Nitrate Dope
 

I've always purchased nitrate dope from the hobby shop. Sig brand...
I know that full scale planes like cubs are cloth covered. do they use nitrate dope to tack the material & fill the weave? If not, what do they use??

What do you use to attach fabric & fill the weave with & where would I find it??

Thanks!

Dave

RE: Nitrate Dope
 

Piper has used Randolph butyrate dopes for years on their fabric.

RE: Nitrate Dope
 

Don't knnowif the first answer got through. Piper Aircraft has used Randolph Butyrate dope on their fabric for yrars.

RE: Nitrate Dope
 

If I remember what my uncle the airplane restorer told me they used to use both. You would start with the nitrate, don't remember if it attached fabric but do remember it was used to fill the fabric because it filled faster than butyrate. After that the plane was finished with butyrate, usually the silver and then the color. The silver was used for UV protection and an undercoat for the color.

You can do models the same way but butyrate is hot fuel proof and nitrate is not. I have mixed the silver with powder and used it for an undercoat and it does make some colors look better it seems but it takes a lot of dope around to do all of that.

Cliff

RE: Nitrate Dope
 

Nitrate sticks to the fabric better than butyrate. So it is used as an adhesive and sealer. BTW, you can paint butyrate over notrate, but not the other way around.

Sig probably still sells their nitrate. I have a couple of quarts. Brodak sells nitrate and butyrate that are blended by Randolph for model use. They are a little spendy, but excellent. www.brodak.com
The web site is a little clutzy but the service is superb. Phone and web orders sometimes go out as quick as a couple of hours. If you need more, try Aircraft Spruce and Speciality for quantitiy buys of Randolph. http://www.aircraft-spruce.com/

RE: Nitrate Dope
 

I always used butyrate for the whole process, until this year. Then I came across an article on traditional dope finishing. You can find it, I think, on the Randolph website.

Now my process is: nitrate, sand, silkspan, nitrate, nitrate, nitrate with filler (talc), sand, silver butyrate, sand (repeat silver-sand process as many times as you like - it keeps getting better) butyrate colour, clear, clear clear.

Nitrate shrinks better, is easier to sand, and is lighter.

I am buying the nitrate at the local aircraft supply store. I'll probably still buy the colours at the LHS, since you need so little.

The results are well worth the additional effort. And actually it is not much more work, since it dries so quickly, you can do a few coats every day.

RE: Nitrate Dope
 

As an FYI, I realized recently that talc has one disadvantage as a filler. Being ground up rocks, it's really heavy. I realize that you shouldn't end up with much on the plane, but still...weight is weight. Next time, try zinc stearate. You can get it from chemical supply places or Tom Dixon in Atlanta.

And I am playing with #410 filler from West Systems right now and thinking it will be good, too. It is like 1/16th the weight of talc and sands very nicely.

RE: Nitrate Dope
 

Thanks for the tip: I'll look for that.

If the covering is well sealed, you shouldn't be leaving a lot of filler behind anyway, but every bit helps.

The silver coat is really just the fine filler.