Easiest way to copy angles from an exhaust to make another?

Hi,

I havent been on here for a while as I've got married and been really busy over xmas!

I started TIG welding last year as I wanted to make up some exhausts....I'm going to pick it back up this week again. I made a Jig last year for the original exhaust, so I have a template to make sure it will fit correctly onto the car.

My question is:

Whats the easiest way to copy the engles off of the bends of the original exhaust and replicate them with pre bent pipe?

Is it best to start with the flange on the jig, weld the first straight piece of pipe onto it and then get the bend right for the next piece of straight pipe?

Cheers,

Paul.

Guess i'll have to use trial and error then!

Paul.

Congrats on getting married!

Subsequent exhaust sections would normally be tacked up in situ, underneath the car.

You mentioned a jig (for a 3d structure?). Any photos? They always help a thread get noticed.

You could bend some coathanger wire along the back of the pipe you want to copy, similar to making templates for brake piping.

Its very difficult.

What I struggle with is, you spend as much/more time making the jig than the piece, and you can't normally charge for the jig. For this reason I avoid it. Unless its a run of more than 1 and the jig price can be included.

if you know a friendly plumber who uses 1 1/2" pvc solvent weld waste pipe, used for sinks, you could borrow a selection of bends from him and purchase a length of pipe to cut up between bends, the fittings can be fitted and removed without damage and then the only cost would be the length if pipe, about £4.
i have done this many times and it works well.

Congratulations on getting married Paul R.

I had a quick look on the net and found this.
http://www.ehow.com/how_6945979_figu...aust-pipe.html

Im not sure if its what you're after though.


Thanks

Lee

Whats the easiest way to copy the engles off of the bends of the original exhaust and replicate them with pre bent pipe?

It's not always possible or at least practical. Even if you have a huge selection of mandrel bends to hand you often find the OE exhaust uses different CLR and/or bend angles to what's commercially available, at least at sensible prices.

Everyone i know that does this sort of work will make something that fits the car. Whether we're talking about a decat pipe or a complete system it's easier and faster to make something that fits the car/rest of the exhaust system than to try and replicate the OE part/system exactly (but in stainless or whatever). Typically this is done mostly by eye albeit with the origional part for reference using the techniques already mentioned. If we're talking quantity (say a bunch of decat pipes for a club) then you use the first production piece to make a jig AND keep/make patterns used for the first job.

Obviously depends on the complexity of the part but a jig can be difficult to get right- hands up who's bought a pattern back box for the daily driver only to end up cursing GSF (or whoever supplied the thing) while struggling to get the POS to fit properly!

Hi,

Sorry I've not been around, my little boy has had a couple of ops, so i've been busy.

I've already made the Jig - i'll get a post up later. It's more a case of getting the angles right as I cut the new pipe, I'm just not sure how to do it and get it to mate up square...

Paul.

Originally Posted by hotrodder It's not always possible or at least practical. Even if you have a huge selection of mandrel bends to hand you often find the OE exhaust uses different CLR and/or bend angles to what's commercially available, at least at sensible prices. Everyone i know that does this sort of work will make something that fits the car. Whether we're talking about a decat pipe or a complete system it's easier and faster to make something that fits the car/rest of the exhaust system than to try and replicate the OE part/system exactly (but in stainless or whatever). Typically this is done mostly by eye albeit with the origional part for reference using the techniques already mentioned. If we're talking quantity (say a bunch of decat pipes for a club) then you use the first production piece to make a jig AND keep/make patterns used for the first job. Obviously depends on the complexity of the part but a jig can be difficult to get right- hands up who's bought a pattern back box for the daily driver only to end up cursing GSF (or whoever supplied the thing) while struggling to get the POS to fit properly!

Ok, well I have the jig, how do I make patterns so I can easily replaicate the bends after the first attempt?

Cheers,

Paul.