ES Composite Pipe Repair

[Jerry Budd]

Hey Ed,

Nobody is better qualified to speak to this than I.  I absolutely 
killed myself to get my E=MC3 down to make weight at this years Nats. 
A month prior my E=MC3 weighed 11 lbs, 12 oz.  I had Dick Hanson 
build me a new set of wings to get within a couple of ounces and then 
I started looking at weight on a gram by gram basis at the component 
level.  At the courtesy weighing on Sunday at the Nats I was 18 grams 
over weight.  I then took 2.3 ounces of weight out of the airplane 
and I exactly made weight at the weight checks late Wed and also 
after the finals on Thurs.  I'll leave the math to those who feel 
compelled to check my numbers (Hint: no, it doesn't add up!  BTW - 
Did you know that a standard JR switch harness/charge jack assembly 
w/screws weighs 1 ounce?).  Last year I pulled 11 ounces out of a 
Gator G202 to get under weight for the Nats but it didn't matter 
since I had engine problems on Monday.  Maybe I should write an 
article sometime on how to REALLY get serious about getting the 
weight out of an obese airplane?

Anyway, my experience with the carbon fiber pipes is that they are 
the second easiest/quickest way to save weight at the component level 
via substitution (changing from an aluminum wing tube to a carbon 
fiber tube is the first, wheels are third, and the fuel tank comes 
fourth).  Of course weight gain due to exhaust soak can be an issue 
with some of the more porous composite pipes (like the Bolly) but 
IMHO it is nonexistent with the ES pipes.

As far as the problems with inlet temperature I haven't seen this 
when running a 2-stroke motor so I'd have to say that it's one of 
those costs associated with running a 4-stroke.  My ES pipes are now 
3 years old and in nearly perfect operating condition (I've been 
4-stroke free since 2000).

Jerry


>You wouldn't believe the lengths ( read $$ and time ) I went to to 
>shave mere grams from my EMC. The ES pipe I have weighs exactly 3 
>oz. I'm all for the durability and cost reduction of an aluminum 
>pipe over unobtainium, but that ounce plus is sure hard to find 
>elsewhere. 
>Ed M.
>
>----- Original Message -----
>From: <mailto:Rcmaster199 at aol.com>Rcmaster199 at aol.com
>To: <mailto:discussion at nsrca.org>discussion at nsrca.org
>Sent: Tuesday, September 23, 2003 7:35 PM
>Subject: Re: ES Composite Pipe Repair
>
>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:<mailto:edbon85 at optonline.net>edbon85 at optonline.net
>>Reply-to:<mailto:discussion at nsrca.org>discussion at nsrca.org
>>To:<mailto:discussion at nsrca.org>discussion at nsrca.org
>>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: <mailto:gfowler at raytheon.com>Gray E Fowler
>>>To: <mailto:discussion at nsrca.org>discussion at nsrca.org
>>>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.


-- 
___________
Jerry Budd
mailto:jbudd at qnet.com
=====================================
# To be removed from this list, send a message to 
# discussion-request at nsrca.org
# and put leave discussion on the first line of the body.
#