Film Covering

Film Covering

I'm gradually coming round to the view that film covering has certain advantages; it's quick, relatively easy and quick. There just aren't enough hours in the day to spend finishing planes, so I'm prepared to accept a small penalty in realism in exchange for more flying time.

<rant> And whilst we're on the subject, why isn't Monokote imported into the UK? Eh? Why? It's called for in all the Topflite kits, and there are loads of really useful colours that aren't available elsewhere. It's very poor. Thank you. </rant>

The way I cover solid surfaces in film is very slightly, um, unconventional - but it seems to work very well with both Solarfilm and Profilm. The first pre-requisite is some means of applying a known temperature to the film; I use a microprocessor controlled covering iron and cross-check the iron temperature with a Coverite thermometer.

I also vacuum-clean all surfaces before starting to cover.

The generally-approved method of covering a solid surface is to cut a piece of film slightly oversize, drape it on the surface and iron it down carefully from the middle outwards, using a cool iron (100 degrees Celsius for Solarfilm and Profilm). This works just about OK but it's not perfect because what happens is that the film softens slightly and is dragged by the iron, thus stretching the film and creating unwanted wrinkles which are quite difficult to remove. The process of removing the wrinkles makes it more likely that the wood underneath will be dented.

What I do to get round this problem - and I'll probably be shot for suggesting this - is to reduce the iron temperature to about 70 degrees Celsius before ironing down the film, then when it's all ironed down I increase the iron temperature to 100 degrees and very carefully go over it again.

What seems to be happening at the lower temperature is that the adhesive is initially partially activated, at least enough to tack to the wood, and the film doesn't get soft enough to be significantly stretched by the iron. It is very important to go over the surface again at the correct (100 degrees Celsius) temperature, otherwise the film will probably lift at some point in the future.

The results are usually very good indeed, and film applied using this method does not seem to blister in the sun.