One method that works fairly well is to "V" grind the crack or pieces, preheat, and tack weld. Then, while maintaining the preheat, make short spaced welds,and using a ball pein hammer, repeatedly hammer lightly on each weld as it cools back to the preheat. Continue welding and peining until groove is filled. Continue peining along the length of the weld as it cools. Rod selection needs some attention also, as some rods are not machinable, so if machining is required, make sure the correct rod is selected.

 

One major problem with welding cast iron is getting it clean enough. It is porous and absorbs grease and oils. If all of the contaminents are not cooked out and cleaned off first you'll never get the weld to hold. IMHO welding cast iron is best left to the pros with a lot of experience.

 

I agree with AX. Welding cast iron is not something for the novice. I had two old cast iron cylinders welded. The welds were in high stress locations. I paid the money. It is not cheap since it has to be brought up to temperature, held to boil off any contaminants, thenwelded in an oven and slow cooled in the oven.

 

I just stumbled on this thread when looking for another one, and figured I’d put in some info. For those that I have quoted as saying something incorrect, don’t be offended. I quoted it in order to help others, not as a means of calling anybody out.

Quote:

Originally Posted by Randy Jack

Welding aluminum in aerospace work is always done using TIG and aluminum rod. No flux is required. Shielding gasses are usually helium and Argon. Unlike MIG, the gasses are usually in separate tanks and mixed at the weld site rather than pre-mixed in one tank.

75/25 (ar/he) can be bought at nearly any welding supply place, and is one of the most popular mixes to TIG weld aluminum with.

oh...and if you have ever seen one of Ron Covell's tapes, and paid for it, you will likely feel ripped off. I have his video about working with tubing, and learned absolutely nothing watching it. In fact, it was so boring that I had to ff through much of it. I could only imagine how horrible his welding videos would be.

Quote:

Originally Posted by mrxlh

309 can be used for joining stainless to steel by AWS standards, 308 may not.

Although it is reccomended (not by AWS) to use 309, they don't say that you can't use it. They just say that you have to prove that it is a filler that wil produce sound welds that keep the integrity of the base metal, or exceed it.

In other words, if you (for some reason) wanted to use 308, and qualified the procedure using it, then AWS is fine with your using it.

Quote:

Originally Posted by mrxlh

Aluminum I highly recomend 5356 over the 4043.

If the part has to be anodized, you must use 5356, rather than 4043.

Quote:

Originally Posted by mrxlh

Better-Built truck tool boxes (Daws MFG.) produces their super shiny (clean) welds by using the same material as filler rod. So for any of you doing any home projects out of sheet aluminum that you will polish or anodize afterwords, do yourself a favor. Buy a larger piece of sheet than you need, take it to a sheetmetal shop and have them shear you off 1/8" wide strips to use as your filler metal for welding said project together.

That's not a very good idea, especially with items that need strength. Think about it...they make boxes, not stuff that really has to be strong. Places that shear off strips of sheet to weld with do so because they're cheap.

I don't think you would be able to find a metallurgist or welding engineer that would reccomend doing this.

Quote:

Originally Posted by Brian_B

Downhill makes a pretty weld, but it won't hold worth anything.

It can hold if done properly. For example: I taught a welding class at a semi-tank trailer company. I found that before I got there, they had only done "face bends" on the welding tests. To prove what COULD pass a bend test, I took two pieces of 1/8" stainless. I put no bevel on them, and fit them with about 1/16" gap between them. I put them up and welded them vertical, downhill. The weld didn’t penetrate through the plate at all, in any place. I got about 50% penetration though. I asked them if they’d accept a weld like that and they said no. I then cut strips of it and bent it. It held fine. So…I can tell you for a fact that downhill welding CAN hold, if done properly.

Quote:

Originally Posted by Brian_B

In every shop I have been around its considered illegal and can get you fired.

There’s a reason for that. If the welding procedure was qualified by welding uphill, then your procedure likely doesn’t allow downhill welding. That’s because the progression (either up or down) is considered an essential variable by some welding codes. ASME will not allow any progression other than is shown on the welding procedure. I’m not sure about AWS, but I think it also considers it an essential variable.

