abufletcher

After a lot of testing, what looks best is a 2-3mm wide strip of stitching doped onto the white under-surface (Koverall) and then the silk is applied on the entire surface (as on the tail feathers) over the rib stitching.

TFF

How easy is it to keep the silk down on the stitching? I think a whole wing would be a big fight to keep it from lifting. It does look good.

Mein Duff

Looks very convincing Don... go for it I say !!!

abufletcher

I suppose I won't really know until it's flown for a couple seasons. But my impression is that once the dope in the Koverall binds with the dope in the silk, the two layers are more or less inseparable. On my of my early tests I used polycrylic to apply the silk and while that initially seemed fine, the silk could easily be peeled off. I see my koverall+silk combination as essentially the same as the old silk+tissue technique.

There's a little wrinkle (literally) in my attempt to make the stitching strips. I decided to use (thinned) dope on the threads and then do a top layer of white glue, but when I brushed on the dope the silkspan wrinkles up horribly. Also I noticed that many of the threads aren't actually making contact with the background. It might help if I used something to "lift" the backing material a bit to push it up against the threads.

abufletcher

I had misread your post. Not doubt that applying the silk over the stitching adds yet another level of complexity to an already complex (re)covering task. What concerns me most is how applying large sheets of silk may differ from applying the small pieces on the tail surfaces. By the time I get the dope on one end of the wing, the dope on the other end will likely already be dried. And I wonder if I'll have time to properly brush the silk down over the stitching. Another question is that my test piece is flat, while on the wing I would have to contend with the fabric dips between the ribs.

So many unanswerable questions.

abufletcher

No, my board, as nice as it looks, doesn't work at all. The thread are not being held down against the silkspan backing. There must be a slight curvature to the board. Maybe if I just lay down a couple layers of newsprint underneath the wax paper that will force paper up against the threads. Also I still haven't been able to solve the wrinkle problem with the silkspan. I might have to use koverall instead, though to be honest I find working with Koverall to be a really pain in the neck. It doesn't cut well, it frays easily, the weave can easily be disrupted.

gabriel voisin

Hi Don,

new infos from Koloman, ...Eberhard Albatros back in the air.
You will love it, see the color scheme.
greetings Matz

http://www.theaerodrome.com/forum/re...24-flying.html

abufletcher

That is truly, truly beautiful...and the perfect landscape as well! I'm afraid I have to admit that the color of my covering isn't really a match. It's much too dark and a bit on the orange side. But I suppose as an impressionistic solution on a small scale model it's acceptable.

What we really need in in terms of WWI modeling products is a fabric covering that looks like clear doped linen (just like on the DII replica).

gabriel voisin

The most modellers make a big mistake, they do everything with colors and additionally with the wrong colors.
None of the wood was stained in the German aircraft, but only conserved.
The color of the linen fabric was characterized by the color of the basic fabric and not with the dope.

Matz

abufletcher

This is a very good point. The more we can use authentic "manufacturing" techniques the more authentic our models can be. Still, I have seen some very dark fuselages on some of the Albatros 2-seaters and I have to believe that some of them weren't just clear varnished. Some were obviously just like Koloman's DII, but some of the BII's and early CIs have what looks like a dark stained fuselage (which is what I've reproduced on my model).

Can you tell us something about that products were used for "conservation?" Was it similar to boat varnish? Did it darken the wood? Of course, another problem we modelers have is that we're working with different woods. For example, the "hardwood" we use seems to be very VERY light (almost white) and it's difficult to get the right color without stains. I've tried many many clear lacquers and varnishes to get an authentic look on struts and it's always wrong because the wood is wrong.

That's why we need some suitably colored fabric for our modeling uses.

abufletcher

At least in spirit, this is what I was trying to achieve. While my "double cover" technique is certainly not true to the original, I wanted to avoid using paint to get the color I wanted. Painting for CDL just seems wrong. And I'm happy that I'm using dope. But at least in my case, the applications of dope do noticeably darken the look of the fabric.

I'm anxious to see what the finished wings look like out in the sunshine. The tail feathers look a bit dark in my workshop but my experience is that colors lighten up significantly when seen out in open sunshine.

abufletcher

Whatever I'm doing wrong, my attempts to make the stitching strips aren't working at all. AT ALL. []

This time I first moistened the silkspan and then taped it down over wax paper and that helped eliminate most of the wrinkling. But then applying the dope was a disaster. I brushed on the same thinned mixture I used on the tail, but it didn't want to dry. It just sat there. Previously, on the tail, it was drying very quickly. Eventually, I peeled the dope-soaked silkspan off the wax paper, hung it up and force dried it with a heat gun...which left all sorts of blotchy blushing. And even 8 hours later there's still wet residue on the wax paper. What's up with that???

And then even after I managed to get three coats of dope on the silkspan, as before, the threads don't make uniform contact with the silkspan and the dope doesn't seem to stick the threads down.

It's really like the dope isn't functioning at all.

This should be dead-simple.

TFF

Try this. Build a picture frame and attach the silkspan. Wet and attached to the frame like covering a wing. Let it dry, dope it for stability, dry, put your thread down...

TFF

I woulds probably dip the thread in straight dope, not thinned. then put down. Do most people use this method with iron on coverings instead of straight fabric?

abufletcher

The frame might work, but I'm quickly running out of silkspan...though I think I have some Japanese modelers silk that I might be able to use. Koverall just doesn't seem like a reasonable option since it's so hard to work with. But I still don't understand why the dope isn't drying. The other day it was cold and rainy. Would this have prevented the dope from curing?

