Newbie Welding question

[kdog_x]

I went to a few local shops to see what it would cost to get cats put on my stang so I can go pass emmisions by the end of the month and they all ended up telling me around $500 or so. I saw some hi flo cats for sale on ebay for $40 a peice and I looked into getting an oxygen and acetylene tank as well as the torches and thats gonna be about $200 alltogether.

Anyway, I figured I could use a torch anyway so I'm gonna do it myself and save a few bucks. I'm a newbie welder so this might be a bit basic, but my question is, when you weld exhaust with an oxy-acetlylene setup do you need to use filler rods to fuse the peices together or can you just heat them till they stick? If I need rods, do you know what type? Also any other suggestions would be appreciated.

thanks

 

[ratrapp]

wouldn't it be cheaper and easier to just get another h-pipe?

 

[kdog_x]

with the longtubes, the cheapest I can find a shorty h pipe is around $360 without shipping - at least with cats anyway. plus it'll only be on there for a day, someone must know how to weld exhaust on here though, it cant be that hard.

 

[shttygtstang]

it is the cats go near the bellhousing if there not right then your screwed...ive done it before and screwed it up

 

[kdog_x]

it is the cats go near the bellhousing if there not right then your screwed...ive done it before and screwed it up

my car currently has a shorty pipe with cats on it, but they are hollowed out. If I buy some replacement cats it shouldn't be any more than cutting the old ones out and welding the new ones in. And they have LOTS of clearance from the bellhousing, I'd have to be off by about 2-3" to screw that up. I'm more worried about possibly having to find pipe to extend it an inch or two if the replacement cats are shorter than the current ones. Anyway I'm just looking for a simple answer to my welding question, if you did it before then maybe you can help me, did you use filler on the welds or no? Also, did you use an oxy-acetylene or did you have a MIG?

 

[shttygtstang]

welcome to my world i did...and aso i have a aod and theres no room to screw up

 

[jrichker]

A MIG welder from Home Depot would probably be a better choice, and eaiser to learn.

Oxy-Actelyene welding uses the torch to form a moltem puddle of metal to which you add the welding rod with material similar to what you are welding. It is easy to make holes and takes some experience to make quality welds.

The cheapest way would be to get the cats and have them installed by a muffler shop. They are usually pretty good at welding thin tubing like exhaust pipe. Cut out a section of pipe from one side and slide the cat in & weld it in place. Cut the outer side and do the same. Then drop the pipe and finish up the welding all the way around the cat joints. When you are done, bolt it up and everything should line up since you only cut one side at a time and the other side held things in alignment.

 

[kdog_x]

A MIG welder from Home Depot would probably be a better choice, and eaiser to learn.

Thanks, thats what I was asking. I've used oxy-acetylene for cutting before, it was pretty easy to make holes - maybe I'll stay away from trying to weld with it. If I did get a MIG welder, would one of those smaller 100 amp ones work OK or would I have to break the bank for a larger one? And as far as what you were saying about keeping things lined up, did you mean just to cut out the cat and make a temp weld to hold the new ones in before dropping the pipe? That does seem like a better idea than dropping the pipe to begin with.

Sucks about your ride shttygt, did you do it as jrichker advised or with the pipe off the car?

 

[jrichker]

And as far as what you were saying about keeping things lined up, did you mean just to cut out the cat and make a temp weld to hold the new ones in before dropping the pipe? That does seem like a better idea than dropping the pipe to begin with.

You got it...

I had the muffler shop weld a patch on the H pipe segment that connects the two parallel pipes together using that method. They tack welded the patch real good in several places and then removed the H pipe to finish up the welding. It worked very good, and the H pipe didn't get all twisted and out of alignment.

 

[Venom4.6]

Since you have long tubes, the H-pipe is straight. Go out and buy some cats. Measure the H-pipe so you have a reference. Cut out a section of pipe on each side of the H. Slip the cats onto the H-pipe and use exhaust pipe clamps to secure everything. No welding required and you can take the cats off and on when you need to. Buy some exhaust pipe extensions and couplings at the auto parts store to fill the void when you go back to catless.

 

[shttygtstang]

ya sorry i used a little ark welder from sears thats more than enough ive done quad frames with that thing make shure you use the rite wire or it doesnt work