Peening a weld

As far as I know it's not necessary.

Street rod frames tend to be made of mild steel; while they do crack after long (or hard) use, the cracks tend to be due to stress induced by use -- your brackets don't break close to the welds because of residual stress, your brackets break close to the welds because that's where the metal gets a lot of back-and-forth stress that leads to fatigue.

Engineer the frame correctly, weld it up in a good workmanlike manner, refrain from actually hooking up the outer two carburetors on that impressive polished intake manifold, and you should be fine.

rson wanted to prevent stress cracks in somethign like a t bucket frame, is it a good idea to peen weld areas? Can an air operated needle descaler wor k? Is hand peening possible?

I was considering some sort of free plans on the internet such as these: ht tp://

I think it is made of 2x3 rectangular tubing.

One probalem I have is I can "farm weld". I have a bobcat ac welder but adm ittently not real good with stick. I have a Hobart 110 mig with flux core c apability and gas. I have a bottle of argon/co2 also. Worried the little 11

0v wont be adequate.

I have oxy and could try to weld with it. (Never tried)

One thing I have wanted to try is to buy a bottle of gas and a tig torch fo r the bobcat. Watching tig on mild steel does not look too hard (I know loo ks can be deceiving.) I am not surehow well this set up connected to the bo bcat would work. I have been wanting to give tig a try this way. The welds look neat but I know that TIG does not have very good penetration on thicke r material.

Another thought I had was taking the thing togther, taking it to a local we lder and having it welded there. However, sometimes even having a "professi onal" weld something does not mean it is a good job. Recently I was reading about someone who bought a t bucket frame from a company that makes their own frames. The frame brke in half while transporting the t bucket on a tra iler. The person said it was a stress crack in the frame. That is why I was asking the question about peening.

There's a lot of places that count as "a company that makes their own frames". Some are good, some are crappy. Some of the owners are honest, some shouldn't be trusted with your lunch money. Not all of the honest ones are the talented ones. Life is like that.

There's also a lot of guys out there who -- knowingly or unknowingly -- will totally screw up the parts they're sold, then complain bitterly when they break in exactly the way you'd expect.

(My dad's company, Wescott's Auto Restyling, sold car bodies. Our customers helped to educate us on all the different ways that street rod builders can screw things up, and tell stories about them. Very often the mistakes were simply an under-educated car builder doing something that you learn not to do, and not realizing that they shouldn't have gone there. Sometimes it was a guy doing something wrong and not being able to accept that anything that he touched might not be golden. Once in a great while it was someone being malicious -- there's all sorts out there.)

Without knowing the details, you can't know.

I'd suggest that you get good at MIG, or tack it together and take it to a good welder. If you live close to a decent community college, go take a welding class to get good at MIG welding. Assuming that you feel the teacher is trustworthy, tell him what you've got for a MIG (or take it in) and ask him if he thinks it'll be up for the project. If the thing can get enough penetration then you can probably do the whole frame, but you may need to do it one inch at a time with long rests in between to cool your welder.

If you just want to buy a good frame and build a car, call Karl at Wescott's Auto Restyling and ask him if he has a recommendation. Wescott's doesn't sell T-bucket stuff, but when I was there some of our dealers did. It's been so long since I've been involved in the business that I couldn't know -- the names that were on the top of the list in the

1980's and 1990's were Total Performance and TCI, but I think that TCI has been sold, and Total Performance taken over by the founder's daughters.

For a first-time street rod, I highly suggest finding someone with a good reputation that has a unified catalog worth of stuff. That way you can buy a frame with all the trimmings, and get all the suspension parts, etc., to just bolt on and go. It'll cost more $$$ up front, but it'll be much easier and you'll gain valuable knowledge that you can use to build the next one more from scratch.

Get a tank of plain jane Co2 and use that. It will increase the apparent amperage of your little 110 welder by at least ..at least

25%. Co2 burns hotter and of course deeper than C25 by a significant amount.

And Co2 is a hell of a lot cheaper than C25 as well. The weld may not be as "pretty" as a C25 or Argon only weld..but it will be nice and deep.

Its been my experience..(take it for what thats worth..shrug) ..that if your 110 welder gives you a 90 amp output..running Co2 will take that up past 125-130 amps..minimum.

