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General Forums => The O' Club => Topic started by: F22RaptorDude on February 22, 2012, 08:16:22 PM

Title: Anyone know how to weld?
Post by: F22RaptorDude on February 22, 2012, 08:16:22 PM
I'm beyond eager to learn how to, I want to get some knowledge so I can build my own scratch build go kart, and possibly a air soft tank for me and a few buds

I've heard that MIG welding is the most common and easiest to use? But i'm still not understanding how it works?
Title: Re: Anyone know how to weld?
Post by: Melvin on February 22, 2012, 08:19:43 PM
Find someone to show you how to weld.

It can't be taught on a bbs.
Title: Re: Anyone know how to weld?
Post by: M0nkey_Man on February 22, 2012, 08:23:31 PM
Find someone to show you how to weld.

It can't be taught on a bbs.
^this. I'm still learning from my grandfather :aok
Title: Re: Anyone know how to weld?
Post by: F22RaptorDude on February 22, 2012, 08:28:54 PM
Need basics, I hear a person can self teach them?
Title: Re: Anyone know how to weld?
Post by: Spikes on February 22, 2012, 08:31:53 PM
http://bit.ly/yHjSyq
Title: Re: Anyone know how to weld?
Post by: StokesAk on February 22, 2012, 08:32:49 PM
Magnesium and some a match, make sure to hold it real tight.
Title: Re: Anyone know how to weld?
Post by: F22RaptorDude on February 22, 2012, 08:33:31 PM
I figured i'd go to people who knew rather than just get tripped up over the internet
Title: Re: Anyone know how to weld?
Post by: Melvin on February 22, 2012, 08:37:33 PM
I figured i'd go to people who knew rather than just get tripped up over the internet

Exactly.

Find someone near you that can show you how to weld using various methods.


Surely there is a weld program in some school near you. Lacking that, you may wish to find a local manufacturing company and express your interest.

It is a fantastic talent to possess, I highly encourage you to follow up.
Title: Re: Anyone know how to weld?
Post by: Golfer on February 22, 2012, 08:37:56 PM
I figured i'd go to people who knew rather than just get tripped up over the internet

This IS the Internet.
Title: Re: Anyone know how to weld?
Post by: Maverick on February 22, 2012, 08:57:32 PM
Check out the local Jr College. Chances are there are some welding classes available there.
Title: Re: Anyone know how to weld?
Post by: vorticon on February 22, 2012, 09:00:28 PM
i'm assuming you arn't in high school and can't simply do it in shop class...

for what it will cost to tool up, you should be able to get a evening course through a local tech school.

or...buy the cheapest MIG welder you can find, read a bunch of books, practice lots on scrap steel and otherwise spend a lot of time and money getting nowhere with toejam tools and no way of knowing if you're actually doing anything right.

and if you really want to read up about stuff on the internet...start here: http://www.lincolnelectric.ca/knowledge/articles/content/arcweldfund.asp
Title: Re: Anyone know how to weld?
Post by: cattb on February 22, 2012, 09:04:00 PM
 I weld, go-to to school. There is different types of gas, size of wire and different types of wire, types of steel and more. There is setting the gas pressure when welding,the wire speed, and more.

How are you going to design your go kart? What are you going to build it out of? If you  use tube steel, who is going to bend it? It goes on and on.

Could also get a book from library and enhance your brain with knowledge and then have someone help you and practice.

If you plan on being a do-it-yourself type person, then learning to use a torch set, brazing, and welding is a definite plus.

Good Luck

Just a note, I learned welding from night school, then I learned from experienced welders. Also learned from many hours of welding and mistakes.
Title: Re: Anyone know how to weld?
Post by: homersipes on February 22, 2012, 09:15:59 PM
I taught myself how to weld, my first project was a 1854 triumph chopper, I cut the fame and welded it back with torches, had it going on 9 years now and no stress cracks or anything and the bike has around 60000 on it so I must have done something right lol.  I wouldnt weld a frame or anything like that for someone else.  I now have a lincoln mig, much easier.  want to tig but cant afford one of those yet
Title: Re: Anyone know how to weld?
Post by: 68ZooM on February 22, 2012, 09:21:54 PM
My son's high school offers a basic and advanced welding classes, he got the bug after watching me weld for years, today i went in for my interview at Keith Manufacturing, i spent 3 hours doing my welding postion tests which were 2G, 3G, and 4G for plate and my 2G,3G and 5G for Pipe, the interview i thought went very good and they want me to come back in 5 days when the structural weld test results are back for my welding samples i did today.

check out gowelding.org and read up on the profession, granted its smelly, dirty and can be very hard at times, but if you're a person that likes building things using you're hands welding is a great job and big bucks can be made depending on what field you enter, to bad you didn't live closer i would give ya one of my older MiG welders and within an hour i could teach you how to lay a weld down, its not that hard once you learn the fundamentals of how welding works, good luck to ya Lil dude  :aok
Title: Re: Anyone know how to weld?
Post by: saggs on February 22, 2012, 09:38:15 PM
Be careful who you learn from.

