exhaust system coatings

[Tom G]

During my annual in the summer of 06 my exhaust system had to be replaced. I tried going the stainless route but it was just too involved and was going to take too long to get. I went with mild steel and of course it is rusting and looks terrible.

Here it is not even two years after spending over $500 and it looks like hell. Is there any way that I can extend the life of this system by treating it with something? Everything I've tried to coat these things with in past years really didn't do much.

If anyone knows of anything that truly can extend the life of these mild steel systems I'd appreciate your suggestions.

Thanks everyone!

[Marv]

Re: exhaust system coatings

Tom Speedway Motors, sells a product they call " Exhust Manifold Dressing". It is made of stainless steel and ceramic compounds. It is suposed to withstand 2400* of heat and they say a exhaust manifold rarely gets 1200*. I have not used it yet but freinds with antique cars that have used it swares by it. For $12.95 it is worth a try. Just brush it on and run the engine for 10 minutes. Check it out with online catalogue. at "www.SpeedwayMotors.com" Marv

[flyguy]

Re: exhaust system coatings

There is another high temp paint that all the guys on the 2nd Generation Camaro forum report as holding up well. It is sold at Auto Stores and used on exhaust headers which are the same material. I have new cans but have not used it yet. You will have to sand blast the outside first. I'll get the name for you--don't remember. It comes in two versions. Have to be sure to get the hi-temp 1500 degree version. I can confirm their 1200 version will not hold up on manifolds
DC
EDIT: It is marked "VHT," and is available at Auto Zone, Kragen, ect.

[flylo]

Re: exhaust system coatings

Your going to think I'm nuts,but on ultralight exhaust we use olive oil. Clean the rust off good,brush on the olive oil,fire it up & let it get hot. It turns black & seems to bake right in & seal the steel. I've never tried it on a Tcraft, mines stainless,but it has worked great on a couple ultralights I've tried it on. Eric

[flyguy]

Re: exhaust system coatings

Eric, I have always wondered what organic one could use to produce a carbon coating like that. I'm sure it just cooks out all the volatiles and leaves the carbon. Like making charcoal from wood. I suspect that on the higher temperature applications-that is, approaching red heat, that the carbon might burn off as well.
DC
In case someone doesn't go back to check, the paint I mentioned above for up to 1500, that the Camaro guys like, is marked "VHT."

[VictorBravo]

Re: exhaust system coatings

Go to the local powder coating shop and ask about something called Jet Hot.

There is also a high temperature coating from Kal-Gard (new company name now, check with Google).

[M Towsley]

Re: exhaust system coatings

I went to the local powder coater and had them use a high temperature silver. Turned out great and it lasts, too.

[Guest]

Re: exhaust system coatings

Your going to think I'm nuts,but on ultralight exhaust we use olive oil. Clean the rust off good,brush on the olive oil,fire it up & let it get hot. It turns black & seems to bake right in & seal the steel. I've never tried it on a Tcraft, mines stainless,but it has worked great on a couple ultralights I've tried it on. Eric

I remember treating wrought iron items we made in jr high metal shop by that method. I can't recall if it was olive oil or another vegetable oil or mineral oil. But it did work.

Dave

[Guest]

Re: exhaust system coatings

During my annual in the summer of 06 my exhaust system had to be replaced. I tried going the stainless route but it was just too involved and was going to take too long to get. I went with mild steel and of course it is rusting and looks terrible.

Here it is not even two years after spending over $500 and it looks like hell. Is there any way that I can extend the life of this system by treating it with something? Everything I've tried to coat these things with in past years really didn't do much.

If anyone knows of anything that truly can extend the life of these mild steel systems I'd appreciate your suggestions.

Thanks everyone!

Hey Tom,

This is the best I came up with.

Start having a stainless steel system made now. Take about a year to get the best price/deal.

Install it anywhere from 12 -18 months from now.

Put your old steel system in the attic or garage.

That's what I did. My steel system is still in good shape, its been in the garage since '98.

That's the only way they seem to last long for me.

The stainless system on the a/c has been outside for 10 years, no problems. You don't need a shiny SS system, don't pay extra for that.

Dave

[Tom G]

Re: exhaust system coatings

Thanks to all of you that responded. Marv, I'm going to order some of that paint you pointed out.

Dave, what you are suggesting I have thought of, I should start making preparations now to put on a stainless system. Where did you get yours? Also, I see you are in Poughkeepsie, I'm in NJ. We are both long time Taylorcraft people. I soloed in my plane in 1967 at 16.

Thanks again everyone!

[Guest]

Re: exhaust system coatings

Tom,

I soloed in '66 in a Colt, I guess I was 17 then, then flew an Ercoupe then in '68 got a BL65. Been t-crafting ever since.

It was a '39 that had been stored since about '41 till '68 when I got it.

It took me many years to realize that it was likely owned by someone that went to war and never came back.

So here's how I got mine. I bought some new flanges and 90 and 45 degree bends from a supply house for the cylinder connects, and got some straight and 90 used pieces from a a/c salvage yard and made a system to replace my steel one. I spent about $35 + $80 + $20 + $40= $175

I did reuse the steel muff ends. So I suppose that made it technically a repair.

Ironically I did not write it up as a repair and it went right thru the FAA office with no issues.

Its a lot of fitting up and adjusting. I used MIG on some parts and then I realized MIG is too fast for that kind of work so I went to oxy/actl to finish it.

I made it twice. What I mean is I made it up by fitting to engine and tacking it together then finished the welds. After that it warps and won't fit back on the engine so I cut some slots in it adjusted to fit and welded the slots back up.

If I was making them in quantity I would make a jig that was bigger or smaller were needed to after warpage the system fit the engine but would not fit back on the jig.

I wonder if the Foundation has drawings ?

Dave.

[dadam]

Re: exhaust system coatings

I had my exhaust "repaired" at Acorn welding in Edmonton, Alberta, Canada. they take the Stainless spacer ring off the aft crossover tube (they all have that peice in stainless) and "repair" what is left, in stainless. they provide repair documentation, all legal, and they require your old exhaust as a pattern. From removal to flying for me it was two weeks, and $1600.00 (shipped on the bus took 5 days of that) There must be a shop in the states that does the same thing. If not, look up Acorn...
Very happy with mine, will probably outlive me.
Darren

[Tom G]

Re: exhaust system coatings

Thanks again to everyone for the information.

Dave, we should meet up sometime.

[SteveR]

Re: exhaust system coatings

I intend to have my headers ceramic coated, as someone else mentioned. I've done this on two cars before, and the coating looks great for a few years even on a car that is driven every day. I'd imagine it will last a decade or two on a plane's exhaust. Google "ceramic coated headers" to find pictures. A local powder coating shop should be able to do this for you.

With any coating, you should probably verify that your carb heat still gives an adequate RPM drop with the new coating. Some coatings claim to reduce heat transfer through the exhaust, although personally I doubt it is very significant.

[astjp2]

Re: exhaust system coatings

You need more than just an RPM drop, you need to make sure that you can get a 90 degree F temp rise, if you dont, then something needs to be fixed. Tim