Starboard PA-12 O235 exhaust replacement

On getting a small crack fix welded this morning, another crack became apparent in a different place, which became a big hole when grinding down to the ends of the crack

It’s now decided that this exhaust is past its useful life and I’m looking for a replacement, preferably just this section. Can anyone recommend suitable suppliers please?







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Philly5G said:

On getting a small crack fix welded this morning, another crack became apparent in a different place, which became a big hole when grinding down to the ends of the crack

It’s now decided that this exhaust is past its useful life and I’m looking for a replacement, preferably just this section. Can anyone recommend suitable suppliers please?

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Wow, I'm usually really good at research, but I can't find an off the shelf supplier for one of these PA-12 right stack assemblies!! Are they all made to order?!!

Usually a shop will repair them by replacing everything from the flange to the end. Then, from the now acceptable repaired part, the shop cuts the flange off and replaces that.

Original ones are made of unobtainium.

Half way around the World, but they do excellent work. As previously stated, the finished product will likely be totally new.
http://www.dawleyaviation.com/home.html

Philly5G said:

Wow, I'm usually really good at research, but I can't find an off the shelf supplier for one of these PA-12 right stack assemblies!! Are they all made to order?!!

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Yes, they are all made to order these days and because of differences from aircraft to aircraft (??) the repair shop will typically need the orginal sending in, so it can be used as a template. In my research for this, I've found that repairs are more common than buying new ones and the appetite and acceptance for repaired stacks has pleasantly surprised me We're going back to the original shop to revisit the repair or new decision. I've also found that the vast bulk of these exhausts are/were stainless, a few in mild steel and NONE in Inconel - which I'd been advised was the norm!! Can anyone else add anything to which metals were used?

skywagon8a said:

Half way around the World, but they do excellent work. As previously stated, the finished product will likely be totally new.
http://www.dawleyaviation.com/home.html

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Thanks SW! I've been in contact with Dawley Aviation and they can definitely repair the stack, cost seems reasonable and turnaround is a couple of weeks. I'm following up 2 other options first, but good to know there's a recommended shop in my back pocket if need be

Aerospace Welding (AWI) in Minnesota & Knisely in California are both highly regarded exhaust shops also.

hotrod180 said:

Aerospace Welding (AWI) in Minnesota & Knisely in California are both highly regarded exhaust shops also.

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I have had very unsatisfactory results with Aerospace Welding.

I have used Dawley a few times and always been pleased with their work.

skywagon8a said:

I have had very unsatisfactory results with Aerospace Welding.

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I used AWI for an Aerocommander Lark exhaust overhaul four years ago. They sent back all new stuff and it fit.

N86250 said:

I used AWI for an Aerocommander Lark exhaust overhaul four years ago. They sent back all new stuff and it fit.

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It was much more than fit.

skywagon8a said:

It was much more than fit.

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What went wrong?

N86250 said:

What went wrong?

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I bought a completely brand new exhaust system for my 185 from an outfit in Canada that makes new STC'd/PMA mufflers and exhaust systems. They in turn bought the exhaust system exclusive of the muffler from AWI. AWI's exhaust pipe developed a crack which went almost completely around the pipe on the very first flight of less than one hour. The outfit in Canada told me to send it to AWI for a warranty repair. AWI fixed it and sent me a bill for well over $200 and refused to return it unless I paid. So now I'm out a lot of money for a new exhaust system and the repairs which should not have happened. I reinstalled it. What do you suppose happened next? It cracked again in the same place after about five hours. This time I had a friend who used to weld for Helio come to my hangar to repair the crack on the airplane. This lasted for a little over 100 hours before more cracks in a different location developed. This time I sent it to Dawley for repair. They told me that it wasn't built anywhere near the way it was supposed to be to begin with, which is why it cracked. There had been a 1/2" misalignment between the stacks and the muffler. It had been so misshapen that there were built in stresses all over when the nuts were tightened, even though it was not apparent during the installation. After Dawley returned it, it went on like it should. It fit beautifully. No comparison at all to the AWI system.

I will never do any business with AWI again. And, I very highly recommend Dawley. Their customer relationship and workmanship are top drawer.