Looking back I realize that taking the plunge into learning to weld was a big step in this project. Because I want this site to be helpful to the person in the same situation that I was, I figured it would be good to add some information about how I got started.
The welder I ended up buying was a Lincoln Pro-MIG 135. It cost about $450 from Lowes, a home improvement warehouse-type store, in 2002. They presently offer what looks like an identical machine, Pro-MIG 140, for $429 in mid-2006. The important thing is that as a beginner, you need to have gas. I still haven't used my welder with the gasless welding wire, but welding with the shielding gas produces a cleaner weld, and to start out you need all the help you can get.
You'll be welding 22 gauge sheet metal, and it's actually the toughest welding you can do. I remember that after a couple of winters welding the thin sheet metal used on the body of the Midget, I needed to repair the handle on my lawnmower, which was about 16 gauge. It seemed like the easiest thing in the world, and my welds came out great. The thin metal wants to burn through and warp, which makes it challenging. It's worth remembering if you're frustrated welding the thin stuff that it's something like tackling calculus before you've learned algebra.
The most important tool that comes with your welder is the owner's manual. And in my case, there was also a video. You won't need one of those welding hammers unless you use the gasless wire. You will need to get the shielding gas that's used with the welder. I went to a gas supply place and bought my own tank. The gas is 75% Argon and 25% CO2. The tank cost about $100, but then when I need a new one I just pay about $25 to exchange it for a full one. In the course of my project, I used about 2 1/4 tanks.
You need to have a fire extinguisher. I never had to use mine, but it needs to be right where you can grab it if you need it. The first time I used my welder I set a piece of metal on my woodstove and cleared every combustible item for about a ten foot radius. Then, just like the manual says, I started by putting a welding bead on a piece of scrap metal. It was exciting. It made sparks. But it wasn't anywhere near as dangerous as I'd imagined. Over time, I've probably gotten too careless about what I weld near. But I've always removed the fuel tank before doing any welding on the car. That's just been my method: I take the car off the road for the winter, remove the fuel tank, engine and transmission, and then start doing bodywork. I don't think it's necessary, but that's just how I ended up doing things. A little paranoia is probably a good thing.
I think that learning to weld was a little bit like learning to play golf. In 9 holes as a beginner most of my strokes were horrific and really made me mad. But a few of them each time were pretty good, and that's what I remembered when I was replaying the round in my head. Over time, there are fewer bad strokes and more good ones. The more time you spend preparing to do your welds, the better they'll be. Clean metal, well clamped, with your tools and your body well positioned to control the gun, will pay off by improving your chances of getting a good weld. You need good, clean metal to clamp your ground cable to, and it needs to be near where you're welding. If you're getting lousy welds, it's worth stopping to try to figure out why. To get clean metal, I used aerosol brake cleaner after wire brushing, but I've heard lacquer thinner works well. Any paint or rust in the equation will lead to poor results and frustration.
Buying the welder. $450 is a lot of money. Especially to someone as cheap as me. The way Sue and I looked at it was that I was committed to the Midget project, and the welder was necessary to do the job. And I'd have the ability to do welding for the rest of our days. I've done other welding for projects around the house, as well as for family and neighbors. It's a useful capability to have. I also considered a welder that Eastwood offered. It probably would have given me the same results at a little less money. There have been times that I wished I could have spent a little more money and gotten a Miller unit that has variable power settings, instead of the stepped settings that the less expensive units offer. With mine, there are four power settings, A is the lowest, D is the strongest. I've never used the D setting, but there have been times welding thin metal that I think the B was too much and the A just wasn't quite enough. (The B would burn through, but the A wouldn't give me the nice puddle of molten metal that makes a good weld.) I think the Miller was about $650.The mask. The mask that comes with the welder is inexpensive. It's often a challenge to hold it while you're trying to get positioned to make a weld, especially when you're working under the car. An auto-darkening mask would probably have been a good investment. I think the prices have come down on them to under $100. The mask that came with my welder has a small window consisting of two rectangles. The outer one is clear and can be easily replaced for less than $3 when it gets too clouded up with welding debris. The inner one is special dark glass, and they probably give you a level of darkness that errs on the side of caution. It's hard to see your welding even in the best of conditions. I stuck with it, but I think that a slightly less dark glass would have been smart to buy. I don't know the numbers for sure, but I think I had about a 12 or 14 level of darkness, and a 9 or 10 might be safe enough and give you a better chance of seeing what's going on. I think they're about $12.
