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Broken exhaust hanger

Yes, they have broken before. It is a simple piece of stainless tubing, easily fabricated in a few minutes after you source the tubing... from Vetterman Exhaust if you like :).
 
maus92 said:
Discovered during condition inspection. Has any ever had one of these break before? Any tips on ordering a new one? I believe this is a Vetterman system, but I don't see parts on their website (also called Friday and left a message - although it looks like they keep limited hours on Fridays (I wish I could do that.))

https://www.dropbox.com/s/qb172t5jb5iz7yz/IMG_0934.png?dl=0
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RVers have been repairing exhaust hangars since....there were RV exhaust hangars. :)

Go to your local auto parts store and pick up a length of 3/8" steel brake line. A piece a couple of feet long will keep you stocked with exhaust hangers for many years to come. Gently flatten one end of a piece of brake line, drill the bolt hole, loosen the clamp on the rubber hose and replace your broken hanger. Keep a short piece of brake line in your flight kit for repairs when away from home.
 
Left unresolved, a broken hanger can cause bigger problems. A good reminder to give each pipe a wiggle test as part of your preflight procedures.
 
I had a recurring ploblem with these flattened steel tubes breaking off just like yours. I replaced them with solid aluminum rod. Never had another problem.

Carl
 
Replacement Hangers

After I discovered a couple of broken ones, I sourced new ones from the folks up at Vetterman, who have designed a thicker, more robust set.

Approximately 100 hours since I?ve replaced them all with the newer ones and no breakage so far. Looks like a good fix.

I check them every time I pull the cowls off...when it?s also a good time to hit all the exhaust pivot joints and unions with a healthy dose of Mouse Milk to keep them able to move as they are designed to do.

You will develop a list of items that you?ll check every time you un-cowl ?just to be certain? or after having had an issue inflight...

The exhaust system and components are a good candidate for this list...among others.
 
A couple of items I've learned after nearly twenty years of fiddlin' with exhaust hangers on the RV-6:

1) If you use steel tubing, the flattened end should be made with a gradual swage, not an abrupt swage as will result if you just slam the vice jaws down on it. A small radius swage is much more likely to break.

2) My earliest set of hangers used not only the flattened ends but also a bend in the flattened portion. That is certainly a recipe for failure. After repositioning clamps to eliminate any bends reliability went up considerably.

3) The aluminum/steel rod instead of steel tubing is a good solution if it fits the particular installation.
 
Sam Buchanan said:
A couple of items I've learned after nearly twenty years of fiddlin' with exhaust hangers on the RV-6:

1) If you use steel tubing, the flattened end should be made with a gradual swage, not an abrupt swage as will result if you just slam the vice jaws down on it. A small radius swage is much more likely to break.

2) My earliest set of hangers used not only the flattened ends but also a bend in the flattened portion. That is certainly a recipe for failure. After repositioning clamps to eliminate any bends reliability went up considerably.
Click to expand...

Agree 100%.
 
Sam Buchanan said:
If you use steel tubing, the flattened end should be made with a gradual swage, not an abrupt swage as will result if you just slam the vice jaws down on it. A small radius swage is much more likely to break..
Click to expand...

What is your recommended technique for producing a gradual swage Sam?

Thanks
Erich
 
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erich weaver said:
What is your recommended technique for producing a gradual sewage Sam?

Thanks
Erich
Click to expand...

I've done it with pieces of soft, rounded-edge wood in the vice but when I needed to make several of these swages on a different project I made some dies out of aluminum angle. I'll see if I have a photo somewhere.

Edit; went out to the shop for a couple of photos:

tubing_swager-1.jpg


tubing_swager-2.jpg
 
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cool technique

Thanks Sam, great timing. I've made a few of these that have not worked out, and have recently ordered some more tubing. Thanks for sharing your technique - very clever!
 
Adding to the noise...

Decades of working with 300 series stainless steel (what the hangers supplied by Vetterman for my exhaust were almost certainly fabricated from) made me leery of using it for anything that involved possible large amplitude vibration mixed with abruptly changing cross section (cue Sam's swaging trick), sharp edges, etc.

I happened to have a piece of 3/8" OD x .035" WT (I think) 4130 chrome moly tubing lying around from some long forgotten bicycle frame project. Perfect. Enough to make all the hangers I needed. The stuff required heat massage to flatten nicely but 640 hours later no failures. The rust I feared turned out to be a non-issue. My Lyclone doesn't leak much but it dispenses just enough anti-corrosion fluid to keep it at bay.
 
i went another route. took some solid steel rod of the same size and flattered the end with a sludge hammer on some steel plate. 5,000 hrs later no problem. stronger is better. impossible to break. ;)
 
MK77 said:
I just had two adel clamps where the hangars attach to the engine mount break.
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What many of us have done is abandon the "attach to the engine mount" method. Instead, all the exhaust supports (still with isolating rubber hoses) are attached to the engine, usually a couple of sump bolts. That improves the probability the tail pipes will be vibrating in concert with the engine and reduces the chances of broken mounts.
 
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Just a reminder...there are other exhaust hanger designs.


Exhaust Hanger.jpg


Exhaust Ramp Finished.JPG
 
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