Make your foamy bullet proof( unbreakable to an extent)

Started by jerry, January 06, 2010, 09:52:59 AM

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jerry

Ok, I thought I can share some experience in this thread

If you wanna build a foamy crash proof- (Use simple model first and once you are proficient enough to do this.. Go and build a good one :)

(1) buy epp or depron or even regular cheap styrofoam.
(2) Buy couple of yards of Fiberglass Cloth 3/4 oz
(3) Some how get epoxy resin or similar resin like z-poxy

Next step is easy...

Download a free pdf plane plan(the first one I ever used was from graysonhobby.com) and the cut the foam in their respective shapes(sand it so the surface will be smooth for later resin application). Glue it together. Wait for a day or two. After its good enough to go, Apply the resin(if its not thin use 95% isopropyl alcohol or pure rubbing alcohol to thin it out) on the plane part by part and lay the pre cut fiber cloth on to it. You have to use a regular stiff paint brush to spread it even. Its that easy. Do use too much resin as its increases the weight of the model. Weight for a day before you use it. Then use a sand paper with mini grit and sand it until it is smooth and then you can paint some primer and then any paint you wanna use.

Put your electronics in(weigh your model and use a respective motor). And you are good to go.
Suggestions- use balsa wood or similar light weight wood for making ailerons and elevators.

If you need help or any clarification...Please ask :)
Jerry
Jerry Thomas Azhakathu

tg

Pics will be real good or possibly post the links where you may have seen similar work explained with pics.  :)

vinay

Will this not increase the original weight by twice?

jerry

Yeah this process will increase the weight by 70% but looking at the positive effects. I would definitely wanna do it...
Jerry Thomas Azhakathu

vinay


b4ggu

Why go for fibreglass woven fabric and epoxy and spend so much when you can get the same results with "SCRIM TAPE" which is plasterboard joining tape looks like a normal first aid bandage, loosely woven but made out of glassfibre rather than cotton. I have friends who have even used cotton bandage tape. This is then coated with diluted PVA or Fevicol... See images below...... The wing has a carbon spar underneath the yellow packaging tape covering.
Ramesh's RT Fizz has a carbon rod cut into the EPP sheeted wing.
Deepak

tg

fiber tape in sensitive areas and cf are more than enough. The foamy is typically cheapest to build and doesn't need to be a flying fortress.     

ashJR7202

Quote from: tg on November 24, 2010, 03:21:55 PM
fiber tape in sensitive areas and cf are more than enough. The foamy is typically cheapest to build and doesn't need to be a flying fortress.     

i agree!!!! i put CF rods on critical parts, like underneath which help while landing!!!! and fiber tape, that helps a lot !!!!
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rajathv8

The everyday glass that we see although transparant has millions of tiny cracks in it. So when a force is applied the cracks spread out, compramise the strength and break.
When a glass rod at the midpoint is heated at sufficiently high temperatures it will melt. The two ends of the rod can be streached appart to large extents forming a very thin strand of glass. This glass wire is devoid of the cracks and is very strong. It is flexible and 6 times stronger than steel. The fibres are then knitted into a cloth - fibre cloth. This cloth is made stiff by applying resign. When a force is applied the resign stops the cracks from spreading thus imparthig tremendous strength. This is fibreglass :)

Fibre glass is used with aluminium to form - glass reinforced aluminium ie layers offibreglass and aluminium. This material is used on the entire outer shell of A380 to give it srength and lightness. Aluminium for rigidity and fibreglass for strength and lightness.

Saw this on TV and thought il put it here :)

b4ggu

Well said Rajat... That was indeed a very informative programme.
Did you see them firing skinned chickens through a cannon at it....

rajathv8


vinayak

I m a beginner......
plzz tell me how to stick Styrofoam......
any glue available at a cheaper rate????

saikat


vinayak


lastRites

What thinner should I use to get the epoxy mixture runny? I don't want it to eat through the foam(HD thermocol) :p
It is the pervading law of all things organic and inorganic,
Of all things physical and metaphysical,
Of all things human and all things super-human,
Of all true manifestations of the head,
Of the heart, of the soul,
That the life is recognizable in its expression,
That form ever follows function. This is the law.

RCNeil21

Quote from: lastRites on June 10, 2013, 01:35:33 PM
What thinner should I use to get the epoxy mixture runny? I don't want it to eat through the foam(HD thermocol) :p
Hey i think tg's way(post #6) is better and it isnt too messy also, why do you want to use messy epoxy and fibre cloth?
Build planes like feathers rather than tanks, both handle bullets equally well.

lastRites

I need it for my thermocole boats.. When you put over 600Watts on a 15inch boat, you need it to be bulletproof :P
It is the pervading law of all things organic and inorganic,
Of all things physical and metaphysical,
Of all things human and all things super-human,
Of all true manifestations of the head,
Of the heart, of the soul,
That the life is recognizable in its expression,
That form ever follows function. This is the law.