Silkspan for hulls?
- Thread starter cdcoyle
- Start date
I think that won't help much as it shrinks, it will contour toward the center of the bend leaving a nice wavy surface just like an airplane wing.
In balsa modelling it is called the starved horse effect, where the tissue sinks slightly between formers. You can eliminate it by having lots of structure to hold the tissue up (heavy if you fly) or by practising a lot!
You might escape the tissue shrinking too much and twisting the formers by pre-shrinking it. This involves attaching the tissue to a frame or taping it to a window then misting with water. Use when dry.
But in the end I think the tissue will always pull to a straightest path between attachment points so a hull would still be scalloped between the formers.
Tissue covering is fragile so you would need to wrap it in a second layer quickly... which brings me to papier mache, like when children cover a balloon to make a mode head, this might work on a really large hull...
I will stick with foam, either from a can or cut from blocks.
D
You might escape the tissue shrinking too much and twisting the formers by pre-shrinking it. This involves attaching the tissue to a frame or taping it to a window then misting with water. Use when dry.
But in the end I think the tissue will always pull to a straightest path between attachment points so a hull would still be scalloped between the formers.
Tissue covering is fragile so you would need to wrap it in a second layer quickly... which brings me to papier mache, like when children cover a balloon to make a mode head, this might work on a really large hull...
I will stick with foam, either from a can or cut from blocks.
D
In fact, to continue with papier mache...
Kartonbau.de - Alles rund um's Kartonmodell... | Bauberichte | Baubericht: Great Eastern (Schreiber Bogen)
D
Kartonbau.de - Alles rund um's Kartonmodell... | Bauberichte | Baubericht: Great Eastern (Schreiber Bogen)
D
Seems to me you'd have to be very careful and very lucky to avoid warping the hull in unintended directions. And as noted, you're going to end up with the "starved horse" effect between the bulkheads.
Interesting idea--and ALL ideas are welcome here--but probably not practical.
No worries,
--David
Interesting idea--and ALL ideas are welcome here--but probably not practical.
No worries,
--David
Sort of off topic. Thanks very much for the heads up on a Great Eastern build David.
I have a semi completed, unsatisfactorily, partly built model... That got me hooked on card modeling in the first place.
As for silkspan,...hmmm 25 years ago, from memory,... we would paint the "silk" with "dope", and would always get the hungry horse affect. Take it or leave it.
Gippo
The reason i suggested dope/silkspan was from previous experience useing it on somewhat stable structures, solid structures. Useing it between airplane wing ribs will indeed give you the scalloped look which is exactly what they were looking for any way. We have used it over foam with wbpu, over cardboard with dope and over balsa with dope and it does still shrink but not as much at all. The suggestion of pre-shrinking is a good one. But basically, as i suggested, which ever technique you try you should still test on a test structure of some sort.
Styrofoam not silkspan
The comments about the problems with silkspan are right on. The solution is regular old styrofoam, the stuff in which products come packed.
Cut it so that it fits the sections between bulkheads....on any model we card types like to build. A bit of rubber cement will hold it in place. Do not use epoxies or glues containing VOC's (volatile organic compound) as they will eat the styrofoam. Elmer's white will hold it in place, too.
Then, using a nichrome wire cutter, trim the styrofoam to shape using the bulkheads as a guide.
Do bit of finish sanding to smooth everything out. With some care, you can even sand in contours so that they appear curved instead of straight lines. This, of course, assumes that you can apply contour to the paper, which you can with careful rolling.
Works like a champ!
The comments about the problems with silkspan are right on. The solution is regular old styrofoam, the stuff in which products come packed.
Cut it so that it fits the sections between bulkheads....on any model we card types like to build. A bit of rubber cement will hold it in place. Do not use epoxies or glues containing VOC's (volatile organic compound) as they will eat the styrofoam. Elmer's white will hold it in place, too.
Then, using a nichrome wire cutter, trim the styrofoam to shape using the bulkheads as a guide.
Do bit of finish sanding to smooth everything out. With some care, you can even sand in contours so that they appear curved instead of straight lines. This, of course, assumes that you can apply contour to the paper, which you can with careful rolling.
Works like a champ!
B
Bionic Modeler
I dont' understand the obsession with perfectly smooth hulls. In the real world (I live near some of the largest ships in the world) the hulls are anything but perfect. After a few voyages they look pretty much like what we end up with when building our ships without all the effort to make them perfectly smooth. I like the fact that paper allows a more realistic look. If we want perfect, why not go back to (dare I say it here) ----plastic? Then they can look unrealisticly smooth.
(Sorry if I offended anyone)
(Sorry if I offended anyone)
Smooth Hulls
What I wouldn't give for an unrealistically smooth hull!:twisted:
I could understand a beat up WWII corvette or even a world weary bulk carrier but at a scale of 1:200 or less it could look kinda crude.
I strive for smooth because I like to see the look of amazement on my friends faces! "That's never paper..."
(BTW I think we aim for an idealistic and perfect hull because that's what ship models should have- particularly full hulls. I guess this is because shipyard and owner's models are fantastic examples of model making with perfect hullls (made in wood).)
D
What I wouldn't give for an unrealistically smooth hull!:twisted:
I could understand a beat up WWII corvette or even a world weary bulk carrier but at a scale of 1:200 or less it could look kinda crude.
I strive for smooth because I like to see the look of amazement on my friends faces! "That's never paper..."
(BTW I think we aim for an idealistic and perfect hull because that's what ship models should have- particularly full hulls. I guess this is because shipyard and owner's models are fantastic examples of model making with perfect hullls (made in wood).)
D
I completely agree...
While I'm not a ship modeling expert by any standards, I have to say I prefer the look of a beaten up slightly warped hull, I loved the way barry's Tarawa Hull came out looking pretty much exactly like a lot of the pictures I'd seen of the Tarawa herself. My Daring Hull, designed by barry, has turned out the same way and I couldn't be happier with it. I'm aiming for a "used and abused" look in the finished model.