Posted for "richard  titsworth" <rtitsworth@mindspring.com>:

 Walter, etal,
 
 Some of the posts here speak of coating both the inside and outside of the
 pipes.
 
 Just curious... Is it possible to only coat the inside?  Or coat both and
 then remove the coating from the outside?
 
 Seems only coating the inside would reduce the heat transferred "into" the
 metal and would retain the original ability of the metal to dissipate heat
 outward.
 
 If the goal was to reduce the heat radiated from the pipe, only coating the
 inside would (may) reduce the heat (temp) that the pipe has to radiate.
 i.e. Rather than coating the outside and holding the heat in the pipe, why
 not coat the inside and reduce the heat transferred into the pipe in the
 first place.
 
 Rick