REFLECTOR:STRUCTURAL ADHESIVE

[reflector@tvbf.org]

I'm saying that for a laminate of the same strength or of the same 
stiffness you'd use fewer plies (and thus have less weight) with ProSet 
than with WEST.  (Note that they're both made by Gougeon)

One of the strange things about engineering composites is that usually - 
and almost always with fiberglass - you're engineering for stiffness rather 
than for strength.  Lets say that you want an airplane that has an ultimate 
load factor of 6 Gs.  So you come up with exactly the right laminate 
sequence so the wings will break at 6 Gs.  You'll find that at about 2 Gs 
the wings will be bent so far upward that the ailerons don't work anymore.

I wouldn't make any primary structure out of WEST.  I would feel 
comfortable *assembling* primary structure out of WEST.  Just as an 
example, I wouldn't make a spar out of it, I wouldn't make strake skins.  I 
wouldn't do foamcore wings in WEST.  But I'd have no problem installing 
strakes and bulkheads with WEST.  I'd have no problem doing T tapes in WEST 
and bonding on the top strake skin with WEST flox.  (But Pro-Set gelled 
adhesive works much better)

At 09:28 AM 5/5/03 -0600, you wrote:
>Richard,
>
>Are you saying the Pro-Set Epoxy is OK for structural laminates and 
>the  West System brand is not?  On the West System web site there is very 
>detailed instructions on how to do laminate lay-ups with West System Epoxy.
>
>Scott
>
>richard@riley.net wrote:
>>The epoxy people use the terms laminating epoxy and assembly epoxy.
>>They think of MGS, EZ-Poxy and the like as laminating - that's what you 
>>actually *make* things out of, like spars, bulkheads, skins, etc.  WEST 
>>would be an assembly epoxy.
>>If you're building from a kit, the overwhelming majority of what you do 
>>is assembly, especially if the wings are pre-molded.
>>Gougeon's laminating system is Pro-Set, and it's a joy to work with.
>>They also have a Pro-Set line of thixotropic, gelled resin that's 
>>wonderful for closing strakes, it's used with a gun and a static mixer.
>>
>>At 09:41 AM 5/5/03 -0500, you wrote:
>>
>>>I was curious about this a couple of years ago because I liked the quicker
>>>setup times and less obnoxious fumes from the West system.  At that time,
>>>the factory said that they were using West just for filling.  I called
>>>Gougeon Bros. and talked to an engineer there.  He said that the West system
>>>had been used structurally in composite aircraft.  When I looked at the
>>>specs, I think I remember that West had slightly less strength and a little
>>>lower transition temperature than EZ Poxy.
>>>----- Original Message -----
>>
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