Covering curves on tail feathers?

[nhk750]

I'm new to covering so I have a question. I have watched a few videos and some guys will use the stretch and pull method (like used when covering a wingtip) when covering the curves on the flatter tail feathers. Some guys will cut relief cuts around the curves on the tail feathers then iron down. I have used the relief cut method for my tail feathers and it is really easy and worked pretty good. But, if you look close, you can see my relief cuts. If your more than a foot away you cant see them though. If I were building a really scale, perfect work of art, judged model, the cuts may not be acceptable.

My question is, what is the best method for applying the covering on these control surfaces that are curved and not very thick like tail feathers?

See the relief cuts, but came out with no wrinkles and smooth.

 

[jsknockoff]

I almost always just cover the bottom first pulling up while heating, trying to get the covering as far over the curve as possible (minimum of half way). Then do the same on the top trying to overlap between 1/16-1/8". I can usually get a fairly tight radius covered with zero wrinkles this way. The key to it is getting the covering hot enough to conform without melting through.

 

[rockyboy]

Wow - I think that looks great. I'm a very happy camper when my curved and covered surfaces look that good.

Interested in what some of the more seasoned folks have to share for tips and tricks though...

 

[rrc1962]

Is that monocote over foam board? It looks really good to me. I was thinking of trying to cover one with sign vinyl. You can coax it around corners with heat.

 

[rockyboy]

I almost always just cover the bottom first pulling up while heating, trying to get the covering as far over the curve as possible (minimum of half way). Then do the same on the top trying to overlap between 1/16-1/8". I can usually get a fairly tight radius covered with zero wrinkles this way. The key to it is getting the covering hot enough to conform without melting through.

I frequently have a problem getting a pulling / pushing pressure on the covering and work piece without either crushing the workpiece, or growing an extra arm. Any tricks for this?

One of the least horrible ways I've found is to hold the piece flat on the work table near the edge. Then use my left forearm to hold the piece down and with the same hand pull up on the edge of the covering. So while trying to work the iron with the right hand, I'm trying not crush the balsa, and trying to ignore the shooting pain in my back from leaning over at such a stupidly awkward angle. I must be doing something wrong... or at least not the best way...

Then again, maybe this is why there are so few videos online showing actual covering while it's occuring - it's too embarassing

 

[Joker 53150]

Practice practice practice practice practice practice, repeat.

 

[nhk750]

Is that monocote over foam board? It looks really good to me. I was thinking of trying to cover one with sign vinyl. You can coax it around corners with heat.

It's a balsa build Taylorcraft using Hobby King film.

I was worried about damaging the tail fethers trying to pull and heat as they are stick built and fragile. Maybe I will try on the verticle fin as the covering can always be removed easily if I mess up. But, it does seem to come out pretty good using the relief cut method and I'm not getting to picky with this airplane, but the next one I will be.

 

[RCMAN]

The cut corner method works great and is easy if you dont mind the little imperfections. However if you want it perfect you need to learn and practice the heat n pull.

 

[Hai-Lee]

The way I was taught to apply SolaFilm by a annoying perfectionist, (long dead), a life time ago was to treat the curves as a separate entity and cover them first with a strip stretched to the max prior to fitting.

The centre was ironed down first and the iron worked slowly from centre to the edge of the curve. When the film is laid down basically the iron is used along the curves with the temperature increased the further you get from the centre of the curved edge, (to get greater shrinkage of course. At the edge of the curve the film is trimmed before it reaches the flatter portion of the surface.

A final edge ironing ensures that there is not film still not attached. The each of the flatter surfaces is done in turn with a slighted of overlap.

It takes a lot of patience and some of his models took months just to cover but there was never a crease or visible seam on any of his aircraft.

His method summarized is stretch apply and then use the variable temperature of the iron to vary how much you actually shrank the covering. Also never leave an overlap joint on a flat surface where it was easy to notice.

Just what I was taught last century when all models were wooden and RC was #$%@$ expensive.

Have fun!

 

[rockyboy]

The way I was taught to apply SolaFilm by a annoying perfectionist, (long dead), a life time ago was to treat the curves as a separate entity and cover them first with a strip stretched to the max prior to fitting.

The centre was ironed down first and the iron worked slowly from centre to the edge of the curve. When the film is laid down basically the iron is used along the curves with the temperature increased the further you get from the centre of the curved edge, (to get greater shrinkage of course. At the edge of the curve the film is trimmed before it reaches the flatter portion of the surface.

A final edge ironing ensures that there is not film still not attached. The each of the flatter surfaces is done in turn with a slighted of overlap.

It takes a lot of patience and some of his models took months just to cover but there was never a crease or visible seam on any of his aircraft.

His method summarized is stretch apply and then use the variable temperature of the iron to vary how much you actually shrank the covering. Also never leave an overlap joint on a flat surface where it was easy to notice.

Just what I was taught last century when all models were wooden and RC was #$%@$ expensive.

Have fun!

*poof*

Mind blown. It seems so obvious in retrospect.

Yep - that's how I'm going to try my next build now.

Thank you!!

 

[nhk750]

I actually thought about doing that like I did on the corners and it makes total sense to do that. Then you wont be fighting a large piece all at one time, just smaller pieces on the curves.

Well, got home early and finished the tail, I tried the stretch and pull method and it worked pretty good on the verticle fin, where I had problems was the inside curve at the bottom, how the heck do you do those? Probably the smaller piece method would be best there. I am going to call this good enough for my first model and move on for now.

 

[Joker 53150]

Inside curves like that are a pain, and that spot on my Kadet Senior has the same imperfections. After applying the film I do get some of them out with the heat gun, but you have to be VERY careful doing that so you don't release the film and let it shrink away from the balsa. Normally I just live with it as my planes aren't show-pieces and I'm my own worst critic.