In all looks so simple whenever I see anyone demonstrating this technique. And my little test piece came out just fine.

abufletcher

But the biggest problem is this: Unless the backing lies ABSOLUTELY FLAT, the threads don't make contact an so you can't dope them down. In many areas there's at least 1/16 inch between the thread and the backing. I wonder if this is because my board is too wide.

Again this is supposed to be a simple tried and tested modeling technique. Why can't I get it to work for me?

I've now wasted the better part of a week trying to make these strips...not to mention scarce materials. Time to go back to square one.

TFF

Trying to post 10 hours ago my suggestion was to cut the silkspan loose from the frame once it has been doped and dried and then put on your loom. With RCU being hit or miss the last 3 days, you are probably done with the plane now.

abufletcher

The silkspan just doesn't work. (And it's really not possible to dope a large piece on an unsupported frame.) So I'm giving Koverall a try. I have a small sample piece "on the loom" at the moment. So far it seems promising. I pre-ironed the Koverall, primarily to remove the creases. It certainly lies flatter.

abufletcher

So here's what's coming up, when I eventually get the silk on the wings. At that point, I'll be able to finalize the covering on ailerons. If the silk-on-coverall looks the same as the silk-on-solartex, I'll use solartex on the ailerons to minimize the chance of warping them. Actually, as on the original, a twist is built in and I just need to make sure it stays that way. This will require some careful tightening since the frame of the ailerons are still fairly flexible.

But the really big deal will be that with the silk on the wings, I'll be able to add the fittings for the struts, which have already been made, and then it'll finally be a biplane! There are a thousand little things that I could be doing (like painting the guns or working on the engine cowlings) but sometimes you just want to focus on one thing.

Nieuport nut

My Feedback: (10)

While I like Koverall, I have become a believer in Solartex for rib tapes and edge tapes. It rips in straight lines perfectly. I understand your current approach is an attempt to do stitching in a mass production manner, (and I sure hope you find something!). And the huge challenge is stitching on CDL.

A friend did a Bristol Scout in CDL - Solartex Natural which ended up looking a little too transparent, but no matter for this next part. He then applies his stitching. This is coloured thread that he has brushed with Sig Stix-it heat activated adhesive. With a trim iron, he tacks the end of the thread in place over the rib and then pulls up against a sharp blade to cut the thread. Then he moves on to the next one. IIRC he took 6 minutes per rib. Then he used ripped Solartex for the tapes and ironed them on over the stitches.

Now I know you don't want to use the Solartex because of the colour/transparency questions but the stitching method may be of use, especially as there are infinite colour choices there.

Martin

abufletcher

Thanks for all the suggestions. It all helps. For example, it got me thinking that I could stick my stitching strips down with stix-it instead of trying to attach them with dope (which loosens the threads). And my Koverall test seems to have been successful and I'm just now waiting to see how a sample strip looks under the silk. If it looks like the last photo I was able to post, I think I'll go ahead with this method.

The primary challenge, as I've said before, is one of scale. Even if I could solve the color matching problem I'd still have to use rib tapes no wider than perhaps 5mm over stitching 2mm wide. By putting the silk direction over the stitching strips I can use 2mm strips over the 5mm balsa rib caps and the width of the rib cap should look as if it's the rib tape.

abufletcher

It looks like similar problems are starting to develop with my latest attempt to make the strips...problems caused by doping the backing (Koverall) while in contact with the wax paper. I'm starting to think that the only solution is to build a sturdy frame, attach the koverall to the frame, and work with it that way. In short, all of these ways I've ever seen this done by other people aren't working for me.

gabriel voisin

Don, why are you doing this so complicated.

I've mentioned it before, that you can do these stitches with the sewing machine, also the "Hexenstich".

I have already made ​​many of the seams on the sewing machine.

The seams are only for decoration and are glued separately.

It does not matter because the "base" (that is, the strip on the fabric at the seam.) and is in the original from another tissue, and has a completely different weave pattern.

I have a cardboard frame with a size of 30 cm x 40 cm, and in the center is a 20 cm x 30 cm large recess.
I span a piece of fabric over this frame and fix him with tacks.(I don't know the right word).
Then I draw some parallel lines on the fabric. On the sewing machine of my wife, I can also adjust universal seam pattern.
After sewing, I take the fabric from the frame and cut the patterns in stripes.
The stripes I glue with 1/5 dope to the tissue and then come about this stripes the serrated belts.
When everything it's glued, the complete wings will be painted with dope.
Finish.

Greetings Matz

This is our machine:
http://www.inventa.li/products/house...NM_1800_DE.pdf

abufletcher

Two problems with that:

1. I don't have a sewing machine.
2. I don't know anyone who does have a sewing machine.

At least the pattern looks right, though.

http://3.bp.blogspot.com/-WNodJE-818...g+stitches.jpg

Anyway, maybe by the time the RCU photo upload is working again, I'll have my solution. It's not helping that it's taking FOREVER for the dope to dry (6Ëš C / 70% humidity). I put the last coat of dope (a 60/40 dope/thinner mix) on the threads 9 hours ago and it's still tacky.

TFF

If your panel is out in 6C it will take forever. 25c=75f? Maybe 60f I would paint but not cooler. Warm with heat gun.