PVC Pipe

[tgrimey09]

So from what ive seen pvc pipe is bad for a rack but its ok to be used if dug into the ground. What if I was to take milk crates and layer the outer edges of the crate with wood, drop 12 or so pvc pipes in the crate (using consumer fireworks), then fill the crates with cement. Would that be pretty safe? I don't see consumer shells remotely phasing concrete at all. Thanks

[davidh]

I would seriously shop around for a good price on consumer fiberglass mortars. They will save you work and weight. If you shop around without getting in a hurry, you can probably get them for cheap. BTW, flying concrete is NOT safe. I know this from experience with cakes using concrete plugs.

Edited July 30, 2018 by davidh

[Arthur]

The nice thing about earth is that it moves and froths a little if a shell goes off where and when it shouldn't, anyone too close gets sandblasted. The NASTY thing about concrete is that at the point of failure a bullet size lump of concrete flies out and can do great harm.

 

The tubes that came with the shells make OK mortars, GRP, and HDPE gas or water pipe also make good mortars.

[OldMarine]

I use 1" pvc for building cakes but I wouldn't upsize them. Pvc shatters rather than splitting and HDPE pipe is cheap and easily obtained.

I buy Mighty-Mite since they have a formed bottom and last forever in pyro years.

[Arthur]

ABS and PVC will always be vulnerable to brittle failure which can leave someone filled with plastic and leaking blood.

 

HDPE as found in plastic water and gas main pipe is much more forgiving as it expands then splits when ill treated.

 

For commercially made consumer shells the accompanying cardboard tube is a very good mortar if kept dry.

[pyrokid]

I can't see any reason to use pvc. Consumer hdpe mortars are available for ~$2.00/piece online. On what planet is mixing concrete to secure pvc fragmentation bombs a better choice?

[Arthur]

HDPE as used in the UK (and probably the USA) for water and natural gas mains, stretches to about twice its size before it splits, it usually doesn't make fragments. ABS and PVC pipe smashes into fragments and those fragments fly fast shredding whatever is in their way. I've seen a 2" HDPE mortar split at about 4" diameter but critically -just split no fragments at all. All because someone used flash as lift in one of my mortars

[BetICouldMake1]

So I know pvc is bad to use for mortars because it shatters, but it seems like lots of people use it for 1-1.5 mini shells or small mines. I'm thinking of the skylighter tutorial on film canister shells along with OldMarine's comment above. Is it generally accepted that pvc is ok to use for these applications?

[OldMarine]

I wouldn't shoot a barrage of 1" salutes from my pvc cakes but I feel safe enough with star mines and single comets. I don't shoot shells from them either so there's only the ½ teaspoon or so of lift to contend with. Pex piping is easy to find in diameters up to 2"and you can crimp fit a plug in it easily. I haven't tried it even though I'm a plumber and have it laying around since I built my cake racks according to Kyle's article on passfire and have reused them several times. Edited August 14, 2018 by OldMarine

[OldMarine]

Lately I've begun wondering if the cakes are worth the trouble since the chicoms build some nice ones. Edited August 14, 2018 by OldMarine

[zzzybil]

You must have a ton of pvc pipe laying around ..........I do.........still NOT using it for pyro .........

 

Took a while but managed to collect plenty enough cardboard , fg , & hdpe tubes . Still a newbie , my goals are ; value the knowledge I can comprehend , accept being a good pyro requires discipline , apply sage advice and never cheat for convienence over safety.

 

Good Lord ''a cement crate of pvc '' Bad idea on so many levels ! seriously

 

Nothing wrong with thinkin outside the box . Maybe you could FG up some diy cardboard and make tubes ? IDK I'm with yuh '' everything '' on the want / need list can be overwhelming . Just read the diy WOOD gerb tooling thread haha been thunking on diy tooling ...how to fab up ?...... As much as I value the tools I have - ohhhhhhh well ....... When I hit the lottery ........ I'll do some shopping at the real Woody's ,

 

good luck on your tube collection - you'll get there

[Tim1877]

I use 1" pvc for building cakes but I wouldn't upsize them. Pvc shatters rather than splitting and HDPE pipe is cheap and easily obtained.

I buy Mighty-Mite since they have a formed bottom and last forever in pyro years.

Where do you get your HDPE pipe from I have looked everywhere around here and on the net with zero luck now pre made mortars are easy to get but I want to save a few bucks and make my own

[Arthur]

Just compare "a few bucks" saving with a month's lost salary and a month stay in hospital and see what the starting costs of an accident will be. Then decide whether it's worth it for you.

 

Sometimes in pyro it pays to do it right to best possible standards. This is why experienced pyros read old books and share modern techniques just to learn what works best and what doesn't.

 

Done to best standards pyro is a safe hobby, done for cheapness it's NOT.

[OldMarine]

The mighty mite mortars don't have plugs to rot and can be used for fuel mines with no modifications. Mine are several years old and the only reason I've bought more was to go bigger!

[OldMarine]

Here's the bottom of a 4" gun.

[PhoenixRising]

Been playing with rolling my own tubes lately.

 

A good 1.25" tube can be made with piece of 1 inch (id) PVC as the case former, 24 inches of 70 pound kraft paper and woodglue/water mix.

 

Here's a test shot with 4 grams of Bp and a little 1 inch Chinese-style can.

 

https://youtu.be/Kn6Pi9qunCo

 

I know the video doesn't show the tube, but trust me it's there. Going to do nothing but cakes this NYE and I'm not paying top dollar for disposable tubes.

 

This tube was still good for another shot, so they can be reused a couple of times pending you keep them away from humidity.

[Mumbles]

Sealing the tubes in with water glass and calcium carbonate should also help to improve their lifetime, and make them more resistant to humidity. You can actually rinse them out with water to remove the hygroscopic lift residue after treatment.

[PhoenixRising]

That's good to know, maybe I can save my cakes this year then. It would be a shame to waste all those tubes, even if it's still cheaper than buying them.

 

Time to go Google the in's and out's of 'water glass.'

[Mumbles]

This would be the treatment I was talking about. http://www.pyropage.com/Misc/cardboard.html It's getting harder and harder to find this original source, though reproduced around the internet now.

[PhoenixRising]

Nice, I've never seen that article before, even with all the pyro-snooping I've done online.

Best part is, Lowe's and HomeDepot carry that stuff.

 

https://www.homedepot.com/p/Pool-Mate-8-lb-Pool-Calcium-Hardness-Increaser-1-2808B/305231833

 

https://www.homedepot.com/p/Rutland-1-Gal-Water-Glass-Cement-Floor-Sealer-Gallon-Jug-146/300981927

 

Checked SDS sheet on both. Apparently they call the water glass cement "Sodium 'poly'-silicate" which I'm guessing is just a blanket term for the various anions. (ie. Meta, Ortho, and Pryosilicate.)

[Mumbles]

Many ceramic suppliers carry water glass too. You'll probably have to dilute it to use it. At full concenration, it's basically a syrup.

[thehobbyshop]

As been said many times before, PVC shatters into many fragments, very dangerous. HDPE pipe is the best for making your own racks. I had a plumber friend order 40' lengths and cut them down to 10' for transportation. I found it's almost cheaper to just buy the already made tubes. It actually cost me more to make my own!

 

Todd

fireworks@thehobbyshop.us

thehobbyshop.us

Hobby maker of Cobra Cues.