Welcome, Guest. Please Login or Register
Stick and Tissue Logo
 
  HomeHelpSearchLoginRegister  
 
 
Page Index Toggle Pages: 1
Send Topic Print
Polyspan (Read 549 times)
Reply #11 - Dec 12th, 2018 at 11:20am

Kingbird49   Offline

Old school rules! :-)
Clovis, CA

Posts: 38
 
I obtained some Polyspan and some Brodak Heat Shrink covering, and decided to test them against each other and some Silkspan I had on hand.  I posted the method and results of the experiment in detail at:

https://www.rcgroups.com/forums/showthread.php?3168923-Polyspan-Sig-Coverall-Bro...

The conclusion I reached was that, although the product is reasonably light and shrinks and finishes nicely, I probably wouldn't recommend Polyspan for much of anything.  The reasons for this are two-fold:

First, the product is not very resistant to damage.  I did a coin-drop test on the three finished panels and the coin left no damage in the Silkspan or Brodak coverings.  However, the coin penetrated the Polyspan twice leaving very visible tears.

Second, Polyspan is more expensive than either Silkspan or the Sig/Brodak products.

As a result, I think I'll stick with good old Silkspan or tissue for small models and use the Brodak/Sig covering on the bigger powered RC birds.  Meanwhile, I have a pretty good supply of Polyspan on hand that I'll probably use up covering sheeted areas prior to finishing.  If anybody wants me to send them some just PM me and, for a very reasonable consideration and the cost of the postage, I'll share what I have left!  LOL

Cheers!
 
IP Logged
 
Reply #10 - Nov 30th, 2018 at 5:46pm

Kingbird49   Offline

Old school rules! :-)
Clovis, CA

Posts: 38
 
FYI, I just learned today that Brodak heat-shrink covering is the same thing as Sig Koverall.
 
IP Logged
 
Reply #9 - Nov 27th, 2018 at 8:15pm

Kingbird49   Offline

Old school rules! :-)
Clovis, CA

Posts: 38
 
I've  been researching polyspan as I try to decide how I will finish my Ercoupe that's currently on the bench.  In the process I've found several very interesting and informative blogs/articles that explain the product, its benefits/drawbacks, and how it is best applied.  Here are two that I found quite helpful:

http://www.rcmodel.com/2011/07/building-the-old-flyline-great-lakes-2t-1a-kit-20...

https://www.rcgroups.com/forums/showthread.php?1954932-Polyspan

I have come to the conclusion that I'm going to give it a try on my Ercoupe.  I'm at least a couple weeks away from covering it but I have been posting a build log at http://www.stickandtissue.com/cgi-bin/yabb2/YaBB.pl?num=1542512627

Once I've applied the stuff once I'll share my thoughts on it in that thread.

Cheers!
Doug
 
IP Logged
 
Reply #8 - Nov 17th, 2018 at 8:32pm

Kingbird49   Offline

Old school rules! :-)
Clovis, CA

Posts: 38
 
Huey -

I've laid down a  bunch of silkspan but that's been many years ago.  Thanks for the reminder.   Smiley

Doug
 
IP Logged
 
Reply #7 - Nov 17th, 2018 at 3:58am

Huey v77   Offline
Senior Member
I hate P51's, live east
of Cleveland Ohio.
Orwell, Ohio

Posts: 301
****
 
Doug, if you haven't used silk span before, the fuzzie side goes down, smooth side up..... Found that out the hard way....
 
IP Logged
 
Reply #6 - Nov 16th, 2018 at 11:09am

Kingbird49   Offline

Old school rules! :-)
Clovis, CA

Posts: 38
 
Thanks Mark.  Good info.

I've decided to stick with good old silkspan for the next project since it's not a very big model and I'll be looking to shave every gram I can.  I may give the polyspan a try when taking on a bigger bird due to the additional strength.

