ES Composite Pipe Repair

[Rcmaster199 at aol.com]

Maybe it's me but I just don't get this apparent love affair 
with the carbon pipes. Epoxy as the binder, as Gray states, is marginal in 
almost all 4 stroke cases I have heard about. And to make these things super 
light, you have got to make then thin, so strength is doubly compromised, 
especially on four strokes with their 500+ degree stack temp.

 A hi temp plastic binder such as a PTFE emulsion, or maybe polyimide 
emulsion is a better alternative but then the cost would be 2x and impractical.  And 
ceramics, aka Space Shuttle heat shield tiles, are out of this world (sorry 
Gray, I couldn't resist)

How much weight is actually saved over a "lightweight"ally pipe anyway? The 
Greves is a little over 4 ounces, the Macs 20 cc is a little over 5 ounces and 
the Hatori is a little over 6. Are we talking, what, 4 ounces tops??
 Isn't there someplace else one could remove 2 to 4 ounces?

Hey, I am a big proponent of progress and composites offer great advantages 
in the correct places, but I have to question if this is one of these places

Firesuit..... hell forget the firesuit> I'm thick skinned enough, literaly, 
so fire away

matt K

> Subj:Re: ES Composite Pipe Repair 
> Date:9/23/2003 6:38:01 PM Eastern Daylight Time
> From:<A HREF="mailto:edbon85 at optonline.net">edbon85 at optonline.net</A>
> Reply-to:<A HREF="mailto:discussion at nsrca.org">discussion at nsrca.org</A>
> To:<A HREF="mailto:discussion at nsrca.org">discussion at nsrca.org</A>
> Sent from the Internet 
> 
> 
> 
> Gray, I'm listening. A short lived $200 plus pipe is not affordable either. 
> Short of going back to aluminum and the weight penalty, do we have another 
> alternative ??
> Ed M.
> 
> >> ----- Original Message ----- 
>> From: <A HREF="mailto:gfowler at raytheon.com">Gray E Fowler</A> 
>> To: <A HREF="mailto:discussion at nsrca.org">discussion at nsrca.org</A> 
>> Sent: Tuesday, September 23, 2003 5:40 PM
>> Subject: Re: ES Composite Pipe Repair
>> 
>> 
>> 
>> Concerning this repair, there is not a commercially available adhesive that 
>> is going to do the job long term. The adhesive I used on Wayne's pipe is an 
>> aerospace grade epoxy called Hysol 9394, rated at 350F. AT 350F this epoxy 
>> exhibits about 25% of its room temperature strength-and this is about the 
>> best room temperature curing high temp epoxy available-in short  all the stuff 
>> such as JB weld is crap at the temperatures we are talking about. The inlet 
>> temp of our mufflers makes for a brutal environment and unfortunately 
>> anything that cures at room temperature just is not going to do the job very 
>> well. In reality Hysol 9394 is borderline. No easy answer here, and is evident 
>> by the constant postings about burned out inlets....there is a problem with 
>> the composite mufflers.  Actually there is an answer, but I do not think our 
>> pattern market can afford it. 
> 

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