Nitrate verses Butyrate

[PHS Paddy]

Which is preferred when covering a rubber powered aircraft or static display aircraft with Esaki tissue or silkspan? I have Nitrate dope and thinner in the locker but have heard that some folks prefer Butyrate but don’t know the reason. Back in the covered wagon days I had been instructed to use Nitrate.

Hope I’m not beating a previous subject to death.

Paddy

[ADW 123]

i use nitrate. but a lot of the older folks use butyrate. butyrate is fuel proof for one, but i also hear it shrinks less than nitrate. or maybe thats aorogloss dopes. i think that its a lot of matter of oppinion. but im sure someone has somthing to say bout that

[lukebozek1]

For tissue vs silkspan it's a matter of choice, although on some of the peanut scale frames that silkspan might be more than the frame can take. Nitrate is supposed to shrink, but my jury is out on that one. Butyrate was fuel proof and was mandatory for the old 1/2 A and up engines that would dissolve a nitrate finish before the end of flight number 1. Trust me on that. But if you are doing rubber or electric it should not matter.

[PHS Paddy]

ADW & luke: Thanks for replying. Thinking about this, in the back of my mind is a germ of a thought that maybe buytrate does not shrink as much as nitrate. Don't know that, just thinking out loud.

Paddy

[ADW 123]

there is only one way to find out.

[PHS Paddy]

there is only one way to find out.

True, true.

[Phugoid]

I have heard (and this is not through first hand experience mind) that they are much of a muchness for FF, other than the fact that Butyrate is a lot less sticky, and therefore less effective to use for sticking down tissue. So if you like to use the dope and thinners method for attaching your tissue then it might be best avoided

Esaki tissue everytime for me. It is lighter than silkspan from what I can tell, but I believe that Silkspan is easier to handle wet.

[cliffm]

I've been told nitrate is way more flammable than butyrate ( in it's finished state) although butyrate will burn, it is far less accelerated.

[flyright]

Nitrate shrinks less..much less..than Butyrate. Nitrate is what you want to use on stick and tissue models that do not require fuel proofing.
Butyrate is fuel proof and is used more on larger silk span covered gas models. When nitrate is used on tissue it should be thinned. I use 50/50.

[kittyfritters]

Tip from the "covered wagon days"...a drop of castor oil mixed into an ounce of nitrate dope will plasticize the dope and keep it from shrinking the tissue forever. Yes, if you keep a straight nitrate doped model for a long time you will find it gets very brittle since the tissue never stops shrinking.

I don't use dope at all since my wife is very allergic to the fumes, even if it is out in the garage. I fix my tissue with Krylon Crystal Clear fixative. Use #1303, gloss, #1305, UV resistant gloss, or #1311 matte on tissue. The #1305 seems to fill better on silkspan. These are acrylic fixatives and can be painted with acrylic paints or acrylic airbrush inks. Krylon does have a very slight taughtening effect on tissue as it dries.

Aside from the lower chemical signature the main difference between Krylon fixative and dope is that the Krylon is water-resistant, not waterproof. If you are building a real seaplane, use dope. Kryloned tissue will sag on a dewy morning but tightens back up as the humidity goes down. Acrylic paints or inks carry a very large load of water so the tissue will also sag alarmingly when sprayed, but it will tighten right back up as it dries.

I have seven year old models done with Krylon that are still flyable.

[PHS Paddy]

Thanks gents for the replies.

If memory serves me I do believe I have a bottle of Sig Castor oil in the locker somewhere.

kittyfritters: Thanks for the info on Krylon. That very interesting. I’ll check out the art department at Hobby Lobby next time I’m and see if they have any in stock.

Now, would you please tell me what you use to attach tissue to the airframe with?

If memory serves me I do believe I have a bottle of Sig Castor oil in the locker somewhere.

Thanks again all.

Paddy

[PHS Paddy]

Help! Where's the EDIT button?

Paddy

[kittyfritters]

I attach my tissue with Uhu permanent glue stick (Purple).

[PHS Paddy]

Return from the shop and in the paint locker I found a quart of Sig Nitrate Dope, couple quarts of Sig Nitrate Thinner and a quart of Sig Pure AA Castor Oil.

Now, its been store un-opened for a number of years but I’m thinking its probably all OK to use. Since I have all that maybe that’s what I’ll try.

Guess the next thing is to order up some Esaki tissue.

Paddy

[BillParker]

Been using Butyrate Dope for ... since the 50's... sheeesh!

Butyrate is hot fuel proof so you can fly 1/2a u-control without the tissue falling off mid flight. (an inconvenience...) Thinned 50/50 with pure Acetone from Handy Depot...

I buy SIGSUPERCOAT Butyrate Dope by the quart online, generally 4 quarts at a time as freight is just crippling.

http://www.sigmfg.com/cgi-bin/dpsmart.e ... _02Dope_01

specifically:

SIGSD145 SUPERCOAT CLEAR QUART EACH $15.99

50/50 elmers and water does work, but our humidity down here can destroy a project fast, so back to dope, for us...

On the big planes it's cotton muslin fabric, (like an unshrunk bedsheet) shrunk and sealed with 50/50 laquer and laquer thinner...