TIG welding for a new frame

[JimGolden]

OK, I've graduated from my welding class and am getting ready to plunk down some green to buy a new welding machine.

I was all set to get a 250 amp mig machine when I started digging into it a bit deeper. Other than this trailer frame, most of what I want to do is going to be smaller and more precise. I'm thinking I might be better off with a tig machine.

I'm looking at Lincoln Precision TIG machines. Looks like they just replaced the 185 with a 225 amp unit. It sells for about the same price as the 255c mig I as looking at.

Is there any reason I can't weld a trailer frame up using TIG? I know it'll be slower than mig, but other than that, any reason not to? I know NHRA wants race car frames to be tig'd together.

As well, the Precision TIG units also do stick welding, so I could stick weld the frame together as well.

What do you all think?

Thanks,

[Smuzz]

Tig welding is much better than mig. It will allow you so much more control and a broader application of metals it can be done on. I would go for a TIG welder in just about any application.

The big downside to this is if you have just completed a welding class you may not be skilled enough to start welding a frame yet. Unless you are just a natural and the class was mainly focused on Tig welding.

Though, I say buy the tig and spent alot of time practicing welding with it and show it to someone who knows what they are doing and see what advice they have for you. You really need to practice on the vertical and overhead welding if you have just began welding. If you can't get the hang of the tig you always can fall back on stick welding.

I have used the lincons you are talking about I like them but a real nice addittion to them is a water cooled torch. Always buy a machine with as high amps as you can afford or you will regret it later on if you don't.

[axleman]

I agree 100% with Smuzz.

TIG is the way to fly. Get some training first. Perhaps some classes are offered for that where you learned to MIG!

When I was working on my welding certification we started TIG class by learning to Oxy/Acetylene weld. Sounds strange but looking back - it was completely beneficial. It really teaches you the hand/eye coordination that you will use during TIG welding. Additionally - TIG will open the door to work with exotic metals.

Good luck Jim.

Best Regards,
Henry

[Jim Clark]

Originally Posted by axleman

I agree 100% with Smuzz.

TIG is the way to fly. Get some training first. Perhaps some classes are offered for that where you learned to MIG!

When I was working on my welding certification we started TIG class by learning to Oxy/Acetylene weld. Sounds strange but looking back - it was completely beneficial. It really teaches you the hand/eye coordination that you will use during TIG welding. Additionally - TIG will open the door to work with exotic metals.

Good luck Jim.

Best Regards,
Henry

I learned how to weld the same way. We had to Oxy/Acetylene overhead. That was over 40 years ago so I am not sure I could do it now.

Jim

[klattu]

Each welding type has benifits...

TIG
Super slow
Super precise
Super beautiful
No sparks

If your torch is water cooled you may weld non-stop.
Most below 200 amps are air cooled = cycle time on and off.

I use it every day at work...a Lincoln 275..excellent and expensive
At home I have a small 120 amp cheap generic combination TIG/Plasma cutter.

Main problem with a TIG is access to weld area, and controls.
A thumb control would solve the foot pedal problem while welding on your back.
You have your hands full and reach is limited.

MIG dumps metal and is fast, be carful with penitration.
Shoots out great balls of fire too.

Stick is the standard to base judgement.
Cheap
Messy
Easy
Long reach, with new sick
Penitration is great and controlable.
Lots of sparks and slag.

Having a TIG in your shop is one of those really special 'toys' that makes a big differance in your projects success and quality.

[fastrob]

Jim,
When I saw the guys in the welding class burn a rod the idea of doing my own went away. The beauty of the flow was sweet. They sucked up fumes and shook off burns that made me cringe.
Our welder is there in case of emergency.
Some guys would want to do their own.
Recomend you get a good professional, there are hacks.
R

[AlbertF]

As noted, MIG is fast, and penetration can be a problem. In my experience, this is particularly an issue with short welds on small parts. It's not likely to be a problem when welding something like a frame, as long as the voltage is high enough.

TIG welds are beautiful and strong, no question. However, on an Airstream frame no one will ever see them again!

[JimGolden]

Thanks for the replies everyone.

In my class, I didn't actually do TIG. I did oxy-fuel, which is similar in practice anyway.
I've got a buddy who is an expert welder that does TIG and I could get guidance from him. As well, I've got a guy at work who is a Master Welder and who has offered to tutor me. He is not bashful about telling me how terrible I am

Seriously though, I've done a lot of stick welding. I then got into MIG. I really like MIG. I do realize you have to be careful of the penetration. But I know how to look for that. I think I could do a bang-up job on the trailer frame with a 250 amp MIG.

BUT, the other stuff I'd like to do isn't really so suitable for MIG. Namely, weld 4130 tubing together. You either TIG it or oxy-fuel.

