Vinyl Covering

[sruelle]

I have been using for the last 10 year that vinyl covering technique, had have been really happy about it. Friends have pass it on me, I will do the same.

I was just sick of having bubbles under my shrink material, probably I was not good at it as I have seen some other planes without them.

Any way, I was in need to find a quicker, easier and more reliable technique : The vinyl technique was waiting for me.

First, the material is from the brand ORACAL probably some other companies are manufacturing similar one but I have always used this brand, it work well is durable so why changing!

Ref Is Oracal 651, you can also find 641 that is a bit thicker but fine to. Speaking of weight this is probably heavier than shrink material but we are not building TD plane so it doesn't matter. I will need one day to weight the material to have exact number, (one day.....)

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=732&d=1301882739

All you need is on this picture, basic stuff. Air dryer and iron are here just for the tips, the great news is you don't need them anywhere else!

NEVER use heat gun, hair dryer is already too powerful for what we are looking.

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=726&d=1301882720

The key in this technique is to apply the material that already has glue on his back. easy if you are doing it on the right way, messy other wise.

I had done tonight the two upper part of the wings of my resurrected ASW22 5m, it took me 1h30mn including setting it up and cleaning. The remaining work on lower surfaces will not take more than one hour.

I have to edit some pictures and video and will post them then, Just a view of the finished work

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=725&d=1301882718

stéphane

[Tom]

Very good!
Just in time because I'm going to pick mine up this week and have a go at the 1/3rd Duo Discus wings....
I like your shop...doubles as a place to make and eat food! ;);)

[JimD]

Stephane,

More great information! A couple of questions: usually with iron on plastic coverings we do the bottom of the wing first and then the top so that the overlapping joints are on the bottom, is there a reason why this technique is better to start with the top? And what about the overlapping of seams, how necessary is that with this covering?

Jim

[sruelle]

Jim,

Doing bottom or upper face first doesn't matter with this technique. With shrink material it matter because if you are covering the bottom face the last, with the speed, if the material doesn't glue well you can strip the covering material just with the air flow.

The advantage of Vinyl is has it is strong adhesive material in comparing to shrink material, so you won't unglue and peel the overlapping parts.

You can still do the bottom face the first. I chose the upper one because I did found that I was paying much more attention @ the start of a work than at the end. So I want to focus my attention on the visible part, the upper one.

So I leave on the bottom edges 1/3 to 1/4in (0,5 to 1 cm) from the upper surface covering material. Just using a blade to cut it in position with a ruler.

Then when I apply the bottom part, I just cut it straight to the shape of the bottom, so any overlapping is on the bottom part.

You can decrease the overlapping, but I focus on long term view. the more you got the better it last.

Stéphane

[JimD]

I chose the upper one because I did found that I was paying much more attention @ the start of a work than at the end. So I want to focus my attention on the visible part, the upper one.

Now there is a very honest answer! :D I am still laughing!!!

[sruelle]

Lets speak of the initial step.

Of course it can apply to obeshi wings. It will not work for open structure wings as you are not able to apply tension on the covering material (just see my spoiler in the fist post as an example). But it also can be used on fiberglass finish, repairs; that's the case for theses ASW22 wings. They are obeshi damaged one that I did end up glassing, as I was looking for a minimal weight addition, the vinyl is the better one, much lighter than paint for a finish that is quite good.

The hard the surface is the better it is, allowing you to remove the vinyl an apply it again if you were not exactly in position. A little bit like Oracover.

If your are covering plain wood, it will work but then no room for mistakes as if you remove material some of the wood will come with it. Placing it back will be then a disaster. Avoid all cost Balsa covered wings.

An elegant way to fix that is to put some light glossy wood veneer. You can apply it quickly with a piece of foam. Do not use a paint brush, you will leave far too much liquid.

Also is you wood is balsa, be careful as it will suck a lot of product, risking to go on the other side of the wood and melting down epoxy and foam (toluene if there is some in the paint). That is why you need a small coat, applied fast.

After letting it drying, just sand with 320 grit sand paper, vacuum the wings and you are ready to apply the covering material.

If you are putting filler on you wings, if it is a colored one (pink like Bondo or blue) you need to spray a coat of white paint to avoid been able to see it by transparency. That is why I did end up painting my ASW22 wings.

It is all that I can think of for now, will be back shortly for the next step.

Stéphane

[Tom]

I'll do the bottom first.....because...horrors of horrors I'm going to put either dark blue or dark red on the bottom of the Duo-Discus.

