Polycrylic...again with questions.

I suspect that this has been discussed before, but I wanted to bring it up again. After "Theo" Walker's discussion on use of Polycrylic, I thought I'd give it a try and used it when making some new flaps for my classic plane. I did like the stuff. Sands easy and seemed to lock the balsa down pretty well. No silkspan at all and the flaps came out pretty well. Question is, has anyone had any success using this over silkspan and open bays? I thought I'd set up a test to see if it could be used over open bays and silkspan without any dope at all, but I thought that if this had been tried previously and doesn't work, I wouldn't bother.

I recently had to do a repair on a plane that I used silkspan and dope on the base substrate then K-36 primer and urethane from there up. Repair was a real pain in the backside with a lot of crinkling and resanding and such. I got it done, but it wasn't much fun. I'd love it if I could use something like Polycrylic exclusively and keep things a bit more compatible.

Thanks for any information.

This may help a little. http://clstunt.com/htdocs/dcforum/DCForumID9/59.html

What about Polycrylic over Carbon Fibre? Has anyone tried to use Polycrylic over carbon fibre? I have a roll of .2 CF and wonder will it work the same as silk span.
Jay

LAST EDITED ON Aug-03-03 AT 06:43 PM (CDT)
 

jay whatsup.

I talked to Mr. Walker on the phone, I had tried the polycrillic over polyspan (the stuff tom morris sells) and he said that they had done that before, he said they had done carbon before as well.

I tried the polyspan because it is VERY hard to tear in one direction so I used it in the hard to tear direction.

THE WARNING I HAVE IS!
Do not let it overlap, I have found that the polyspan is VERY hard to sand if there is an overlap, you will be sanding like a mad man trying to get the overlap out, unlike silkspan and dope or nitrate where they tend to sand out easily. I learned this the hard way others may have some tips on this, just my findings.

anyway guys the stuff is great and it does seem to really stiffen things up, this week I paint!

I would also like to say that Brad was really cool to talk to and VERY helpful and I promised to call him back as I started getting finished to give him a report.

Randy,
You've in part touched on a question/s I've been wanting to ask. Will it do the silkspan thingy sans dope,..as your asking. And again, as you ask, hows it for repair techniques. I know Zilla and company sing the praises of PC and turn out some might fine work with it. They also total off there models, be it bird strikes, broken lines, what ever , making repairs not needed. With their use of foam cored wings and sheeted structures the question of the open bay and dope use has not come up as yet in regards to PC and auto finish use (at least I've missed that part, nothing new there. ) I'd think that the auto finish system will allow a fix as any auto re-finish might in the body shop,..but how do you get around the open bay dope fix? Or do you just stay away from a dope shrunk covering medium in total? I was bending my local UAP suppliers ear this week about getting into auto finish mediums. He may give me a break on price and let me sample a few things as a starter. Info gained here would help. Got a couple .15 profile Goodyear Racer kits to try out the PC on perhaps. Open bays though,..that is the question! One answer is to go sheet wings, which is something I like anyway. But bays look nice too. Bring it on gents. Come in Zilla, come in Zilla.

>Randy,
> You've in part touched on a question/s I've been wanting
>to ask. Will it do the silkspan thingy sans dope,..as
>your asking.

I know Bill does it. I will call him and see if can get a primmer.

To answer your qestion, yes. It does not shrink as much as dope though. That is why I alsways say nitrate the open bays, and PC the rest. For a bulletproof job, use polyspan on open bays, shrink with an iron, and PC for base.

'zilla,

So, it can be done, but doesn't work real well? I may try just the open bays with nitrate and the resty with PC. Hmm... have to think about that.

I got an 8 ounce can of polycrylic today, should be fun to play with.

My questions are, can you color it with pigments used for boat resin/epoxy and, is it fuel proof by itself?

>I got an 8 ounce can of polycrylic today, should be fun to
>play with.
>
> My questions are, can you color it with pigments used for
>boat resin/epoxy and, is it fuel proof by itself?
>
>
>Thanks,
>Giffy
...as has been said may times, many ways... the water based PC is NOT fuel proof. The oil based stuff is.

Why use the water based PC if the oil based is fuel proof??

>Why use the water based PC if the oil based is fuel proof??
uhhh... because it's water based

really, water based can be a good thing: almost no smell, very easy clean up and it makes a great primer for what ever you're going to put on top of it...

Is there any way to add color to polycrylic?

Giffy,
As polycrylic is water based, you would thin it with water, dye it with water soluble dye (RIT from the supermarket), and should be able to add pigment, metal flake and pearl, in dry powder form from the auto paint supply store. Perhaps the best deal would be to add both dye and pigment, but less pigment than normal, to save weight. Let us know how it works, and don't forget to clearcoat over.
Sammy

LAST EDITED ON Aug-03-03 AT 07:06 PM (CDT)
 
After "Theo" Walker's discussion on
>use of Polycrylic,

Thaaaattt got me chucklin'....