There are lots of guys out there who can "weld".  But some of the "welds" I've seen from these kind of guys are pretty scary.  Being a bad welder is easy, being a good welder is not so easy, but it's not terribly difficult either.

Like others have said your best option is to take a beginner community college (or high school if your still there) course.  That way you get real information and help from people who really know what they are doing, and you get to use decent equipment, and get to try various disciplines and materials.   It will be good to get that kind of broad overview, then you will learn what kind of discipline you want/need to become really good at, and also what kind of equipment you want to invest in, good welding equipment isn't cheap, and cheap welding equipment isn't good.  As a bonus if you take a HS or college course they may even let you weld your go-kart frame on their equipment as a final project.  When I took welding in HS way back, I remember all kinds of student projects from winch bumpers, to squeeze chutes to (what I built) a flatbed utility trailer.

You are correct that wire feed is the easiest to learn, and probably most useful for various tasks as well.  Some of the little 120V machines from Lincoln or Miller are pretty handy for light work and can be picked up for ~ $500-$600.  I'd stay away from flux-core wire and use gas though, I don't like flux-core.

Title: Re: Anyone know how to weld?
Post by: F22RaptorDude on February 22, 2012, 09:44:19 PM
i'm assuming you arn't in high school and can't simply do it in shop class...

for what it will cost to tool up, you should be able to get a evening course through a local tech school.

or...buy the cheapest MIG welder you can find, read a bunch of books, practice lots on scrap steel and otherwise spend a lot of time and money getting nowhere with toejam tools and no way of knowing if you're actually doing anything right.

and if you really want to read up about stuff on the internet...start here: http://www.lincolnelectric.ca/knowledge/articles/content/arcweldfund.asp
I'm a Sophomore in High school, the only class like that is automotive and they don't talk about welding
I figured I would do that, buy the cheapest one and watch as many tutorials on you tube and read as many books as I can find

I weld, go-to to school. There is different types of gas, size of wire and different types of wire, types of steel and more. There is setting the gas pressure when welding,the wire speed, and more.

How are you going to design your go kart? What are you going to build it out of? If you  use tube steel, who is going to bend it? It goes on and on.

Could also get a book from library and enhance your brain with knowledge and then have someone help you and practice.

If you plan on being a do-it-yourself type person, then learning to use a torch set, brazing, and welding is a definite plus.

Good Luck

Just a note, I learned welding from night school, then I learned from experienced welders. Also learned from many hours of welding and mistakes.
There's probably a book or two about it at the library at school, I won't get my hopes up though they don't have a whole lot of stuff, Tubular steel you need a device to bend it, what are those called I know I have seen them before!

I taught myself how to weld, my first project was a 1854 triumph chopper, I cut the fame and welded it back with torches, had it going on 9 years now and no stress cracks or anything and the bike has around 60000 on it so I must have done something right lol.  I wouldnt weld a frame or anything like that for someone else.  I now have a lincoln mig, much easier.  want to tig but cant afford one of those yet
I want to own my own mechanics shop later in life, knowing how to do this is a good step in that direction, may I ask on how you self taught yourself?


My son's high school offers a basic and advanced welding classes, he got the bug after watching me weld for years, today i went in for my interview at Keith Manufacturing, i spent 3 hours doing my welding postion tests which were 2G, 3G, and 4G for plate and my 2G,3G and 5G for Pipe, the interview i thought went very good and they want me to come back in 5 days when the structural weld test results are back for my welding samples i did today.

check out gowelding.org and read up on the profession, granted its smelly, dirty and can be very hard at times, but if you're a person that likes building things using you're hands welding is a great job and big bucks can be made depending on what field you enter, to bad you didn't live closer i would give ya one of my older MiG welders and within an hour i could teach you how to lay a weld down, its not that hard once you learn the fundamentals of how welding works, good luck to ya Lil dude  :aok
Thanks for the link reading up on it now, I want another garage I can work in besides my parents, parents have 2 cars and I have one as well so theres most often 2 in the garage, biggest problem I can think of right now, can you rent garages?

Be careful who you learn from.

There are lots of guys out there who can "weld".  But some of the "welds" I've seen from these kind of guys are pretty scary.  Being a bad welder is easy, being a good welder is not so easy.

Like others have said your best option is to take a beginner community college (or high school if your still there) course.  That way you get real information and help from people who really know what they are doing, and you get to use decent equipment, and get to try various disciplines and materials.   It will be good to get that kind of broad overview, then you will learn what kind of discipline you want/need to become really good at, and also what kind of equipment you want to invest in, good welding equipment isn't cheap, and cheap welding equipment isn't good.  As a bonus if you take a HS or college course they may even let you weld your go-kart frame on their equipment as a final project.  When I took welding in HS way back, I remember all kinds of student projects from winch bumpers, to squeeze chutes to (what I built) a flatbed utility trailer.