Quote:

Originally Posted by ferguson777

And feel free to explain whether stitch welders are any good for sheet metal

If you can show me a link or tell me what a "stitch welder" is, I’m sure I can tell you…but I don’t know what you mean.

Quote:

Originally Posted by AXracer

Arc or stick welder (buzz box):

thin steel: poor

thick steel: v. good- excellent

ht steel: no

aluminum: no

SS: no

Disadvantages: requires a nearby 220V outlet, lots of sparks and splatter, welds require chipping of flux.

Actually, with the right electrodes (stick rods), you can weld aluminum and stainless with a stick welder. Also, you can now get stick welders that run on 110v power. Example: Miller Maxstar 150.

The proper term is SMAW (shielded metal arc welding), or stick. "Arc" may be the term used often, even in ads for welding machines, but keep in mind that MIG, TIG, sub-arc, and others use an arc also.

Quote:

Originally Posted by AXracer

TIG (heliarc):

Some background on the term "heli-arc"… Years ago, helium was the only gas used for TIG welding. That’s where it got the name… however, with helium not even being the most common gas used for it, the term heliarc is and/or should be considered obsolete.

Quote:

Originally Posted by WillyB

If you are good with a torch, you can cut the nut off a bolt and not ruin the threads - or a stuck bearing and race off a shaft. Try that with your plasma cutter!

Can be done. I’ve done it.

Quote:

Originally Posted by AXracer

If the bead edges turn under at the metal you did not get penetration, increase heat or slow down.

What you’re describing is "cold roll" or "cold lap"…which is seldom a result of welding too cold. It is most often a result of moving too slow.

Quote:

Originally Posted by AXracer

If they are below the surface of the metal you were too hot cut back the heat or go quicker,

that would be called undercut. Typically, if welding on flat material, undercut is caused by the material being dirty (millscale, etc) or by traveling too fast.

Quote:

Originally Posted by AXracer

With metal 1/4" + bevel the edges ~ 60 degrees each side to 1/8" thick and fill the channel in a couple passes.

If you put that much bevel on a piece of 1" plate, the top of your bevel would be pretty wide. Typically, the bevel people use is more like 30-40degrees off of each plate. This is enough to get the weld down into the bevel, but not an excessive amount to fill.

Quote:

Originally Posted by 49willard

A well respected street rod builder in Ma. used to hammer weld with TIG.

Maybe I’m not hip with the slang that many so called professionals use, but what is "hammer welding?"

Maybe it’s some term that he uses to make it sound like he’s doing something special.

Quote:

Originally Posted by Brian_B

The shop I worked on for so many years doesn't even use an Arc for welding anymore at all. They went to MIG for almost everything 15+ years ago (aluminum too-spool gun attachments).

They should get a push-pull gun and then they'd not have to hold up the weight of a spool of wire on their gun. It would then have a large spool at the machine, just like most mig machines do.

Quote:

Originally Posted by Brian_B

They did a titanium job a few years ago that had to be done in a presssurized atmosphere of pure (argon?). It looked like an incubator that they have babies in (gloves and all).

Likely was Argon, but doesn't need to be pressurized.

More comments to add:

Cast metals aren’t what they used to be. Years ago, it was seen as impossible to weld cast aluminum. That’s not much the case anymore, but there’s still some crappy cast parts being made. Most is of much better quality than what we had years ago. I have been successful in welding all cast pieces I have attempted….but the rear stump housing from a Ford truck. I hate to say that here, but it was the case. It kept cracking as fast as I could weld it. I weld one crack and hear another one PING! I have done well welding cast steel with Ni99 tig wire, even without preheat or postheat.

If I was doing body work fulltime, I’d want to use a mig machine, not tig. It gets the weld down fast, with minimal heat input. With tig, it’s a lot slower to put down a tack. It’s easier to control warpage when heat input is kept low.

I have one welding machine at home, and it’s a tig/stick machine. I don’t even own any stick rods though.

 

Yes, it can hold, but it will not penetrate for a stress situtation. 50% is not good enough. Not even close to good enough under stress.

This thread is for amateur welders. They could get away with downhill on a body panel, but I would never encourage one to try it on a frame or something that will end up with stress on it. We are talking people lives in that situation. I will not encourage someone to do something dangerous.


