build light

Basically what I am asking is what is an average price per yd for silk?

I know there is more to this than asking how much a gallon of gas is but I am so out of my league here.

Obviously for covering, I do want lightness mostly. Also prints are mostly out as well.

When not otherwise mentioned how thin ( or light, sheer etc) is most silk fabric?

What is the thinnest generally available and would the thinnest be too thin?

Finally what sort of dye would I use?

Robert

Silvaire

My Feedback: (50)

Robert,

You might get a good response to this if you ask this over in the Vintage and Antique forum.

Edit 3/12:
It seems like there is lots of silk knowledge right here in the Half A forum.

I was only tryin' to be helpful....

Arlen

(Personally I have never had the patience to try the stuff. A well done silk job sure looks beautiful though!)

buzzard bait

Search on Thai or Habotai and you will find several threads that will answer your questions. Jim

Andrew

Does that mean that some of us old dopers here would be classified as Vintage and Antique too?

rainedave

My Feedback: (1)

I hardly qualify as Antique.

http://www.thaisilks.com/index.php?cPath=1_2

build light

Thanks guys I am learning quick but there is still more to come. Boy is there ever some over priced stuff on the bay... At least that which is good for covering planes with!

Robert

burtcs

All & RD:

Me either...To answer you weight question, it comes in different grades or weights. Lamp shades, drapes, and clothes are made from this stuff but I won't use this on a small model airplane. Get the lightest stuff you can.

regards - Steve B.

rainedave

My Feedback: (1)

I grabbed this off of some web site. It explains the "mm" value of the various silks.

Momme (mm)
A Japanese weight equal to 3.75 grams which is applied to a piece of fabric measuring 25 yards by 1.49 inches (an area of 1.035 square yards) Thus a 1 momme silk would weigh 3.62 grams per square yard.
An 8 momme silk would weigh about 1 oz per square yard. Habutai is woven from 2.5 to 60 momme. China silk is commonly in the 8 to 14 momme range. Momme is abreviated by 'mm'

So, you can see that the 5mm silk is extremely light and a great choice for 1/2A models.

build light

One of the things I learned was that I need something in the single digits as far as thickness (thinness?) is concerned. I have seen a range of between 30 and 5 momme or mm.
I have seen one mention of 4.5mm

I am assuming so far that around 5mm is about where I should be looking.

I mentioned that I might stay away from prints, but there are a few really nice patterns that can be found. I still think I need to stay away from those as most do not show a scale to understand how large some of the prints are.

One other thing I noted were the plaids! Somehow in the back of my mind that just don't sit right. Dunno what's up with that.

So much of the stuff on the bay gives no mention as to the momme of the material.

Robert

rainedave

My Feedback: (1)

Sig Koverall is 1.25oz per square yard, so that equates to 9.45 momme. Koverall is maybe a bit on the heavy side for 1/2A stuff. Therefore, I'd say that 8mm silk is as high as you would want to go, 5mm being ideal.

hogflyer

RD,

If the 5mm is good for 1/2A, which would be good for .40 - .60 size planes - the 10mm - 12.5mm?

Hogflyer

BMatthews

Model silk is quite translucent where I know Koverall is more opaque.

COvering a model with silk is far more tough than using tissue. The weave of the silk is quite open and it is also easy to make it run like a cheap stocking. One of my buddy's that does a lot of silk covering taught me a few tricks that I have yet to try.

Dope the framework with about 3 coats on all the surfaces the silk will touch. Sand to remove fuzz. Lay the silk down over the frame and carefully pull and tease to get the weave laying span and chordwise to a find degree. Using a soft brush flow thinner through the silk to activate the dope below. A layer of plastic layed over the glued area and rubbed lightly with a finger will force the silk into contact with the softened dope without pulling the fibers out of alignment. Once all is secure and the dope has dried for a while then mist the silk semi thoroughly to shrink it. If you mist it too lightly it'll shink in only the spots the water hits and that leads to bazillions of little puckers.

Dope with a foam brush and lay it on without going back over a spot. If you go over a spot it will push the dope through and result in runs inside which are very visible. If you get a run anyway turn it over and try to suck it out with capillary action with a brush held from below.

I know of at least one old timer model builder (as in both him and the planes) that holds his silk covering overhead and paints from below just to help avoid inside runs for the first couple of coats until the silk is filled.

I've got a few yards of proper model silk I can spare. I can send you a pack if you like. For a 1/2A model one pack should be enough. Do you like Hot Pink? I've even got a few other colors if you're not a Hot Pink sort of guy...

build light

Hot pink could easily have a place on a plane. I would have no problem with that.

Thanks for the great tips on doping the cloth. I ran into the interior runs on a Li'l Tomahawk C/L model in my early days. I was not able to solve the problem as it was on the inside. I do understand how to fix the problem now. As for avoiding it I would stand the work vertically as i knew of no way to hang it where it would be stable.

