silkspan where to get

http://brodak.com/silkspan-medium-white-only-2-sheets.html

Brodak also has lightweight silkspan.

The product we used to know as silkspan is no longer sold (with a few exceptions) the new version is not as well liked... Brodak sells the newer stuff as well as several Free Flight sources

Many have move on to polyspan like JPvelo linked to and it is a very good product but NOT silkspan ...Polyspan goes on dry and is later heat shrink to tighten, then doped to fill the weave mostly with Non Tautening dope but some use tautening in the open bays

If you are any good at using silkspan...there is not a real good reason to not just use real silk from Dharma....get the Habotai 5MM white (you can dye it colors) china silk...as far as I can see the cost is actually less than silkspan...it has a tight weave and does not take too much dope to fill in

http://www.dharmatrading.com/fabric/silk/silk-habotai-fabrics.html?lnav=fabric_silk.html

I'll just poke my nose in here :-)
If you order the silkspan from easy built models, it's very similar to the medium silkspan of days past... http://www.easybuiltmodels.com/parts.htm

I'm known as more of a monokote guy, but that's what I've used and what came highly recommended from some top notch builders.

Brodak lists two weights of silk. Which source is better?
What I came here to ask is whether 10 year or more old Silkspan is good. I have never heard that it is acid free paper and lasts a long time.

David when I came back to modeling in 2012 I bought several very old 1960s~1970s kits and the tissue (silkspan?) in the original kits, even grayed or yellowed some, still worked as well as I remember from my youth building those models. Since I was painting with clear and then colored dope I did not care about the age induced discoloration of the tissue

Been a while since I looked at the Brodak or RSM silk but I do remember the price was exceptionally high VS Dharma or the other mail order place (I forget the company name)

I have bough and used BOTH the 5MM in white and 8MM (heavier) in Blue and Yellow ( pre dyed)

A piece of 36" wide Dharma silk is something like less than $4 per yard... I do NOT recommend buying Dharma silk 36" wide by 1 Yard...buy 2 yards:
Reason... you Must be able to place the silk length wise (span wise I guess) with the silk weave oriented so the biggest shrink is span wise

Most all the silks sold today shrink 3 to 7% in LENGTH and only 1~2% in Width

If you get a 36" by 1 yard swath...you have a square piece and it is very hard to tell what it the width vs the Length...with 2 yards of materiel you know the length wise orientation

Thanks Wild, that is interesting. I wonder whether my old Sillkspan is old type or new type.

Thanks, Fredvon. I ordered two yards. I knew a Swede once who had used sink. He said it was strong and heavy, but he flew rubber powered and usually used tissue. I wonder where on Earth they got 5 mm. as a weight. Maybe, now that we trade with China, Silkspan is no longer needed.

I did not know too much about silk a few years ago, but remember helping my dad silk and dope models when I was a kid

Like you when I came back to the hobby ---After all the modeling sources sticker shock to get silk ----I was pointed to Dharma like I did to you

Before buying, I poked all over their web site and read a lot about silk and Dyes

I too though 5 MM was a strange convention to describe a weight... thinking millimeter...but I learned that MM is shorthand for the weight

From their web site:
"mm" means momme, the unit of measure used to designate the weight of silk. Bigger number, heavier weight silk. Under 8mm is pretty sheer.

I have some of the exam table barrier paper that has been discovered recently. Ther is a couple of threads on it on Stunthanger. There are two weights of the stuff that mimic the old K&S GM medium weight stuff and SGM heavier weight stuff. I have a supply of the medium weight stuff, not referred to as "Docspan" by some and can sell it to you for a buck for a 21" by 36" sheet. It will be shipped folded flat in a large envelope. I have sent out a couple of packages of 4 or 5 sheets to guys this way and it has traveled well. I think I can get 10 or 12 sheets into an envelope this way, if you would like to try it. Postage and handling will be 2 to 3 dollars this way, paid by the buyer. Just drop me a line to my email address and let me know. Paypal address is my email address. I also have an add in the Classified section.
Type at you later,
Dan McEntee

What finish should one use on silk? Butyrate dope? Will that shrink too much?