So that is my dilemma: MIG + Oxyfuel? Or TIG + Stick? The former takes two rigs, the second is one. Of course, with the oxy-fuel, I could also cut. But, my dad has an oxyfuel rig I could bum.

I'm not sure what to get.

What I really wanted to get was Lincoln 350MP, which is a multi process machine that is a 350amp MIG, a 350amp stick, and a TIG machine all in one.

I figure I'll practice all winter, whatever machine I get. I can get all kinds of metal scraps at work. I figure between practicing for a few months and having the mentoring of the two guys I know, that ought to cover it.

And yes, my vertical up isn't very good right now. But practice will make perfect

[scottanlily]

hello jim ,

All good answers to your querry on the machines .I would go for the mig
for the frame ,mainly because you will be exhausted trying to weld a huge frame with a TIG .Agree on all the benefits of TIG .My stainless water tank
in my trdwnd (round cylinder type) was TIG welded (of course) and it came out great .I myself am looking to buy one at some point to do sheetmetal
for auto /truck restorations ,patch panels and floor pans and such.
The MIG in these applications just is too brutal for lack of a better term
and youll get a more proffessionall results with the TIG and be happier .
The MIG for the frame ,250 amp ,then a nice TIG for the other projects
you will want to do .I have a MIG and A 225 lincoln ,still need the TIG .

Scott

[Ultradog]

Jim,
One advantage to buying a tig machine is that it is constant current. That means they usually can be used for both tig and regular stick welding and theyusually have the plugs, heat ranges, and so on for both types of welding.
A good water cooled tig machine would be a real cool tool to own.
That said, I kind of think using a tig machine to weld up your trailer frame is a little like using a Lamborgini to haul trash. It'll surely do the job but at what cost.
But if you gots the dough...
I've welded a couple AS frames now and used 3/32" LH 7018 stick.
Some folks have just as good of luck using a wirefeed but I must admit that I'm a little old school when it comes to welding and just never had the liking for one of those newfangled "squirt guns".
Keep us posted as to what you buy.
Jerry

[JimGolden]

Ultra, Scott,

You guys both make very good points. If I was only going to do stuff like this trailer frame, I'd go with the big MIG and be done with it.

But, I want to build a tube frame car. And, I'm a big time EAAer and have been looking at building a bush plane which would use 4130 tube for the fuselage and tail. So for that, a big MIG wouldn't be the right tool.

I'd also be doing various and sundry other projects. Not too much filthy stuff like fixing broken plows, but more new fabrication type stuff.

So that's kind of my dilemma. I guess about anything I could do with the TIG, I could also do with oxy-fuel. But I asked my teacher about it (who is excellent at both) and he said hands down TIG would be his preference for welding up 4130. But, that being said, he also stated that oxy-fuel is excellent for tubing, and that on his farm, he uses oxy-fuel even more than stick.

Where I work (a Civil Engineering place that builds big structures), all we use is stick. But we're using it in the field, where it's often filthy, you're welding through muck and concrete spatter and rust. They use 7016 rod and just burn through whatever crud is there. So, the "old timers" there all tell me stick is the way to go, and pooh on MIG.

So anyway, the MIG would be great for the trailer, good for some other stuff, but not the ideal for a lot of stuff I want to do. The TIG/Stick machine (Lincoln Precision TIG 225) would have TIG for the finesse work and stick for the down and dirty. I've seen guys (who are WAY better than me) make some beautiful looking joints with stick. So I know it can be done.

Maybe I'm talking myself into the TIG/stick machine here. I wish I could afford one of each. That Lincoln 350MP (my "dream" machine that does stick, MIG, and TIG) is huge money though. Cheapest I've been able to find it is $3400, and that's a chunk of change in my book. Cost you another $500 for the torch adapter to actually do TIG with it. I'm still thinking about it though.

Heck, a $600 Miller Thunderbolt 225 amp AC/DC stick unit would weld my frame up just fine.

The more I research, the more confused I get.

I thank you all for your guidance. I think welding is fun and cool. I wish I'd learned it 20 years ago

[Smuzz]

After reading what you are wanting to do after you finish the airstream I think you just about have to do a tig. You can burn a stick real fast if you are worried about speed for the frame and use the tig for your tubing and little projects. I would try to buy just the biggest tig unit I could afford and forget about the mig.

I weld for hire on a daily basis mainly in the street rod and custom cars but we also run a farm. Alot of people bring me stuff to weld and when they ask me what i am going to weld it with and I say stick they cuss and rant and rave, because they are used to stick weld being made by people I call gobbers that just make gobs of weld on top of the metal. Most of these people still don't believe me I stick welded it after they see it unless they watch. You can make some really pretty welds with stick. You can also make some really pretty welds with mig you can knock off with a chipping hammer.

If you are considering a oxy-fuel setup then I am really happy with a little torch I have it is a henrob 2000. I think it is the handest thing since sliced bread. I have alot of control with in and is really good at making a small heat effected zone. It was sold by a different name it is early days that i can't think of now.

