Joingin body parts: brasing, mig brasing, body filler, lead...

[webhead]

Hi there,

Being occupied on renovating my home I'm left with pondering about restoring my classic.

I'm still confused on how to weld my body parts.

1) Fully mig weld it. Welding the entire seam, grinding etc. This seems like the everlasting solution but I'm scared to death about warping panels. I know that I should take my time and keep moving around so not to overheat anything...

2) Weld it with an overlap, plug welding (punch out some holes etc). This seems easier then perfectly matching a panel to fit but then...

- do I use body filler to smoothen out the gaps in the patch ?
- I heard brasing/ using lead or other "solder" is the way to go to make lasting, elastic joints. I know someone who swears by it.
- should I overlap and weld the entire seem, again, grinding until flat ?​

I'm willing to learn and polish my technique but I'm not into excessive shrinking, metal slapping, hours of hammer/dolly work just to get my metal flat after welding it.
I'm looking for a quality way of restoring a car but without going completely overboard.

How about it, any opinions out there?

 

[Sean]

personally i use the first when putting a new area of metal into a panel and the second when the edge of that panel meets the other one - so its like the original fabrication

as for heat distortion, only weld a short section then weld as far a way as possible - never return to a bit untill its cold enough to touch with a bare hand and only when it feels mildly warm.

blend in the weld using flap wheels in a grinder

Sean

 

[webhead]

Hm,

So you always weld up the entire seam and grind it down?
Do you sometimes need some filler to even it out ?

With an overlap weld there seems like an inevitable small depression on the edge of the offset...

 

[Sean]

Hm,

So you always weld up the entire seam and grind it down?
Do you sometimes need some filler to even it out ?

With an overlap weld there seems like an inevitable small depression on the edge of the offset...

sometimes yes, a little skim of filler is required and a bit of dolly work if you can get in the back of it.

always weld the seam joddled and spotted welds always leave me feeling like its going to erupt in rust at some point plus its a no no in structural areas which is prettymuch everywhere when it comes to mot man.

 

[500e]

Lead work is an acquired skill.
Cleanliness is next to godliness & lead work, clean & clean again, flux & tin surface, apply body lead comes ( soft flame just enough to get body solder to flow) in sticks roughly 1 x 12 inch soothe out with wood block soaked in tallow, did a lot of old Jag & Bristol bodies the Mk11 Jag rear wing to window x panel + the dinky side lights mounted on top of wing were leaded in, the rust still came through in time though.
There were some fearsome tools used like spray on soldering guns, a bit like a gas blow torch with liquid solder being blown out of nozzle
Saw one used once Scary

 

[anjum]

Most of the time I use overlapped and joddled joints, sometimes with a couple of plug welds to hold it in place, which I then seam weld. Again weld a bit at a time.

I then use a flap disc in an angle grinder to grind the metal flat.

I sometimes use lead as a tiining/ rust prevention stage.

The next stageis to thoroughly clean and apply some 2k epoxy primer, you can brush it on at this stage. Then fill on top, once set. If you leave it too long you will need to give it a key.

Once the filler is sanded flat I apply another couple of coats of 2k epoxy primer, then prime and paint as per usual.

If the work is in somehere that doesn't show I normally leave the welds unground, and may use POR-15 instead of the epoxy (you have to use "metal Ready" on fresh steel.

The inside is as important to treat as the outside otherwise the rust will bubble through from the inside and through any cracks.