Thread: Welder question

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I've got a little craftsman 120v flux-core welder, adjustable speed, non adjustable current just a high/low switch. do you think it's up to the task of some body work and maybe even a little frame work (replacing rusted out sheetmetal rear fraim rails on a 72 nova with competition engineering replacement rails) or if not then temporary spot welds then take it somewhere to get permanently welded in? i know i really should be using a better welder or take somewhere to get done but i don't have the money for either and i really want to do it myself so i can learn.

my bad, it's a 110v, and it's a voltage switch (same idea i guess), and it looks like it's 60A @ 21v and 85A @ 27v, also says min thickness is 18 ga. and max is 3/16in. i would assume it would be up to a little frame work with some different techniques but then again i'm not that experienced and that's why i'm asking

that was my next step, trying some scrap pieces of frame rail. i just wanted to see if anyone was going to tell me it wasn't a good idea with the welder i got, considering it's not very adjustable and it's gasless.

That welder will do body work, and could possibly do framework. But, since you had to ask, I'm going to have to say, no. The reason, your life depends on your frame and you should at least wait until you have enough experience to make your own judgement calls on whether or not the welder is sufficient.

get some practice and during that time you can always triple weld(three beads)
do some practice runs, then try to disassemble them to see how they held/
when in doubt you can chamfer/preheat for better penetration.

Did my whole frame with same welder only a Century brand.
Mistakes take all day to grind and separate.
Remember, it's thousands of pounds of tensile strength per cubic inch of weld,
just guesstimate/calculate and go for lots of weld. If anything your life reaLLy depends on, like an A frame, get it TIG'd

It should work excellent on sheet metal . If you are using it for structual welding , it does have it's limits . I would say 1/8" max on a 110. If your welding a frame you need more penetration . A tig set up with Argon and ER-70S-6 filler rod 1/16" will work . Or try a stick welder with 7018 rod 3/32 . If you are bound and determined to use the 110 use unishield gas with .030 wire . Bevel all the steel first.

With sheet metal it will be fine. Your travel speed and wire speed can compensate for the non adjusting voltage or amperage setting. Just make sure it's penetrating correctly. If your doing any frame work then crank it up and be sure your doing it right. I would suggest a root pass on a frame and then cover it with filler welds and that would be good. That is used a lot with stick welding and no reason it will not work with MIG.

I'm going to go a little against the grain here, because I'd rather see you safe than tell you what you want to hear. The welder you have is really limited. It isn't going to be good on sheet metal because that is where you need really good control, and for frame stuff, it just doesn't have the power.

It will work great, though, to spot weld your stuff, and then it can be taken to a pro welder to have it done right. I'm talking about the frame stuff here, because your life depends on these welds holding. I have built more than one car by me doing the spot welding, then going to a pro to have it finished right. I just don't trust my welds for structural stuff. I know my limitations.

Please understand that I am not dissing your welder, it does have jobs it can do. But for the really important stuff, have it done right. The cost is not really that bad, and you will feel a lot safer going down the road. If you want to learn to weld, take a vo-tech course. They have their good and bad points, but usually you can take your projects in and do them on good equipment, with instructors nearby to help you.

JMO,

Don

No one mentioned this butIF you do deside to do your own welding with that rig (which I think would work if you know what your doing) is to make sure the surface your welding is very clean NO RUST in welding area. I've seen people lay a beed that should hold up the Sears Tower but falls apart because they didn't take the time to grind away the rust. No one was born a welder it takes time and practice try welding an old frame section if your replacing the rear frame member that should give you plenty of material to play with. Weld two pc. together then cut them apart with a saw or grinder to see how your penitration is. GOOD LUCK. You'll never know if you can if you don't try.
Charlie

Itoldyouso is right, that welder is NOT good for welding frames and I should have mentioned that but I was just saying that if you weld it yourself (not talking about with THAT particular welder) then do a root pass and then filler. You need a bigger welder up to 220 outlet. Also, IMO I like to LEAVE the welds exposed instead of grinding them down, I do not like them ground down because I don't think it's as strong. Some people will argue and dissagree with it but either way right or wrong I don't trust it so I wont do it.

how many frames are thicker than the approved 3/16" thickness?
Remember, this is spec'ed by engineers with degrees and tensile testing machines that can certify what they are saying.
if you are unsure, send me a test weld and I can certify it on our labs tensile tester (destructive testing) in KSI (thousands of pounds/cross sectional inch of weld).

