"Russell Duffy" <13brv3@bellsouth.net> wrote:


"""
 I just looked up the description of "bid" on the Spruce page, and can't say
 that I can see any difference between that, and normal cloth (e-glass?).  I
 cut the cloth on a 45, and usually have pretty good luck going around
 corners, but I'm sure "bid" is probably better, and certainly my technique
 could stand some improvement.  I'm using the lightest cloth I could find, at
 6 oz, but wish it was a little lighter for the initial layers.
"""

The term "BID" simply stands for bi-directional, and defines the cloth as being woven with warp & weave at 90 degrees to each other.  This is in contrast to "uni" (unidirectional) type cloth in which just about all of the threads run in one direction, with single threads at 90 degrees every several inches just to keep the primary ones intact.  As for weights, you can find much lighter fiberglass cloth at the local hobby shop, with material down into the 1/2oz range.  For what you're doing, you would probably be well served with some 2oz next to the mold, overlaid with several plies of 6 oz to add strength to the exterior and the overall structure.  FWIW....

     <marv>


 Since there are two ducts, you can surmise that I decided not to add another
 scoop to the cowl.  I'm going to have one as an air box on the TB, with the
 air horns inside.  The other goes on the bottom of the right radiator, where
 the old hoses attached.  By the time I'm done, there will be about a 12 sq
 in opening in the radiator duct where the new inlet duct will be added.  The
 two new ducts will be joined by 3" ID tubing,  CEET for now, perhaps
 something smooth walled later.  3" is just HUGE though, so it's hard to
 imagine there will be any restriction now.  I may not get quite as much ram
 air effect as I could with a dedicated scoop, but this system give me the
 option of adding a scoop in a convenient location later, while still using
 the air box that I'm making.
 
 Cheers,
 Rusty (Frances turn North now)