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FT foam board weight

#1
Couldn't find the info so I thought I'd ask here , does anyone know what the weight (per area) of the FliteTest foam board is?

I suspect it is a fair bit lighter than what I am using and would like to confirm this (or else I am really careless with the glue or deficient in some other area :eek:).

Thanks in advance ;).
 
#4
Thanks a lot. A 50x70cm 5mm board of my local variety weighs around 168g, which translates into 0.48 kg/sq. meter or pretty much exactly the same as Westfoam in the comparison above (I am pretty sure the make is different though)

Well, anyone else thinking of emigrating to the US? ;) Meanwhile, I guess one's gotta make do with what's available...
 

Hai-Lee

Old and Bold RC PILOT
Mentor
#5
Heavier FBs tend to have a more dense foam layer, and more rigidity. Some do actually have a heavier paper layer though or even as well.

From previous experiments on the FB here the total paper weighs around 60% of the total weight so removing a single layer of the paper can reduce the weight by 30%. It makes the planes lighter and more FT like in the handling.

Have fun!
 
#6
From previous experiments on the FB here the total paper weighs around 60% of the total weight so removing a single layer of the paper can reduce the weight by 30%. It makes the planes lighter and more FT like in the handling.

Have fun!
Yeah that's my intention, in the case of this particular brand the paper also accounts for about 50% of the weight and removing it on one side seems especially appealing in terms of wing construction - it becomes it not only lighter but also easy to build a wing with a smooth, curved airfoil.

The problem I have is that whatever glue they use in the manufacturing process seems to be somewhat unevenly applied, and as a result trying to mechanically peel off the paper form a large area is nearly impossible - the paper tears and delaminates in the spots when the bond is stronger, leaving little (and sometimes not so little) "islands" on the foam, which are very difficult to remove without damaging the foam itself. I am experimenting now with some chemical means of weakening the bond before peeling the paper off, so we'll see how it goes.
 
#9
And as I am in the middle of experimenting right now I can also say the pre-soaking the paper with sticker/tape removal fluid (the one I used is based on glycols) also seems to work. You then need to wait about an hour or so until the paper dries out enough to be safe to handle (otherwise its too soft and mushy) and then it can be peeled off quite effortlessly.

I am also currently waiting for another sample to dry, this time I used denaturated alcohol (which a bit is less expensive than the fluid).
 

CarolineTyler

Well-known member
#10
And as I am in the middle of experimenting right now I can also say the pre-soaking the paper with sticker/tape removal fluid (the one I used is based on glycols) also seems to work. You then need to wait about an hour or so until the paper dries out enough to be safe to handle (otherwise its too soft and mushy) and then it can be peeled off quite effortlessly.

I am also currently waiting for another sample to dry, this time I used denaturated alcohol (which a bit is less expensive than the fluid).
Quick video of removing the paper with an iron, the quickest and easiest way!!!
 
#11
Well that actually looks amazingly easy , but unfortunately it doesn't seem to work for me :( If anything it felt like the paper was even harder to pull off. It may be caused by the different make of the board and likely a different glueing process being used.

But it may also be that I am not so good with iron though... ;) will try some more tomorrow and play with different temperature settings, nothing worked for me so far though.

FWIW denaturated alcohol didn't work, either. But the glycol fluid does quite well, and it actually fairly efficient in terms of amount required, so at least there is that ;).
 
#12
All right, again - this is likely particular to the foam board make I am using - but I have just found that an oil paint thinner works even better and much faster than the label remover - and is a lot cheaper as well. Seems like a working solution to me, the only downside is the strong smell ;).

The paper is ready to be peeled off within seconds after being soaked, and comes off really easy.

I used one based on "white spirit", at least that's how my dictionary tells me to translate it ;). But from my limited experience it's likely that all kinds of oil paint thinners should work, I haven't never seen much difference - when applying to the paint, at least ;).
 

Hai-Lee

Old and Bold RC PILOT
Mentor
#13
#14
Ok., I've been able to make the iron work. Seems setting proper temperature is indeed the key.

Still I find it a bit more difficult than the paint thinner, especially the initial couple of centimeters. Also, I used a fairly narrow panel and it curved (in direction opposite to the iron) in the process - was the temperature too high or is it normal?

I also discovered the paint thinner has another drawback (beside aggressive smell) - you have to be careful not to over apply, especially near the edges, or the foam simply dissolves on contact with the fluid. So it takes a bit of skill to soak the paper evenly, and then pull it off as soon as possible.

I guess both methods take some skill and practice until perfected, but at least they work ;). Thanks.
 

Hai-Lee

Old and Bold RC PILOT
Mentor
#15
The curving is because the foam actually was hot when the paper was applied during manufacture. Foam has gas inside it locked into cells. Since manufacture the gas has cooled and reduced in pressure. With the paper on both sides the internal shrinkage pressures are resisted by the paper and its bond. When the paper is removed the low gas pressure in the foam cells causes the foam to curl slightly.

It is no big deal and generally a somewhat uniform curling which effectively disappears when the parts are assembled and the glue sets. I believe that the pre-stressed nature of the curve can actually give a slightly stronger tail boom but as yet I cannot prove it!

Have fun!
 
#16
Ok so I went around full circle but I am back to using the sticker/glue residue remover. Not sure what ingredients in it make it work, but it's extremely simple to apply, and it leaves really flat and pristine foam surface, which was the deciding factor.

I've done some further searching and it seems other people are having success with things like rubbing alcohol and window cleaners, but I guess this is what works for me.

The other methods I tried before - heating with iron and using petroleum based solvent work ok - with some care taken - when applied to smaller pieces of foam, but dealing with a larger area is tricky and it's very easy for me to damage the foam in one way or another. Maybe I am just clumsy ;).

The remover is easy, I just apply some with a plastic dropper then distribute/saturate the area evenly with a kitchen sponge and set it aside for 30 min or so. Then the paper comes off quite easily and very cleanly.

 
#17
I've done some further searching and it seems other people are having success with things like rubbing alcohol and window cleaners, but I guess this is what works for me.
Ok so I have now confirmed with some further testing that isopropyl alcohol is the magic ingredient that causes the paper to peel off easily. The difference - when used in pure form is it dries a lot quicker than the label remover, so it's s good idea to brush it in immediately after applying it to foam board so that it permeates the paper fully before it dries (I just used a fairly big flat brush for this).

It also acts much more quickly than the label remover, the paper can be peeled within a couple of minutes.

It is sold as "IPA" in automotive stores here (in Poland), can also be ordered online from chemical supplies sites, and apparently is the basis of some (but not all) versions of "rubbing alcohol" (which I don't know of a local equivalent for).
 
#18
Hi,
I don't want to start new topic, so I'll ask here. I'm really limited with foam board that are available near me, but i succeed to find one with 0.28 g/inch weight. Will it works with the FT Simple Cub?
 

FDS

Well-known member
#19
Yes but it will be heavier overall and you might need to add length in the nose to get it to balance. If you can remove the paper off the inside/underneath of as many areas as possible you will save weight. Some designs translate fine to heavier board, others do not.
You might find 3mm thick board in the same density, that can be substituted for 5mm if you narrow the width of the cut outs for folds etc on your plans when you cut out. The thinner board ends up similar to DTFB overall.
 
#20
Thank you so much for such a fast reply, I think that I would be able to find the same one but 3mm thick. I hope it would solve the problem, but then I'm wondering will it be enough stable.