The fins on all my carded downscale models have "butterfly" folded fin skins. This gives a rounded leading edge when glued over the interior cereal box cardboard.
The printed fins are scored and folded down the leading edge using a dull butter knife tip and straightedge.
A glue sticks works great for the outside skin lamination.
The fins are cut out down the printed border lines. After cutting the trailing edge can end up with a raised lip.
Burnish down the raised lip with a hard round dowel.
Here I used the smooth tapered end of a mechanical pencil.
A bead of white glue is rolled over the outside and trailing edges.
This seals the exposed edges.
After the glue dries, lightly sand with 400 grit. You'll end up with slightly rounded outside and trailing edges.
The smoothed white glue bead won't be a full rounded edge but does take the edge off the squared sides.
TIP: If you like to paper your balsa fins, the folded "butterfly" method works great.
Just round the leading edge and leave the outside and trailing edges square.
In the end you'll have a more aerodynamic rounded leading edge. The other edges will be squared off and even with the fin edges.
Next time, try using a glue stick to adhere your paper skin covering. The glue stick isn't as messy as liquid glue from a bottle and allows re-positioning if needed.
Yep. using a glue stick instead of plain white glue helps to avoid the annoying problem of wrinkled paper skins (due to moisture soaking into the paper). Attaching model aeroplane tissue paper to balsawood is a tad easier than attaching typing paper to balsawood if you're using white glue -- the wrinkles are easier to smooth out with the tissue paper. Technique worked well for me on glider wings (such as on the Estes Scissor Wing Transport kit).
ReplyDeleteHi Naoto,
DeleteI was surprised to find out that builders now use glue sticks to apply tissue to model airplanes. When I was building those I used dope and dope thinner.
Some have yet to accept that glue sticks work well in some areas of rocket construction.
Another odd trick with white glue that could be used when laminating paper -- heat-activated bonding of white glue using an iron.
ReplyDeletehttp://www.oakwoodveneer.com/tips/ironon.html
Hi Naoto,
DeleteI've done that many times when rolling tubes out of 110 lb. card stock. Apply a glue coat, let dry. Roll the tubes around a dowel and use a hot iron to melt the glue and adhere the rolled tube.
Eric Truax carded models showed me that technique. I doubted it would work at first and was surprised by the good result.