Technical Can you Weld your Down Pipe?

[Tripplex]

Hi All,

Does anyone know if you can weld you down pipe back onto the cat?

My one has some how ripped away from the Cat. I've been told that it's hanging from a spring and when you look through the N/S under the bonnet you can see that its broken off about 2cms up from what I was told was the sensor.

I've been told that it's not worth welding as the metal maybe too thin and that the vibrations may make it break again later but there are absolutly no used Cats for sale near me so I'm wondering if welding is really not an option.

Thanks

 

[Ffoxy]

Hi All,

Does anyone know if you can weld you down pipe back onto the cat?

My one has some how ripped away from the Cat. I've been told that it's hanging from a spring and when you look through the N/S under the bonnet you can see that its broken off about 2cms up from what I was told was the sensor.

I've been told that it's not worth welding as the metal maybe too thin and that the vibrations may make it break again later but there are absolutly no used Cats for sale near me so I'm wondering if welding is really not an option.

Thanks

Depends how good a welder / fabricator you are and what kit you have at your disposal really. Anything can be done, just depends on time / money & practicality etc as usual. At some point replacement becomes the cheapest - fastsest - most reliable option.

 

[12[X]]

anything exhaust relater i've welded fell off in a matter of hours (am useless) with the cat (and temperatures there) i'd say it won't hold no matter how good you are.. think the only way is similar to plumbing - melt some metal and use it like 'putty' to seal and hold the 2 parts (but due to movement and temperatures.. well..)

 

[Tripplex]

Cheers guys,

There's a small metal workshop that welds Iron and Steel gates near me. I'll probably check them out and see if they can do something with it.

I was told that most parts of the exhaust were too thin to weld. Do you think the down pipe's one of them?

 

[Ffoxy]

Cheers guys,

There's a small metal workshop that welds Iron and Steel gates near me. I'll probably check them out and see if they can do something with it.

I was told that most parts of the exhaust were too thin to weld. Do you think the down pipe's one of them?

Probably yes for a firm welding thick chunks of steel fabricating gates, needs a special light touch even for thin car bodies, exhausts are very iffy at the best of times to weld as they often corrode from the inside and it can be extremely hard to get a good gas tight weld.

 

[Tripplex]

Ok thanks for the advice matey. Think I'll just have to keep searching through the all the scrap yards that seem to NEVER get any Stilo parts.

 

[PNL]

OK this one is right down my alley..I am retired now but I had my own company many years ago and I'm a qualified fab/welder by trade..

Not had a good look at a cat but I wouldnt mind betting its not the same material as the down pipe ..down pipe is mild steel while the cat is very probably cast steel..OK you say they are both steels but you are wrong because the composition is different ..now if the down pipe is not to corroded then you should be able to weld them back together..I would go to a performance exhaust place cos they will have tig welding equipment ..tig welding keeps the heat and distortion rate down and is perfect for this kind of operation..thin metals are no problem in this case..when the cat was made is was very likely mig welded for quick production and can still be mind you if you have someone available who has a low amp set..easy way to tell the difference between mild steel and cast is to grind it mild will have bright sparks and cast will have dark almost red sparks..

 

[Ffoxy]

OK this one is right down my alley..I am retired now but I had my own company many years ago and I'm a qualified fab/welder by trade..

Not had a good look at a cat but I wouldnt mind betting its not the same material as the down pipe ..down pipe is mild steel while the cat is very probably cast steel..OK you say they are both steels but you are wrong because the composition is different ..now if the down pipe is not to corroded then you should be able to weld them back together..I would go to a performance exhaust place cos they will have tig welding equipment ..tig welding keeps the heat and distortion rate down and is perfect for this kind of operation..thin metals are no problem in this case..when the cat was made is was very likely mig welded for quick production and can still be mind you if you have someone available who has a low amp set..easy way to tell the difference between mild steel and cast is to grind it mild will have bright sparks and cast will have dark almost red sparks..

:yeahthat: :worship:

 

[PNL]

:yeahthat: :worship:

Aww shucks..

 

[Ffoxy]

Aww shucks..

PNL... Former welding god.... I know what my efforts to weld an old Mk1, 2 and 3 Escort were like... neither got anywhere near what I wanted...

 

[Tripplex]

Hi all,

Just thought I'd give you a quick update on this. Had it welded with a gas welder and it lasted for about 4hrs until I went over a speed bump. I was totally skint and had to leave my beloved Stilo parked up for a week until I had enough money to buy another cat for £70 from a breaker in Manchester via Ebay. He despatched it as straight away and it got to me in Greenwich in two or three days.
When we finally got around to installing it we noticed that there was a bracket just past the sensor on the down pipe which was missing on the older one. We assumed that the extra vibration and stress on the down pipe caused by the missing bracket must have been the reason why it had broken. Anyway, installed the new cat but couldn't find a bolt small enough to go into this new bracket so my Dad told me to pop down to a garage and get one.
Within two days the bloody thing broke again before I had a chance to get the bolt for it and guess what??? It was in exactly the same place, just past the sensor. I couldn't believe it! No way could I afford to fork out another £70. My dad agreed and took it to his garage and they done an electric weld on it . That was about a month ago and so far (touch wood) its been alright!

 

[Tripplex]

Oh yeh. Whilst welding they attempted to bolt it but found that the thread was missing. The nearest place to me that rethreads charges £65 per hole and they have a 2 week waiting list. Any suggestions???

 

[ROWENA]

you have 2 options here

1 drill and tap it oversize

2 helicoil insert

any decent garage/engineering firm will be able to do either for you or you could DIY the job as both are easy to do

Helicoil [ame]http://en.wikipedia.org/wiki/Threaded_insert[/ame]

taps http://www.tapdie.com/html/taps_metric_taps_metric_fine_t.html

hope this helps

Karl

 

[Andymacselespeed]

Problem with anything but expert welding that near engine is that they tend to crack soon afterwards.

I am rubbish with a welder, I tried welding a small blowing split in my old Ford Orion exhaust about midway along the mid section, it looked fine, but then a few days later, the whole pipe broke!

My first and last time at welding!