What I really want to build is something like this http://www.youtube.com/watch?v=S2-JE_Skdf0 (http://www.youtube.com/watch?v=S2-JE_Skdf0) the go kart will be something I do to get to know how it works and as I plan, 100% scratch build besides the engine which i'm currently looking for
Thinking about it I could probably get some help from my grandfather, he's to old to use his tools anymore plus their garage is full of nothing but junk so its hard to get over there to the tool side. I've never seen any welders in there but I'm sure he know's how to, he taught me how to solder wires when I got my first rc plane a few years back
Title: Re: Anyone know how to weld?
Post by: icepac on February 23, 2012, 09:03:17 AM
Maybe the "industrial arts" class has the welder instead of the auto shop like most high schools do.

I chose the "industrial arts" class instead of auto shop yet still drove a 650hp car to school.

Choosing your type of kart is important as there are "general karts" and "specific karts".

It's best you find a basket case kart of the type you will be needing based on where you will be driving it.

Then you fix it to suit the task you require.

Title: Re: Anyone know how to weld?
Post by: olds442 on February 23, 2012, 09:08:54 AM
dont put your hand under what your welding.

thats hot.

dont even think about put your finger on that.

dont hold it in one spot.

its not broken you just suck.
Title: Re: Anyone know how to weld?
Post by: Shuffler on February 23, 2012, 12:42:34 PM
When we hire a welder.... we go through maybe 80 to 100 applications to find one with a good hand. They are not up to our standard but they can be taught if they have a good hand.

Welders are a dime a dozen... good ones are hard to find.
Title: Re: Anyone know how to weld?
Post by: zippo on February 23, 2012, 01:15:03 PM


Welders are a dime a dozen... good ones are hard to find.

  What he said...anyone can run a bead....I can run a bead but I'm no welder.

  And never ever weld while wearing sneakers.   It hurts when it burns through your shoe and kinda sticks there.  Still have the scars.
Title: Re: Anyone know how to weld?
Post by: saggs on February 23, 2012, 01:31:50 PM
  What he said...anyone can run a bead....I can run a bead but I'm no welder.

  And never ever weld while wearing sneakers.   It hurts when it burns through your shoe and kinda sticks there.  Still have the scars.

 :lol  Everybody who's done much welding has those.  After working as a production welder for 4 years, the inside of my arms/inside elbow area are covered in burn scars.  And nope, I didn't wear leathers, the environment I worked in was already to blasted hot, and we had to move quick.   I wore canvas aprons and cotton pull-on sleeves which would be shredded after a week or two.

Since we're on to safety tips.  Never weld galvanized steel without a fresh air system, I learned the hard way about zinc poisoning, it ain't much fun...   :old:
Title: Re: Anyone know how to weld?
Post by: Flench on February 23, 2012, 01:43:27 PM
Need basics, I hear a person can self teach them?
I did but had help with what rods to use from the store I got them from . Stick welder that is .
Title: Re: Anyone know how to weld?
Post by: Reschke on February 23, 2012, 02:16:06 PM
Flux core wire is good for certain applications. We use it when welding heat treated pipes to withstand burst pressures because the pipe we weld has to pump upwards of 18k psi concrete at a pressure of at least 250-300bar without bursting for a minimum of 20k strokes from a concrete pump.

We also use some really weird gas mixtures as well since the beads have to be almost like aerospace quality welds. The welders we had here in Alabama were good hands and one was a great teacher/welder. All three of them made $20+ an hour and worked 60+ hours a week till we shut down operations and moved it all to Wisconsin.
Title: Re: Anyone know how to weld?
Post by: saggs on February 23, 2012, 02:17:42 PM
I did but had help with what rods to use from the store I got them from . Stick welder that is .

Just don't use --2- rod for vertical or overhead.  Somebody dropped a 7024 rod in with a pile of 7018 on me once, buzzing along an vertical weld, grab a new rod, then suddenly "what the heck?"  That's when I noticed the rod was a different color  :o .

What I really want is one of the fancy SMAW and TIG in one machines.  They're kinda pricey though.
Title: Re: Anyone know how to weld?
Post by: Flench on February 23, 2012, 02:27:52 PM
Just don't use --2- rod for vertical or overhead.  Somebody dropped a 7024 rod in with a pile of 7018 on me once, buzzing along an vertical weld, grab a new rod, then suddenly "what the heck?"  That's when I noticed the rod was a different color  :o .

