I put this little ditty together on another forum:
Although welding is not my specialty, I weld a lot. A thread in the projects forum prompted me to give my humble advice on using the 90 amp Harbor Freight welder that many people end up buying for a first machine.
These tips are in no particular order, and some are more important than others. This is meant as a guide to hopefully give you a better chance of having decent useable welds the first time you try. Read it from the bottom if you want, it says the same thing but with some faint satanic ramblings if you listen real close. Oh wait thats my Ozzy album.
--------------------------------------------------------------------------------
The 90 amp harbor freight welder is a good purchase either way. It actually has a 125amp max rating, and the rated 20% duty cycle is far below what it will actually handle. Also it is a DCEN current to the torch as opposed to AC. This is good.
I must preclude my suggestions for better welds with a stern 'you shouldn't learn on a bike'. Practice on some other #$%*. Like a quad, or a Dodge. Please.
Sleeve and plug weld all tube joints. Search the welding forums to learn what this means, and don't ever ever skip these steps. You are NOT a welder, so you need to add a level of safety, and sleeving and plug welding is the way to do it.
Fit your pieces correctly. There should be virtually no air gaps between properly fitted pieces. This means trial and error, or more math than I am willing to do, so often trial and error. An experienced welder can bend this rule, but an experienced welder is also less likely to have poorly fitted pieces in the first place.
Throw your harbor freight wire in the trash. Go buy some Lincoln wire from a place that sells a lot. The longer wire sits, the more moisture can attack it.
Clean the area to be welded to a point where you wonder 'can it be TOO clean? No, it can't. Neither can the piece of metal that your ground is attached to, which will by the way be located as close to the weld as possible so the current stays consistent.
Grind the ends of the pipe at an angle, so that when the two pieces meet, it creates a 'v' to weld into. And since you took my advice and sleeved the joint, this will allow enough penetration to reach the sleeve as well. If you did it right.
I used to have one of these. I added a ground clamp so that I could attach one to each side of the weld. I am not an electrical engineer but I can tell you it worked much better after that mod. I also replaced the puny little power cord with a much heavier gauge wire. The last thing i did was eliminate the low power circuit that was only good for bodywork then rewired the high power circuit to see less resistance by eliminating the switch.
I once welded an entire custom model t chassis with that welder. The car sports a healthy 350 and has been ripping the track for over five years now so I'll call it a success.
Never kink the torch. It should be as untwisted as possible to allow the wire to feed consistently.
Do not use an extension cord with this welder, the performance will suffer greatly. Unless of course you have a very large gauge 110v ex. Cord, and most do not.
Get an auto dark mask from HF as well. They kick ass for the price, my latest one is an obvious upgrade over the last model. This tool is irreplaceable in respect to allowing hands free operation for the duration of your welding procedure.
If you want nice looking welds, you have to look into the weld puddle. This in my opinion is what separates good welders from bad. Its kinda like picking your head up before a golf shot, bad form. Yet many just look AT, not INTO, the puddle.
Never quench welds on mild steel with water. Let it cool on its own.
If you stop on the middle of a weld (try not to) you should clean the weld before beginning again. With experience this rule can be bent, but I don't recommend it.
Heating the area to be welded before you start welding will almost always benefit the final product.
Don't lead your wire too far out. Keep the tip of your torch close to the workpiece.
Fire is hot. Hot metal is hot. Hot stuff will burn you. Melted metal will burn into you. Melted metal will fall, and burn anything under it.
Cover any area on the bike you dont want burned with welding blankets or damp towels. Have a fire extinguisher handy. If this is not possible, at least do this:
Drill a small hole into the cap of a plastic liter pop bottle. Fill it with water. Squirt your buddy in the face with it to make sure it works. Put out fires with it.
Thats enough for now maybe i'll add more but im real lazy so probably not. There's more, but that'll confuse you enough to get lucky. Just like in the bedroom.
Feel free to add experienced (as in, have used the machine in question) info.
