Hi all, just putting this out to see what you all think.

you could use carbon sleeve or carbon fabric.  Maybe even the carbon/kevlar fabric as the kevlar will add some impact resistance which might be useful on a heavy landing.

You could try wetlaying the fabric then wrapping it in the composites high shrink tape.  That when heated by a heat gun will shrink 10% or so compressing the fabrice helping consolidate the laminate. will also help squeeze out some excess resin at the ends.

Might be worth experimenting with a bit of old card tube as if the tube is too weak, the force might damage the card.

The tape would leave a relatively smooth surface with only a fine line where the tape winds round the tube. That could easily be sanded off smooth.

Id do the fins after.

Hi Colin,

I'm with Warren all the way. Certainly make the tube then add the fins on after. I'd be looking at wet-laying the reinforcement and then using shrink tape to consolodate it and squeeze out any excess resin. You'll get the same pressure from shrink-tape that you would get from vacuum bagging but either could be in danger of crushing the tube so do some tests first.

Carbon fibre braid would be easy to work with because it's already tube shaped. Our nominal 125mm Carbon Fibre Braided Sleeve would open up to accomodate the 140 diameter tube. Alternatively carbon fibre fabric, carbon/kevlar, or all kevlar are all options; it just depends what property you prioritise. Carbon fibre cloth will give you the stiffest tube, kevlar cloth will give you the most unbreakable tube and carbon/kevlar will give you a compromise somewhere between the two. We also have a brand-new carbon/black Twaron fabric if you want the performance of carbon/kevlar without the bright yellow fibres.

Here's the Composites Shrink Tape and EL-2 Epoxy Laminating Resin that we're both suggesting.

All the best with your project.

Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

if youve got a metal pipe/pvc pipe of almost the right outside diameter to fit in your card tube, then you could add that during moulding to temporarily strengthen the tube.

Thanks Matt Got the black Twaron to do the main body. Going to wrap 2 layers of this along the 1.7 meter length using the slow el2 resin, then a tight wrap of peelply and finish off with a wrap of 50mm wide shrink tape. need to sort out the upper part (payload section) fins and nosecone.

Hi Col,

Going to wrap 2 layers of this along the 1.7 meter length using the slow el2 resin, then a tight wrap of peelply and finish off with a wrap of 50mm wide shrink tape. need to sort out the upper part (payload section) fins and nosecone.

You might find the peel-ply pretty hard (not impossible but pretty hard) to remove. Do you need the peel ply or could you just wrap the shrink tape (or some release film then shrink tape) direct onto the wetted out reinforcement.

I dont want it all in twaron as it is just too black, how about the carbon with colour weave in it?

No reason why not (the coloured fibres are polyester so won't have the same tensile strength as carbon or Twaron but the rest of the fabric is carbon so should perform well).

Also what quantity of resin pr square meter of cloth? i heard 500g per m2 but not sure. Anywher I cam post pics of build on here?

Reckon on 50/50 by weight with the fibre which means for a square metre of 200g fibre you'll use about 200g of resin. 500g sounds like much to resin-rich to me.

All the best, Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Thanks Matt. Used peelply on a project a while ago when vac bagging a part, came off ok. what males you think its will not come off (thought it was designed to peel off)

Hi Col,

The peel-ply will come off I just suspect that on a cylinder shape with a shrink-tape over the top it will be hard work; I wasn't sure whether it was neccessary, that was all.

RE the nosecone, covering polypropylene will always be difficult because nothing (including paint!) will stick to it!

Matt Statham
Easy Composites / Carbon Mods - Technical Sales