Help! Foam board problem and first plane advice.

DhruvS/Magnetar

New member
Hello! I am looking to build and fly my first rc plane in about 2 months time (April). So any advice on that would be appreciated.

I live in India and I am having a hard time finding paper laminated foam boards. I bought the wrong type of foam boards (just foam without any paper lamination on either sides. I tried cutting and folding it but it just keeps breaking.)

It looks like this:
1548949716463687859977740259009.jpg
15489497745026559715694969269010.jpg

As you can see, there is no paper lamination on either side,which means I cannot do the special "A" and "B" folds.

I tried mixing white glue with water and pasting brown paper over the foamboard but after drying, the foam board warps (I am guessing it's due to the water. If I don't add water, I cannot peel the foam off the paper to create a groove).
But when I use newspaper instead of brown paper on a smaller piece of foam, the warping reduces a bit. Is there any other material out of which I can build the plane? Please do help me out. Please contact me for any details.

Thankyou.
 
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ajit.mahajan

New member
Amazon sells the Depron sheet....before building the plane, apply tape on one side and then start....it works well....
 
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FDS

Elite member
If you look for non FT designs for foam planes, there are plenty for Depron foam, which is what you have.
You could try spray contact adhesive to attach paper to your foam board, it’s not water based so doesn’t soak the paper like your current glue is doing.
 

mayan

Legendary member
There is also a way that you can laminate the boards yourself. @Hai-Lee can surely share a lot of information about that, but just for the basics, you can use wide masking tape on side. I have added masking tape on some models to the laminated foam boards and it gave it extra durability.

EDIT: you can use white Gorilla glue or Super 77 to glue the brown paper at least that's what I know works.
 
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Hai-Lee

Old and Bold RC PILOT
Whilst I build a fair bit in FB I have also rendered FT designs in Depron and often remove paper from the DTFB equivalent I use to save weight and so do not use the A or B folds at all.

You will need a glue that really glues the foam together! Hot melt glue cannot take a lot of force without the paper on the A or B fold.

During construction I use cheap packing tape to hold the pieces together while the glue dries. For pieces where the strength of the paper is required to provide a modicum of rigidity I often insert CF strips or coat the pieces in white glue and allow them to dry fully before use. The use of white glue will require practice as it shrinks as it dries and if not careful a curved or warped surface can easily result.

On larger FY builds, (Larger than the minis), You can or should use support strips behind or on the inside of all joints where possible. the strips are just lengths of Foam 5 x 5 mm glued to the inside of the joints to provide extra support for the joint/seam. On even larger builds you can even laminate foam together to make the pieces twice the thickness and thereby add rigidity on larger pieces.

Finishing can be done by wrapping in tape, sealing with varnish/paint or whatever you desire.

Have fun!
 
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FDS

Elite member
Got any pictures of this process? If not could you snap a few for us when you next do a pure foam build?
 

Hai-Lee

Old and Bold RC PILOT
Got any pictures of this process? If not could you snap a few for us when you next do a pure foam build?
Will do/have already started I was doing a collaborators build of a Mermaid which has been shelved due to other builds including orders for others. I intend to finish it this year :rolleyes:, and unfortunately It will require replacement wings as I stored it under a pile of other planes!

Just wait for the "Mermaid" to resurface!

Have fun!
 
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DKchris

Member
If you would like a bit of a "How to" on the whole tape covering thing, i'd suggest to go take a look at this guys youtube channel: https://www.youtube.com/user/ExperimentalAirlines . He's been building very simple FFF, DTFB and depron/Hobbyking foam based models for close to a decade, based on covering the foam with 50mm wide packing tape. Works like a charm. Go see his vid on his "Tape covering foamboard", it'll give you a bunch of nice pointers on how to get it good and nice looking without too much hassle. Then you can try building one of his extremely simple and fast to build planes, if you like, or simply use the covered foam to make FT models same as if it had paper on it. Personally, I tend to cut out the FT parts first and then cover with tape after that, as I can then focus my use of tape and the direction of it to make the best possible use of it's strength and also possibly save a little bit of weight in the process (Like applying it spanwise on the wing after putting the wing halves together and such). Just get started experimenting, you will soon get a hang of how to do this. And you can go thorugh some of ExperimentalAirlines' build vids, and you'll likely catch a lot more pointers on how to do stuff like bending foam by first applying a layer of tape to the outside of a bend and many other things.

Another thing you can do, if you decide to go with FT models, is to simplify the build a bit by scaling the drawing(and hence the plane) to fit the foam you are using. For instance the standard DTFB is about 4,5mm thick, and the Depron-like foam I use is 6mm, so I go with ~133% of the original FT size. If you foam has a different thickness, adjust accordingly. To scale the plan, I simply open the untiled PDF drawing in Adobe reader (Ver. IX or newer), go to the print menu, select "poster" print and set the new scale in %. It's fairly simple.
In my case, using this 133% scaling actually makes for some very nice sized planes, if you build the standard swappable series ones. And as a weird side effect, my planes have actually ended up about with the same AUW as what FT spec's for the DTFB standard sized ones, simply because Packing tape is far lighter than the DTFB paper, and have been able to fly them very nicely on the same power packs. They do of cause have 1.33x1.33 ~1.77 times the surface area, so this way they end up being quite floaty to fly, do not have power for "immense" speeds, and are probably best for reasonably light wind conditions. But both the warbirds I have done (Spit and Mustang) have been able to do full aerobatics with the standard power packs, and to do so very nicely at nice fairly slow speed, helping a bunch with the learning curve of said aerobatics. A bit more power doesn't hurt either though, and they can easily handle the extra weight.
 
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