Thread: Everybody that is currently building a car...

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Originally Posted by brickman

so the copper or brass is acually helping filling the hole or are you using it just for a heat sheild on the inside?

It just blocks the heat and material transfer, and prevents blowing a lot of holes in your work. Really does an excellent job for filling trim holes, etc, too!!!

Or in other words, being a dissimilar metal the steel doesn't "stick" to it.

Originally Posted by Bob Parmenter

Or in other words, being a dissimilar metal the steel doesn't "stick" to it.

There ya go!!! That's what I was babbling about!!!!!!

That makes great sense, once again I have learned something from here today, I can now let my pea brain rest the rest of today!

Welders use em at work to rebuild keyways in shafts . Should have came to mind and brought some home.

Thanks rc yeah it does and to allmost any thing , Auto makers are giving some new cars the low roof right form the factory .

Originally Posted by bluestang67

, Auto makers are giving some new cars the low roof right form the factory .

.......and sometimes by accident...........

Hey guys I'm really not trying to be the fly in the ointment here, and I am absolutely open to learning new things on this; but, as I recall, using dis-similar metals in the bonding process radically speeds up corrosion (rust) at the joint. This is due in part to the fact that, as our wise Uncle Bob said, it prevents the steel from "sticking" to it and allows moisture to attach itself to the bare metal between the to materials. It is also, as I recall, due in part to the make-up of the materials being used at the elemental level, and their reaction to each other when bonded. In any event, I would think it would be something to watch out for.

Maybe, I misunderstood what you guys are saying, as I understand it, you are doing this to act essentially as a heat sink, to allow the heat to dissipate through the copper or brass and not the surrounding metal; but, I didn't catch if you were removing it afterward?

I also may be just overly concerned about this; but I did remove a braized brass section on the fender of my '55 during the build-up and had to also replace a good bit of the surrounding metal because it was well on it's way to the cancerious stage. The bondo that they had used on it was still holding up though...

Thanks for all the help on this guys,
Dutch

Originally Posted by Firechicken

........ but, I didn't catch if you were removing it afterward?

Yes, it's merely a tool used as a backer during the welding process to keep from "blowing through".

It's just used as a heat sink & removed after the welding is done.

Thanks Bob and Pro.

I'm tracking what you guys are saying now. As brickman said earlier, it does make perfect sense now, and I do indeed learn something new everyday. Some days the process just takes a little longer.

Thanks again,
Dutch

Bob looks like they did some channelling to it also .

Also have the welding figured out. I turned wire feed down below 1 and i have to move really slow but the bead is great very workable and no blow holes .

Slow wire feed causes the welder to be hotter right? I may be confused about this?

Originally Posted by brickman

Slow wire feed causes the welder to be hotter right? I may be confused about this?

No, think about it like this, higher the wire speed the higher the amperage, you can vary the temperatue of your weld by changing your arc length, increased arc length = cooler weld shortened arc length is a hotter weld you should hear a higher pitch noise from your welder as you go in close.
You also use your voltage coarse and fine control switches to tune your welder.

Brick im getting alot better bead control . I think with the faster wire feed its pulling out more amps to melt the wire .

Southern i have a weld pac 100 lincoln a-b-c-d settings with a flux core wire.. I have tried the longer wire burn but slow and close is giving the results .

Brickman, do you want to work the metal after welding ? With sheet metal on body panels you want to grind the beads down so they are reasonably flat. Also the hotter the weld the deeper and harder the weld, so therefore welding depth is ruled out on panels to a certain extent. Unless you like blowing holes ! Flux cored wire has its advantages and disadvantages, but for doing panelwork I prefer usinga shielding gas as I have more control over my heat. But to each his own, depends what technique best suits you.