I think the best way is to use thick carbon fiber skins laid up in
female
molds  and bond them together at leading and trailing edges. Clamp
them back
in the mold and inject them under pressure with syntactic
foam. Syntactic foam

Paul, Far and away better is to wrap the prepreg around a rubber form,
(hollow)
place it in a female mold with clearance to trail the fiber out the
trailing edge.
Then close the mold pressurize the rubber form and heat the whole
mess. The resultant
blade has a "single sheet" strength the trailing edge is trimmed and
you are done.
The layers of the trailing edge are clamped togeather and the leading
edge is continous.
My $.02. If I'm making the molds that is how I'll do it.
Bill Jepson

That sounds like a less labor intensive way of doing it.
What do you use for the rubber bladder Bill? How closely must it be
shaped
to the final planform of the prop blade? Can a section of bicycle inner
tube
be used?

Send me some sketches on this process. Would it help if a flat wood
insert
was placed in the rubber bladder the shape of the prop blade plan form?

Paul Lamar

Talk about a blast from the past.  I used to be head lackey for Bill
Laister (of Laister sailplane fame) when he was developing a clamshell,
self contained, self heating/cooling, bladder pressurized alternative to
autoclave tooling.  It allowed for cycling about 4 parts per day out of
a mold instead of only one.  We were working with Boeing on F-22
wingribs.  I have some actual pix around here somewhere....

Chris C.
microcosman.com/aircraft

How did you make the bladders Chris?

Paul Lamar
 
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