__________________________________________________ _____________________________________________

Now on to another point. It was brought up earlier in this thread, that the best idea for a frame graft may be to fit it all up and take it to a professional to weld. Why is that? Here is my .02 on it.





Let's use the example of a guy (just like you and I) who decides to swap in an LTD front end on his 53 f-100. He cuts the frame, fits the new one perfectly, welds it all up. It fits great! He finally finishes his truck and takes his family for a drive. He is only doing 35 down a two lane highway when something that he welded breaks. He hits a honda head on killing all inside as well as his 3 year old and injuring his wife. He walks away unharmed. Whos just killed all those people? He did by driving an unsafe vehicle that he welded. If you think his life is bad now (losing a child), just wait until the other families lawyers get finished with him and his wife divorces him and takes most of whatever is left.

Again...thats just my opinion. I see some scary welds on front end grafts and "C" notches online. Not so much here, but people should be warned.

 

Not every weld has to be or should be a full penetration weld, and that does include items that lives depend on. Actually, most welds done on structural steel buildings (I=beams) are not done with full penetration.

I agree with your point, but people also need to keep in mind that just because somebody makes a living welding, it doesn't mean they're very good at it. Very few "professional" welders will turn down welding something that they likely won't be able to do properly. They either won't say no, due to pride, or they don't realize their own limitations. Another example would be that you could hire a painter to paint your house, but then find many places he missed, after he leaves. The moral of what I'm saying is that when choosing somebody to do the jobs that you don't trust yourself to do, choose wisely!! Ask for certifications, pictures, stuff like that. Every welder will say they can do everything, but only few can walk the walk.

 

Engloid,
Thanks for your insight, you evidently have had a lot of experience with industrial welding, But others here don't have that background and/or are only amatuers concerned with welding applicable to body work or light fabbing and that's the audience being addressed. I don't feel offended, but would like to comment.
Maybe you felt ripped off by the Covell tape you bought because it was far under your experience, but it doesn't mean that others won't find benefit in it or the others he has put out, since they are geared towards the amatuer with little to no experience. I have been shaping metals for over 30 years as a jewelry craftman, but I found his video "basic techniques for working with steel" to have given me a great deal of information on how to shape, weld and work with sheet steel in body work. I don't believe he has ever produced a video on welding alone.
I find your explanation of the causes of rolled under and undercut bead shape in MIG welding to be diametrically opposite anything I have read or been taught. Perhaps you were refering to TIG?
I"m aware of the origins of the term heliarc and it's outmoded usage for TIG, but it is still is seen and heard in the hot rod field so I included it for completeness.
You're right, I should have said 60 degree included angle not off each side.
It was pointed out later in the posts that a stick welder can be used for aluminum and SS but I still feel it would not be the best choice for a novice to use, especially since hotrodders are typically working with thin materials. Maybe you could do it sucessfully, but I wouldn't choose or recommend a stick welder to weld a SS exhaust system for example.
Hammer welding is a term used to describe the process of reducing shrinkage distortion while welding sheet metal by using a hammer and dolly on the still hot bead to stretch out the shrinkage caused by the weld heat. It's another one of those common misnomers. Speaking of which, what's a "rear stump housing"?

 

Good points as well. This is interesting. No...Structural steel and a lot of other things do not require full penetration. Most are in fact fillet welds or some even butt welds and usually in heavier materials.

Downhill welds are not allowed according to any engineering drawing that I have ever seen. Any structural engineers on the board?

For a body panel it won't hurt anything, but I am strongly against using a downhill for anything serious. Its up to the writers of the article if they include it for anything else, but my opinion is known. I can't say it any more clearly. Its dangerous.


You are completely correct about "professional welders". That is great advice for anyone.

There is only one shop here locally that I would let weld anything of mine (if I were not doing it myself). And even there, only 2 of the employees would I trust out of a crew of about 20 to weld up my frame. Side note: I am not grafting my frame, just a point for trust.

Just because billy bob (no offence to anyone with that name) has a welder does not mean he knows what hes doing. Ask for references and too see the work. Preferably the welder (or the shop) has done similar work in the past and you can speak to other satidfies or disgruntled customers. Just an a mechanic or body man, or any other service, check them out first.

