Welding between spot tacks

[stevo96]

Hi Guys,
My first post so go easy! And don't hold the fact that I'm posting from Australia against me, I'm originally from sunny Wigan....

I am attempting to restore a VW camper and ive tacked on the replacement panels, do I need to fully weld in between each of the tacks or can I use filler to go over the whole panel which I have to do anyway? The van is not a keeper so when restored it will be sold on, I still want it to last though.... The reason I ask is the panels I'm replacing have already been replaced before and the previous owner just tacked them on.

Cheers
Steve

 

[troppo]

G`day Steve
Usually like for like is plenty strong enough, so if the panels were spot welded from the factory then spot welding should be fine (prepairing for a hail of bricks ).
And dont say sorry for being here in Australia,be bloody proud lol
cheers mate
Troppo

 

[stevo96]

G'day Troppo

The spot welds are not factory, the pieces welded in are replacement panels that would normally be part of a full panel if you know what I mean... Im thinking I can bridge the gap with filler as they are not structural? The tacks are every inch or so. Might be best if i post a pic later..

Cheers

 

[troppo]

Well i`ve known worse to get through a roadworthy check. I`d put a tack between each of the existing tacks and then weld then up, space your welds out to minimise heat distortion. Your choice really, i saw a lot of dodgy things pass a roadworthy when i was in the car yards, depends on how "friendly" the inspector is lol

 

[stevo96]

The panels will be hidden behind the filler and paint, I should of pointed out that I meant body panels - not chassis work....

 

[kelsham]

The only problem is that most fillers are porous, this means that if water/condensation can get to the back it will absorb it and the filler will soon fall out.

I learned this the hard way in the 1960s. The filler I used to repair a Renault Dauphine wing came out after a couple of months.

One remedy is to use a bridging filler with fibre glass in it. This is bordering on a bodge. I have succesfully used it on the rear of repaired panels to seal pinholes and the filler applied outside of the panel is kept dry, an alternative is seam sealer on the back of the panel.
The advantage of using bridging filler is that it can be used both sides of the panel if carefully applied.

Some repairs I have done are still sound after ten years.

Regards Kels.

 

[stevo96]

Cheers - I intended on using seam sealer on the back to avoid that. The panel im replacing had tacks spaced every inch and filler in between - the panel has rusted out again but not in that particular place so I figured it must be OK....

 

[bigbadbugga]

Weld it fully, use the thin metal technique.

In the UK it would have to be fully welded unless it was only tacked at the factory.

It's easier to fully weld it than to mess about with seam sealer and filler filling the joint IMO.

 

[keith19]

Depends what your local MOT test or equivalent is like, Steve.
Over here years ago in the trade we used to tack 'em up if it was just a panel job, usually tacks about 15 - 20mm apart. Then pass them on to the body men for finishing. I've rarely seen a pro filler job drop out; seen plenty of home brews do it, though.
If it was an expensive resto' or a keeper it got seam-welded, and the owner got charged more.

But we got some funny regulations over here now; everything has to be seam-welded, even if it doesn't need to be, like an upper body panel. You can understand it, I guess, because as the metal gets thinner it needs more welding to stop a panel falling out. Increases the time factor, and can lead to warping the panels, so if you join the tacks up do it well spaced around the job to keep distortion to a minimum.
Some of the panels are so thin now they can't weld them any more, they have to glue 'em together....

 

[keithski122]

I've been old that the correct way is to spot/tack repair sections in, that is if its not in an motable place.That is if you put a lower outer section on a door panel, fold the edges, flange the upper edge and spot it under.Seen loads of rear 1/4 repairs done this way on vw bay window vans.
Its not something I would do myself as I believe any flange is a rust trap.I would butt weld a section in carefully and for the full length.

 

[stevo96]

Thanks guys, if it was a keeper i'd seam weld. As im fixing up to sell I think ill tack it and fill over it from what I've heard above. They dont have MOT's in QLD! They do a quick roadworthy when you sell the car on which is like a very leniant MOT. Here is a pic of what im talking about, you can see where I've tacked it on - this was my first attempt at welding, I have a cheapy 140 amp gas/gasless mig running on 0.6mm wire. I have it on the lowest setting....

 

[keith19]

Should be okay if you use a flap disc gently to level it out, then a skim of good filler. Check all the tacks are good before you fill - if any are only sitting on top they will come loose after flapping, and you'll need to redo them.

For future repairs on panels consider joggling the edges of the parent panel, then dropping the repair panel in before tacking it, or plug welding it.
You use a little more filler this way, but don't need to grind or flap the welds down so much. You do need to seal the back of the panel, as usual.
Often used in the trade.