What I really want is one of the fancy SMAW and TIG in one machines.  They're kinda pricey though.
Oh no that would be a bummer . A SMAW and TIG in one machines would be nice but I don't have to do that much welding . I just welded a 5 foot piece of angle iron of the axle of my deck boat to help support the weight . Don't know why they did not put two axles under it with all that weight . I just did not trust it but do now .
Title: Re: Anyone know how to weld?
Post by: Shuffler on February 23, 2012, 03:47:11 PM
:lol  Everybody who's done much welding has those.  After working as a production welder for 4 years, the inside of my arms/inside elbow area are covered in burn scars.  And nope, I didn't wear leathers, the environment I worked in was already to blasted hot, and we had to move quick.   I wore canvas aprons and cotton pull-on sleeves which would be shredded after a week or two.

Since we're on to safety tips.  Never weld galvanized steel without a fresh air system, I learned the hard way about zinc poisoning, it ain't much fun...   :old:

Our welders work in Air Conditioning. :D
Title: Re: Anyone know how to weld?
Post by: Shuffler on February 23, 2012, 03:49:48 PM
Flux core wire is good for certain applications. We use it when welding heat treated pipes to withstand burst pressures because the pipe we weld has to pump upwards of 18k psi concrete at a pressure of at least 250-300bar without bursting for a minimum of 20k strokes from a concrete pump.

We also use some really weird gas mixtures as well since the beads have to be almost like aerospace quality welds. The welders we had here in Alabama were good hands and one was a great teacher/welder. All three of them made $20+ an hour and worked 60+ hours a week till we shut down operations and moved it all to Wisconsin.

My number one welder makes over 100K a year. We do everything from the farmer down the road to NASA. Mostly MIG and TIF... rod only when doing cast or some other material where you can't get wire.
Title: Re: Anyone know how to weld?
Post by: VonMessa on February 23, 2012, 03:52:19 PM
Tube welding, if chromoly tube, cannot be MIG or stick welded.

O/A torch welding is optimal, but it can be TIG welded if done carefully and the welds must be normalized afterwards (by using a torch)

O/A welding tube is way cheaper than buying a TIG setup.

Title: Re: Anyone know how to weld?
Post by: Shuffler on February 23, 2012, 03:56:10 PM
Tube welding, if chromoly tube, cannot be MIG or stick welded.

O/A torch welding is optimal, but it can be TIG welded if done carefully and the welds must be normalized afterwards (by using a torch)

O/A welding tube is way cheaper than buying a TIG setup.



We TIG it............
Title: Re: Anyone know how to weld?
Post by: Flench on February 23, 2012, 03:59:26 PM
My number one welder makes over 100K a year.
Darn ! 100K a year . You need a welder . I would move for half that , lol .
Title: Re: Anyone know how to weld?
Post by: Jayhawk on February 23, 2012, 04:01:55 PM
I did a little stick welding, I could make things stick together, but it's not very pretty.

Gave myself one heck of a sunburn on my arm once, that was stupid.  :cool:
Title: Re: Anyone know how to weld?
Post by: Flench on February 23, 2012, 04:07:54 PM

Gave myself one heck of a sunburn on my arm once, that was stupid.  :cool:
Don't feel bad I did the same thing , lol . Live and learn I guess .
Title: Re: Anyone know how to weld?
Post by: cattb on February 23, 2012, 04:34:48 PM
  What he said...anyone can run a bead....I can run a bead but I'm no welder.

  And never ever weld while wearing sneakers.   It hurts when it burns through your shoe and kinda sticks there.  Still have the scars.
I had a hot-one go into my workboot. I ended up going to the doctor and was back at work 2 months later.

Title: Re: Anyone know how to weld?
Post by: texasmom on February 23, 2012, 04:50:34 PM
Need basics, I hear a person can self teach them?

Bad idea.
Title: Re: Anyone know how to weld?
Post by: Jayhawk on February 23, 2012, 04:53:28 PM
You can read every book on welding and still have no idea how to weld.  In my experience, it's one of those things you have to DO to learn.
Title: Re: Anyone know how to weld?
Post by: texasmom on February 23, 2012, 04:55:42 PM
My son has been taking welding classes 3 hr a day for the last few years.  I went to his shop a few weeks ago. I was astonished to seethe difference between what i thought it was, and what it actually entailed.  Wow to welders (including my kid).  Scarey stuff!  Shop is not a proper place for a Mom, danger radar was on overload.
Title: Re: Anyone know how to weld?
Post by: Flench on February 23, 2012, 04:57:59 PM
You can read every book on welding and still have no idea how to weld.  In my experience, it's one of those things you have to DO to learn.
Thats not true for me . I can weld pretty darn good and no one showed me . I went from what I was told and read and many year's doing it .
Title: Re: Anyone know how to weld?
Post by: Jayhawk on February 23, 2012, 05:07:20 PM
Thats not true for me . I can weld pretty darn good and no one showed me . I went from what I was told and read and many year's doing it .

