gas welding a trailer

John, Go to

They have plans and info for building.

You are going to need some big tips, I'm not fimilar with Victor so can't give you a no. Smith would be 7-9 , use some 1/8" rods and you might also get a rosebud tip to pre-heat the area to be welded first. It won't take so long to bring the joint up to temp that way. Gas will make some fine welds, just make sure you have enough heat.

John, no offense, but if you have to ask which tip to use, you are not ready to gas weld a trailer. Victor makes a pocket tip guide with cutting tips on one side and welding tips on the other. Its either free or costs around $1. That axle size would dictate 3/16" or 1/4" angle, but you could go thinner with tubing. Spend a lot of time with your torch and the tubing you decide on before trying to make a trailer. Lots of lives at stake if something lets go at 60 mph.

John, no offense, but if you have to ask which tip to use, you are not ready to gas weld a trailer. Victor makes a pocket tip guide with cutting tips on one side and welding tips on the other. Its either free or costs around $1. That axle size would dictate 3/16" or 1/4" angle, but you could go thinner with tubing. Spend a lot of time with your torch and the tubing you decide on before trying to make a trailer. Lots of lives at stake if something lets go at 60 mph.

I'm about to build a trailer the same way. I have a mig welder but I'm going to use my O/A setup anyways. As far as a welding tip goes, I use a #6 for 3/16" and #5 for 1/8" but my setup is made by Harris. The manufacturer usually has a list of what size tip for what metal thickness. Practice with the metal thickness you'll be using on your trailer before you start welding the trailer. I've found T joints to be rather difficult with O/A and require some practice. Butt joints and lap joints havent been too difficult though.

Brian

For your trailer's welds, you'd want to use a #3 tip.

Gary

This guide is red and about 3x5. Most any welding shop will have it and it is usually free. You would most likely want to use a #3 tip. But you probably ought to do a little practice with scrap material of the thickness you will use.

cope wrote: (clip) Spend a lot of time with your torch and the tubing you decide on before trying to make a trailer. Lots of lives at stake if something lets go at 60 mph. ^^^^^^^^^^^ Please listen to this advice. I have a couple of serious reservations about your plan. 1.) It is possible for a beginner to make some good looking, but weak, welds with a torch. You should not only practice, but TEST YOUR WELDS. 2.) In order to minimize distortion, it is important to tack weld, and then come back and sequence the welds properly. This is not hard to do with an electric welder, but with gas, you spend so much time getting the pre-heat, you'll be tempted to keep going, and then your joints will be out of square after they cool. Even if you like the idea of gas welding for some reason, I would still consider a used buzz-box for the tack welding. The amount you will save in gas cost will probably pay for the welder.

I suggest you make a non-hazardous dry run of your scheme by building some patio furniture first.

Yes. I welded a rack for a truck once with gas. It works, but it is

r e a l l y s l o w.

Can you really weld something like a trailer strong enough using OA?

Yes you certainly can. You can weld railroad rails with O/A. Now I'm not saying it is particularly *easy*. You need a big enough torch, and big enough bottles to feed it. You also need a modicum of skill. But it certainly can be, and has been, done.

Gary

uh, couple of you guys are jumping to conclusions. You're assuming I'm inexperienced because I asked about tip size. I use MIG and TIG at work, and have been using O/A on small stuff for quite some time now (that was my refrence to the meco midget torch). Plus the usual tech school welding classes. :)

The reason I was asking about tip size for this project is because we're talking about a great big heat sink here, and the experience I don't have with O/A, is large projects like this. The meco midget will do 1/8" thick steel, but thats on relatively small parts. When we get to the trailer frames, thats just too much heat being wicked away from the joint.

John

John Thompson wrote: uh, couple of you guys are jumping to conclusions. You're assuming I'm inexperienced because I asked about tip size (clip) ^^^^^^^^^^^^ I admit I was picturing a beginning welder--however, I don't admit I "jumped" to that conclusion. I was "pushed." You must admit that asking "What size tip should I use?" is a strange question coming from a professional such as yourself. When I gas-weld, I have the whole range of tip sizes available, and I change size according to the particular weld I am making. An edge-to-edge weld takes less heat than the inside of a 90 degree joint, and more than the outside of a 90. If it's a short weld, I am likely to choose a larger tip, just to speed up the pre-heat and get it over with. On a long run, I would rather size the tip a little smaller, and spend the extra time that it takes to come up to temperature. I don't know of any way a tip size can be stated in advance for an entire trailer.

I hope I don't sound snippy, but I can't quite figure you out.

John, as I said, no offense intended. I have welded a lot of things with O/A, but welding a trailer has never crossed my mind. I would either use stick or mig. I've stick welded several trailers, but my next one will be mig.

I'm not a professional welder, although welding is part of my job. The gas rig is my own personal setup, and as I mentioned, its been for small stuff with a Meco Midget. I've rarely used a "normal" torch since I finished the welding classes in tech school several years ago. It's been all tig and mig until I finally got this victor firepower set in anticipation of building my own plane over the next few years, and the MM is highly recommended for this, so thats what I've used 99.9% of the time. So in other words, my gas welding time with a "normal" torch is pretty minimal, so I don't have much recent experience with heat ranges with them.

John

P.S. The torch tips for this unit are something like $27 I think, in the MSC catalog. That's pretty steep, so I guess I'll take it to the welding shop and see what they have.

John

Hi John,

not trying to be an a** but fabricating anything out of angle iron ....where long pieces and multiple joints are used "like a trailer " i would think an A/O setup would be the last choice.

I would think it would be the least cost effective as well. since you need to heat up a large area on different places just to get a puddle going. Now if this is in the winter time and you are also trying to heat your garage by this method.... well may be ( just kidding )

needless to say there will be fitting issues , so you will have to stop frequently, the torch may need to be shut off and re lit many times . penetration will be questionable, it will take forever to complete. I am not even sure how much heat distorsion will there be.

Personally I would only use A/O for a trailer assembly if i would try to find the most challenging, the longest time consuming, the most $$ spent way to assemble a trailer.

why do you insist using A/O if I may ask ?

My first choice wouldbe MIG - fast , clean , cheap. second choice , stick weld -- fast , have to deal with some slag, cheap.

I'd use a MIG too, but my circuit panel is full up ampwise. If I could find room, then I'd find an excuse for a 175 size MIG.

John