Another Miata bodywork thread

I did do a repair on my first Miata with steel and epoxy. It looked fine. I inadvertently blocked the drain hole while doing it so it rusted through again in a few years. About the point the floors were rusting through.

I am close and have a welder (but haven't learned that skill yet despite having the welder for 5+ years now). Needs the gas cylinder filled, but you are welcome to use it - it's an older Millermatic140.

boileralum wrote: I am close and have a welder (but haven't learned that skill yet despite having the welder for 5+ years now). Needs the gas cylinder filled, but you are welcome to use it - it's an older Millermatic140.

We could both learn and berkeley up my car in the process, i supply beer?

Swank Force One wrote:

boileralum wrote: I am close and have a welder (but haven't learned that skill yet despite having the welder for 5+ years now). Needs the gas cylinder filled, but you are welcome to use it - it's an older Millermatic140.

We could both learn and berkeley up my car in the process, i supply beer?

You could be on to something. Surely there is someone else close by who can tell us how to somewhat properly use it. I know a while back there was someone on IIC who said he would give some basic lessons.

Swank Force One wrote:

boileralum wrote: I am close and have a welder (but haven't learned that skill yet despite having the welder for 5+ years now). Needs the gas cylinder filled, but you are welcome to use it - it's an older Millermatic140.

We could both learn and berkeley up my car in the process, i supply beer?

I have a foolproof way to teach people how to weld body metal. Takes about half an hour and you have to be able to count to one. Without using your fingers.

It really is that easy. The Millermatic is a good tool. Will work just fine as long as you don't try and use stale wire.

Spill it!

I am also interested in this count to one method, and I can sort-of weld.

OK. Without actually being there to drink your beer, here is the process:

Put new wire in machine.Use 0.023 wire for body metal. Use the correct tip also. If the wire has been in the machine for more than a few months, it is rusty and is going to make your life harder than it needs to be. By the same token, the wire should be Lincoln or Miller. Cheap Chinese wire sucks. You will know the wire sucks because it is going to make like a sparkler when you weld.

Clamp two pieces of tin together. Does not matter if 22 or 18 awg.

Does not matter if you want to do a lap or butt-joint. Just make sure that the seam is tight.

Turn the machine on and open the gas valve. Set the flow to about 15cfm.

Ground the workpiece.

Pull the trigger (torch in air, not at workpiece) to let out some wire and trim to about 3/8" from tip.

Using two gloved hands to keep the torch steady, ( I pretty much hold the tip) line the wire up right on the crack. I like lots of light when I am welding and tend to have a light source as close to the work as possible. I also get my face right in close so I can see what the tiny little bead is doing. (at this point helmet is still optional as long as you close eyes, best practice? not really) Pull the trigger and do a slow count to one. DO NOT MOVE THE TORCH.

Now, open eyes and look at your weld dot.

If you have a hole in the metal, either turn the heat down a bit or turn the wire up a bit. (pushing wire is like adding ice to a drink, so turning heat down or adding wire both achieve the same result) Try again.

If you have a rounded lump of wire sitting on top of the tin and no evidence of the weld on the backside, increase heat or decrease wire. Here is what you are aiming for. (actually, I would say the tacks are a bit too cold)

The gist of this process is that you are adjusting the machine so that a one second pulse on the trigger is going to produce a bead that is hot enough to penetrate the workpiece and not so hot that it burns a hole. You do this by using the one second weld as the constant and playing with the other two variables. Gun movement is not a issue.

Once you have the machine set and the counting down, you are ready to go. There is not anything else to learn.

This is where you put the helmet on.

Assuming you have two pieces of tin tacked with nice tacks, just point the gun the front or rear edge of one of the tacks. I like to kind of face the wire into the tack, not critical. The idea is that the molten wire is going to slide of the slope of the existing bead and slide into the seam via capillary action.

Holding the gun steady with both hands, pull the trigger and do a one second count. Release the trigger.

As soon as the color red disappears from the tack you just did, have the wire-repositioned so it overlaps the tack you just did. Hit it with another one second count. Repeat as needed.

You should have something that looks like this: (you can tell he had to count to one twelve times to do that "bead")

The examples I found on line were for a lap joint, but this is good for any type of sheetmetal joint. If you flip the work over, it should look pretty much the same on the backside of the weld.

Some things to keep in mind: Metal needs to be as clean as possible on both sides for best results. welding paint, rust or bondo is never going to give the best results.

The fix for the inevitable hole you are going to make is still the one second count: just go around the edges of the hole until it gets filled in.

If you have a gap that is a bit big, stay with the one second count, just zig side to side to bridge the gap. At all times you are working on adding molten steel to the face of the last tack,NOT into the weld seam.

This wont make you a welder and I don't claim to be one. Its a one trick pony that gets bodywork done without really having to know a lot about what you are doing.

I just found this (linked via e-mail from the GRM powers-that-be). Thanks for that quick and simple tutorial.