Well, we had gotten numerous posts regarding the negatives of coating and wrapping the outside of the exhaust systems.  All have merit and all are important contributions to the subject.

 

To add to the subject, my stainless system is coated on both the exterior and interior.  Weld repairs, in the first year of operation for cracks, were made as well as the addition of a ball joint with no problems.  As a result, I do not see that coated systems hinder repairs as an issue.

 

But there hasn't been much posted on the subject of interior heat coatings for the exhaust system.

 

My stainless system, Lancair supplied (Snowline Mfr.), and heavily modified to make fit (by Snowline and myself) has been ceramic heat coated on the interior since the planes completion nearly 13 years ago (1999).  With the exception of the first years fly-off test period, where exhaust system repairs were made (including adding a tail end spring), I have had no problems with pipe wall failure or cracking.

 

All in all I still feel that the exhaust system is one of the weakest items firewall forward and so make regular system checks of it every time the cowls are off.  Because of potential crack issues from vibration and expansion, I might go with a mild steel system if I were to do it again.

 

I welcome any input on the aspects of interior heat coating of the pipes.

 

Gary Edwards