KFM2 - With or without paper

[jpot1]

Looking for advice. I am currently building a flat wing plane based on some plans found on RC Groups. The wing has a second section on top over the first 1/3 of the wing.

Would folks recommend removing the paper from the surfaces that will be in contact? As well just hot glue or spray adhesive or both?

I've built multiple FT planes but none that I recall had the wings or other major pieces setup this way.

Thanks!

 

[kdobson83]

Kinda sounds like the way the FT Delta is setup. Go check out the build video. If I remember correctly, Josh did not remove the paper in between these surfaces. I would simply use hotglue leaving paper on. It really just depends on what kind of environment your gona be in. Really humid? If so, you may want to remove the paper or water proof it with tape or something. But anyway, check out the FT Delta build video.
Good luck

 

[rcspaceflight]

I say remove the paper, but do NOT use hot glue, it'll melt the foam. I suggest using Gorilla Glue. But use very little. Spread it as thin as possible and focus on gluing the edge. Use a book or something to keep it flat while the glue dries and let it set for, probably, at least 12 hours before you touch it.

I only say remove the paper because literally half the weight of Dollar Tree Foam Board is the paper. You'll save a lot of weight by removing the paper and using a thin layer of Gorilla Glue than using hot glue. ... Well, maybe not a lot of weight.


I'm guessing that the weight savings doesn't matter on your plane, so feel free to use hot glue, but then you have to keep the paper on.

 

[kdobson83]

You can use hot glue on exposed foam, just don't goop it on there. How else do u think Josh and everyone else reinforces the control surface hinges with hot glue? Or Seal the leading edges with it? It will melt the foam, maybe, if you really put a lot on, but as this is not a load bearing surface, just a thin layer will do fine. But yes, gorilla glue will work too but it's too much hassle in my opinion.

 

[jpot1]

Kinda sounds like the way the FT Delta is setup. Go check out the build video. If I remember correctly, Josh did not remove the paper in between these surfaces. I would simply use hotglue leaving paper on. It really just depends on what kind of environment your gona be in. Really humid? If so, you may want to remove the paper or water proof it with tape or something. But anyway, check out the FT Delta build video.
Good luck

Thanks. My first FT build was the FT22. I skipped over the nutball, delta and flyer. Just looked at the video and he just used hot glue.

 

[rcspaceflight]

You can use hot glue on exposed foam, just don't goop it on there. How else do u think Josh and everyone else reinforces the control surface hinges with hot glue? Or Seal the leading edges with it? It will melt the foam, maybe, if you really put a lot on, but as this is not a load bearing surface, just a thin layer will do fine. But yes, gorilla glue will work too but it's too much hassle in my opinion.

For hot glue hinges I always put the hot glue directly onto a scrap piece of foam and then smeared the now cooler hot glue onto the hinge with the scrap piece.

 

[kdobson83]

For hot glue hinges I always put the hot glue directly onto a scrap piece of foam and then smeared the now cooler hot glue onto the hinge with the scrap piece.

I always just run a thin line down the hinge and then smear it on with a piece of scrap. Same with all exposed edges, cut a foam thickness piece out of some scrap, then run a thin bead down the surface, then wipe with scrap. Works really well and haven't melted any yet.

 

[earthsciteach]

I would remove the paper and use 3M77 spray to adhere the two foam pieces. I've done KF foils in this way in the past and it works very well.

 

[Grakon]

I would not remove the paper from the foam board. I have built several surfaces with double foam board (paper not removed.) I then sanded the surfaces such as my rudder and elevator and it worked out fine. I always put color packing tape over the foam board and you cant tell the difference.

I tried removing the paper on the surfaces and the foam board becomes very flimsy even after using yellow glue to bond them together.

Rich

 

[Basic]

Take paper off of one side make the top 50% of the bottom fold it stick a spar between the layers. Leaving the paper on lets you fold the foam without cracking it. Glue it down over the spar. To remove the outside paper just dampen it with lens cleaner and peel it off.

I cut the ailerons half way through along the seam and use 2" clear packing tape on the other side. Heat the tape with a iron to seal it down then cut the adjoining side through and bend the aileron down. Last step is to sand a v notch by bending the aileron down 90° to sand it. Done.