Gunner

Peening on a steel frame won't do much. Ir works well on iron and cast iron and cast steel, but not so well on rolled steel, steel plate, or pressed steel.

And "welding it up in a good workmanlike manner" does NOT mean you weld the full length of every joint. That's part of the "engineer the frame properly" part that is not so easy - and is in fact very often counter-intuitive.

Actually Gunner , my experience has been that while CO2 burns hotter than C25 , flux core burns hotter than either . Welds look like crap though , so do multipass and grind/flap wheel smooth . FWIW stryped , IMO your plan to try TIG with your bobcat power supply is only going to cost you money and cause frustration . It AIN'T as easy as it looks , even with a "real" TIG machine . I bought one recently , and I learned just how difficult it really is .

Tig can have excellent penetration on thick metal, but it takes a BIG Tig unit. (and a lot of experience) Nothing wrong with stick welding a hotrod frame if you know HOW to stick-weld properly. Unless you are an expert wit a MIG, forget it. I've seen more good looking crappy welds on hotrods than crappy looking good welds. And I've been on the safety lanes with the Canadian Street Rod Association as well as the NSRA at runs across the country..

You are absolutely correct in the difference between fluxcore and gas mig.

Most of the weld peening I've seen done was basically an attempt at counteracting the bead shrinkage that normally occurs. I watch a bloke weld a broken mounting foot on a cast iron motor base. He veed it out with a grinder and welded it with 6011 rod. He'd run a short bead and then peen the hell out of it. Then go away for a while the weld cooled and come back and weld, and peen, a little more. The job took him several days and apparently was successful as I asked him sometime later about it and he said "Well, it never came back".

For those who will likely mention high nickel rod, it isn't available in small town shop in rural Thailand :-)

I read my bobcat is capable of tig, but it lists it as "non critical". Why would that be?

One other question, I read that a root pass is not supposed to be peened? I dont quite understand that but does that mean you cant use a needle descaler to remove flux?

Also, is it good or bad to grind a weld flat after welding? Seems I read the heat from grinding can cause problems as well.

I believe that the general standards are not to grind welds as the raised bead actually contributes additional strength to the joint. A guy that built welded steel boats told me that in order to pass certification the welds could not be ground flat.

As the parent metal is actually melted in the welding process it seems illogical to believe that any additional heat generated by grinding will effect the strength, excepting of course an "air hardening" alloy which is common in bicycle frames and probably less common elsewhere.

If it is better to not grind a weld, is there a way to make a weld "appear" better? What I am getting at is the case of flux core mig welding. It is hard at least for me to make it appear nice looking.

stryped fired this volley in news:694fb054-1b45-4ff9- snipped-for-privacy@googlegroups.com:

Switch to gas and learn to weld. LS

[troll info snipped]

I broke a new knife yesterday in an attempt to get the press-fit end off. (BUDK $10 M-16 replica bayo) It was welded on, I found out later. Not to worry. I fired up the old HFT tigger and listened to it purr at me for about 20 seconds per side and the tang is now firmly back in place. It passes the drop test and hand bend/break test. I sure love that little machine. It makes me look like a real weldor. The copper plated rod is great for keeping me from sticking the electrode to the workpiece, too. (scratch-start, not HF) I should probably invest in some decent rod. Got any suggestions for general repair work?

I also found some extra 3/16" steel plate and will cut and weld on some extra beef to the 1/2-width tang this time, then ensure that it is annealed before attaching it to the shaft of a spear I'm toying with. How does generic steel weld to stainless knife stock? I guess I'll find out later today.

I apologize to everyone for the on-topic post. I'll self-flagellate in atonement later.

You mean oxy welding? I have the equipment but never tried it.

Do you use the ~$200 HFT or the ~$400 HFT TIG box?

stryped fired this volley in news:9e035da0-0bc6-4e1f- snipped-for-privacy@googlegroups.com:

You can, and you can do beautiful welding with it (well weldors can).

But no, I was talking about MIG (or TIG if you're so-inclined).

Lloyd

stryped fired this volley in news:9e035da0-0bc6-4e1f- snipped-for-privacy@googlegroups.com:

Just to be clear, Stryped... there's long haul between podging together metal with flux-core and "welding". If you were smart, you'd learn to oxy- acetylene weld (weld, not braze) first, then move on. By the time you've learnt that, you'll be a whiz at the more automatic methods.

Lloyd