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KNO3 rocket with report


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Posted

Anyone know of how to make a black powder report on a pvc KN03 rocket ? im trying to avoid using flash powder as i am still new and want to learn the safe way first then slowly move up to safe flash powder usage

Posted

insutama, please reconsider using PVC for rocket casings. Should one CATO, the plastic shards will be razor sharp projectiles. The safest bet is convolute rolled paper tubes.

  • Like 1
Posted

how do you pack the powder in the casing ? with pvc its easy to hammer down with a dowel

Posted
It is easy to press or ram composition into a paper tube as well too. With good strong tubes (see the NEPT thread in the same section) you do not need a tube support to hand ram a BP rocket.
Posted

do you have any rocket tooling?

Posted

how do you pack the powder in the casing ? with pvc its easy to hammer down with a dowel

roll your own tubes with kraft paper and wood glue, it's surprisingly strong. You might not even need the wood glue to make small rockets, but it will make the tube stronger.

Posted

Look on YT and search for "How to roll pyro tubes", He's has a very good tutorial.

Posted
Good video but no speaking. Is he using wheat glue or would that work if not?
Posted
Awsome thanks guys I'm gonna check out how to make my own casings and no I don't hAve a tool to make them
Posted

Good video but no speaking. Is he using wheat glue or would that work if not?

Wheat paste works but you have to account for shrinkage by using an oversized mandrel (a few turns of greaseproof paper or baking parchment works). Dont be tempted to force dry a wheat pasted tube or it`ll likely end up more oval than round.

Posted

I tried many different glues a while back and it seems like watered down white school glue worked the best of the ones I tried. I imagine wood glue would be even better. I know I tried wheat paste, dextrin, and a few others but don't remember all the details and don't have my notes.

 

I bought a bunch a while back that I got a really good deal on so haven't needed to make any except the occasional small one where I use gummed paper tape. If you make some make sure you use a board to roll them to press out any air bubbles and tighten it up.

Posted

I`ve tried pretty much everything and the ones i stick with (no pun intended) are casein/dex and casein/dex/silicate.

Posted (edited)

but you have to account for shrinkage

 

Yep, No one likes shrinkage

 

 

Edit....ok why did my quote come out like that?

Edited by captainG
Posted

Yep, No one likes shrinkage

 

Keep those tubes warm, boys! :D

Posted
Cause you somehow deleted the quote tag at the end. Should have looked like:
Posted
Ahh thanks, trying to figure this forum stuff out
Posted

Is there any place i can buy Pre made tubes in canada or maybe at a hobby store or somthing. Im sure eventually i will make my own but for now i kinda would like to skip that step lol

Posted

I use tight bond III wood glue and water. I make a thin glue out of it and paint it on the paper, roll and dry. Your done. :)

Posted

That stuff is expensive over here, $10.27 for 237ml. If i watered down 50/50 it might be enough for 15 1lb tubes, so thats $0.68 per tube just for the glue :)

Posted (edited)

I use the same stuff titebond 3 for tube rolling. Make wheat paste and add 3 measuring tablespoons per cup of medium thick wheat paste. Don't force dry with heat or a bunch of wind. They stay round and dry hard.

Edited by Sparx88
Posted

How much should i water down wood glue before i use it on tubes ? also should i let tubes dry on the wood dowle that i rolled it with

Posted

also should i let tubes dry on the wood dowle that i rolled it with

Not unless you want to make said wooden stick a larger diameter.

The tube shrinks slightly when drying. With sticking to the rod, your going to have a hard time getting it of.

B!

Posted
50:50 Would be a good place to start when watering it down.
Posted (edited)

Not unless you want to make said wooden stick a larger diameter.

The tube shrinks slightly when drying. With sticking to the rod, your going to have a hard time getting it of.

B!

+1

Its best to use aluminium or thick wall plastic tube which have low surface energy (aka non stick). Glue with a high water content will tend to soak right through the paper on the first turn and adhere to the wood. The higher the water content the greater the shrinkage so you may need to adjust/increase the mandrel diameter to offset it. You`ll need to roll a tube to check how much shrink you have and go from there .

Drying the tube on the mandrel may be necessary with an overly wet tube to keep it straight and round as it dries, removing it periodically will keep it from sticking but if the shrinkage is excessive it`ll eventually become impossible to remove. Drying it off the mandrel adds warping to the equation, luckily bent/ oval or otherwise iffy tubes can be used for gerbs.

Edited by Col
Posted

great thanks

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