 

I understand your point, but I didn't even feel that was the problem with the tape. It seemed like it was really basic for a professional, but for a novice, he just skipped over some things that should have been in there. An example, in car terms would be a video that said that when you change the timing belt on a specific car, the timing gears must be aligned...but then they didn't tell you how to do it. The expert already knows, and the novice isn't given enough information to do the job correctly.
Nope...it's all about the shape of the weld, not even the process used. You can get undercut on all welding processes.
Yes, I think maybe it's one of the terms they like to use cause they like the sound of it.
Typos happen, and sometimes the fingers are faster than the mind... at least they can be in my case. I type pretty fast.
I definitely agree. Stick welding stainless or aluminum is a lot different from carbon steel. they're not all that bad as long as it's flat, but in other positions, they're pretty dificult. If a person wanted to use their buzz box to weld an exhaust, and didn't care what it looked like...sure, it would work. However, if they want it to look good, tig is the only way to go.
Ok. I could see where that would help, but for a novice, they could easily hammer it too much and cause warpage. You agree?
Rear differential housing. I am from Tennessee, so we do have some different terms we use here.

 

It doesn't take long to get the feel for how much hammering you should do if you work short sections at a time. It's much more difficult to try to figure out how to correct it afterwards when you find the patch you welded it looks like a pillow or you now have an oilcan in a once flat panel.
You always have to stop somewhere in an article or a video, but at least by telling the audience the timing marks need to be lined up it clues you in that there is something I need to get more info on rather than skipping over it completely which may be disasterous for someone following it as their only source of info.

 

This has nothing to do with the article, but whats a push-pull gun for aluminum?


I have not worked in steel fab for a while, but I like to know what everything is. The shop may have them now or the one at the college may.

 

Keep in mind that structural engineers are not welding engineers.
Your welding procedures are usually only referred to on a drawing. In other words, the specific welding procedure may called for on the drawing, but in most cases, all the specs are kept elsewhere...like in a welding procedure book.
I figured I'd look this up and see exactly what the code says, so we both will know, a well as others that read...
Here's a cut from AWS D1.1 Structural Welding Code:
3.7.1 Vertical-Up Welding Requirements. The progression
for all passes in vertical position welding shall
be upward, with the following exceptions:
(1) Undercut may be repaired vertically downwards
when preheat is ...
(2) When tubular products are welded, the progression
of vertical welding may be upwards or downwards,
but only in the direction(s) for which the welder is
qualified.
So, it appears that ASME and AWS are different on this issue. However, in section 2 above, if the tube was horizontally placed, the welder would have to either start on the bottom and weld each side upwards, or start on top and weld downwards...whichever direction he qualified. I don’t have a copy of ASME code, since it’s probably $10k+.
Would I reccomend a novice weld a life/death bearing item downhill? No. I'd advise them to not weld it at all.
It's pretty sad that incompetence in the workplace has become accepted these days. Half the professionals, in any field these days, is not very good at his/her job. I hate to hire people to do things because it seems they always doo crappy work that I could have done myself, as a novice. I just got done doing tile in my bathroom. It was my first tiling job, and I'm pleased. Sure, it's not perfect, but it's probably as good as I'd have gotten if I had paid a "professional" to come do it.
Soon to be famous quote by me: "I can count, but that doesn't make me an accountant."
Push=rollers at the machine
Pull=rollers in the gun

With only rollers at the machine, the drag of wire rubbing the liner becomes great enough that the wire bends between the rollers and the tube that goes to the lead. With the pulling rollers, it helps to pull the wire through and reduce the amount of force the pushing rollers have to do. With a push-pull gun, you have a large spool in the machine, rather than a small spool built into the gun. Miller has a couple out now, called the Edge and Python. They also used to have the "Cobramatic." The XR is another one they sell.

 

As far as the "welder certifications" mentioned above, there are different places for that as well. I am not familiar with who the main ones are (been too many years), but a lot of certifications don't mean anything.

Perhaps Engloid will fill in the blanks here. Please?

There is a 1 year (9 month) college vo-tech programs that teachs welding to high school students in the afternoons. They have a few hours of hands on welding a week. I am speaking of one in particular, but I am sure there are a lot of them.