[sruelle]

Tom,

I you are doing bottom first you will then have a white seams on the trailing edge. If you are doing upper first you won't have any

Just I thought

Stéphane

[sruelle]

So.

Pick a table that have a glossy surface as the kitchen Formica table. Really convenient if the vinyl glue to it! you can then easily remove it!

Cut a piece of vinyl that is minimum 2 inches wider than the wings. because if you are not starting straight.....

Then you need to grab couple books, encyclopedia work great to have your wing elevated from the table to avoid as you can the vinyl to touch the table. Glossy book are best for the same reason than the table!

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=729&d=1301882725
http://www.rcaerotowing.com/forum/attachment.php?attachmentid=730&d=1301882726

Before bringing your wing, vacuum it one, twice to not bring dust in the area you will work in.

Put the vinyl and it protection material on the wing, align it. Then put some flexible books on the top of it to avoid the vinyl to slide on on e side or the other during the startup.

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=728&d=1301882723

Then peel one side and place the protecting material as a roll under the vinyl that is still protected. You need to start putting the vinyl on the middle on the wing and then work a little bit further before placing the vinyl to the leading edge or trailing edge.

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=723&d=1301882716

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=727&d=1301882721

Little bit by little bit you need to remove the protecting material and brush the vinyl with circular movement to make it gluing to the surface of the wing. The heat you are generating by friction will help softening the glue. Also drawback you are creating a lot of static electricity... so no dust in the area.

Once you have started you want to peel the protecting material on a symmetrical manner to be sure not creating any fold.

Material is stretching but if you start stretching in the middle of the wing to correct mistakes, you have lost the battle, it is better trying removing it and putting it back.

Pay attention to any transition like spoiler holes, ailerons... that is where you have chances to create wrinkles. Do it slowly.

Once done you can cut some of the excess material, leave 1 inch to be able to fold it on the other side.

By applying some pressure on the leading edge and trailing edge you can conform the material to bend it over the other side.

Then what you need is trimming with a ruler and a blade the excess material to leave 1/4 to 1/3 in of material.

I will take some picture tomorrow for that as none are good today

Next, some video and the tips.....

Stéphane

[sruelle]

Because it is far easier than explaining it!

First is about how to start it from the main rib


http://www.youtube.com/watch?v=zXMO6mDzkRU


Second it the step just after, extending the area


http://www.youtube.com/watch?v=pNDJMFOThuA

[sruelle]

This time getting out of the spoiler area


http://www.youtube.com/watch?v=UtTgtFBxVZM


And folding it on the other side


http://www.youtube.com/watch?v=2c3tsfSNBMg

Enjoy!

Stéphane

[sruelle]

Here is couple picture with close look on the seams

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=788&d=1302042751

I messed up with the master rib, could have done better work, but was at the end, and finaly doesn't matter has you don't see it once the model is put together...

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=792&d=1302042774

The Spoiler hole just need to be cut straight, no need to put the covering material down in the side. With the glue on the covering material, it won't peel off

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=791&d=1302042769

Voilà

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=787&d=1302042743

Tonight bottom side

Stéphane

[sruelle]

So tonight the bottom

really easy, same manner, laying the vinyl, removing the protecting material, brushing.

Once done trimming with a sharp blade the covering material on the trailing edge.

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=795&d=1302057001

An trimming close to the leading edge with a ruler.


http://www.rcaerotowing.com/forum/attachment.php?attachmentid=796&d=1302057015

One done, taking care of the main rib and the tip the same manner than the upper surface.



That's all.

See it is really quick to do it. I did spent probably as much time typing than covering.

http://www.rcaerotowing.com/forum/attachment.php?attachmentid=797&d=1302057030

Stéphane

[sruelle]

If you have any question, I will be more than happy to answer them

Stéphane

[sruelle]

Couple question received by email :

- Where to buy it : here is my supplier

http://www.advantagesignsupply.com/

you will find here the pricing for rolls / if you want smaller quantities you can go to the sign shop where you live

- Wood grain how much of a finish is needed : Depending on the wood quality and level of expectation

usually no need of filling wood grain in the case of regular obeshi, like Graupner kit for example. Surface Finnish need to be good, if there is bumps, the vinyl won't cover it

- Sealing using iron : on normal situation (leading edge or trailing edge) no need of it it will glue well as is. For the tips specially when you are stretching the vinyl, it is where once the vinyl is applied you want to get a quick ironing on the seems of the vinyl only


If you want to see it, just come to see me at Muncie or JR, I will be more than happy showing you and helping you.

Stéphane

[yyz]

Killer thread, Stéphane! Thanks for taking the time to document your work. Videos really helped!

Mike