PC (polycrylic) and Film

LAST EDITED ON Dec-15-03 AT 07:18 AM (CST)
 
Unfortunately, I am one of those individuals who is "finishing challenged" – I lack both the skill and the patience. I stand in awe of those who put those magnificent complex dope finishes on PA models with low added weight.

As a result, I use a lot of film (Monokote and Ultrakote) on my planes, with non-dope paint usually on the fuselages. I’ve been playing with PC and find it much easier to use than epoxy or dope to get a nice smooth finish on raw wood or wood covered with silkspan, fiberglass, silk or Koverall, in preparation to using either paint or film - and without the smell.

In a recent thread, it was stated that you can put PC over dope but not dope over PC. I’ve been using Nitrate over PC without problems. In fact, I find that nitrate works as well as Balsarite for attaching film, especially when using low temperatures – 200 to 230 degrees F – to avoid bubbling. The bond is much better than film to bare wood.

I’ve also found that Monokote will not stick very well directly to PC at these low temperatures but that opaque Ultrakote will – the transparent Ultrakote will not.

Has anyone else had experience using film and PC that can expand on these results?

I haven't used any other covering film since I bought (literally) a ton of the polyester film I sell as SLC covering. It irons on over any subcoat I've tried, except straight epoxy. It's treated for painting, so you can cover over it with silkspan and polycrylic for a nice, sandable finish.

Polyurethane glue makes an excellent seal for the edges of covering. Put a tiny, tiny bead along the bare edge, rub it in, and wipe the excess off.

Another trick is to slide the iron over the bare edge with a wiping action to seal it down tightly all along the edge. Most times fuel and oil get into the covering joint where the edge wasn't tightly sealed down. Capillary attraction will pull it into the tiniest pinhole and it will work its way from there.

what is slc covering? Interested in this stuff, maybe.

It's a really good iron-on film. It's transparent, and goes on at low temperature so you can iron it over bare foam. And it's relatively cheap compared to Moneykote etc. Phil sells it.

I've used Phil's covering stuff....it's all he says and more!

For the first time, an iron=on job that I have done looks presentable!

All of the other materials that I have tried point immediately to my lack of skill, practice and patience!

See Ya

Paul, at first glance I thought you were refering to "politically correct and movies". Just goes to show you, don't think too much, read it first. Ha.

Sorry for being dim but I still haven't worked out what PC means. I'm pretty sure it's not Police Constable, Personal Computer or Politically Correct. Help !

Sorry - it means Polycrylic - a water based clear finishing liquid made by Minwax.

Paul,

You say you use PC "in preparation to using either paint or film". Have you tested PC (Minwax Polycrylic) for fuel-proofness as a possible final finish coat? The impression I get from the many and various threads on this subject is that Polycrylic (water-soluble) is not fuel-proof at 10% nitro, but Polyurethane (non water-soluble) is fuel-proof at 10%.

I'll be breaking in a couple of engines in the next couple weeks, and that's a good time to run fuel-proofness tests. I have read on the board that not everyone gets the same results with the same brand/type of product, and results can vary over time, which is why I'm asking about your recent experience. I will post my results also.

Thanks,
Kim Mortimore

No, I have not tested the fuel proofness of PC. I use it as a prep to get the surface smooth for paint or film. But, like you, I have heard it is not fuel proof.

According to Godzilla, it's not fuel proof.