MTFCA Forum

I need to do some patch work on my pickup and have body for a speedster that cracks. Does anyone use a flux core wire welder for this type of thing? Also is there any type of rod that can be used with a lower temp than acetylene?
I know gas wire feed is best but more than I want to spend at this time.

I have used flux core wire feed welding...it's a little more sloppy than gas shield but it works.

Brass will work, but you need oxy/acetylene for enough heat.

Another possibility is panel adhesives.

https://www.3m.com/3M/en_JM/collision-r ... l-bonding/

This topic ranks high on the controversial topic list along with what type of motor oil and leaded/un-leaded gas discussions. This should prove to be a popular thread...

Of course the “best” welding methods happen to be the most expensive, but are also the most controllable, and have the fewest side effects. But any welding method can be used if done with proper caution and preparation.

No matter what welding method you use, ensure that your weld joints are as tight as possible, and clean! The tight joint will prevent undue shrinkage as the weld cools, as the surrounding material will support the hot area during rapid cooling. It’s a bit tricky to adjust a MIG (gas shield or flux core) welder to get full penetration without a joint gap, but it’s worth the effort to do so. Propper cleaning of the material will help ensure quality welds, in turn preventing welds from cracking during hammering (stretches weld filler material to offset shrinkage and restore intended panel shape).

With good technique, it is possible to butt weld flat panels together with minimal overall panel distortion. Lapping panels is an easy way to prevent weld burn thru... but at the cost of uncontrollable shrinkage, and a horrible scar on the inside of the panel. Some may not care in the moment, but a good looking repair on the inside is typically the measure of a “quality” repair after the filler and paint are applied.

Lead and brass used to be common practice in body repair, but have fallen from grace not only because of the obvious, but the residual flux can cause filler/paint adhesion issues and also aggressively corrode the sheet metal if not cleaned properly.

I like to use a mig welder for my body work. Stack tack welds around the panel to avoid distortion. Grind and fill. Take your time. I get it that you don't want to spend the money right now, but a decent mig welder will pay for itself in the years to come. I have been down the gas welder route for welding or brazing, they have their place; go get a mig welder for body work.

I'm surprised no one has mentioned "hammer welding" as a technique for patching or fabricating sheet metal forms. A good hand with oxy-acetylene can weld accurately butted pieces without using hardly any filler rod, and the result requires only minimal finishing. Parts are tacked in place then "stitched" to complete the seam, the "hammering" part meaning edges are brought back into alignment with a hammer and dolly block as needed as the work progresses.

"Back in the day" many manufacturers did extensive gas welding in this manner to make complex forms on fenders and bodies as some shapes could not be stamped on dies even if production numbers could justify the expense of tooling. Most independent auto makers' cars were thus pretty much "hand made" up to WW II.

(Mind you, I ain't sayin' I can do it, but it's mighty impressive to see it done ! )

like this?:

and ending something like this?

What I learned from all that is: Buy A Better Car To Start With

@Kevin Pharis you forgot water pumps!

Hammer welding works good but sometimes the section will get bigger during the process.

I've never experienced expansion when hammer welding, except to create it to un-do shrinkage. If it did in fact expand, there are a couple methods to shrink metal without a whole lot of trouble.

This panel had a bulge in it like someone threw a bowling ball into the trunk...bulge is gone and panel is straight with no filler:

Scott, EXACTLY like that !! Good on ya for truly "restoring" that body.

Thank you Rich

Just goes to show what a person can do if they have enough time and nothing better to do (also helps to be crazy)

Scott if you had better metal to work with then you would have to find something else to do for therapy!

LOL

Hank

Somebody on another forum had mentioned using old Chevrolet truck doors for patch panels. They work well for the bottom of the body because they have a brake line in them already but not quite 90*, and the metal is slightly curved already. I know this isn’t a T body but it’s similar. The back doors were attached so I used those skins to make one door skin, the other side was better.

See Scott, Corey has real therapy!!!

Hank, yer killin' me!

I used a flux core welder with reverse polarity. I used a copper back up strip riveted to hold the patch panel to the original sheet metal. Once done, I removed the copper strip and welded up the rivet holes. It took some grinding and a second pass to get a solid weld.