Re: Welder Amp/duty cycle question?
I heard a slightly different version of duty cycle...it's the % it can run out of 10 minutes at full output. For instance, 50% means you can run it 5 out of every 10 minutes while welding.
In regard to shielded gas v. flux core, I use flux core for the vast majority of the mig welding I do, it's cheaper, if done properly can be just as strong, and it was a simple jump since I started with stick welding. If you monitor your stickout distance carefully, and spend a little extra time cleaning the weld between passes, your welds will be just as good. Monitoring the stickout is what will control the penetration of your weld just as much as heat setting and travel speed...
If I was reccomending that someone buy a welder, for everything except body work, as a first welder, I'd strongly reccomend an arc welder. They're cheap, easy to use, will last forever, and are terribly versatile. A decent 220V AC/DC arc welder will weld anything (aluminum, stainless, etc.), will do beautiful welds on materials that are very thick (don't tell anyone, but we've welded 1/2" plate steel with our old Forney 220v...) and can weld thinner materials as well. The disadvantages are chiefly two-fold. 1. The length of weld that you can do uninterrupted is limited by the length of your welding rod (not that big of a deal in a shop setting...bigger deal in production setting) 2. Sheetmetal welding sucks. On the other hand, it's way cheaper to buy, the consumables are cheaper, the welding can be of equal quality, and it prepares you for all sorts of welding, including trail welding with on-board welders and/or batteries.
As far as using a 110v machine to weld 1/4" steel, I've yet to see one that has enough snuff to make welds that I'd consider strong. Multiple passes? You're still only welding _/16" thick. If you ground in and then welded the ground down spot in...it still wouldn't be as strong. The more passes you make, the greater the potential for weld porosity, contamination, and weakness... I put the AMC20 truss on my "to do" list, but haven't gotten to it yet. I'm not sure the thickness of the axle tubes...1/4" is probably about right... I definetly agree with the "buy more welder than you need" comment...because you soon will need more than you need right now. You can probably find a 220V AC/DC arc welder for the same price as a 110V DC mig welder...assuming you have access to 220V power, I'd say that's the way to go--especially if you're not the most experienced welder. The Forney 220V welder we have is over 50 years old, and it still works perfectly.
Moneyless, Will weld for jeep accessories.