I need to do some repairs on the bottom of my 2S blade. The corners need some help from the cutting edges being worn too short, and the whole thing needs to be straightened. My question is was the bottom of the blade welded at one time or has the weld been worn off? It really spread apart when I took the cutting edges off. After straightening should I leave it, weld it, or add more material then weld it? There's about 3/4" of metal left below the bolt holes for the cutting edges, except the corners where it's worn into the holes.

Do you have another photo of the front showing the bolt holes and another the back of the blade?

If I had to do it, I would get the new cutting edge and see if I couldn't bolt it on offset to one side so you have a straight edge to work from and can lay your repair piece against it and perhaps bolt it tightly using some large flat washers while you securely tack it in place from the back of the blade. Later remove the cutting edge, move to the other edge and do that one. Finish the repair welding from front and back just a short section at a time so you don't end up with a curve from the welding pulling as you go along all in one long bead.

You will have to do any straightening you can ahead of time since it's certainly possible to bend a cutting edge bolting it to a bent surface. If it's just gapped open after the old edge was removed, it should be good to go once you bolt it back tight.

The finished product should be welded together along the bottom edge of the moldboard to join the front skin to the cutting edge support.

I just snapped a couple more pictures, they show the wear I'm talking about. I had already planned on building up the corners, but can do the whole thing if necessary. After my first post today I was able to straighten both pieces back out and started grinding out a couple of corner cracks. The box section of the blade is now absolutely straight, I got the bends out of the ends of the moldboard but it still bows out, it easily flexes back towards the box section and fits nicely when clamped. As I stated earlier there is about 3/4" of metal left between the bolt holes and the lower edge of most of the blade, if this isn't enough far should it be built up?

I for one think it is enough. Once you weld the skins back together it will regain a lot of strength.
You may want to consider some gussets to help support the load, and you can extend them below the skins for the cutting edge to bear against.

On the blade below the bolt holes were worn all the way off, and I did not replace it with a bolt-on edge, but your results could be similar.

CS

Thanks for the replies. I'll build the corners back up and close that gap, then go from there. I didn't think of making gussets for additional support, it might be a good idea on this one.

Well, this is what I decided to do. I got the worn down corners cut out, then straightened and clamped the bottom and welded it back together. After considering several options, I decided to put some heavier material in the corners. I had some 5/8" thick steel that made for a flush finish on both sides. I used the cutting edge to clamp one side at a time, mark out the holes and drill, then tack welded them in. I made gussets out of 1/2" thick steel to both reinforce the corner pieces and support the rest of the botton edge of the blade. I let them stick out under the bottom to act as a support for the back side of the cutting edge. I also left the corner pieces long at the bottoms for the same reason. Once everything was tacked in place I finished welding it all in. It don't look like factory but when the cutting edges are installed none of it will be seen. I'll attach a couple pictures, and yes I know they ain't the purtiest welds

My late dad would have said that your finished product was "hell for stout", meaning it was built very strong. Congratulations on finishing your project. GWH

Looks real nice, Toby. I didn't notice any bad welds, just pretty paint...

CS