Canvas wings

[Ken Pugh]

This thread is to show my technique for modeling canvas wings.  The Sopwith Pup model is 1/32nd size.

To start, many dig grooves in their wings to simulate rib detail.  After closely looking at actual aircraft, it seemed to me this was not to scale.  Most all drawings I have seen of planes of this era, however, show deep scallops in the fabric.  Again, this is not scale.  Consider these actual aircraft.  All are from the US Air Force Museum in Wright Patterson AFB.  These are actual restored aircraft.



http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1288



http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1287



http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1286

Notice in all cases, you can see the ribs, but the valleys between the ribs is very slight.  This all depends on the properties of the fabric, it's application, it's shrinking, the finish, and the rib spacing.  One may find some earlier aircraft with heavily scalloped fabric, but the practice quickly disappeared.  When we build RC models, we get the heavily scalloped effect, but that is due to rib spacing and the material used.  When you look at the actual aircraft, the depth of the valleys may be the same, but at the proper scale, the valley is very shallow.

My thought was to use the solid wing core to depict the valley and to use cardstock to show the protruding rib.  I then covered it with modeling tissue.

Ken Pugh

[Ken Pugh]

Now this is how my technique looks after finishing.



http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1290



http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1289

There is no dry brushing to accentuate the detail.  That is the result of the light playing on the painted surface.  I think the use of tissue and acrylic paints captures the look of painted fabric.  It may actually be larger than scale, but sometimes we need to exaggerate on our models to make the eye/mind see what we want them to see.

Ken Pugh

[Ken Pugh]

So how do we do it?  It's actually very simple.

First off, make your wing from solid wood as you normally would.  Using your drawings, mark in the rib locations, including the partial ribs on some leading edges.  Cut strips of cardstock the width of the ribs, or the width you want to show your ribs.



http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1293

Glue the ribs down with glue stick.  I find that UHU brand is the best there is and I usually can find it at Michael's.  Other brands will work, but UHU is the best.  If you need to undo these glue joints, alcohol with dissolve the glue, not water.  The purple stuff is good because it shows exactly where you have applied glue and it dries clear.  Whatever you use for your ribs, carefully consider it's finish.  If it is too porous, it will not look right.

I then apply tissue over the surface, again using glue stick.  You can also use white glue thinned 50/50 with water.  This is recommended by Guillow's as a substitute for dope and the free-flight rubber guys swear by it.  They say it works great, but they prefer glue stick.  The tissue needs to be sealed so you can paint over it.  This is especially true if you are covering open strutures, like a fuselage.  If an open structure, shrink it first.  I use regular rubbing alcohol.  It dries quicker than water and does not warp structures as bad as water.



http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1292

Here the ribs are applied.  I sometimes seal before applying the tissue.  Many do not seal wood but I do because acrylic paints have water in them and water can raise the grain.  Sealing wood just allows you to get a finer sanded finish because the sealer actually seals the grain.



http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1291

In this photo the surfaces are covered with tissue and probably sealed.  I use sanding sealer.  Works just as well as dope and is cheap.  You could also use polyurethane.  If you have way too many brain cells on hand, feel free to kill some with dope, but it just isn't necessary.  Beware, if you seal with anything water based,  it will make another shrinking cycle.  If your structure is not stiff enough, it will warp.  I prefer sanding sealer that cleans up with mineral spirits.

After the sealer dries I like to apply a gray primer.  I just use a gray color of whatever brand of paint I will be using.  This will help with subsequent color coats but also shows the condition of the surface.  You never know when you need to repair something.  By the way, if you need to repair the tissue, just apply a tissue patch.  Use the same techniques.  A very thin patch will actually look very realistic.

When painting, try to keep in mind grains and directions actual paint was applied.  For instance, think of the Fokker Dr 1s, like Werner Voss, that had a blue background and streaked olive drab.  You can see in the wing of the Pup where I brushed fore/aft.  If you go along the span, you may build up paint against the ribs and mess up the effect.  Go fore/aft and brush it out and the subtle detail will stay there.

I think I covered everything, but if there are any questions, please post.  Realize the materials I chose came from the free-flgiht rubber guys and they have tried an awful lot of stuff and this is the stuff that consistently produces the best results for them.  Like I said in the Fleet topic, they use Krylon Crystal Clear to seal the tissue.  Many other clears have been tried but the Krylon is absolutely the best.  It just isn't waterproof.

Ken Pugh

[lastvautour]

Thanks Ken. I tried puzzle glue as a coating and it appears to work out quite well. It is acrylic and clean up is easy. It is quite a bit lighter than dope and paint covers it nicely. Your instructions are clear and easily understood. Thank you again.

Lou