Huge angle

[Heavy Metal Doctor]

I'd have absolutely no welding advice on this one, I'm just wondering about the application.....you mentioned the yards of dirt and 72K machine.....are you making this tow bar to put behind the D9 and then pull a dissabled loaded scraper or something???

[DSW]

My guess is they are using the D9 to help pull a Pan. I see that quite frequently on sites.

[MMW]

I would set them up so you wind up with an outside corner weld. This would give you approx a 3/4" weld. Tack it every six inches. Position weldment so you are welding in a vee (sitting like a diamond), then weld one pass 12 inches on & 12 inches off on one side. Flip over & do the same on the other side. Flip over & finish welding first pass on first side. Flip over & finish welding first pass second side. Then weld continuous second pass one side, flip, continuous second pass second side. Same for third pass. Let cool & straighten as needed. I would use 1/16 esab 7100 ultra because that is what I use. If there was a few of these to make I would probably get .072 wire & try to do it in two passes each side.

[c wagner]

I look forward to seeing the end result!!!

[swamp donkey]

just my two cents worth but whenever ive had to do great big long weldments on a column of plate where there is gonna be distortion we would either try to brace it up to keep it from bending or if that isnt an option i would alternate my welds...tack it all up first and then weld 6 inches or so on one side and then roll your "tube" and then weld 6 or so more inches on that side on the other end and basically just keep welding and flipping and staggering your heat to avoid making it look like a banana.
Just a question for my curiosity... what made you choose to weld 2 angles into a box instead of buying a 10' length of tube. Is availabilty, cost, design, weight or any other factors that made you choose this route instead of a peice of 8x8x3/4" tube? would love to hear your answers and see pictures... last time i remember pulling stuff in general with a big ol cat is always fun... stuck or not

[FATFAB]

One of the more interesting threads I have seen on this site.

TJ

[Steve]

I should have had the angle, but alas not in the shop. A few other things got in the way, tis the dirt season. This tow bar will be hooked to a D9 cat to pull a 630 scraper. So there is just a straight pull. Two angles welded are allegedly cheaper than 8 x 8 3/4 square tube. Plan to bevel, tack with 2 in welds/foot and half both sides, then go for the gusto and weld. As the welds are opposing sides by the time I'm done it will still be straight by 1/4 in. 1/4 in in 10 feet you will not see and not affect the end goal. Not to pull disassembled but to pull the scraper loaded to move dirt. Sorry I forgot the camera these last two days. Will not tomorrow.

[Steve]

Update : Got the angle in shop finally. Its cut in half and project was moved back in priority. Seems there is a scraper with the floor ripped out coming in monday.

[MIKEDOGG]

A continuous weld seems unnecessary. Seam welds create distortions, and as previously mentioned, the zipper effect. If I had to prepare and weld the joints described, I would first select Coreshield 8 Weld Wire - Diameter .072. This wire deposition allows a welder to finish with just two passes per stitch. The idea of positioning the angle pieces in a diamond orientation is right on and I would lay this out such that I tacked at the beginning of each stitch and at the end of every stitch to be welded. I would commit to 6" on 12" and start with the first stitch skip one and jump to the next until I got to the end, flip the weldment and repeat. Flip again and fill the first pass on each stitch skipped. Flip and repeat. Now it would be time to make all cover passes nice and pretty using the same system. My main question would be are we sure that two pieces of 10 foot angle welded together ends up being cheaper than one piece of tube only ten feet long?

[Sberry]

If most of the load is in the pull the weld is likely a moot issue anyway. Its built heavy, probably overkill anyway, probably not so closely engineered that it all makes a lot of difference. These issues would be different at absolute max high cyclical loading but if bending is an issue I would weld it all the way.