Getting down to brass tacks.When you're ready to actually do some welding on your car, start with an out of the way spot where you won't have to look at the results and cringe every time you pass by. I think my first welding was a 2" x 3" patch on the trunk floor.
I chose to do a butt weld there. Partly because I didn't think it sounded possible to actually get a patch to fit that closely in a hole. I first cut the hole in the trunk floor, measured, cut a piece of 20 gauge stock, then marked the patch and ground close to the lines on my grinding wheel. I kept marking and grinding until it just fit in the hole. It's surprising what you can do when you're patient. And clinically obsessed. Butt welds are pretty easy to do once the metal is fabricated. I think I propped this patch up with a stick on the garage floor just long enough to tack it into place. Then, like I've said elsewhere on the site: tack, tack, tack. Then connect the tacks. Then grind the area with a sanding disc that's not worn out to try and make it look respectable. Somebody that really knows how to weld probably wouldn't have to spend more than a half a minute grinding to clean it up. And then there's the rest of us.
The other method I used was an attempt to try to replicate a spot weld. I'd drill an 1/8" pilot hole in one side of the metal, either the car or the patch depending on the situation. Then open up the hole to 7/32" or so. (By the way, you'll want to either be able to sharpen your drill bits, or have a whole bunch of these two sizes on hand.) The idea is to weld around the inside of the circular hole to create a strong bond between the two pieces every 1 1/4" or so. This shows some patches I made for the area just under the steering column.
Two things I should mention here: the holes for the spot welds make it easy to put in a couple of screws or rivets to temporarily hold the patch in place until it's tacked in, and second, whenever you're going to create an overlap like this with bare metal over bare metal that will never see paint, it's a good idea to use a "weld-through" primer. It's a zinc-rich primer that supposedly doesn't interfere with the quality of the weld because the zinc is conductive. Just about any auto parts store sells it, but they may call it cold galvanizing spray or something like that. Spray both surfaces that will be hidden, then wire brush away any of the coating that isn't hidden. I would even take a sharp awl and scrape away the primer within each spot weld hole to get the cleanest start that I could. Then just fill in the holes with the welder.
Sometimes you can't live with the overlapped joint showing. Sometimes you can get the results you want by joddling the joint. There are hand joddlers available, and air operated. I made my own joddler by making two attachments for my vise.
When mounted on the vise, they provide a gap of about 0.035", and it allows me joddle about 5" at a time.
Here's an example that shows where I used it on the top of the patch on the front of the footboard panel.
I should have mentioned that the metal I used to make the attachments for my vise are the same thickness as the metal I used for most of my repair patches, 0.035", so it produces a 0.035" joddle.
When you're using a purchased patch, it comes with a black primer. Grind that primer off wherever you're going to weld. This shows a footwell side panel with holes drilled for imitation spot welds, black primer sanded off and zinc primer sprayed on.
This shows the inner sill, black primer entirely removed, zinc primed, and spot welded from the inside.
And the outer sill gets the spot weld treatment. Notice that the black primer has been removed from every spot weld. The zinc isn't visible from the outside, but was sprayed on the side that contacts the inner sill.
Last thought on welding: The manual says to look not at the bright arc as you're welding, but at the puddle of molten metal. This doesn't come naturally, but it's good advice to get better welds. It's the puddle that you're interested in, but it takes practice to get your eyes to look at it instead of the arc.
Okay, this is the last thought on welding: Take your time. Spend extra time preparing the weld. Extra grinding for a good fit, extra wire brushing to be sure your metal is clean and the paint is removed from both sides and there's no undercoating nearby to catch fire. Spend time physically going through the motion of how you'll move the gun before you hold the mask up. And most of all, spend time letting your spot welds cool before you continue. Take up cigarette smoking if you have to, so you'll walk around a bit and let the heat dissipate. Or listen to what's on the radio. Or, imagine how great it's going to be to drive the car once it looks respectable and it's a June morning and 75° and you've got the day off. Like today, for me.Close this window