The finish would depend on what kind and size of model.For a typical C/L model, butyrate shrinking dope will be fine, If the structure is kind of light, maybe one coat of shrinking butyrate, ( called tautening dope) and then finish off with non-tautening dope to avoid warping and twisting the structure. The old fashioned way of controlling this is to add castor oil to the dope to plasticize it. Dave Brown Products sells a product called FlexAll for this purpose also. SIG sells there dope both ways, and they call their nontautening dope "lite coat". I think all of their colored dope is mixed using Lite Coat dope to help with over shrinking. The models will age better also, as tautening dope will continue to shrink over the years and cause light weight covering like tissue and silk span to split. Go to the SIG web site and I think they have a web page on the doping process like they used to put in their paper catalogs. It may have been covered pretty well here in this forum, and I know thas been covered extensively on Stunthanger and Stuka Stunt Forums.
Good luck and have fun,
Dan McEntee

Thanks Dan, great answer!
I think i was in 7th grade when i built my first Banshee, not knowing a lot, i kinda used dope as a filler instead of proper prep work, later in my early 20's i got back into control line again and decided to rebuild it...until i pulled off the silkspan, there was not a straight rib on the wing, the dope had continued to shrink and pull, that and every control surface was badly warped!

Just had another thought (yeah, it happens!) A guy on Stunthanger has spent a lot of time collecting and up loading a LOT of Windy Urtnowski's old videos from VHS format to YouTube. Windy did a really nice video on dope applications, and explains why at each step. The information is out there and pretty easy to latch onto. Bob Storick, (Sparky, the owner of Stunthange) has a YouTube channel and tons of stuff posted there also. You could probably spend a whole weekend watching the video screen about the subject!. But downloading and printing out the stuff on the SIG site will be handiest for the workshop.
Good luck and have fun,
Dan McEntee

I am not able to register at StuntHanger.  It keeps on saying "That user name does not exist."

Is it right that Aero Gloss is less strong and less shrinking than SIG Super-Coat or Lite-Coat?

David

Stunt hanger initial registration demands a real world name...then later you can assign a "screen name" if you wish

I just searched and there is NO previous member as David Ingham

If all else fails...send Sparky...AKA Robert Storick a PM or e-mail...he will set you up

David
There are fans of
Aero gloss
Or ---Only Randolph
Or ---Only Brodak
Or ---only Sig Mfg
DOPES and Thinners

Mostly ----Aero gloss is no longer produced and ---

Sig/Brodak/ and some other real world aircraft suppliers get----- SOME -----version of Randolph dope

In all cases, there is Nitrate and Butyrate... the later being a BIT fuel proof
Nitrate can never go over ANY OTHER dope or paint...period
Also there is Tautening and Non Tautening

Nitrate Dope has some what greater Glue/adhesion properties ----and is the ONLY allowed first substrate on Real World aircraft construction with fabric wings

Some of us learned to eliminate the multi concoction buy/store/use grief--- and decided that Butyrate Dope is good enough for ALL MODEL airplane use...

I think in the last 5 years, my reading is telling me, the ONLY AERO gloss Dope--- and colors ---are ALL OLD STOCK and
--- about all that some few Hobby stores carry, is the AERO GLOSS Balsa filler/ sanding sealer...

Sort of same thing with True Ambroid cement... original stuff is gone... the Canadian expensive 4.0z tubes are runny and not as WE remember...Sig-Ment is closest substitute

I might add that many of us NOT interested in Nats 20 Point finishes and by nature are lazy or CHEAP

We find that Rustoleum, DuPont, and other Enamels or Lacquers work well

We also found that Oil Based OR Water Based Poly Urethanes work pretty darned good.... Min-wax Poly...brush on or spray

On SH check out Larry Reneger's "SLC over Poly span" threads.... NO NEED FOR ANY dope

David--- I am not trying to over load you but since 1950 to now.... There are EXPONENTIALLY more ways to skin the balsa airplane covering CAT!!!!

Ask away I have spent the last 5 years relearn all this stuff so YOU should not make mistakes I/WE did

BTW David

I am aware I did NOT answer your exact question...

cuz I have no way to determine (even on all my 1960 to 2017 models) the shrinkage of any of the various concoctions

I did build a Gillow's stick n tissue WW1 BiPlane once in the 70s and the Dope I used on the watered tissue made me sick to my stomach when I came home from a week in the field to find about 60 hours of work crushed by the shrinkage

I have built some flimsy wings that warp if you look at them---- and some that take two men and a boy with a steam iron to get the warp out of...

