|
|
Divinycell H-80 is 5 lb/cubic foot and will pretty much double your
compressive strength and modulus. Do you know if they were using Rohacell
then?
Another option is to use ultralight density aerospace grade balsa core. This
is 4-5 lb/cu ft. density and is off the scale strength wise compared to
foams. I would specify the AL-600 coating also which helps prevent excessive
resin absorbtion. You will find that NOTHING beats balsa for toughness,
compressive strength and high modulus. It is still the standard for aircraft
floor panels for airlines. As an aside, the earliest failures in the floor
panels were caused by women's high heels (remember when airline travel was
glamorous and everyone got dressed to the nines?) and the food carts causing
core shear failures. Balsa fixed that and has yet to be beaten. It comes in
all the standard thicknesses. There were incredible loads placed on the end
of a spike heel! And if you have to sand a side after bonding you will
remove the AL-600 coating so be sure to hot coat it with epoxy or whatever
resin you are using. This is to prevent excessive resin absorbtion which can
lead to resin starvation in the fabric and incredibly low peel values. Like
you can peel it off with your fingers.
You can get it in small quantities of this balsa (from Baltek) at Fiberglass
Hawaii in Watsonville, California near Santa Cruz. They also have good
prices on all kinds of fabrics and resins. Probably anything you need
materials wise plus gloves, mixing equipment, etc. Sorry I don't have their
number here with me, it's at the office.
And one fiberglassing tip of the day. If you have to sand fiberglass or carb
on, (I find carbon itchier than glass), spread some barrier cream on your
exposed skin before you start. It washes off with water and prevents most of
the dust from getting in your pores thus ALMOST eliminates itching.
Available at hardware stores, one brand is "Liquid glove" but there are all
kinds. And most don't wash off in acetone or MEK.
Good building!
Dan Newland
Super ES
|
|