I bet it took you a while to get good at it.  I didn't mean one couldn't teach themselves, but it actually takes doing it to learn (like most anything).  So if he wants to weld, he needs to find a welder.  Whether he has someone teach him, or practices himself, he won't be able to get a welder, sit down at his go-kart, run a practice bead and go.
Title: Re: Anyone know how to weld?
Post by: Flench on February 23, 2012, 05:09:32 PM
I bet it took you a while to get good at it.  I didn't mean one couldn't teach themselves, but it actually takes doing it to learn (like most anything).  So if he wants to weld, he needs to find a welder.  Whether he has someone teach him, or practices himself, he won't be able to get a welder, sit down at his go-kart, run a practice bead and go.
I agree he need's to have someone to teach him . Save him alot of time and money in the long run .
Title: Re: Anyone know how to weld?
Post by: cattb on February 23, 2012, 05:38:07 PM
I have never done a go kart. Still may need tack bars and possibly spacers. There is nothing worse then welding someone elses poor setup or assembly thats not tacked together properly.

So building this go kart is alittle more then just welding.

I stopped welding where I work about 5 years ago because of the garbage I would run into.
Title: Re: Anyone know how to weld?
Post by: saggs on February 23, 2012, 10:04:25 PM
Tube welding, if chromoly tube, cannot be MIG or stick welded.

O/A torch welding is optimal, but it can be TIG welded if done carefully and the welds must be normalized afterwards (by using a torch)

O/A welding tube is way cheaper than buying a TIG setup.



Why not?  Is there some guideline from the AWS or similar organization on this?

I'd always heard this, stories that MIG welded chromoly would stress fracture at the weld  quite easily, and I used to take it as gospel.   So a few years ago I decided to do my own non-scientific experiment.  I MIG welded some scrap chromoly tube (made a 90° mitered corner), without pre-heating or normalizing, just let it air cool, put it in the vise and beat it with a sledge for a good 10+ minutes, then I put a 3-4' cheater bar on it and wailed on it in both directions for several more minutes, to no effect.  Having believed what more experienced folks had told me I was honestly surprised that I could not break it.   So then I gave up breaking it and cut it in half... and everything looked fine, then I was skeptical.

Having read and learned a bit more since then, I now believe that MIG welding 4130 chromoly is perfectly fine and safe, as long as you let it air cool at a moderate temp, and don't quench it in water or oil.

Also, as better evidence I know that both Cub Crafters and Maule (possible others too)  MIG weld all their fuselages with 4130 chromoly steel.  Granted they have better control and facilities then some guy in his garage, but it must be possible and perfectly safe or the FAA would not have certified those airframes.  There are hundreds of Maules and Carbon Cubs that get beat around bush flying daily, and I've never heard of any stress fractures at the welds on them.  In fact Cub Crafters claims that their fuselages are stronger then the original Piper ones.

What's really neat is some of the new technology like "friction stir" welding, no gas, no electric arc, just friction from a tip spinning very fast under pressure.  Makes a beautiful flat weld with no filler.
Title: Re: Anyone know how to weld?
Post by: FiLtH on February 23, 2012, 10:05:08 PM
By airsoft tank, do you mean an armored vehicle, or a pressurized vessel for storage of gas?  Ive welded a little bit and got pretty good at basic stuff, but I'd never try to build a pressure tank.
Title: Re: Anyone know how to weld?
Post by: Jayhawk on February 23, 2012, 11:44:25 PM
By airsoft tank, do you mean an armored vehicle, or a pressurized vessel for storage of gas?  Ive welded a little bit and got pretty good at basic stuff, but I'd never try to build a pressure tank.

Oh yeah, second that on not building a pressure vessel.

Oh and if it's an armored tank, just put a cardboard box over your head.
Title: Re: Anyone know how to weld?
Post by: homersipes on February 24, 2012, 05:40:54 AM
was building a bumper for my honda odyessey and was chipping the slag off(no safety glasses) a piece of this hot crap went into my eye.  Rubbed it real quick and it felt fine, well the next morning my eye was all red and hurt like a SOB.  The piece was embedded into my eye you could actually see it on my eyeball.  My wife and friend made me go to the doctor and he used what looked like a dremel tool with a cutting tip on it to get it out of my eye.  Ever since then I use safety glasses.
Title: Re: Anyone know how to weld?
Post by: VonMessa on February 24, 2012, 07:33:14 AM
Why not?  Is there some guideline from the AWS or similar organization on this?

I'd always heard this, stories that MIG welded chromoly would stress fracture at the weld  quite easily, and I used to take it as gospel.   So a few years ago I decided to do my own non-scientific experiment.  I MIG welded some scrap chromoly tube (made a 90° mitered corner), without pre-heating or normalizing, just let it air cool, put it in the vise and beat it with a sledge for a good 10+ minutes, then I put a 3-4' cheater bar on it and wailed on it in both directions for several more minutes, to no effect.  Having believed what more experienced folks had told me I was honestly surprised that I could not break it.   So then I gave up breaking it and cut it in half... and everything looked fine, then I was skeptical.

