Randolph Butyrate Dope and Thinner by the Gallon
After experimenting with some of the newer finishing materials and paints, none have
really given me the satisfaction of a good, old-fashioned Silkspan and dope finish. Dope,
however, is a relatively high cost option, both for nitrate and for butyrate. There is
a way to help bring down the expense by buying it by the gallon, if you don't already
do so. Sig and Brodak are fine dope products, but even in the quart size cans it costs
2x to 3x the amount of getting it by the gallon from Aircraft Spruce.
I have a vintage Carl Goldberg 1/2A Skylane configured for control line that is now
in the process of being covered, and a vintage control line Sterling F4U-1 Corsair is
nearing completion of the construction so it will be getting covered soon. On top of
that, I have a vintage Top Flite P-40 Warhawk control line kit that will be next in line
for building and covering. Finally, plans and balsa have been procured for a long-awaited
control line Douglas DC-3 control line model that will also be covered with Silkspan
and dope. That's a lot of dope to buy. Naturally, I want to save money wherever possible,
so buying in gallon quantities makes sense.
For example (see photo below), a gallon of butyrate clear dope costs $49.00 by the
from Aircraft Spruce. The largest can of clear that Brodak sells is a
quart, for $23.89 (Crystal
Clear is $32.99/gal., but is not equivalent to the Randolph product). That works
out to $95.56 per gallon (95% more). Fortunately, Aircraft Spruce also sells white butyrate
dope by the gallon for $76.25. Brodak only sells color (including white) in
16 ounce cans at $16.49. that works out to $131.92 per gallon (73% more). Butyrate
thinner from Aircraft Spruce costs $42.70 per
Thinner from Brodak is costs $18.19 per
quart. That works out to $72.76
per gallon (70% more). So, as you can see, an overall cost saving of 75-80% can be realized
when buying it by the gallon.
The best bet for buying color other than white is still through Brodak or Sig, because
it is $60-$85 per quart from Aircraft Spruce. Here is the insane thing: Buying it
buy the gallon costs LESS at $55-$75 per gallon. Go figure. If you need enough colored
dope to buy it by the gallon, then it's a great deal.
Here is a tutorial I did on
covering with Silkspan and
dope. It include a few videos of the process.
Posted October 25, 2012