Curving foam with no paper laminate

[Matthewdupreez]

Hey guys, so due to the fact that I can't get dollar tree FB here in Sa... I'm experimenting with using just plain foam (no paper laminate) to build with..
So far I've found the ft simple planes to be amazing... And surprisingly it is actually quite strong...
But now I want to build some more master series planes, and I do not feel like making foam board... Don't have time to...

Do you guys have any ideas to help foam mild and bend without a paper laminate???

 

[wilmracer]

Do you guys have any ideas to help foam mild and bend without a paper laminate???

I work exclusively with foam board that does NOT have paper on it (MPF or foam from hardware store). What I'll do if I have to make curves that would otherwise crack the foam is put a layer of packing tape (or painters tape) on one side where the paper would be and then round like you would w/ DTFB. Works just as well and when you pull it off the part is lighter and sandable.

On occasion when I'm planning to cover parts in low-temp covering I'll apply that to the part before shaping and that will generally do the trick as well, with the added benefit that the part is easier to cover without wrinkles when it is flat.

 

[Parramon]

Hi Matthew,
The foam board without paper is called DEPRON. It isn´t a expensive material and there are in various thick. The Russian guys of www.alnado.ru build planes with this material.
I hope do helpful. Sorry for my english.

 

[wilmracer]

Hi Matthew,
The foam board without paper is called DEPRON. It isn´t a expensive material and there are in various thick. The Russian guys of www.alnado.ru build planes with this material.
I hope do helpful. Sorry for my english.

To be fair DEPRON is specifically extruded polystyrene and there ARE other foams available with and without paper and with different properties. And there are other XPS foams that aren't generally considered Depron (Like the owens corning stuff from the hardware store). It is an ideal building material though, particularly if you want to fiberglass a model or if, like me, you live in a really humid area and even the water resistant FB delaminates in a few days.

Definitely check out the Russian builders though... they have some cool stuff

 

[SSgt Duramax]

You can get spray adhesive and stick this to one side. Should be available locally too. Whatever store you buy gift wrap and stuff at there. Just remember, foam can compress, but not stretch.

https://www.amazon.com/dp/B07KRNXKVD/?tag=lstir-20

 

[Matthewdupreez]

You can get spray adhesive and stick this to one side. Should be available locally too. Whatever store you buy gift wrap and stuff at there. Just remember, foam can compress, but not stretch.

https://www.amazon.com/dp/B07KRNXKVD/?tag=lstir-20

What I'm trying to avoid is having to buy stuff and apply paper.... I want a quick and easy way to use the foam that I have tons of... 👍...

 

[Matthewdupreez]

To be fair DEPRON is specifically extruded polystyrene and there ARE other foams available with and without paper and with different properties. And there are other XPS foams that aren't generally considered Depron (Like the owens corning stuff from the hardware store). It is an ideal building material though, particularly if you want to fiberglass a model or if, like me, you live in a really humid area and even the water resistant FB delaminates in a few days.

Definitely check out the Russian builders though... they have some cool stuff

Ya, that's true.... My foam Is a little different from the ft foam... Slightly denser

 

[Matthewdupreez]

I work exclusively with foam board that does NOT have paper on it (MPF or foam from hardware store). What I'll do if I have to make curves that would otherwise crack the foam is put a layer of packing tape (or painters tape) on one side where the paper would be and then round like you would w/ DTFB. Works just as well and when you pull it off the part is lighter and sandable.

On occasion when I'm planning to cover parts in low-temp covering I'll apply that to the part before shaping and that will generally do the trick as well, with the added benefit that the part is easier to cover without wrinkles when it is flat.

I've tried packing tape for me and it just feels off... But that other tape.... We call it masking tape I believe...
Should work perfect....
Another thought I had was to use a hairdryer and heat up the foam first....

 

[SSgt Duramax]

You could try forming it in hot water. I've done that with bare foam before, awhile back. I have melted foam with hair dryers and heat guns. You would want to make sure it was good and dry before you did anything with it.

 

[Matthewdupreez]

You could try forming it in hot water. I've done that with bare foam before, awhile back. I have melted foam with hair dryers and heat guns. You would want to make sure it was good and dry before you did anything with it.

thats quite a good idea

 

[SSgt Duramax]

thats quite a good idea

My method was filling the bathtub with hot water and sculpting the foam in it.

 

[Matthewdupreez]

My method was filling the bathtub with hot water and sculpting the foam in it.

does hot glue work in hot water??

 

[Taildragger]

does hot glue work in hot water??

I can say from experience hot glue will dry very quickly but will not bond, just fall off the foam

 

[SSgt Duramax]

White gorilla glue, foam tac, or even wood glue are good for bare foam. Hot glue and bare foam dont mix... for me at least.

 

[Baron VonHelton]

You could try forming it in hot water. I've done that with bare foam before, awhile back. I have melted foam with hair dryers and heat guns. You would want to make sure it was good and dry before you did anything with it.

Can you do that with the paper still on, or will you just make a mess?

 

[Baron VonHelton]

White gorilla glue, foam tac, or even wood glue are good for bare foam. Hot glue and bare foam dont mix... for me at least.

Wood glue.......Elmer's?

 

[Bo123]

You could cover the foam with tape, and then curve it like you curve normal FTFB.

 

[Tench745]

If you haven't, check out any of NumaVig's great videos on Youtube. He uses XPS foam and Depron to build some great looking planes.

Most curves can be made by hand by lightly crushing the foam while bending it, but really tight bends can be backed with masking tape to keep the foam from cracking.

 

[Matthewdupreez]

If you haven't, check out any of NumaVig's great videos on Youtube. He uses XPS foam and Depron to build some great looking planes.

Most curves can be made by hand by lightly crushing the foam while bending it, but really tight bends can be backed with masking tape to keep the foam from cracking.

Thanks 👍😌

 

[L Edge]

If you use Depron, I used the the heat from a 180 degree hot water system where I bent the shape of the Shuttle around the pipe in the cellar. You got to go slow and make sure it's heated before you bend it further (2 cracked trying it bend it too fast). I also have done it with the blue foam real easy.