Having read and learned a bit more since then, I now believe that MIG welding 4130 chromoly is perfectly fine and safe, as long as you let it air cool at a moderate temp, and don't quench it in water or oil.

Also, as better evidence I know that both Cub Crafters and Maule (possible others too)  MIG weld all their fuselages with 4130 chromoly steel.  Granted they have better control and facilities then some guy in his garage, but it must be possible and perfectly safe or the FAA would not have certified those airframes.  There are hundreds of Maules and Carbon Cubs that get beat around bush flying daily, and I've never heard of any stress fractures at the welds on them.  In fact Cub Crafters claims that their fuselages are stronger then the original Piper ones.

What's really neat is some of the new technology like "friction stir" welding, no gas, no electric arc, just friction from a tip spinning very fast under pressure.  Makes a beautiful flat weld with no filler.

Well, when I finish building my Bearhawk, I would like to show in my builders log that all welds were crafted properly so my DAR gives me an airworthiness certificate.  That coupled with the coin that I shelled out for my EAA class on welding leads me to believe that the pros know what they are doing.

 It is physically possible to perform MIG welds on 4130, but if the joint is cooled too quickly, it will be a brittle weld.  There is no other way about it.  It is the nature of the steel because of the carbon content.  The "41" denotes a low alloy steel containing nominally 1 percent chromium and 0.2 percent molybdenum (hence the nickname "chromoly"). The "30" denotes a carbon content of 0.30 percent.  If you heat 4130 to the point where the carbon comes to the surface and then cooled too quickly (even a drafty garage is too quickly), it develops Martensetic qualities (a crystalline structure typical of steel containing carbon that has been heat treated) the weld will become brittle.  If this happens, it has to be tempered just like tool steel or it will develop stress fractures and possibly break.  An O/A flame weld has less tendency to do this

When welding an airframe, especially the clusters where there are lots of tube joints, there is a tendency for that area to become hot enough that the joint requires normalization.  A MIG or SMAW welded airframe, if performed by a homebuilder, will not pass the DAR's inspection.  This much I know.

Having a TIG welder at home would be nice, especially considering all of the welding that I do on my Wrangler and the parts that I fab for it, but I cannot justify the cost, especially since I dumped money into a lathe and mill.  In fact, TIG welding is becoming the method of choice for homebuilt aircraft enthusiasts and when I am ready to start assembling my frame, I may consider buying one.  For now, all I that I have been welding are the steel parts for the wing assembly (control surface/flap linkage/stick, etc) which are easily done with my O/A setup.  Besides, torch welding has an almost zen-like quality about it :)  Some of the older builders swear by it.  I have seen some older welders repair construction equipment in the field with nothing more than a portable O/A torch and a coat hanger and still make the weld look like a stack of dimes  :O

As for the friction welders?  I could only wish  :pray
Title: Re: Anyone know how to weld?
Post by: saggs on February 24, 2012, 02:00:39 PM
Well, when I finish building my Bearhawk, I would like to show in my builders log that all welds were crafted properly so my DAR gives me an airworthiness certificate.  That coupled with the coin that I shelled out for my EAA class on welding leads me to believe that the pros know what they are doing.

 It is physically possible to perform MIG welds on 4130, but if the joint is cooled too quickly, it will be a brittle weld.  There is no other way about it.  It is the nature of the steel because of the carbon content.  The "41" denotes a low alloy steel containing nominally 1 percent chromium and 0.2 percent molybdenum (hence the nickname "chromoly"). The "30" denotes a carbon content of 0.30 percent.  If you heat 4130 to the point where the carbon comes to the surface and then cooled too quickly (even a drafty garage is too quickly), it develops Martensetic qualities (a crystalline structure typical of steel containing carbon that has been heat treated) the weld will become brittle.  If this happens, it has to be tempered just like tool steel or it will develop stress fractures and possibly break.  An O/A flame weld has less tendency to do this

When welding an airframe, especially the clusters where there are lots of tube joints, there is a tendency for that area to become hot enough that the joint requires normalization.  A MIG or SMAW welded airframe, if performed by a homebuilder, will not pass the DAR's inspection.  This much I know.

Having a TIG welder at home would be nice, especially considering all of the welding that I do on my Wrangler and the parts that I fab for it, but I cannot justify the cost, especially since I dumped money into a lathe and mill.  In fact, TIG welding is becoming the method of choice for homebuilt aircraft enthusiasts and when I am ready to start assembling my frame, I may consider buying one.  For now, all I that I have been welding are the steel parts for the wing assembly (control surface/flap linkage/stick, etc) which are easily done with my O/A setup.  Besides, torch welding has an almost zen-like quality about it :)  Some of the older builders swear by it.  I have seen some older welders repair construction equipment in the field with nothing more than a portable O/A torch and a coat hanger and still make the weld look like a stack of dimes  :O

As for the friction welders?  I could only wish  :pray

I see, does Bearhawk specify in the builders manual oxyacetylene only, or can you TIG it?  Cub Crafters and Maule might do some kind of normalizing or baking after thy MIG their airframes, all I know is that they do the actual welding with MIG.

