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Raw Foam edges

#1
Hi Guys,
New to the RC scene and also scratch builds, I’m currently building an f22, plans from FT.
How can I cover the edges where foam is exposed to give a neater finish? im looking to spray the plane with acrylic, is this suitable? thanks
 

BATTLEAXE

Well-known member
#3
Hi Guys,
New to the RC scene and also scratch builds, I’m currently building an f22, plans from FT.
How can I cover the edges where foam is exposed to give a neater finish? im looking to spray the plane with acrylic, is this suitable? thanks
Welcome to the forums, the FT-22 is a great plane, I have built about 4 different versions of this plane and loved everyone of them.

As you asked you are looking to clean up the raw edges of your plane, and I have the perfect solution for you...
There is 3 short successive vids all linked at the end of each vid. Subscribe and go into my playlist and you will see some other helpful build tutorials and over 70 other flight vids to entertain you. Hope this helps and keep us posted on your progress
 
#4
Thanks guys.
Checked the vids out and will use the iron on future builds but have already got the plane built!
B3B6539D-016B-4936-94ED-ECCCCEFFC829.jpeg

All part of learning I suppose.
Trying to neaten up the edges before spraying, @BATTLEAXE you mentioned in your vid the glue smear? As the planes built anything else you can suggest as might struggle with the iron.
Cheers.
 

Hai-Lee

Old and Bold RC PILOT
#5
Ironing is something some swear by and others swear at! it can make a mess unless you do it properly. I have still to master it.
For those I make for sale, (retail) I just seal the edges in white glue and when dry I just paint over the edges.
Where the edge is a little rough I sand the edges first to smooth them.

In places I need a more streamlined finish I take a little notch out of the foam, (or sand the foam with the sandpaper wrapped around a bit of thick music wire and then apply a little glue and stitch the edges together with a little adhesive tape until the glue is dry.

The choices for finishing the exposed foam edges are numerous. Find out what works best for you and use that.

Have fun!
 

BATTLEAXE

Well-known member
#7
@Hai-Lee thanks for that advice!! 👍🏼
Paint needs to be acrylic right? Otherwise melts the foam?
Yea there is another video on my channel of how to prep the plane for paint using oil based polyurethane. It seals the paper to make it waterproof and is a lot easier to paint, and it all can be done after the plane is built. Link is here. Ever since I found out about this I have been doing it to my planes and will take any kind of paint over top
 

Hai-Lee

Old and Bold RC PILOT
#10
I just read the labels on the varnishes on offer and buy the cheapest polyurethane varnish.
Wipe it on and wipe it off.

When it is dry I just use the cheapest rattle can of paint of the colour required. Light coats with a little drying time between coats and all is sweet.

Have fun!
 

Merv

Well-known member
#11
....Paint needs to be acrylic right? Otherwise melts the foam?
Its mostly the solvent and propellant in the paint or glue that eats foam. One trick is to hold the rattle can 18 inches or so away from the foam, this gives time for the nastiest to evaporate.

It’s always a good practice to test any new glue or paint on scraps. I have found water based products to be foam safe.
 
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danskis

Well-known member
#14
You can iron the edges of the F22 after its built. I did. You have access to most of them and its now standard practice for me. In fact, you can iron anything you see. Got an edge sticking out with a little too much hot glue?....iron it. (disclaimer is I've done this with Adams readyboard). Want to round a corner....iron it. Also, the spray (oil based) does not work as well as the brush on....I don't know why but ask me how I know. If you really want the plane to last put some tape over the polyurethane after it dries. It doesn't add hardly any weight. Also, on that F22 you'll want to reinforce the area where the fuselage meets the wing. Its a high stress point and tends to bend in hard "landings".
 

TooJung2Die

Well-known member
#15
You can iron the edges of the F22 after its built. I did. You have access to most of them and its now standard practice for me. In fact, you can iron anything you see. Got an edge sticking out with a little too much hot glue?....iron it.
Great advice. Whenever I plug in the hot glue gun I plug in the iron. Those lumpy blobs of hot glue are ugly. I go back over almost every hot glue seam I make with a hot iron to smooth it out. Use a hot iron instead of a foam scrap to smooth out glue fillets. Use a hot iron when spreading the hot glue on hinge bevels to smooth it out and make it nice and thin. Use the iron to flatten out those A and B folds that didn't quite close up before the glue set.
There's no reason you can't iron the edges on an assembled airplane. The trick is getting the iron temperature right. When it's right the foam will melt slowly resulting in a sealed edge with both sides of the the paper touching in the center of the edge. A little softened foam will ooze out the sealed edge. Lightly sand any rough edges smooth. Test the iron on some scrap foam board. Watch Battleaxe's videos.
 
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Keno

Well-known member
#16
This is my way of doing this some may disagree but that is OK. I close open ends of foam board with Power Grab. Smear with a art spatula and wipe off the excess with paper towel you can add a bit of water to the towel as it helps. It easy and quick and seals the board from moisture and your painting.
 

FDS

Well-known member
#18
It won’t radius the edges, all the glue does is seal it. If you want smooth, curved radii on all the foam edges you either have to iron them or sand them. Once the shape is how you want it with sanding you use PVA to seal it so any paint won’t melt the foam. If you use an iron and radius the edges it won’t need glue sealing. Example of ironed painted edge-
image.jpg
 

Keno

Well-known member
#19
Is that the stuff you put on with a caulking gun? What does it look like before painting? Does it makes the edges smooth?
A photo will help.
Power Grab is made by Loctite. It is an adhesive and it does come in caulking gun tubes or in smaller squeeze tubes. It is white but you can mix in some acrylic paint for color. It can be cleaned up with water before drying. I also use it for laminating foam board as it give you working time not so with hot glue. You can smooth it with a art spatula, or with a damp cloth or paper towel. After drying its kind of like a hard rubber so not so good for sanding smooth. You can also use for mounting things like ESC's, servos. etc. Great product to have in your shop
 

TooJung2Die

Well-known member
#20
I just finished this Simple Scout. Haven't flown it yet. All the edges are ironed. Using an iron is great for the poster board turtle deck seams. Stick it down with hot glue like they show you in the video then go back over the seam with an iron to get it to lay down perfectly flat and smooth out the glue that oozes out.
cropIMG_1876.jpg
Keep a paper towel handy to wipe hot glue off the face of the iron.
Jon
 
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