Almost every student walks out the door "certified" in all sort of positions, materials, and machines. There is no way they spend enough time and get enough experience in those short high school classes to truly know what they are doing and yet they are certified.

Like the acountant thing, I can go online and in probably 10 minutes I can have a dachelors degree in something. Its not worth the paper its printed on, but its legal to have it. If you are going by certifications, look for the names that I hope Engloid can supply. (insert names here)

There are also certifiable welders. Whats the difference? Some customers (refering to a shop) specify that all welds must be performed by certified welders (They usually specify the certifying body).

However, a lot of customers simply require that the welds must be certifiable. If a welder has enough experience and has passed x-ray tests, etc., etc. His welds can be certifiable without the piece of paper saying he is certified. Records of the test he passes must be kept by the company to prove this.

Who would a company do this? simple economics. Its cheaper than the full certification and they don't have to pay an emplyee as much. Guess what...I am certifiable in several materials and positions, but not certified. The shop I worked at only had one certified welder and he came from one of those big welding schools already certified. On a side note: He truly knows what he is doing.

 

The two big ones are American Society of Mechanical Engineers (ASME) and American Welding Society (AWS). AWS certifications are what most schools do because the certifications follow the welder wherever he/she goes. The bad part about a lot of schools is that they charge you for each certification. Therefore, they often have you take more tests than necessary. For example, on 6G pipe (pipe on a 45 degree angle) test for ASME, it certifies you for all positions of pipe. Likewise, you could take the horizontal and vertical tests to qualify you to weld all positions. So, if you pay by the test, you are better to take the one 6G test. Schools like to run you through a lot of certifications that are seldom even something an employer cares about, such as oxy-acetylene welding. It's pretty much obsolete these days, but schools want you to go through it, pay for the cert tests, and then you get to do other types of welding. Schools are businesses. They're really not there to help you. They're there to make money.
I could have my mother certified within a day if I wanted to. AWS D1.1 says that if you fail a test, you can retest "after further practice or training." This means I can explain to you why your test failed and then immediately retest you...over and over until you pass. They don't require that the welder set the machine up or prep the plates either.
As mentioned, an AWS cert will be good wherever you go, as long as you keep it current. An ASME cert will not, and is held through your employer. It is good only at the employer that you tested for. So, if I work for Boeing and am ASME certified, I can't "moonlight" at another company that requires that same cert, unless I take a test for them also.

Therefore, a "certifiable" welder may be one that has shown a history of being able to pass tests...but the employer knows that THEY must test the welder and cannot play on the existing or expired certs the welder has/had. Example: I work at company A, have had several certifications there and on other jobs. I have a history of many certifications. Company B is a place that's hiring people and they must have ASME certified welders. They may look at my resume and know that I have the ability to do the welding, but I still have to pass the test FOR THEM...even if I already have the same cert at company A. In short, look at the term "certifiable" the same you would a person that is able to pass a driver license test, but doesn't have a current license.
This may be some sort of "in-house" thing that companies do. Often times, a customer will only require that the welders be certified...but not specify how or to what code. Therefore, you as the employer may simply look at a welder's work and say the magic words and it's done.

It's all a money thing in most cases. Companies don't want to do ASME testing unless they have to. ASME Section IV is the Boiler and Pressure Vessel code. If you make boilers, you will have to work in compliance with it. There are laws that require it, insurance companies demand it. It's very costly to do. Lets say you want to start making and selling compresor air tanks. You can make a 100% perfect weld on them, but wait till your insurance company finds out what product you're making. Your insurance will be cancelled very quickly. IF you decide to do things right and continue making the tanks, you will pay THOUSANDS just to get it all set up. For one, if you're doing ASME coded work, you are supposed to have a copy of the code at your facility. Now, if the AME guys come in and you literally have a xerox copy, they will likely demand payment for a genuine copy, refuse to certify your plant, or sue you for copying their book. It's all a money thing...
But you also have to keep in mind that if you're the welder and you're making pressure vessels in accordance to a certain code, it's only right that you have access to it so you can comply with it. It is also fair for ASME to be upset if they find out you've made illegal copies of their tuff.

 

most weld certifications are only in ansi/aws
i have current AAR(american association railroads) certs as well which are the same as dot certs for the most part