opinions in methods for critical welds

[scott_shot]

hey all. As you can see from my work of art i haveattatched i need to weld some 6mm flatbar to make the mounts for my A Arms for an off road kart. anyways i could o with some advise on how too weld all the different bits. The main reason i am asking is i only have a supermig 150 and as these are "critical" i would like you guys opinions on what you think the best way to go about it is

Ive also conveniently Numbered the welds to maybe help save some hassle

 

[KartFab]

Get a welding chart(or app), avoid flux core if possible, if you are worried about penetration, chamfer the edges. If you are worried about weld strength, do multiple passes.

Clean the weld areas prior to welding, tack everything up. The more tacks the better. If you are going to do multiple passes, let the weld cool completely before doing another pass to avoid as much war page as possible.

 

[Doc Sprocket]

avoid flux core if possible,

Why? I've built stuff that gets towed at 75MPH using FCAW. In fact, most convertible (GMAW/FCAW) machines have a greater thickness capacity in FCAW.

 

[scott_shot]

Get a welding chart(or app), avoid flux core if possible, if you are worried about penetration, chamfer the edges. If you are worried about weld strength, do multiple passes.

Clean the weld areas prior to welding, tack everything up. The more tacks the better. If you are going to do multiple passes, let the weld cool completely before doing another pass to avoid as much war page as possible.

Thanks for the input, im all good with the general process though its just any tips from the pro's that i might not know. I am actually starting to think i just got carried away doing my masterpiece on paint and that i may know what im doing afterall haha

Why? I've built stuff that gets towed at 75MPH using FCAW. In fact, most convertible (GMAW/FCAW) machines have a greater thickness capacity in FCAW.

as for this i do agree toystory that the gasless gives burns hotter and in comparison the same powered gassles mig will give more pen than yer normal GMAW

 

[DaiSan76]

Move around to spread the shrinkage from heat input around. If you start at one end and make each weld in order, you will likely end up with warping somewhere. And just in case it needs to be said, do not quench it.

 

[OzFab]

Yet another helpful tip: Lean your torch more towards the 6mm than the SHS, otherwise, you'll be burning through the thinner metal & not penetrating the thicker.

Also, weld in a zig zag pattern, back & forth from one piece to the other, concentrating more on the 6mm. It may be worth practicing on some scrap first...

 

[scott_shot]

Move around to spread the shrinkage from heat input around. If you start at one end and make each weld in order, you will likely end up with warping somewhere. And just in case it needs to be said, do not quench it.

Yet another helpful tip: Lean your torch more towards the 6mm than the SHS, otherwise, you'll be burning through the thinner metal & not penetrating the thicker.

Also, weld in a zig zag pattern, back & forth from one piece to the other, concentrating more on the 6mm. It may be worth practicing on some scrap first...

troops, will be practicing a bit but i reckon i will be just fine

 

[fowler]

they must be the front mounts
first thing id do is ditch that idea and get hold of the double a arm plans
much stronger and handles much better

as DiaSan said
make sure u evenly spread the heat
u would be wise to completely tack weld the frame together
firstly because then its easy to change anything
and it will limit the chance of warping

alterantely what some have done is to add a peice of 3mm plate between the frame rails to add rigidity and to stop frame damage in a crash

 

[scott_shot]

they must be the front mounts
first thing id do is ditch that idea and get hold of the double a arm plans
much stronger and handles much better

as DiaSan said
make sure u evenly spread the heat
u would be wise to completely tack weld the frame together
firstly because then its easy to change anything
and it will limit the chance of warping

alternately what some have done is to add a piece of 3mm plate between the frame rails to add rigidity and to stop frame damage in a crash

I know i would love AA front but i have started already so on his so dont want too change done enough repetition, and terrain is fairly tame that im driving on But i am going Double A Rear and Porsche cv manly to handle the power better. Also seen a few ideas on strengthening the rear end components o the edge forum. that coupled the majority of critical and stressed parts on the rear will be welded professionally I think i will be ok, will i? lol

Will be, i always do opposite like tightening bolts, and let it cool after each, i prob wait too long but hey no rush eh

As for tacking do you mean the nose or the whole chassis eg top and bottom?

Also the 3mm plate between what rails exactly? take it you mean bottom chassis 30x30 where steering rack is mounted?
Sound a good idea though

 

[fowler]

Usually u would tack the whole frame together then go back and properly weld it

Yes 3mm plate under the rack

 

[scott_shot]

Although..... I have just been reading a thread.. again more thoroughly this time and a change to double A front is not really too hard after all even if single is fully welded. I will certainly count that as an upgrade worth doing once i try out how single is.

 

[scott_shot]

Usually u would tack the whole frame together then go back and properly weld it

Yes 3mm plate under the rack

I did tack and check the top and bottom then went back and welded, but i did not relise the whole frame together roll bars the lot should be tacked then welded in its complete form Dammit

you will know what i mean by the page in plans about the chassis building and thats what i took from it but obv now i was wrong

 

[fowler]

It won't matter that much

It's more a rekomendation than a requirement

 

[scott_shot]

Yeh suppose. il not beat myself up too much then i just hate those moments lol. Will follow that recommendation form now on. do you have any sexy cheeky pics of your chassis when it was being built you could PM me

 

[fowler]

Nope because I didn't build the basic frame

I had some pics of my first buggy but who knows where they went

 

[KartFab]

Why? I've built stuff that gets towed at 75MPH using FCAW. In fact, most convertible (GMAW/FCAW) machines have a greater thickness capacity in FCAW.

