Heat Shrink on Exhaust Springs

I was wondering if anyone has tried using heatshrink on the exhaust springs rather than the Red RTV like the picture on this website.

http://www.ultralightnews.ca/advisories1/exhaustspringtips.htm

I used Red RTV on my springs and it seems to be working well, but on one spring the RTV has peeled off and and is dangling. on closer inspection it is obvious that the RTV is having trouble bonding to the smooth surface of the spring. its possible that the spring had my finger oils on it when i applied the RTV.

I could roughen up the spring to give the RTV more bite, but id rather not scratch or otherwise scuff the spring unless I have to.

I also found this Heatshrink at local big box store that is pretty thick and tough. Anyone tried this before?

What’s the heat rating on the heat shrink? I suspect it will melt completely off before you finish taxiing to the runway

Not sure, how hot do you think the springs get?

EGT is around 1400F so I’d guess maybe around 1000F?

A few thoughts;
Some heat shrink can go to 500f but I think it would be very pliable at that temp and wouldn’t provide any dampening.
High temp RTV is good to 600f and does a good job, so I don’t think the springs see 1000f.

My red RTV is rated to 750f, and it looks pristine on the other springs. Im curious how much of the EGT heat is shed through radiance to the springs.

You could try
Permatex 59703 Ultra Copper High Temperature Gasket Maker
it's advertised for use in exhaust & turbo areas, & oily areas

Also if only one spring is affected, possibly the tension in that spring is torqued less than the rest?

Make sure the springs are clean of oil and other substances. There's no reason the RTV should not work fine on clean springs. Make sure it's quality RTV and high-temp type.

Heat shrink won't accomplish the same thing as the RTV, and could prevent seeing potential issues if they were to occur with the springs. Not recommended.

greghughespdx said:

Make sure the springs are clean of oil and other substances. There's no reason the RTV should not work fine on clean springs. Make sure it's quality RTV and high-temp type.

Heat shrink won't accomplish the same thing as the RTV, and could prevent seeing potential issues if they were to occur with the springs. Not recommended.

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That sounds pretty definitive to me. Thanks for the input everybody.