One color I really want is a nice cream color to go with a darker solid. The cream would go with most any dark solid in my book gfor a nice vintage two-tone effect.

Robert

rainedave

My Feedback: (1)

Another technique - that I have not tried, but supposedly works well - is to lay down a section of toilet paper along the trailing edge of the wing. Then, pour some dope on top of the tp and pull the tp over the surface of the wing. The dope is supposed to flow through the tp onto the silk in a smooth, even layer. Apparently it takes some practice to be able to pull the tp at just the right speed across the silk. I might try it some time in the future.

I would like to find a source for very lightweight Ceconite in the 1/2 to 3/4oz range. AFAIK, Koverall is the same as Ceconite, i.e., heat shrinkable polyester.

build light

Dave that technique sounds so much like using a bow to cut foam cores! I wondered if one could string the TP along a line using a bow but as I understand it you would be better off doing a sheets width at a time.
It really sounds to me like a nice way to even ly distribute the dope without forcing it through the pores.
My question is which brand would be best. one that would not impart too many of its own fibers to the project. Also one that would not disintegrate shortly after its initial use.

Robert

digital_trucker

The tp trick works really well - and not just on silk either. I've used it on both tissue and silkspan. I've found that the cheaper stuff works better than the top dollar cushy stuff. Go with the single ply...

digital_trucker

. edited for lack of relevancy (wrong thread...oops)

Bipe Flyer

I found a couple of interesting links. The second link contradicts the first, but there's more than one way to skin a cat.

http://www.aalmps.com/silk.htm Tips on using toilet paper, foam brushes, gelatin, milk etc.
http://www.tpbweb.com/media/catalog/335.pdf "Forget the toilet tissue, foam brushes, milk, jello or whatever else you've been using..."

digital_trucker

I gots-ta admit, the last link makes the most sense to this unedjamacatered feller.

Andrew

The lightest Ceconite I've found is 1.7 oz (uncertified Ceconite light) from Aircraft Spruce. It weighs about the same as opaque monokote.

Another fabric I've been reading about, but haven't tried, is polycarbonate coated polyester -- trade name Icarex. It supposedly shrinks slightly with heat, has a ripstop weave, comes in many colors and weighs in at .5 oz. If it's coated, a light spraying of clear dope should add almost nothing in weight, keep it tight and fuel proof.


[link=http://ecom.citystar.com/hang-em-high/FabricColorsRipstopPolycarbonate.html]Icarex ripstop[/link]

You can search on Icarex fabric -- it's carried by multiple kite outlets.

Bipe Flyer

The technique described in the second link is also on the bottom of the page in the first link. It makes the most sense to mee too. The idea of spraying thin coats sounds good too.

buzzard bait

Regarding strength concerns, even the 5 mm is heavier than Sig's "Heavy Duty" silk. All of the silk I've gotten from Thai Silks has been very strong. I would not hesitate to use anything from 5 mm up on a .40 to .60 size plane. I only use 8 mm when I want the colors. I think I decided the 6 mm was a more convenient and economical size than the 5 mm, so that's what I have for white silk.

As far as weight, I agree that anything up to 8 mm is OK even for 1/2 As. Once you calculate how much weight it amounts to on an airframe you'll see why. Really, even Sig Koverall is OK, even though it does seem like overkill. I use Polyspan when I don't need a fabric look.

The Habotai China silk from Thai Silks has a tight weave, and the amount needed to seal it seems to be less than the old Esaki, at least when I compare the amount of dope I use to the Model Aviation article.

The challenging part of using Habotai silk is the lack of shrinkage. I put it on wet, attach it at one end and let it set up for a bit, and then stretch to the opposite end and attach there. Then I pull width-wise, doping down as I go. It takes some practice to avoid wrinkles. Also, be patient with the drying--wrinkles that show up after doping may take two weeks to disappear.

Also, I have still not mastered clear doping--I get runs on the inside, even trying to use the Model Aviation article's method of flipping the frame over repeatedly. Holding a paper towel over the run often works if I catch it quick enough. Maybe I'll try the tp method.

Jim

rainedave

My Feedback: (1)

The other side of that coin is that runs on the underside of your silk aren't that big of a deal unless you're entering a Concourse d'Elegance. It's still going to look infinitely better than sagging, bubbling, wrinkling and peeling Monokote. [rainedave's opinions are to be taken as such]

hogflyer

Gee, Dave, don't hold back. Let us know how you really feel about Monokote vs. Silk/Dope.........

BobHH

My Feedback: (18)

I have had good success with using a foam brush from Lowes to apply the clear. Very little build up and if you do get a big glooper use a new foam brush to soak it up!! It also helps when dragged across the silk to bridge the weave with the clear.

Bob Harris