Good luck and let us know when you decide.

[doorgunner]

Hey Jim, I'm a EAA tech counsellor , big whoop. also was a Rans dealer. Here's some info you might want to know, the BIG rant about oxy and tig and normalizing will continue forever. I will tell you that Rans Aircraft migs up their 4130 fuselages and uses the tig process for all flight control related hardware. I've also been a flight instructor and have had students prang and drive the aircraft into the ground. Never had a weld break on a Rans plane. Why the devil you would want to tig a trailer together is way beyond me. Mig it or use some stupid rod 6011 and get on with it. P.S. the Henrob is a very nice hand piece.

[scottanlily]

doorgunner ,you crack me up on "some stupid rod 6011 ",very good ,or even
stupider 6013 ,also works well ,but I agree on the stupid 6011,works good .
When i fabricated my hitch head using the weld together round bar hitch head ,I used the 225 lincoln and the stick is it ,no question ,great penetration
and nice welds ,you can weld nice with stick .
The MIG takes some skill to ensure adequate penetration ,Ive found that
you need high amperage ,given the type of job your doing to get a good solid weld ,the problem is that you can get a nice weld too easy and its crap.
Jims right ,you need to know how to determine the weld penetration .I say
the stick really is a time proven type of welding for good structure welding
such as a frame ,but the MIG will work great also .

Scott

[axleman]

Jim,

I'm sticking with Smuzz on this one (no pun intended). TIG!

The reason that your coworkers stick weld is because they work outside. I was taught that MIG outside is a no-no, mainly because the shielding gas is not effective in the wind. Additionally, most portable welding units are stick for this reason.

I'm confused about several of Doorgunners statements. First about MIG welding 4130. Isn't that chromemoly tubing? NHRA says TIG only for this process. I am not familiar with airplane construction however. Additionally, I thought 7014 was the idiot rod?

Here's my thought - TIG is king because:
If stick can do it - so can TIG. If MIG can do it - so can TIG. But not vise versa.

If you buy the Stick/TIG combo you will have the best of both worlds. Use the stick to weld the frame (they can do a beautiful job as stated by others and it's faster than TIG) and you will be able to TIG your special projects in the future.


Happy shopping Jim - I hope this helps.

Best Regards,
Henry

[Ultradog]

Originally Posted by axleman

Jim,
If you buy the Stick/TIG combo you will have the best of both worlds. Use the stick to weld the frame (they can do a beautiful job as stated by others and it's faster than TIG) and you will be able to TIG your special projects in the future.

I agree. While you are gaining experience a tig machine will allow you to to do small, precise welds better than mig. The more so since you have already gotten used to an oxy/acet rig and using a tig torch is very similar to welding oxy/acet.

Another reason is that a tig/stick machine with all the apparatus is going to be spendy. So get yourself a machine that will do anything you ever want to do. If in the future you decide that a mig machine is in order you can buy one pretty inexpensively relative to the tig machine.
Whatever you do ( if you go tig) get a torch that is water cooled.

[AlbertF]

Originally Posted by scottanlily

doorgunner ,you crack me up on "some stupid rod 6011 ",very good ,or even
stupider 6013 ,also works well ,but I agree on the stupid 6011,works good .
Scott

Scott, I had to laugh. I've heard one even "stupider"; calling a 6011 an "eleven-oh-nine"!

Jim, I find myself in agreement with most others here - if you're going to build a car with chrome-moly tubing, you're talking yourself into a TIG with a constant amperage power supply! Have fun. (I'm a little jealous - haven't welded anything in 15 years, and I'd love to have a 225 box in my garage. Only problem is I learned with MIG, and find stick challenging except for stainless - that flows beautifully!)

[doorgunner]

Henry yup 4130 is chro mol. The NHRA doesn't have jack to say about Experimental Aircraft. They have their own rules to live by.Having said that I have looked at some homebuilt aircraft- tube and rag construction-that looked like Hellen Keller welded then together.I myself would stick or mig a frame, tig a race car and mig and tig an aircraft. It all works My statement about not tiggin a frame- who wants to spend that much time on the ground.Get er done, I would also suggest reading the books by Richard Finch - Performance welding. The EAA has a few pubs on welding lots of oxy-act stuff. I have an old solar mig, a henrob and a Lincoln square wave 175 tig. It all works good luck. Tim

[klattu]

JB weld

[doorgunner]

Henrob is Dillon Mk III, been driving me crazy all day! I remembered tho.My recommendation for 4130 chrome molly if you need tig precision welds is to purchase a torch from Hi-Tech Welding in El Cajon Ca. Check out the HT-9F-12RSFLDH with the HT-9GL kit. I really like this torch allows to get into very tight areas. The JB weld would be great for a crack above the door as long as your running gear is balanced.