Dope, Sig Koverall & heat activated glue

[Richard V-D]

Hi All

Having never used any one of these before, I obviously did a bit of internet investigation beforehand. Came up with this. Use the glue to attach Koverall to frame. Heat shrink Koverall to tighten. Use non-shrinking dope to seal the weave before painting.

Problem is I can only get shrinking dope ( they no longer produce non-shrinking apparently). Tried one neat coat of dope on a test piece and so far so good. However I still have doubts.

Now for the questions:-

1) Just use neat dope to stick the fabric to the plane and forget the glue?

2) Should I not heat shrink the fabric and just rely on the dope?

3) Heat shrink and then use a 50/50 dope to reduce the shrinkage that will occur?

4) Use something else to seal the fabric.

Your thoughts will be appreciated, plus any answers to questions I should have asked, but didn't 'cos I don't know enough yet

The plane is the 1/3 scale Sig Spacewalker. ( I like a challenge )

Richard

[roger graves]

Think non shrinking dope is available from full size aircraft suppliers try asking at your local airfield.

[jrman]

Non shrinking dope is also available from "The Balsa Cabin".

**LINK**

[Richard V-D]

I'll be at Cosford over the weekend, so will hopefully pick some up.

What about the heat activated glue/dope debate about sticking the edges down? Which do you find easier?

 

Edited By Richard V-D on 15/07/2015 22:59:12

[jrman]

I prefer to use dope as the adhesive but have also used thin cyano rubbed through the Koverall with a suitably plastic gloved finger. If you go with the dope as adhesive use it neat. I've never had a problem heat shrinking and then using thinned shrinking dope but that has always been on substantial frames/wings. Nice to hear that people are still using the old ways. You'll be using bamboo instead of balsa next and then covering in silk!

[Danny Fenton]

Richard I did as you suggest as one of your options, doped Koverall onto the rear section of a Brian Taylor Hurricane, shrank with some heat, just enought to make the fabric nice and taut. I then used two coats of shrinking dope over the top. However after a further half dozen thinned coats of none shrinking dope, I still had holes in the weave. The trick is to use a couple of coats of sanding sealer to fill the weave.

Just for interest the model was covered about 4 years ago, and in the sun at greenacres last weekend a planned photo shoot had to be aborted due to the Koverall going all wrinkly! I have never heard of the stuff doing that

The Koverall has subsequently recovered, however I will stick to nylon or silk in the future.......

Hope this helps

Cheers

Danny

[Richard V-D]

Thanks for the replies, they have helped a lot.

I tested neat dope to glue the edges on a test piece and it worked really well. Tightened slightly with the heat gun, a coat of shrinking dope then a coat of sanding sealer. Brilliant! So dope it is.

Cosford on Saturday to pick up bits and pieces, including some n/s dope.

@jr Maybe birds feathers and wax?

[Ernie]

What about banana oil? It's a non shrinking sort of dope.

ernie

[Richard V-D]

Hi Ernie, So good they named it twice!

Was at Cosford yesterday and picked up a tin of n/s dope from the Balsa Cabin. They had all varieties there, including banana oil. Can recommend them.