exhaust welding with a wire feed mig??

[Loochy88]

heres the specs on my welder

its a craftsman wirefeed mig welder. (no gas)
uses .8mm (.030") flux core wire

Primary input volts: 120 vac
Welding Range: 60-120 amps
primary input amps: 20
Phase: single
Frequency: 60 hz
secondary output volts: 17
secondary output amps: 80
duty cycle rating at 80 amps: 20%
open circuit volts (max): 25 vac


manual says its good for steel up to 3/16" with a single pass, 1/4" multi pass.

i just got ahold of some scrap exhaust pipes. i practiced a little bit but my welds are still awful. will this welder work for what im tryingto do? i really want to put together a custom turbo and i would be doing all my exhaust with this welder unless its impossible.

from what i've heard, if i can get it to work, the welds will probably be a bit nasty looking, but im not worried about it being pretty, most of the pipes wond be seen anyway, and ill just clean them up with the grinder if i have to. i just want to know if im going to be able to use this thing to weld some exhaust pipes.

[black98V6]

well so long as the tubing you are using isn't bigger than the welder specs then yes in theory you could weld it, but here is the catch. Most exhaust pipe you buy is "aluminized"(sp?) which means it has an aluminum coating on it so you really need to clean the hell out of the metal to get a good weld this is why most exhaust shops don't weld they auctually braize (sp?). A very simplified explination of this is kinda like soildering with a torch.

anyway I'm sure you can find tubing that isn't aluminized but it would be best to have some type of ceramic coating or at the very least high temp paint on everything after you are done with the fab work.

[Loochy88]

well, thus far ive just been working with scrap from exhaust shops. im sure this stuff isnt aluminized. actually, ive found a fairly large amount of 2.5 inch pipe out here. theres a lot of "truck" guys out here getting exhaust work done all the time, so the scrap pipe is a bit bigger on average compared to what you'd see if they were all driving hondas and saturns. if i find enough in good shape i may just use that on the setup.

[hockeyman]

I have a 130 amp Hobart mig. I welded my new exhaust on and it came out better than I expected. I used a .035" NON-FLUX wire when welding the new system. I also bought a Argon/CO2 tank of gas that I hooked into the welder. It helps the weld lay nicer and keeps some of the spatter down. The tank ran me $100, but I can get 4 solid hours of welding out of it before it's empty.
It takes a few passes before getting something to look nice, but you really shouldn't be worried about the looks if it's under the car. If it looks that bad, go get a portable grinder to shave some of the excess off.

~One more thing, it's a good idea to clean (sand, file, etc) the metal up first before welding. It makes a huge difference as the weld is being put down!!

[zlexiss]

I'm with hockeyman on the non-flux + gas setup. since you're trying to fill in gaps to seal the pipes, the solid wire will give a much nicer fill with less spatter. Which means less little pinhole exhaust leaks.

[Loochy88]

well, i tried it again today. i've got some pics this time

the welder: http://memimage.cardomain.net/member...6_309_full.jpg

self adjusting mask, this thing is wonderful: http://memimage.cardomain.net/member...6_308_full.jpg

first i just tried to law a few beads across this resonator i picked up. you can see my progress from left to right. http://memimage.cardomain.net/member...6_307_full.jpg

once i felt comfortable with it i tried to actually joined two pipes together. i cleaned up the pipe really well, but the weld still didnt come out all that great looking. id got dirtier as i welded it too. i blew through the metal in a few spots so i would just go around the holes on a low setting and fill it in. when i finished it seemed strong enough, but it didnt look pretty at all. http://memimage.cardomain.net/member...6_310_full.jpg

i grinded it all smooth though, and there really werent very many holes at all. once i had it all smooth again, i laid down another bead and this one looked quite a bit better than the first: http://memimage.cardomain.net/member...6_311_full.jpg
i suppose if all else fails i can just take this approach.

[hockeyman]

Not bad. The welds are probably dirty because you're using a flux-cored wire. You can use that with or without the gas, but they are dirty.
If you use a Non-Flux wire, you have to use the shielding gas (argon co2 mix), but they are much cleaner and stronger.
This was a great site for me when I was first getting started. I got alot of help from the guys there.

[hockeyman]

NVM, I see you're already a member... [img]graemlins/slap.gif[/img]

As it's said in the forum you've posted in; Wear protective clothing and most important, get a good mask!. My mask ran me $120 from a local welding shop.
I've already done a few "forbidden dances" when a spat or two laid on the top of my head and began burning through my skin. It burns your arms/shoulders/legs too, but for some reason, it burns ALOT more on the top of your head!

[ October 06, 2005, 05:46 PM: Message edited by: hockeyman ]

[Loochy88]

did ya see the pic of the mask i posted? i love that thing. is there something wrong with that one?

[ October 06, 2005, 08:07 PM: Message edited by: Loochy88 ]

[hockeyman]

A solar mask workes well. I still have an extra one that I bought on ebay when I first bought the welder. The only problem is that it takes them about 1-3 seconds to fully adjust to the flash. Then you see those red dots in your eyes for a few minutes after you start.

[Loochy88]

this one goes dark virtually instantly and it was only 50 bucks at harbor freight. it was a great deal imo

[RicE-ter]

im just jealous THAT U HAVE a welder. well im not one to use cliches but practice makes perfect. and from the looks of your pics it doesnt look too bad

[casketcrewchick]

My ex tried to weld my exhaust and it held up for a while but it looked like complete ****... it had little beads everywhere... some kind of wire feed welder, i cant remember the name. Anyways my neighbor took a strip of metal and welded that over the leak to patch it up and it was so much better. Anyways your pics dont look bad, the weld is a lot thicker than what was previously on my car.

[BLLDOGG]

its looking alot better than some of the welds i have gotten at a few exhaust shops around here. i have been wanting to weld but i decided to take some classes cause i want to weld important things like frames and roll cages. good job man