BTW, not to hijack the thread too much, but which Bearhawk are you building?  

I've dreamed about building one of the Super Cub kits, but most of them are pretty expensive (Cub Crafters wants $66K for the Carbon Cub kit, add engine, prop, avionics, paint, wheels and tires, and it's not much cheaper then their certified version  :eek: )  Anyway, I've been wondering if the Bearhawk Patrol kit which is significantly cheaper is a suitable "cub-like" alternative.  According to Bearhawks website it cruises quite a bit faster (less draggy) but I'm sure sacrifices STOL somewhat to do so.  Probably still pretty good though.  Honestly in my looking at them the only thing I wish the Patrol had was the jackscrew tail trim like the Cub.
Title: Re: Anyone know how to weld?
Post by: RTHolmes on February 24, 2012, 02:35:36 PM
find a good welder to teach you, its a mix of art and science and experience counts for everything. maybe try to get a short apprenticeship with a local shop in the school holidays?


<< taught by a brilliant fabricator, learnt loads quickly, forgotten most of it :D
Title: Re: Anyone know how to weld?
Post by: VonMessa on February 24, 2012, 03:39:41 PM
I see, does Bearhawk specify in the builders manual oxyacetylene only, or can you TIG it?  Cub Crafters and Maule might do some kind of normalizing or baking after thy MIG their airframes, all I know is that they do the actual welding with MIG.

BTW, not to hijack the thread too much, but which Bearhawk are you building?  

I've dreamed about building one of the Super Cub kits, but most of them are pretty expensive (Cub Crafters wants $66K for the Carbon Cub kit, add engine, prop, avionics, paint, wheels and tires, and it's not much cheaper then their certified version  :eek: )  Anyway, I've been wondering if the Bearhawk Patrol kit which is significantly cheaper is a suitable "cub-like" alternative.  According to Bearhawks website it cruises quite a bit faster (less draggy) but I'm sure sacrifices STOL somewhat to do so.  Probably still pretty good though.  Honestly in my looking at them the only thing I wish the Patrol had was the jackscrew tail trim like the Cub.

It can be TIG welded, I just don't have one. I have access to one, but I can't use it in my shop, I have to go to IT to use it.

I'm building the 4-place.  The patrol is a tandem and does not carry enough weight for my taste, but I'm sure you could put the jackscrew on it.  AviPro only makes the kits.  The best person to ask would be the designer, Bob Barrows.  He is very accessible and easily reached by phone.  I dropped in on him while on a road trip this summer.  Nice guy.

I'm scratch building, so I don't know what the kits cost as I never really seriously priced them.
Title: Re: Anyone know how to weld?
Post by: icepac on February 24, 2012, 03:43:02 PM
Original Poster should not be welding a tank.
Title: Re: Anyone know how to weld?
Post by: Golfer on February 24, 2012, 03:46:51 PM
I think he meant a vehicle rather than air tank.
Title: Re: Anyone know how to weld?
Post by: F22RaptorDude on February 24, 2012, 03:50:39 PM
A tank as in the treads and an air cannon in the turret, i'm looking for a steel skeleton with plywood skin, not sure what to do with the engine I can't find one that I can manage

I've asked around my family, not one person knows how to weld, I'll ask around at school again when i get back, i've been sick the past few days


Got inspired by a group of guys on you tube look up "Paintball Tiger Tank" and click the 2nd link, most epic thing I've ever seen and it was 100% scratch built, but I want my own not theirs
Title: Re: Anyone know how to weld?
Post by: uptown on February 24, 2012, 03:56:51 PM
I'm beyond eager to learn how to, I want to get some knowledge so I can build my own scratch build go kart, and possibly a air soft tank for me and a few buds

I've heard that MIG welding is the most common and easiest to use? But i'm still not understanding how it works?
you can get a 110v Lincoln mig welder at Home Depot for around 400 bucks. Those units are pretty good at welding up to 1/4 inch steel. I'd suggest you get flux wire as you won't need sheilding gas or tanks. The flux wire will allow you to weld outdoors alot easier as you won't have to worry about wind blowing your gas away from your wire. You will have a bit more spatter to content with, but that's not that big of a deal, has you should have a angle grinder with a sanding disk to take care of that.

I've been a welder for over 30 yrs. and can tell you for a fact that all there is to it is practice. Find a good beginners welding book if you must understand the techincal aspects of welding and different annoys. Stay away from aluminum material. Though it is possible to weld aluminum with a mig welder, a tig welder is more suited for that.

