Now that you have built yourself a welding machine, you are probably anxious to see what this little arc welder can do. Your first attempt at welding may seem like you wasted a lot of time and effort making a piece of crap that clearly doesn't work. Rest assured, you have built a welding machine that is capable of producing high quality welds with the right welding electrodes and a little help from you.
I will prove my claim by welding together two 3/8" thick steel plates with a 1/16" welding rod and this little homemade welder. Before I start though, let's get an understanding of what happens when we stike an arc with a welding electrode. The size of the welding rod, the available amperage and plate thickness determine weld fusion (adhesion) initially.
In other words, a large diameter welding rod on a thin steel plate will blow right through it. On the flip side, a small diameter welding rod on thick steel plate may not start the arc and, if you do get an arc, the rod metal will not fuse to the plate but simply lay on the surface in the appearance of a weld (an accident waiting to happen). This is where "preheating" bridges the gap. Preheat allows you to use small welding electrodes on thick plate.
Prepare to clean the steel plates by donning your safety equipment, welding helmet, welding gloves and a dust mask for particles. "Junk In, Junk Out", is exactly what you will get if you do not prepare the steel plates for welding. Never weld through trash, rust or scale if you have the means to clean the steel. The bevel should approximate 45 degrees with a 1/8" land (flat) at its base (see photo).
When the bevel has been applied to both steel plates, turn them face down, set the root gap (I use the metal stub of the welding electrode I'm welding with) and employ spot welding to tack them into position.
Now that the plates have been cleaned, beveled and tacked, clamp the steel plate in a position of comfort and prepare to weld the root pass. Gather your welding supplies, gas and torch for preheating, welding electrodes, stinger and your welding machine.
If you look at the top right edge of the flame, you can see the moisture line as water runs from the flame. It is never a bad Idea to preheat, in fact, almost every welding job I perform professionally demands a preheat temp of 400 degrees and up. You will be amazed at how easily the arc stikes and how well the welding rod burns, improving welding quality significantly. Bear in mind, once the steel has reached preheat temp, this temp must be maintained through out the proceedure untill all welding is finished.
Extra care should be taken when running the root pass because If the root pass has good fusion and is water tight, the rest of the welding is just formality especially when welding pipe. Make sure the joint is good and hot and you are comfortable during the weld. Comfort means control.
I dub this part Mindless Welding because you burn rod after rod until you complete the passes. To show clearly what has been done, I have ran the welds in steps starting with the root pass on the right, the intermediate fill pass in the center and the final fill pass on the left. As you step up the welds, pay particular attention to tying in the sides, this is the strength of your welding.
The Cap passes are where you let your skills shine. They can be as few as one or as many as it will take to cover the filled joint you just welded. This is your signature so take your time and get them straight and the proper height. The grand finale' of this episode is to turn the plate over, grind out the root opening down to flawless metal, preheat the steel plate, fill the joint and run the caps, you're done.
This simple proceedure for using your homemade arc welder is the basics of all welding. Welders in many welding
careers performing many welding services and welding jobs use these techniques. They produce quality welds
consistantly with welding wire or welding electrodes and you can too.
''Think Safe! Be Safe! Make Sure You're Not At Risk!''