If you do a Google search on Silkspan and dope covering methods,
a lot of good written instructions can be found. In fact, I suggest you read one or two of them if you
have never done a Silkspan and dope covering job before, or if it has been a while and you want a refresher
course, or if you have tried and never been able to get an acceptable result. There is no special skill
required to obtain a really nice looking Silkspan and dope finish, there are a couple "gotcha" scenarios
that can ruin an otherwise simple process. I believe the two worst mistakes you can make are painting
dope in air that is too humid, and using a thinner that is not entirely compatible with the dope (nitrate
I decided it might be a good idea to make a video of how I have been successfully achieving decent
Silkspan and dope finishes for lo these 40 or more years. My finishes have never won any prizes, but
the tissue (Silkspan) has always been nice and taught and the brushed dope has gone on evenly, with
nice, sharp trim lines.
The subject of this tutorial / demonstration is a Sopwith Camel biplane from a Manzano Laser Works kit. My Camel first flew as a 3-channel
radio controlled model, and was covered with Monokote. It experienced an unplanned encounter with terra
firma and broke off half of the top left wing. Since I had originally planned to build it for control
line, I decided to take the opportunity to strip off the Monokote (olive drab
- the dark colored stains on the balsa are residual adhesive tint) and re-cover with Silkspan
and dope. I never liked the idea of using plastic covering on a WWI biplane, so this time it will look
a little more authentic. Snoopy will still be the pilot, though.
Prior to recording these videos, the Camel had been completely finish sanded and a coat of 50/50
nitrate dope had been brushed onto the balsa framework to facilitate the Silkspan attachment later.
Because YouTube limits video durations to 10 minutes, it is necessary to break the tutorial into
Part 1 is mostly an introduction to the concept of tissue covered models and the
two types of dope - nitrate and butyrate. It also covers tools needed (sharp razor blade, paint brushes,
tack cloth, etc.), and the topic of covering compound curves.
Silkspan Covering - Part 1
Part 2 is A discussion about the logistics of partitioning the covering pieces to
best accommodate the airframe is given, along with preferred grain orientation. It covers where to apply
the base coat of dope to the wood framework, and where not to apply it. A demonstration is given of
how to seal the loose edges of the newly applied and dried Silkspan
Silkspan Covering - Part 2
Part 3 introduces safety concepts, and discusses the compatibility issues of nitrate
and butyrate dopes, along with demonstrating how to identify the Silkspan's grain and shiny vs. non-shiny
side, if applicable. Wetting and applying the Silkspan to one of the wingtips is also shown.
Silkspan Covering - Part 3
Part 4 shows how to trim the overhang from the newly applied Silkspan. A demonstration
is then given on how to properly cover the wingtip's compound curves. Supermodel Melanie, who has been
graciously operating the camera, makes a cameo appearance. In case you were wondering
(you probably weren't), I kept looking down toward the end of the movie because our cat wandered into
the room and began rubbing against the camera tripod, and I was making sure she couldn't tip it over.
Thanks for watching.
Silkspan Covering - Part 4
While preparing for Part 5, I came across a couple items that should be included
in this tutorial.
The first is a method for trimming pieces of Silkspan that are too small to grasp with your fingers
while cutting with the X-acto blade. Being wet makes it even more challenging. I use a pair of tweezers
that has flat tips about 1/4" wide to grab the Silkspan. Those same tweezers work great when applying
the wet Silkspan and a small section folds over onto itself and is difficult to unstick. They are also
good for grabbing an edge of wet tissue to pull it tight across an open span like across wing ribs.
(click for a larger image)
The second is a method for achieving a constant width trimmed edge for creating an overlap area.
I use a popsicle stick, which is about about 3/32" thick, to sit on the edge of the framework, and then
run the X-acto blade along the top of it. Keep shifting the popsicle stick as needed until you have
trimmed the entire edge. If you need a larger overlap, use tape two together or use a piece of hard
just earned an honored
spot in my great hobby shops list. Back in April, I placed an order for a bunch of Brodak dope for use
on my Sopwith Camel. They were chose because
of having the best price I could find. After finally getting around to using the dope, I notice the
Cessna White was missing, so I wrote asking them to see if it was ever shipped. Their records confirmed
it had not been included in the order, so they are sending it now. That is the kind of honesty that
I finally completed the wing repair and totally refinished the entire Camel. About a pint of acetone
and lots of paper towels were used to wipe the color coat of dope off the entire airframe. Then, a couple
coats of clear were applied, and a couple coats of white base color. Sanding was done every other coat.
Even with the white base, it took five coats of yellow to get a good opaque color. Just two coats of
olive drab green were needed, and three coats of Insignia red. Prior to painting, two additional coats
of white were applied in all the areas where white would be needed in order to avoid having to brush
many coats of white over color. When the weather warms up, I plan to spray a light coat of clear over
Melanie with the Manzano Laser Works Sopwith
Camel - Set up for electric-powered control line.