Technique fo stick welding 3/4" plate?

I will be welding with a standard 220v/200A AC stick welder. I will be welding two pieces of 3/4" thick plate togeter at a 90* angle (finished product will look like a piece of angle iron, but 3/4" thickness).

I was planning on beveling both the edges of one piece to get max penetration, and then just make multiple passes to fill.
Is this a good idea? Or can I get away with a standard fillet on the surface?
Also, any suggestions on electrodes and amperage setting?

The application is a farm implement and will be made with new/clean mild steel. Appearance is not important, but strength is.

Any suggestions would be appreciated. Thanks

Sounds like your on the right track so far. As for rod, with AC your limited. I would get some 1/8 7018 AC rod. You will need to chip and brush each pass. 7018 runs stright line best, no whip or weave while welding. Keep an eye on the duty cycle of the welding machine also. Others may have better or easier answers.

There's quite a few ways of doing this joint.

beveling 1 plate from each side like an arrow point will require less metal to fill than if you beveled just one side. On the back side you can bevel the second plate a bit for easier joint access. It's important that you have enough space to get down into so you aren't trapping flux.

You can do you first bead with 6011. It runs pretty nice on AC and digs pretty deep. You could even fill the whole thing with it if you wanted although 7018ac are fine too.

It's going to pull out of square if you aren't careful. A lot of weld in the corner will want to move.

I would do 6011 in the root and either 7014 or 7018AC for the passes. I personally like 7014 and use it for anything that I can weld in horizontal but typically use 6011 for everything - including cover passes.

It would be better to do the joint like SND suggests but weld it on the back of the angle (bevel facing back also). That way, the insides of the joint are square - maybe you don't care one way or the other in this application but the pieces can be restrained against a corner and the joint is easy to get into.

I was planning on tack welding the corners and the middle first to prevent it from shifting out of square.
Total length of the weld will be about 24".
What kind of amperage range should I be running with a 6011 rod (1/8 or 5/32)?

Don't know if it is useful or not: 4 x 4 up through 8 x 8 angle is available 3/4" thick and thicker.

I'd use 7018 because I prefer DC, but with AC only 6011 might work better. V both sides of one plate as you mention. Probably try 3/32" rod for the root pass and hold a short arc to get it stuck together without putting a lot of heat in the plates to pull them around at first. Do like you said and tack a few places. Then hit is hard with the needle scaler and clean up good. Then I would start in the center and weld out both ways with 1/8" rod. Alternate sides, and keep paying attention to which way it is pulling so you can compensate with the next bead. Every time you stop, rattle on it hard with the needle scaler to get rid of the glass and peen the weld.

Then do a top pass on each side to build a slight crown. Either weave a little with the 1/8", or use a 5/32. You will still have to alternate sides and pay attention to how it is pulling.

PS, It is my understanding that full, deep passes are more crack resistant than a bunch of smaller passes. But you will need to strike a balance to control warping the plates out of square.

smt

5/32 7018 rod @ 200 amps
do one straight pass and then do a "weave" over it
that is some thick stuff and 1 little pass don't cut it

...zap!

If you can position this to weld down hand and it's mild steel use 7024 it runs great on AC and will deposit much more metal than other electrodes. Zoom

no one asked- what is your application? load- cantilever, tension, compression. size of plates (LxW)?

mike

If you position the plates so the inside corners touch, rather than one plate on the other, you don't have to bevel at all. Why cut out metal you have to replace, when there may be a different way?

As to tacks, they won't matter much as to squareness. You will be depositing so much metal the plates will move. You just have to work your welds so it is square when you are done.