Q1 Foams


David J. Gall
 

Jorge,

Do not use the fuselage urethane (polyurethane) foam for wings. Also, do not
cut Urethane foam with a hot wire and do not expose Urethane foam to heat or
open flame. It gives off poisonous gasses when heated or burned.

Do not use the fine-cell insulation Styrofoam that Dow makes. The insulation
Styrofoam is called IB foam, for Insulation billet; the blue foam that the
wings and control surfaces are made from is called Dow FB Styrofoam.

FB Styrofoam can be purchased in billets that are 8 x 16 x 109 inches. FB
stands for Fabrication Billet. FB has a coarser cell size that permits a
better mechanical bond between the foam and the facings than IB. FB
Styrofoam should be available at any insulation wholesale supplier. That's
where I got mine. I have some of the original blue foam from a Quickie kit
and it appears to be identical material to the Dow FB Styrofoam.

There is a third type of Styrofoam available called BB Styrofoam. BB stands
for Bouyancy Billet. This material is coarse, similar to the FB Styrofoam
although it may be a different color. BB Styrofoam was supplied in some Q2
kits for wing and control surface cores and seems to be a direct replacement
for the FB Styrofoam.


David J. Gall

-----Original Message-----
From: Q-LIST@yahoogroups.com [mailto:Q-LIST@yahoogroups.com]
On Behalf Of Jorge
Sent: Thursday, August 10, 2006 9:49 AM
To: Q-LIST@yahoogroups.com
Subject: Re: [Q-LIST]

Yes , Dave I am asking if I can use the same foam of the
fuse on the wings , as the KR plane use .And on the Jack
Lambie books ( composite construction) say that hot wire
foams is more easy to work on big and gentle curves than
polyurethanes.
About CG I want to now more , the max forward and the max
aft, I^m 200 pound guy and 6feet toll .
Thanks very much


JMasal@...
 

To piggyback off of GALL's email, the BB foam was an orange color.

In the good ol' days there was much discussion of "peel strength" which I
took to be the amount of force necessary to peel a strip of fiberglass from its
foam substrate. In the case of the Quickie urethane fuselages sides the
density of that foam makes a wonderful bond difficult. You would be astonished how
easy a layup will peel off. It is very easy to carve urethane into pleasing
compound shapes and it resists the damage of fuel in the area of the tank
(This is an area of danger with styrofoam.) but it won't bond well.
Nevertheless, there has not been a lot of crying and wailing over the years so the bond
must be just fine. Personally, I'd use styrofoam if I did it again... except
for some further thinking about the tank area.

I got concerned about peel strength and I don't know that I improved it a
damn bit, but after I had my inside fuselage layup cured I pricked the outside
with a toothpick every 3-4 inches thinking that when I did my outside layup
the epoxy would flow into these holes and make a physical connection between
the two skins.

The Quickie used some pretty stiff gold foam for bulkheads, dunno what it
was, But didn't the Q2 use Clark urethane foam??? I think the seatback
bulkhead has to be pretty stiff or dense to support the weight of the occupants.

Oh, yeah, I DID finish and test fly my Quickie successfully If that adds any
veracity to the above. It is currently an engineless hangar ornament however.

j.