Welding thick metal

[JasonW]

So I’ve finally saved up and bought a pole barn but needed something to help lift posts and trusses. I had bought a scissor lift to help with it but recently got a KX040.

Yesterday ended up finding a homemade/well built boom jib from a KX057. Which has a different quick coupler than my KX040.

So long story short I have to cut the mounting ears off the boom and weld on new ears sized for the KX040.

What would be the best way to weld 1/2” to 3/4” plate? I have experience welding but nothing this thick. I have a Miller 215 and a Miller Thunderbolt XL, and Lincoln square wave 205. So I should be covered on machines.

 

[#40Fan]

Bevel and pre-heat. Lay it on thick with many passes.

 

[JasonW]

Bevel and pre-heat. Lay it on thick with many passes.

Any preference to process? All mig? All stick? Root pass with stick and finish with mig?

 

[EPIC]

Stick or MiG will work…. Assuming you are not welding in a windy area. High winds can blow the shielding gas away.

Concur with bevel and pre-heat.

But don’t forget that weld heat can and will pull material out of square, so make sure you have it braced well before you start!

I would use MiG assuming the wind issue can be solved.

 

[North Idaho Wolfman]

I just use mig.

 

[Tarmy]

As noted…bevel, clean area, heat…lots of heat(amps), and get a good root pass in to layer on top of…watch distortion or movement on early passes.

 

[hagrid]

7018 in 5/32 diameter.

 

[John T]

propane weed burner works great for preheating
I used one for a long time before I discovered the turbo torch

 

[whatsupdoc]

Use what ever method you are better at mig or stick. When I welded for a living (only for a short time)
I would do a root pass with 6010 then fill with 7018

 

[jaxs]

Use what ever method you are better at mig or stick. When I welded for a living (only for a short time)
I would do a root pass with 6010 then fill with 7018

That's what lots of pipe welds spec so it must be good.

 

[JasonW]

I would say I’m better at MIG as I haven’t stick welding anything in probably a decade. I have torches so I’m covered on the preheating.

 

[GeoHorn]

Thick metal isn’t my challenge. THIN stuff is MY problem.

Today, I needed some 12’ Cee-Purlins to be 12-ft long…and all that was available were 10-footers… So I cut one up into 2’ lengths and welded them onto the ends of the 10-footers….

A chop-saw isn’t very exacting when cutting purlins and to butt them together required jumping a 1/8” gap in much of the mating surfaces.…and they are only 16-ga metal…. so it’s easy to “blow” holes all over the place.

It was do-able…but it’s not presentable without “gobbing” it in some places and then grinding it flat again. (Rustoleum rattle-can paint helps appearance.)

(I wonder if a heavy sheet of copper beneath it might help provide support for the bead to “settle” or “puddle” into place..?)