In Part I of our welding series, we introduced the MIG-welding setup and basics, along with the chance to win a Miller welding helmet. We also gave you a good foundation to begin learning how to weld on your own truck. This time around, we figured we would build on the knowledge already presented and go a little deeper. We tackled the issues of welding tubing, steel pieces of various thicknesses, and sheetmetal together. We also tried welding in different positions to simulate actual working conditions.
Using what you learned in the first story (and if you've been practicing your technique), you can move ahead and begin welding tubing together for your bridge, a four-link, or just to make a cool desk. When working on mini-trucks, tubing is a fabricator's best friend. It can be bent and welded in any manner to fit a specific suspension, fuel-cell mounting, interior piece, or anything that you need to make work and look good. Once Mike Alexander became a little more comfortable welding the tubing, it was time to move on to another MIG-welding challenge: welding steel pieces of different thicknesses together. For this task, the tricks are definitely speed, technique, and the voltage setting.
With Mike becoming a more proficient welder, it was time to put him to the test one last time by attacking some sheetmetal work. Welding sheetmetal is also fairly tricky because if your settings are off or you move too slowly or too fast, you risk burning through the metal or warping it. This is an excellent skill to practice, as it will come in handy when the time comes to shave those door handles or anything else you want to permanently remove from the exterior of your truck.
Check out all these techniques and add them to your welding-knowledge arsenal. If you're serious about developing this important fabrication skill, it might also be a good idea to pick up some reading material, videos, or whatever method you learn best from at your local welding supply store. Once you've mastered welding tubing, different-thickness metals, and sheetmetal, and welding in uncomfortable positions, you'll be on your way to building the mini-truck you've always envisioned. For more information, refer to the source box.
Whenever you're welding, the grinder can easily be your best friend (aside from your welder, of course). You always want to clean up a notched tube, a freshly cut piece of plate, or anything that has rough edges. A wire brush is also useful to clean off contaminants before starting your weld. | 
When welding tubing together, a good tube-notcher comes in handy. It's very important that the tube fits well without any gaps. This will ensure good penetration, and most importantly, a good-looking end product. |
After the tubing is cleaned up and ready to weld, tack each end so it doesn't move. Then, if possible, stand the joint up so you have access to laying down two beads. Start at one end of the tack weld and move to the other end, making small circles or curlicues. Be careful with your settings. For welding tubing, you'll probably need to turn down your wire speed so the puddle doesn't become too big. | 
This is how the weld should look around the tubing: not too thick and not too thin, ensuring good penetration into both pieces. |
Whenever you're welding together two pieces of steel that have different thicknesses, it's important to set the welder settings for the thickest material so that the weld will penetrate. | 
Start the weld on the thicker material, dragging the puddle onto the thinner material. This will concentrate the heat onto the thicker material and ensure good penetration, while allowing you to drag the weld onto the thinner material without burning a hole in it. |
If done right, the weld will have good penetration in both the thick and thinner material. It won't burn through the thinner material, and the weld will still have a decent stacked look. | 
Sheetmetal is a little tricky at first, but like the others, it will become easier with a little practice. The trick to sheetmetal is to properly set the welder to a low setting and not concentrate too much heat onto the work piece. |
Whenever you're welding sheetmetal, while shaving door handles for example, you'll want to start the tacks at each corner. Giving the metal enough time to cool between tacks is imperative so that the metal won't warp. In the end, you'll be much happier you didn't rush, because you'll have a lot less bodywork to deal with. | 
The tacks have a distinct look to them; they leave a little dimple in the weld where the wire was released. When tacking thin metals together, leave the trigger on just long enough to join the two metals and penetrate. If you do it too quickly, the weld won't penetrate. Doing it too slowly will cause you to burn through the metal. |
Two of the more awkward positions to weld in are overhead or downward. Whenever you must weld downward, start at the top of the part and drag the weld down. | 
When welding downhill, depending on the material and size, you might have to move a little quicker so the weld pool doesn't get ahead of the bead. |
The downhill weld will present an excellent stacked-dime look, as long as the welder is set properly to the material and thickness you're welding and you maintain the appropriate speed, with the gun at the proper angle. | 
If you try to drag the puddle uphill by starting at the bottom of the part, the weld will look like this. Not too good. |
If you're now consistently making good welds, all your practice has paid off. Make sure to take advantage of the KAIK Products customized Mini Truckin' Miller helmet give-away by checking out www.millerelectric.com/primedia and entering to win. Stay tuned for Part III, where you'll get to see some more advanced welding and a glance at the customized helmet. | |