Suggestions for welding 1/4" doubler plate to 1/8" truck frame using HH140

[pepsilvr]

I have a HH140 and will be welding a 1/4" doubler plate to my 1/8" frame on my truck. Any tips would be appreciated. I am used to welding same thickness material and do not have too much experience with different thicknesses. The doubler plates are going to be for rock sliders, tube bumper, etc. Also, not sure on the 1/4" size? Would 3/16 be OK? I know I saw a few posts that said to use 1/4". Again, any tips are appreciated.

[calweld]

Bolt it, don't weld it.

[pepsilvr]

Bolt it, don't weld it.

Any reason other than being able to remove in the future? My sliders are welded on and they are great. I think it is the same 1/4 doubler plate setup, I didn't install them because I didn't have a welder at the time.

[nograveconcern]

Bolt it, don't weld it.

Not entirely clear what you mean by "doubler plate", but I would weld to the frame as little as possible due to heat embrittlement--especially midway in the vehicle for sliders. I wouldn't be worried about welding frame ends to make a bracket for a tube bumper. Bolt on also looks cleaner IMO.

[pepsilvr]

By Doubler plate I mean a plate about 3.5" X 3.5" that the tube gets welded to and the plate gets welded to the frame so you are not welding the tube directly to the frame. The sliders are already done and professionally installed. I'm just doing tube bumpers now.

Maybe I was too specific with my question. I just want tips on welding a piece of 1/4" metal to a piece of 1/8" metal without burning through the 1/8" and more specifically how this is best accomplished with the HH140.

[Jim-Tx]

I just want tips on welding a piece of 1/4" metal to a piece of 1/8" metal without burning through the 1/8" and more specifically how this is best accomplished with the HH140.

Concentrate most of the heat on the thicker material and wash over to the thinner material. It's done all the time. Now, as for doing it with a HH140, I'm not sure how much penetration you will get on the 1/4" but I'm going to say that a 140 class machine is a little small for what you are doing since it involves a vehicle frame and safety. With proper procedures I'm sure it's possible. Maybe others can help from here...

[Craig in Denver]

A 120v welder is a poor choice for 1/4" structural welding.

There's a better way than welding on your frame. Here's an idea (first post, pic 3):

http://www.millerwelds.com/resources...ad.php?t=18364

Here's a thread about the disadvantages of welding on your frame. You should read all of it.

http://weldingweb.com/showthread.php?t=32568

[pepsilvr]

Alright, so welding on the frame is pretty much a no-no. I will try to figure out some way to bolt on the bumpers.

As far as penetration, the HH140 states it can do 1/4" in a single pass but with flux only . Either way, I wish I bought a bigger welder

thanks for everyone's help so far.

[XJtrailrider]

I have to agree that welding directly to the frame is a no-no. If i understand the post correctly you are trying to mount a front bumper. I do not run a bumper on my trail rig but I do have a front recovery system that is 3/8" steel and mounts using (6) 1/2-13 grade 8 bolts down each frame rail and is crossmembered between the rails with 1/4" 3x3 angle for side pulls. I had this proffesionally built a few years ago but i feel comfortable enough I could build this for myself now.

For structural welding I use the Miller 452 at work, my HH125 is just not enough for me to trust pulling hard against or for suspension related items.

Here is a pic that kind of shows how the front recovery is built. I'm going to add a home built winch bumper to it someday.

[SidecarFlip]

If you want to mount anything to any roll formed frame, you have to bolt it. The rails are heat treated. Drilling a frame usually entails the use of a magnetic drill motor but I've hand drilled them before. It's not bad so long as you know how to sharpen twist drills.

[Mr.Blue]

Obviously you can't weld directly to a frame or unibody uni-frame rail ...despite this being a 100% weld on suspension even rear coil buckets are welded into the rail ...suspension crossmembers are 1/4 thick welded to uni-rail and frame plate/gussets range from10g-1/4 ...Seems to hold up just fine ,and has for countless others running thin sheet metal based rigs ...Pirate4x4 Jeep cherokee section ...It just won't work "you must bolt it "...LOL

[Sberry]

You wont have to worry about burning thru with a 140 but this is an off road truck, etc? Weld your heart out.