Model Forum / General / Rockets / June 2006

I have coated the inside of the body tube near the motor with CA.  This
seems to work on smaller motors (upto about a G or so)  I have also
lined the inside with fiberglass.  This seems to work best with F/G to
I or so motors.  J motors and above just get too hot for almost all the
things I've tried.  I almost always have the motor extend past the body
tube by a 1/2 inch and use JB weld on all connections for motors that
big.

High-temp automotive paint might work, but I thought it took a special
curing process to work correctly (have to bake it on) and so I've never
attempted it.

-Aaron

I'd start by checking your blast deflector, most of the aft end damage
is from blowback at ignition.  Even the best high temp paints aren't
going to protect against incendiary particles in that temperature
range.

Some time with a pair of tin snips and a cheap-o thin walled stainless
steel mixing bowl would yield a design that would divert hot gasses and
particles without the ricochet effect.

Mike Doyle

  One thing I have done on a couple of rockets that has been fairly successful
is to use a disposable heat-sheild made of heavy duty aluminum foil (the kind
used in ovens).  This works well on fairly large rockets with a flat aft end
where the rear centering ring is slightly recessed inside the body tube.  Cut
out a ring of foil that will fit on the centering ring between the motor tube
and the body tube.  You can also have tabs that will protect the sides of the
body tube and motor tube.  Hold it in place with either masking tape or whatever
you are using for motor retention (in larger rockets).  This sheild will last
for several flights.  When it starts to deteriorate you just replace it with
another one.  I make templates of the sheilds and cut out spare ones to carry in
my range box.

Jonathan
-----
Jonathan Sivier
Secretary, Central Illinois Aerospace
jsivier AT uiuc.edu
NAR #56437
Tripoli #1906
CIA Web Site: http://www.prairienet.org/cia/
Home Page: https://netfiles.uiuc.edu/jsivier/www/
-----
"Remember to always keep the pointy end up."

I let get yucky.  If it bothered me, i'd put an aluminum plate on it.
I have one rocket that's flat black.  It isn't affected by that.

Phil

use a standoff on your launch rod.

our club uses spent Estes engine casings. hardly any liftoff damage. bet it
would be non-existent if we stacked two of them.

also, we use angled blast deflectors on the HPR stuff. absolutely no issues

High Temp RTV.  You can buy it at the local hardware store. It has a copper
base and is rusty colored.  I actually have a motor retiention tail cone I
made out of wood and foam.  The motor sits back behind the exit plane of the
tail cone by about 3/4 to 1 inch.  The RTV works great on  the ID of the
cone.  We use the same stuff on real rocket test stands to cover exposed
bolts on tooling that sits behind the nozzle exit cone.  And I'm talking
about a 60 inch dia solid booster that makes the concrete surface pop like
popcorn and the steel deck plate radiate at about 300F for 20 minutes or so
after the static fire test.  Just apply the RTV the day before your launch
with a putty knife or similiar object.  You could try painting it on with a
stiff brush.  I just use my finger.

I also just found a company that makes high temp coatings that you paint on
good up  to 2600F.  They sell a roll of insulative tape consisting of
aluminum and fiber glass layers you could try.

http://www.aremco.com/protective-coatings.html

kt