ron ward

when covering a fuse with one of the film coverings, is it better to have lightening holes in areas that are sheeted solid ?. strength and weight savingswith or without the holesin these areas is of little concern, i am asking this question in relation to whether the filmcovering will work better spanning holes or ironed down to solid surfaces. i see allot of planes with bubbles and wrinkles in the solid areas. is it just from improper covering methods or is it because the covering is heat shrink on solid surfaces?
not at allnew to covering with fabric or silkspan, but never used any the films yet. i haven't made up my mind if i want totry film or usefabric,...still gathering info on filmcovering.
i realize it's all about experience and my first filmjob will have mistakes, i have about as much knowledge as you can get out of the various videos and reads about film covering, so all that's left is to get covering, my airframe is ready , sealed and as smooth as glass,i just want it turn out as good as it can.

MinnFlyer

My Feedback: (4)

It really doesn't matter much if it's sheeted or not, but you want to be sure any wood is completely dust-free so the covering sticks well

SeamusG

When doing large areas you'll be sealing the film along the edges only. The trapped expanding gas will bubble up the center of the film. When it cools the bubble will disappear.

When doing small areas (e.g. hatches) you'll do a similar approach but leave a hole at one end. Then, as you heat the film to shrink the air will exit the "unsealed" hole along one edge. The hole is then sealed off as you push the air out.

Check out the numbers on the arrows along the top. That's the sequence to use to tack "points"along an edge. Keep "halving" an open space until the edge is completely sealed. Then move to another side. Note that the right edge has a hole left in the center. As you heat the film, do it from the left driving the air out from the edges to the center, from the left to the right and then finally seal the opening on the right.

ron ward

minnflyer, thanks for the advice.
seamusg,
thanks for ther tip, makes sence to work in sequence that doesn't intentionaly trap any air.

tacx

My Feedback: (1)

If you have not used films at all, I would suggest you get some scrap pieces and practice first. It's not brain surgery, but I would not jump right onto your project without getting a handle on how film reacts. A very good tool for helping with air bubbles is the "Woodpecker". It has wheels with very sharp points on them for running over your surface to create a zillion small holes, which help to keep the bubbles to a minimum. If you use the Woodpecker, practice with it first, because if you push to hard the pins will tear up small slivers of wood and the holes will show thru. When I use it I always lightly sand and clean the surface afterward and before covering.

KitBuilder

Seamusg... curious... why do you not seal the the middle of large ares but iron down all in smaller areas?

Avaiojet

Holes work for me!

Why not, if there's no issue with strength.