I tend to think---- on Typical Modern or Nostalgia scratch build or kit models...all the current materials are easy to use and not fuss about

Some FF ,or Indoor, or other (MUST BE ULTRA LIGHT WEIGHT) ----models probably need a lot of attentions to the covering tissue/fabric/plastic and any paints or dopes

IN the insane extreme...

I know a guy who built an IRON wood Sterling Ring Master.. Glued the included silk-span to the perimeter with Testor's Green glue...Sprayed the 'span with a bottle of H2O...and when dry... painted the entire model with a Wagner Airless sprayer and Latex house paint...with a big dose of Flo Trol additive...

His ancient 1950s Fox 35 ---sans muff...with a wood 9x6... augers that heavy pig all over a 65' semi circle with plenty of authority and control.......NO crap.... not ONE stunt is a recognizable PAMPA shape..

.but the gosh darned think fly's pretty damned good....for a pig with lipstick.... and the odd burp here n there...

Sig Lite Coat is a very low shrink dope. Supercoat Clear is very high shrinking while the colors shrink less. To properly control shrinkage, follow the color coats with Lite-Coat. Lite Coat can also be used from start to finish if needed. Lite Coat is also the clearest of dope clears. It buffs out amazingly and offers the hardest finish in my opinion. It just won't shrink open bays tightly but works terrific on planked and solid surfaces. Sig Lite Coat has the highest fuel resistance out of any current dopes on the market. Brodak offers a few more color choices but the fuel resistance is quite low. Applying Sig Lite Coat over the color can reap the fuel proof benefits. While not recommended, it works and John Brodak himself recommended the Sig because his storage area burned to the ground.

Aero Gloss is always hit or miss. It has changed so many times through the years. Aero Gloss Swift White just shrinks so much it cracks horribly. While I like some of the products and colors they offered, the stuff you find today isn't the same. I would personally stay away from it. The main problem with Sig dopes and Brodak dopes are the cost.

Thanks.  I ordered SIG Lite-Cote from their Web site.

Here is what ten year old Supercoat looks like. There was still liquid in the jar. Other dope of similar age is still usable.

The cost of dope has more than skyrocketed over the last few years. Whenever I purchase thinner I buy gallon size containers. You use more thinner than anything. Sig thinner is specific in that it's a very slow drying thinner that lends itself to mistakes and a brilliant shine due to it drying slow and allowing moisture to escape. It makes repairs almost undetectable due to it being able to melt itself back in. It levels the product better than Brodak and it can be used in higher humidity climates without issues faced with using the others. Sig lists a gallon currently for $46 dollars with a $32 hazmat fee that incurs when purchasing a gallon. I just purchased a half a gallon of thinner from Aircraft Spruce which was $40. A lot of money for something that essentially evaporates. I was at one time able to purchase Dupont 3608S which is now known as Cromax 3608S for less than $30 direct pickup only. Unfortunately, that too has become victim and this now costs almost as much as Sig. PPG equivalent is $76. Even for small models, it makes it difficult on the wallet.

Sig Lite-Coat is extremely thick when new in the jar. It's thicker than syrup. Essentially you can more than double the amount of material when thinned for brushing and even more material when thinned for spraying. The airspace in the bottle has to be replaced though or else the inevitable takes place as you have in front of you.

Don't feel bad David , i just threw a bottle similar to yours away recently After seeing that and then Ken posted , i just knew he would say a way to rejuvenate the solid , i figured there wasn't when i tossed it .. Thanks for the info Ken i will remember to try and keep the air space to a minimum in the future . Yes its alot of $$$ for thinner i will agree and now that the replacement from Dupont has adopted the price jack up too !! At least you can use Rustyolum or Krylon paints and then for some extra protection a coat of clear LustreKote . Just what the weight !!

I have always considered thinner too expensive and mostly used acetone. When I want something to look really nice, I will get some SIG thinner.

Randolph butyrate thinner from Aircraft Spruce is 11.90/quart.  If you buy in quart containers, there is no Hazmat fee on shipping.