wow. i was going to just drop a comment on this thread and move on, but there is just SO MUCH disinformation on this thread. not least of all, your reply. just wow.
you seem to have read alot on this process. but do you have any practical experience welding? because you sound like an inexperienced "web expert" in your reply.
if a 135A machine isn't sufficent, how many amps will a 240A machine require to burn in 1/8" (.125) steel? i'll give you a hint, around 100A....
disclaimer and 'apology':
since I got my 240V SP175+, that really is my go-to wire feed welder at home. I had to go back in time (old posts and some pictures, etc to refresh my memory) and find/remember using the 120V Lincoln wire feed welder (still have it, haven't used it in a long while). Gauge thickness steel with GMAW and C25 and the 120V Lincoln, just fine. Moving up to 1/8" thick steel and that 120V Lincoln and GMAW, depending on joint configuration and prep, the weld penetration started to get iffy. Doable, but iffy. FCAW using NR-211MP and the 120V Lincoln, plenty of weld output power/heat to melt right through 1/8" steel and could run up to maybe 1/4" thick steel with the FCAW wire and not having to do any 'major' joint prep.
... continue of posting ...
Yeah, I sometimes use a welder.
Not everyday though.
Had to weld up something recently. Used some 1/8" thick angle iron (welded on some 1/8" plate to turn it into a sort of 'tube') and some 5/16" bolts and nuts (plug welded a nut onto the end of the bolt to act like the 'pad' on a C-clamp). Used a 240V Lincoln SP175+ and 0.030 Lincoln L-56 wire with C25 gas though. Plenty of power for the job.
Yup, the welding rule-of-thumb for steel is 1 amp per thou of workpiece thickness. So to weld some 1/8" steel would 'need' about 125 amps, give or take a bit.
Do I have an SP135T? Nope. But I have a Lincoln 'cousin' (very similar 120V input machine, but it's the continuous voltage model and not the tapped voltage model). It is not really 'adequate' in power output to quite get good penetration on 1/8" steel using C25 and solid 0.030 wire. Which matches up with the Lincoln manual and the door chart weld parameter recommendations.
Nice machine(s) up to about 14 gauge for GMAW. Not quite enough snot for
reliable consistent GMAW welds on 1/8" thick steel (and his coupler was probably a bit thicker than 1/8", so he'd need a bit more oomph to get a good weld puddle established on the thicker workpiece and then wash the puddle over onto the 1/8" thick trailer tongue).
Those 120V Lincoln machine(s) have enough power to burn right through 1/8" steel and make 'decent' welds (adequate penetration) up to about 1/4" (or maybe 5/16", depending on the exact model of the machine as Lincoln did slightly increase the power output a little bit over the years) when using some
0.035" NR-211MP FCAW wire. BTDT. And turned the machine down from 'fry' to just 'stun' when doing FCAW on 1/8" steel.
But the 'name brand' 240V machines of 175 amp output or greater (Lincoln, Miller, ESAB, etc, but not some of the really crappy 'import' low end 240V machines, which seem to be so inefficient that even with 240V input power they barely have any more weld output power than 'decent' 120V machines. Yuck.) usually have plenty of power to do short circuit transfer mode GMAW on 1/8" steel. Or slightly thicker than that.
Yeah, one could use some preheat, some bevel prep, and/or some really good puddle manipulation to make
sure to get good weld penetration on a 1/8" steel lap joint. But you sort of have to
know what you are doing and watch that puddle well to make sure you are melting into that flat 'plate' underneath and not just melting that easy exposed top edge of the upper workpiece and not getting penetration into the workpiece underneath.
If I'm trying to 1/8" or thicker steel with short circuit transfer mode GMAW, I'm reaching for the 240V welder and not the 120V welder. For 'gauge' thickness steel, most of the 120V machines with GMAW are 'enough' machine (keeping in mind duty cycle and such).
Of course, once I got the 240V SP175+, that really is my go-to wire feed welder.
For 'thicker' stuff, out comes the stick welder and some 6010 Lincoln 5P+ or some Lincoln Excalibur 7018.
Based on the OP's few pictures of his coupler welds, they look a bit cold and inconsistent to me (from a few pics, over the Net, etc). Not the worst welds I've ever seen (posted or IRL), but not quite looking 'good'. The rosette/plug welds looked like I could still easily see the 'edge' of the original bolt holes on the coupler, which means that there wasn't adequate fusion/penetration into the 'top' metal (the coupler), never mind fusion
into the underlying metal of the trailer tongue.
For a 'critical' weld (and a weld that is supposed to be holding a trailer or trailer parts together is indeed a 'critical' weld in my book), I really-really don't think anything that doesn't look 100% good is quite 'good enough'.
Would it hold? Maybe. But I wouldn't want to be behind that trailer going down the road, or the OP pulling that trailer down the road if the welds don't inspire 100% confidence.
Those welds, done with 0.023" wire and GMAW with a 120V machine, do
NOT seem adequate or inspire 100% confidence.
Lincoln says the SP135T is not quite enough machine for welding 1/8" thick steel (manual and the door chart) with GMAW. Plenty of machine if using 0.035" NR-211MP FCAW wire though.
And the OP's trailer coupler was probably a little bit thicker than 1/8".
with a small 110v welder i wouldn't run a vertical down.....run them up, overlap your weld puddle as you move upward. edit: and dont stop at the corners, run over the corner before repositioning to run the horizontals.
And vintagespeed, I 100% agree with you about
NOT running vertical down here (vert down usually means faster travel speed and
LESS penetration, the complete opposite of what the OP would need here), as well as the reminder to not leave a start/stop right on the corners (run the dang weld bead
around the corners, don't leave a start/stop or crater right there on the corner where tons of stress concentration factors are already happening just from the geometry).
Regarding the weldingtipsandtricks website, go right here:
http://www.weldingtipsandtricks.com/mig-welding-procedures.html
and read the part where he says:
Why use even use mig welding procedures? All I gotta do is crank it up until you hear bacon frying.,,, Then I just weld the dog piss out of it.
Please!
Ever heard that kind of argument? It even works sometimes….but sometimes it does not work. and That’s a problem..
Why? Because mig welding is more likely to have lack of fusion than any other process. Short circuit mig welding that is.
And further down the page:
So what is it about short circuit mig that makes it so susceptible to getting lack of fusion and cold lap? I think one reason is because there are no built in limits to the mig process. Wire speed and voltage can be set extremely low and the machine will still run a bead.
Pretty much what I said in my earlier post.
Also see his nice cross section picture on that page of a T-joint fillet weld with
inadequate fusion or penetration.
And
THAT is what I'm concerned about here. Classic short circuit transfer mode GMAW welds with inadequate fusion aka inadequate penetration aka cold lap aka NoGood. The weld 'looks' OK from the top (sort of, the toes sort of give it away if you look carefully and
know what you are looking for and at), but no real fusion or penetration when the weld is cross sectioned.
To the OP, bolt on the coupler and be done with it.
Just like thumber68 said:
I can not count the number of couplers I have had to cut off trailers for people over the years, at first I would weld the new coupler on but after awhile I started to drill and bolt the new couplers on.
Even on my own trailers I now bolt them on, people just don't take care of couplers and they get damaged often, there is one guy I have replaced his coupler at least 5 times due to being abused.
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