......well, I'm not an engineer & I don't have a collage degree but.... I have welded on/off for around 35 years {10 years straight at one time} & there is NO way that I'd trust that welder to weld a frame on MY car. MAYBE in a situation where I could use gussets to take the stress off of the weld & put it on the metal gusset{s}. Or put a metal plate over the weld to support it {fish plate}. Oh, by the way, you shouldn't use vertical welds on a frame {weld it at a 45 degree angle}. But, no way in a critical spot where the actual weld would be under stress..... And the strong part of the weld is the root pass {the first pass}. You can put a hundred passes on top of a bad {or weak because of improper welder/weldor} weld & it won't be strong..... Small wire welders like that just don't have the power to penetrate the parent metal on a frame. An experienced welder could look at the situation and tell you if it'd be a bad idea or not but if you've got to ask the question then DON'T do it.... Just my opinion though..... Oh yeah, notice adds for pre fabed frames from company's that say; "Mig welded with all critical welds done with Tig???". So these company's don't even use Mig & there Mig's are a whole lot more powerful than yours are. Now I'm not saying you need to Tig it but you should use a more powerful Mig or Arc. But, with Arc welding it requires more skill than Mig {Mig is easier to master}...... Bill

Amen.



Don

Yup, that is pretty much right. A lot of people don't stick (SMAW or ARC) weld and thinks it's old school and not needed. To tell you the truth, I would rather stick weld my frame than MIG. But yes you need to know how to weld with a stick welder like when to whip or stack the dimes with what kind of rod, when to zig zag, under cut, roll over, what rod to use, etc. 7018 for your root pass and probably 6010 for your filler or the other way around. Just all depends. You cannot do the whip motion (meaning go farward and dig out your crater and come backwards real fast and fill in the previous crater with metal) with certain rods like the 7018 because you will trap slag but with 6010 rods you can do that. I do not trust welding the thickest metal my welder can weld at because it's struggling to weld at that base metal thickness and just not trustworthy IMO. But enough said from me, I am sure you get the point and we probably scared you enough as it is.

a friend had a 1970 Firebird with a rusted out leaf spring mount on the rear (obviously).
OK, it's just unibody, but I looked at it from an engineering standpoint, static loads. Figure the car is 3200 pounds, figure half in back.
1600 pounds in back, four double ended mounts (eight).
wow a whopping 200 pounds, static. now that doesn't take into account torque, vibration or abuse, go for 400% safety factor unless you're gonna be doing Dukes of Hazzard jumps.
Most frames would be 1/8" wall tubing, roll bar excepted @ 3/16.

If you can't match or beat the strength of a tinny unibody "frame" with 1/8" tubing 1 3/4" diameter I just don't know what to say. You have at least 6" of weld on each and every joint. Not every joint will be "load bearing" very much, wheelstands aside.
SO not every millimeter of weld on the parent area has to be superduty

I have done it already and believe me it's a bitch when you have to disassemble something you have to move. I am not worried in the least on my tube frame chassis, welded with a 90amp fluxcore 035 wire, triple welded joints.

The only part I had TIG'd was homemade A-frames in front, coz they were CrMo and i wanted an attractive and durable weld joint near the threaaded chrome looking heim ends.

Not worried about it.

Amen.

Oh and the guy never did fix the leaf spring, he sold it and the guy drives ot anyway.