40 replies to this topic

[Phoenix]

Water main pipe is often HDPE, and I think that yellow gas main might also be. I got plenty of offcuts of the blue water pipe when the water mains near me were replaced. They are 70mm ID and have about 10mm thick walls. The ID isn't a standard size, but that's OK if you're just firing your own shells.

[Dan]

i forgot to mention. use sch 11 2" hdpe pipe for consumer shells in the US (and maybe in the UK ). class c 1.75" shells fit perfictly in the pipe. if u go on the manufactures website many time they will tell u the ID of the pipe. many mortars that come with the shells in the big kits are made of hdpe sch 11 2" pipe also.

[Creepin_pyro]

My local army surplus store has a large selection of plastic/metal pipes. I haven't got round to asking them for details, but I'm sure there would be something useable there. It's a great place to buy secure storage boxes for chems, dessicant, lab equipment, electronics, and I've got my eye on a super-sturdy metal frame to make into a press.

[Pyromaster2003]

Hi, just letting you all know that the dissolving saran wrap in acetone did not work to my surprise! It did start some ideas going about dissolving PVC in acetone and using this as a binder and chlorine donor in stars, i will try this when i get the chance and let you know what happens.

[pyrotrev]

Whereas some of the chlorinated rubber compounds like Alloprene and "Parlon" (this name seems to covers a couple of slightly different substances) dissolve in acetone, saran seems to only dissolve in cyclohexanone.
Regarding HDPE pipe, there are various stockists around the UK: in the NW I use Preston Industrial Plastics. Be aware though that most of this stuff is specified by the outside diameter and SDR (ratio of wall thickness to OD) and with tolerances the ID can vary, or just not be convienient!!. As I mentioned a while back, if you have a friendly livestock farmer, ask him for the cores out of reels of silage bale wrap - these are usually black (UV stabilised) MDPE tubes of 76.mumble ID.

[BigG]

Hi, just letting you all know that the dissolving saran wrap in acetone did not work to my surprise! It did start some ideas going about dissolving PVC in acetone and using this as a binder and chlorine donor in stars, i will try this when i get the chance and let you know what happens.

(*Shakes up his head in disbelief *),

Pyromaster ? IT IS NOT GOING TO WORK. Save your effort for more useful pyro.

I except that members like the idea of ?trying out? chemical reactions ? but a more interesting idea will be to read about how pipes are being made and their properties.

PVC pipes can not be ?reversed engineered? to release their chlorine, well, at least not by simply dissolving them in something. I suggest to move on and buy some PVC powder from Skylighter. Very nice people.

[phildunford]

Hate to contradict you big g but you can 'reverse engineer PVC' pipe.

I know, I've done it, it works.

It's a very tedious process, it's hard to get a nice fine powder but sawing and filing will produce a powder that can be added to formula that require a chlorine doner. I did it with a copper oxide blue, it produced a quite acceptable result and if it's all you have available then try it!

[BigG]

Hate to contradict you big g but you can 'reverse engineer PVC' pipe.

I know, I've done it, it works.

It's a very tedious process, it's hard to get a nice fine powder but sawing and filing will produce a powder that can be added to formula that require a chlorine doner. I did it with a copper oxide blue, it produced a quite acceptable result and if it's all you have available then try it!

Well I?ll be damned

Okay, first, when I meant reverse engineer I meant turning the pipe into polyvinylchloride. You don?t do that by shaving or filing or dissolving. None the less, I seen PVC pipes filed, crashed, hammer milled, ball milled and chawed upon and still did nothing to provide any chlorine what so ever!

Please let us know what pipe you were working with ? and the formula?.

[Pyromaster2003]

I already have PVC powder. I planned to mix the PVC gue (PVC dissolved in acetone) with a coloured star comp to see if it would bind the comp and provide a chlorine donor at the same time. Drying time would also be dramatically shortened due to the acetone evaporating quickly.

[phildunford]

I used white PVC electrical conduit. The only way I could get a decent powder was to saw it with a fine toothed hacksaw. This is not a way to make huge quantities, but it does work for 'experimental' lots!

The formula I used was A lancaster Blue chlorate star.

Potassium Chlorate 67, Copper (II) Oxide 13, Dextrin 5, PVC 5, Red gum 10.

Not a spectacular bright blue, but a definite pale blue - without the PVC the colour was more or less white...

[BigG]

I used white PVC electrical conduit. The only way I could get a decent powder was to saw it with a fine toothed hacksaw. This is not a way to make huge quantities, but it does work for 'experimental' lots!

The formula I used was A lancaster Blue chlorate star.

Potassium Chlorate 67, Copper (II) Oxide 13, Dextrin 5, PVC 5, Red gum 10.

Not a spectacular bright blue, but a definite pale blue - without the PVC the colour was more or less white...

I?m sorry This does not count. You have used a formula that HAS a chlorine donor in it (Chlorate). The difference from ?off-white? to ?faint blue? can be down to purity of the chlorate or the change in the wind

To satisfy that the pipe gives away chlorine you need to include it in a formula that does not have any other chlorine donor ? for example ? magnesium/magnelium with strontium nitrate and the chlorine donor.