I’ve a Lincoln AC225 stick welder. That’s an AC welder. I’m needing to reweld some bad welds on a small 4X7 trailer. The guy that welded it was a pathetic welder. I’ve a couple of places with ¼”wide gaps where the weld didn’t burn in. Some places have 3” that weld didn’t connect the 2 metals. Flux covered the spots so without inspecting you wouldn’t notice it under the paint.
Anyway I need to know what rod is best to use that will fill the voids and work well on rusty metal. I have several different rods on hand 6011 being one of them.
Any help is appreciated.
just

6013

Might be good idea to grind the old weld down a bit to if it's as bad as you describe

I can send you some rod if you need it

What he said about grinding. Grind down to bare metal. As for rod get some 1/8" 7018 that is formulated for A/C. First 2 numbers state the strength of the rod, 7018 is 10,000lbs./sq.in. stronger than 6013. The third number tells what position the rod is designed for~~ 1 is all position( flat, vertical horizontal and over head), 2 is flat and horizontal, etc. Make sure you get 7018 for A/C, D/C 7018 WILL drive you nuts sticking!
Dennis

Like stated above. Need to grind the old weld out to clean steel. If it absolutely, positively has to be welder through rust or through paint 1/8th inch 6010 would be my go to rod. Will burn through paint and rust and penetrates like no other. The harder you push a 6010 the deeper it goes.

clean metal, 6010 root, 7018 out

4x7 trailer ? if you got 6011 use them ,you will be fine.

^^this, AFTER grinding out the boogers.

Its been said several times on here, Grind out the old welds if at all possible. Been a career welder for 12 years, trust me it'll save you a ton of headaches if you do, and as an added bonus your welds will look much better for it. Best of luck on this, post some pics of the finished results.

After all the other stuff is done you might want to use some type of filler rod to help close up the gaps before you start welding.

Filling gaps ,I use alot of old wet rods that are spoiled , knock off the flux and use it along with my electrode while welding, just feed it in with the other hand like tig, you probably wont see the youtube pros doing it, but its old school, its the way you get the jobs done. or use flattened out copper tube for backer. if you can get to it.

6010 won't run on a Lincoln 225 UNLESS it has DC capability. I would use the 6011 after grinding off the old crap. The base root pass can make or break any joint. Used to be the only 6011 that would run on the old machines was 6011 LOC.

6011 did a fine job ---if you consider the 2 welders haven't stick welded in 10 years. More for me. The welds ain't pretty but they will hold. I tried to post pix but can't figure it out. How do you add jpeg to a picture?
Anyway thanks for the help guys.
Bob

Good deal

Now onto your next project

Oh I'm not done with this one. I need to widen it 8" and lengthen it 13" Its gonna be a teardrop camper dedicated trailer.
BTW how do you measure for a new axle?
just

There are so many types of axles to answer your question.

Torsion spring, leaf spring, etc?

Two things are important.

One it runs straight with the trailer

Second it leaves enough tongue weight to pull better.

The trailers I have built I always place the axle back a little from center.

Problem is the camper itself is lower in front so that needs to be figured in also. That's the reason I'm needing a dedicated trailer. With the trailer its on now I need several concrete blocks inside for weight distribution.
just

If your not sure of where to set up the axle, you can mount the axle, springs, and spring hanger to a piece of angle iron and either U bolt to the frames or make up some bolted clamps to mount the angle to trailer frame. Then you can move around to where it works best. I did this to one boat trailer I made, and never did change it to mounting directly to the trailer frame! LOL
Dennis