose ends and it's off to powdercoat! Thanks a ton to everybody. I'm tired as hell and by back hurts but so stoked to have come this far!

I'm glad ya got it! 8)
Do ya see what I mean about the clutch shaft support or did your new pan include it?

Mon Jan 19, 2015 9:31 am

Just went back and checked for the clutch bracket. They are WW pans but they only have one threaded nut on them. I guess I need to find one of those brackets. Where could I get one of those, or does anyone have dimensions? Doesn't look too hard to make.

Mon Jan 19, 2015 10:03 am

I used the one from my old pan.

It would not be difficult to fabricate one . . . just two holes tapped for M8 bolts.

If you make your own, you could even make it larger and weld to the crossmember and tunnel flange to prevent any movement in your clutch pedal shaft.

Also, look closely and you can see that I had to shrink out an area of the pan sheet metal . . . the area where that plate is welded to needs to be flat and level with the side of the pan. Take care of that BEFORE you powder-coat!!!

LMK if ya want to see another photo.

Mon Jan 19, 2015 10:53 am

Thanks bro. I would appreciate a couple of dimensions though of where to weld it in. And I see what you mean about flattening the spot where it goes. The WW pan has a stamping right there, but I can take care of that. The plate looks to be about 1/4" think or so by 1" wide and 4" long. Is that close? I want to take care of everything like this before powdercoating so when I get it back it's just a matter of putting the suspension in and making it start looking more like a car. All the wife sees right now is rusty metal and thinks I'm crazy for "wasting" all this time working on it.

Mon Jan 19, 2015 11:15 am

Sorry, but I am unable to measure right now, however, the dimensions are not critical (we are NOT doing a stock restoration, right?) except for the bolt holes.

I bolted my pedals in, placed the "pedal stop plate" and "clutch shaft pivot plate" on the pedal clutch shaft, and marked the holes up top. Those plates have slotted holes . . . I marked in the center of the slots. You can also see that there are a couple holes that I welded closed. I modified my clutch shaft to have an additional bushing, so yours will look slightly different, but the procedure will work fine!