If welding is something you really want to learn, start off with tack welds then run some 1 or 2 inch beads until they are consistant as far as width, height and depth. The try welding 2 pieces of steel together. Most importantly keep in mind that welding isn't something you'll be good at overnight. If ya have any questions just give me a holla. Good luck  :salute

P.S. alway keep that helmet down when ur getting ready to strike an arc. You don't want your eyes burnt..trust me. I've burnt my eyes half a dozen times over the years and haven't welded for a living in several years but I still have eye problems today because of it. I used to use a Miller pulse welder and those bad boys ain't no joke. :old:

Title: Re: Anyone know how to weld?
Post by: VonMessa on February 24, 2012, 08:04:00 PM
you can get a 110v Lincoln mig welder at Home Depot for around 400 bucks. Those units are pretty good at welding up to 1/4 inch steel. I'd suggest you get flux wire as you won't need sheilding gas or tanks. The flux wire will allow you to weld outdoors alot easier as you won't have to worry about wind blowing your gas away from your wire. You will have a bit more spatter to content with, but that's not that big of a deal, has you should have a angle grinder with a sanding disk to take care of that.

I've been a welder for over 30 yrs. and can tell you for a fact that all there is to it is practice. Find a good beginners welding book if you must understand the techincal aspects of welding and different annoys. Stay away from aluminum material. Though it is possible to weld aluminum with a mig welder, a tig welder is more suited for that.

If welding is something you really want to learn, start off with tack welds then run some 1 or 2 inch beads until they are consistant as far as width, height and depth. The try welding 2 pieces of steel together. Most importantly keep in mind that welding isn't something you'll be good at overnight. If ya have any questions just give me a holla. Good luck  :salute

P.S. alway keep that helmet down when ur getting ready to strike an arc. You don't want your eyes burnt..trust me. I've burnt my eyes half a dozen times over the years and haven't welded for a living in several years but I still have eye problems today because of it. I used to use a Miller pulse welder and those bad boys ain't no joke. :old:



Woke up at 2AM feeling like someone sandpapered your eyes?  :D
Title: Re: Anyone know how to weld?
Post by: spammer on February 24, 2012, 10:02:08 PM
I think I would go with an Heliarc. A Tig welder can weld any metal, both Ferrous and Non Ferrous materials. Welds are stronger and cleaner. A Mig welder is easiest to learn, The Tig welder separates the Men from the Boys. If I were to build a frame for anything mechanical with my life depending on it......It would be Tig welded. For production purposes, the squirtgun would be faster as long as you didn't have to clean up the welds. (Steel Only)

Tig welding is Art, Mig welding is Slop.

Don't beat up on me guys, I own both Mig and Tig Welders, and I buy American, "Miller". I'm true blue.

Good luck on your endeavors.
Title: Re: Anyone know how to weld?
Post by: rpm on February 25, 2012, 06:40:13 AM
When we hire a welder.... we go through maybe 80 to 100 applications to find one with a good hand. They are not up to our standard but they can be taught if they have a good hand.

Welders are a dime a dozen... good ones are hard to find.
My Bro In-law owns a fab company that builds oilfield machinery. His shop is booming but he can't find enough good welders to keep up with demand. There is zero room for error. Everything has to pass X-Ray.
Title: Re: Anyone know how to weld?
Post by: homersipes on February 25, 2012, 08:50:40 AM
I always enjoyed oxy-acetolyn welding.  Kind of lost art now with the mig and tig.  I tried tiging when I was in metalshop in high school, could never get the hang of the foot control I think I might be able to do it now that I am older and understand a little more but cant afford a tig until my rich uncle gets outta the poor house lol.  RPM my dad works in the oilfield so he might use some of his stuff.
Title: Re: Anyone know how to weld?
Post by: icepac on February 25, 2012, 11:10:18 AM
I've found the most important thing in welding is ensuring the welder is not being hamstrung by running on a circuit that isn't up to the task.

This is most important if you go with a 110 welder since they draw more amps than a 220 welder at the same amperage.

I use a ck systematics welder that runs on 110 but has a special (as in super heavy) transformer and can run continuous (100% duty)  but.......it's being a 110 welder really can cause any weakness in your shop/house wiring to show.
Title: Re: Anyone know how to weld?
Post by: VonMessa on February 25, 2012, 11:50:49 PM
I always enjoyed oxy-acetolyn welding.  Kind of lost art now with the mig and tig.  I tried tiging when I was in metalshop in high school, could never get the hang of the foot control I think I might be able to do it now that I am older and understand a little more but cant afford a tig until my rich uncle gets outta the poor house lol.  RPM my dad works in the oilfield so he might use some of his stuff.
 

The motions (of controlling the heat source and feeding the fill wire) are somewhat similar for TIG and O/A welding.