I'm defininately not an expert but I did a lot of research before buying my welder. The reasons I would avoid flux core are as follows:

Slag inclusions, a higher chance of porosity because of the flux core gases not escaping as the metal hardens. More fumes generated vs other welding methods, and splatter.

But with all that said, the weld would still hold, just my opinion on why to avoid flux core vs solid wire. I put flux core down there with stick welding. Tig and gas mig are higher up on the preferred method of welding for me. (I had to stick weld a BBQ smoker last weekend because of windy conditions though, so each method has its advantages/disadvantages).

 

[Doc Sprocket]

I can certainly see why you would equate FCAW with SMAW. when it all comes down to the wire (pun intended) they are the same. FCAW wire is SMAW stick turned inside out.

Porosity and slag inclusion are nothing noteworthy with a bit of practise and the right settings. It is likely the easiest process to learn, and the second cheapest. A bottle of gas can really set you back, and if you shop carefully you can get a machine for $100 or so.

Indeed, a bit of a breeze can ruin your GMAW, GTAW or oxyfuel welding plans. I have welded in gale winds with FCAW and ultimately the problem was the gusts affecting the arc. FCAW fumes are indeed nasty, but then again, we need to protect ourselves from any and all welding fumes as a metter of good practise.

The spatter can be reduced with settings and position, but cleanup is still a PITA. I get the best results with a knotted wire wheel on a grinder.

FCAW is also very tolerant of rusty, dirty, metal.


either way, there's no wrong answer, just budget and preferences. I just hate to see FCAW get an undeserved bad name.

 

[machinist@large]

I can certainly see why you would equate FCAW with SMAW. when it all comes down to the wire (pun intended) they are the same. FCAW wire is SMAW stick turned inside out.

Porosity and slag inclusion are nothing noteworthy with a bit of practise and the right settings. It is likely the easiest process to learn, and the second cheapest. A bottle of gas can really set you back, and if you shop carefully you can get a machine for $100 or so.

Indeed, a bit of a breeze can ruin your GMAW, GTAW or oxyfuel welding plans. I have welded in gale winds with FCAW and ultimately the problem was the gusts affecting the arc. FCAW fumes are indeed nasty, but then again, we need to protect ourselves from any and all welding fumes as a metter of good practise.

The spatter can be reduced with settings and position, but cleanup is still a PITA. I get the best results with a knotted wire wheel on a grinder.

FCAW is also very tolerant of rusty, dirty, metal.


either way, there's no wrong answer, just budget and preferences. I just hate to see FCAW get an undeserved bad name.

(Potential Rant Alert)

Having been trained on and have used SMAW(stick), GTAW(tig), GMAW(mig [both solid and flux core]), as well as gas and braze welding, they all have pro's & con's; used properly, you could use ANY of them to build the frame and suspension components for a cart or buggy.

What it comes down to is what you have and/or what you are comfortable with, combined with knowing what the limits of that particular type is/are.

All that being said, mig (in both solid wire and flux core) are about the easiest processes to pick up. From what I can tell, the biggest problem most people have with flux core is the wire they have in the machine. The cheapest machine will give you excellent results with quality wire; conversely, you'll have a holy time trying to get a decent weld out of the best machine in the world if you're pushing wire thru it.

If you're on a Mc Budget and have to watch the pennies, skimp wherever you have to; just don't start with the wire you're running. I personally like Lincoln, Hobart is good too. There are more good brands out there; Linc. & Hob. are most commonly found available in consumer sizes (spool sizes).

Sorry about the length of all that..... Pat

(Rant Off)

 

[Doc Sprocket]

I'm not sure I'd call it a rant, Pat- that was good info. I agree about the wire, too. I usually use Lincoln Innershield NR211MP. One day I ran dry and cheaped out, buying a 2lb spool of the chinese welding noodle (lol) from Princess Auto. I will never do that again. The moment I finished what I was doing, I tore that useless crap outta my machine, and lobbed a 3-point shot off the backboard and into my scrap bin...

 

[machinist@large]

Reference books that might be usefull

Here's a couple of titles for reference books that are still used when I was in college in the mid '90's. Two were published in the '70's, one as far back as the 1940's. We were still using them as late as 2003 when I was last signed up, because none of the basics have changed (basic as in whatever you might try to build in a garage or small shop). There's some really weird new stuff out there; it's just so wacked out overkill that I'm personally not going to worry about it unless I need it for work.

So, on to the list!!!!

1] "Welding: Principles & Practices" (revised) ISBN#0-02-666140-3
Copyright 1981, 1976. Originally published as "Theory and Practice of Arc Welding" original copyright 1943, 1960 by the same author.
This is the big one; my primary welding textbook. Chapter 3 alone is worth it; has 29 in all. covers all the process's that you or I will probably ever need (and it doesn't have anything like "Set your transwarp series capacitive inductance to......"). Just all the basics, well written.

2] "Forney Welding Manual" by the Forney Industries company, copyright 1972. No ISBN#, but I can still find it at the hardware store. Forney welding cat. #75200, on the welding supply rack (Forney's, of course!!). Nothing specific for Mig or Flux core, but all the joint design and layout, as well as how to weld something with a chance of it being straight is identical for all the arc processes. It's also the cheapest of the 3; $10~$15 or so, versus over $50 for "Welding".

3] "Pipe Welding Procedures" Rampaul, copyright 1973, ISBN# 0-8311-1100-3 ; I'm throwing this one in for the advanced frame builders here. If it's good enough to teach pipe welding for a Nuclear plant, your buggy frame should be in good hands. Not sure about price though.

Hope this stuff helps!!!! Pat