Alternate Fabric Covering

[John Rickett 102]

I’ve used Sig Koverall to cover many models over the years but sadly this is another product, like so much of the goods we’ve relied on, which is no longer available.

 

Until discovering Koverall, Solatrex was the material I’d use for large(ish) models but went off it due to its weight and tendency to eventually lift as fuel crept under the edges. Koverall, once adhered using the proper adhesive, could be doped and painted which completely sealed it from fuel creep and getting grubby.

 

My Plan B for when I’ve exhausted my nearly depleted stock of Koverall was to use Diatex 1000 as its only marginally heavier than Koverall and, from memory, roughly the same price.

I started thinking about alternate coverings and had read on other websites (mainly American) that curtain lining or dress lining had possibilities. A search on British websites showed that there is a polyester fabric, primarily intended as a dress lining, which is light, available as a 5 ft width and best of all. cheap. Its called Polyester China Silk or Habotai and can be bought in white translucent or pre-coloured. I thought I’d get some and give it a try.

 

First a test panel was made up, simulating an aerofoil section and also incorporating a right-angle inside curve to see how well it would adhere to a rather severe change of direction and if it could be heat shrunk.

 

The test panel

 

 

The panel covered but not shrunk

 

 

 

 

The panel shrunk and one coat of non-taut nitrate dope applied.

 

 

The unsupported edge has pulled in markedly which shows that this material will shrink.

 

 

Available colours

 

My thinking now is that for vintage models particularly or build up flat-field gliders, this fabric could be a suitable alternative to Solartex or Diacov, which although I’ve not used it, seems to be Diatex with an adhesive layer on one side and a coloured layer on the other in much the same manner as Solartex. As I fancy building an electric assist flat-field glider, China Silk will probably be put further to the test.  

 

Comparison Chart

[Paul De Tourtoulon]

That looks really good, I have some silk dress lining from my sister-in-law, which is thicker, and it's completely useless it just won't shrink.

[John Rickett 102]

This stuff is imitation silk - polyester, which seems to have the qualities useful to us. As far as I can determine, all the modern aircraft coverings, regardless of the weight, are polyester.   

[David Davis]

Perhaps polyester over doculam would save on dope.

[John Laird]

It does - I give it 2 or 3 coats of 50/50 dope thinners- which is enough to water and dirt proof it.