Here's a link to the YouTube video I was referring to:

https://www.youtube.com/watch?v=2oJrkbC3vLc

Cheers!
Doug

 
IP Logged
 
Reply #5 - Nov 15th, 2018 at 9:38pm

Huey v77   Offline
Senior Member
I hate P51's, live east
of Cleveland Ohio.
Orwell, Ohio

Posts: 301
****
 
KB, I've covered 8 full scale aircraft with ceconite. The process, when using Randolph products,( a nitrate and butyrate dope system) is to brush in two coats of nitrate first. Nitrate incapsulates the smoth fibers of the synthetic fabric. Than butyrate dope is sprayed, in several coats, to fill the weave of the fabric.
So, Polyspan is a lot like silk span in that it doesn't have a given pattern of the weave. You should use nitrate for your first couple of coats.
The issue I have with it is shrinking it. I've used my Mono-Kote irons on full scale jobs and they work great. On the Polyspan not so much. I've acquired a heat gun to see if it will work with out singing the Bulsa. My garage is not heated and with the white stuff on the ground and roof I haven't had a chance to try it. I'll let you know how it works.

I applied the Polyspan using the dope method. You'll need several Good coats on nitrate to get it to adheir to the frame.

Mark
 
IP Logged
 
Reply #4 - Nov 15th, 2018 at 9:00am

Kingbird49   Offline

Old school rules! :-)
Clovis, CA

Posts: 38
 
Huey v77 wrote on Nov 9th, 2018 at 6:31pm:
Has anyone here used Polyspan? I test covered the turtle deck on the Gee Bee. I used Nitrate to secure it to the frame. I've tried both of my irons ( Mono-Kote large shoe and small foot ) each on high, to shrink the material. No luck!

Any suggestions?


I Googled polyspan a few days ago thinking it might be a good choice for my upcoming Ercoupe build.  My understanding is that Polyspan is just a very lightweight version of the stuff used to cover real airplanes.  It seems the best way to apply it is by first applying a heat activated adhesive such as SIG Stick-It to the edges of the subject.  Then it's not much different than working with Monokote as you tack it down with a film-iron.  Pull out the big wrinkles as you seal the edges, then shrink it with a heat gun.

There's a pretty good, albeit lengthy, video on YouTube.  This fellow demonstrates using it to cover an Albatross wing complete with undercamber.  It turned out pretty darned good.  He said that he finishes it with clear dope first then colored dope to desired finish.
 
IP Logged
 
Reply #3 - Nov 10th, 2018 at 6:51pm

Sky9pilot   Offline
Administrator
Stick & Tissue
Kelso, WA 98626 USA

Posts: 10266
*****
 
I didn't note whether you shrank it before you doped it.  I usually do that first so the poly(plastic) shrinks first then seal with dope.
 

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
IP Logged
 
Reply #2 - Nov 10th, 2018 at 2:58pm

Huey v77   Offline
Senior Member
I hate P51's, live east
of Cleveland Ohio.
Orwell, Ohio

Posts: 301
****
 
I an now a proud owner of a new heat gun, didn't own one, I'll give it a shot......
 
IP Logged
 
Reply #1 - Nov 10th, 2018 at 12:27pm

Sky9pilot   Offline
Administrator
Stick & Tissue
Kelso, WA 98626 USA

Posts: 10266
*****
 
I've never used Polyspan...sorry I can't help, how about you other modelers?  You might try googling youtube for some ideas.   Did you try a heat gun?  I used the Monokote heat gun to shrink my covering when I was into RC.
Tom
 

If God is your Co-pilot...switch seats...
Your attitude will determine your altitude!- John Maxwell
And ye shall know the truth, and the truth shall set you free. Jn 8:32
IP Logged
 
Nov 9th, 2018 at 6:31pm

Huey v77   Offline
Senior Member
I hate P51's, live east
of Cleveland Ohio.
Orwell, Ohio

Posts: 301
****
 
Has anyone here used Polyspan? I test covered the turtle deck on the Gee Bee. I used Nitrate to secure it to the frame. I've tried both of my irons ( Mono-Kote large shoe and small foot ) each on high, to shrink the material. No luck!

Any suggestions?
 
IP Logged
 
Page Index Toggle Pages: 1
Send Topic Print