Newb here - supply problems for homemades

K.o.R · Post by **K.o.R** » Wed May 02, 2007 8:34 pm

Well howdy folks, it appears I've been here a year and haven't posted anything, so here goes:

Well my current armoury consists of a single Flash Flood which I loved to bits, until the flood valve broke and started leaking out of the side - my "repair job" unfortunately resulted in it being unusable, leaving me with a still very nice balanced gun, but no riot shot option.

However - what I'm really interested in doing is building a homemade, but parts seem impossible to come by here in the UK. I can get some semblance of PVC tubing at places like B&Q etc, but valves and adaptor pieces seem impossible to get - almost as hard as Super Soakers themselves (what's going on with our shops? Don't they know it's nearly summer?).

I was toying with the idea of using Hoselock one-way (sort of) valves and normal garden hose for the purposes of getting the water into the pressure chamber, then use what limited pipe styles I can get for the pump and firing mechanism (don't have a superbly clear design in mind just yet).

Do I have a hope, or should I pray for something new coming soon to our Toys'R'Us shelves?

Silence · Post by **Silence** » Wed May 02, 2007 8:47 pm

Welcome to the community, since I haven't said so before!

PVC is indeed hard to find in the UK, although it's used in all construction efforts and is found in all stores here. Check out Jo's copper SPCgH to see a homemade built using copper. insanitys_engineer, who also lives in the UK, had a copper question thread and a picture of [url=http://forums.sscentral.org/t3734/his homemade[/url].

Copper is a good bit heavier and more expensive than similarly sized PVC, but it can withstand much more pressure (the thick UK copper I believe can take over a thousand PSI) and it's not nearly so likely to crack if you drop it. US copper is much thinner, with 1/64" walls.

The real problem I can think of with copper homemades lies in the pressure chambers. Larger copper tubing is really expensive and heavy. You'd have to use "different" chambers, perhaps soda bottles like on those two homemades I mentioned.

But at any rate, I would try to contact joannaardway to see if she's found any other resources or suppliers. She's fairly active here, so a private message would work, or email.

K.o.R · Post by **K.o.R** » Wed May 02, 2007 9:03 pm

Copper's an interesting idea, though I think it would be way out of my price range.

The coke bottle as a PC is another interesting one - would it have to be vertical or is there a way to keep the air in the correct place with it horizontal? (something about pistons :S )

I'll try and get an mspaint pic done as I think i can actually manage this even with the very limited pipe ranges

Silence · Post by **Silence** » Wed May 02, 2007 9:07 pm

You don't actually need large PCs - a more recent discovery. But larger PCs have more volume and are *slightly* more efficient for a few reasons. But volume is the main reason. If you're limited to certain sizes, a longer pipe will always work.

The bottle will have to be vertical unless you use a piston to separate the air and the water, as you say. Now, the problem is that sticking in a sealed piston isn't possible with a soda bottle, although it would work fine with tubing.

My next homemade will be a small water gun with a piston in a 2" or 3" chamber. That type of thing is feasible with copper, disregarding price and weight.

K.o.R · Post by **K.o.R** » Wed May 02, 2007 9:37 pm

If I could find some way to adapt normal waste pipe to itty bitty PVC, could I stick something like a block of polystryene in as a piston seperator? With appropriate seals natch

Hopefully here is a diagram to make it look a little clearer.

I believe the pipework is 22mm (~7/8") that fits these connectors

K.o.R · Post by **K.o.R** » Mon May 07, 2007 4:32 pm

Well I've started constructing it with the (rather expensive) parts from Focus-Do It All, and so far it's ok - I can get some pressure in the temporary PC, but I need something else to use as the pump plunger as wood just absorbs water, expands and gets stuck :/

The gun as it stands
Tank connector and pump intake valve
Trigger valve, PC and pump exit valve
Pump housing without plunger
Trigger valve and PC

K.o.R · Post by **K.o.R** » Wed May 09, 2007 9:37 pm

Woot! After several days of cursing and about a mile of various kinds of tape, I have a working water pistol. Ok, so it only shoots for 1/2 a second and requires me to dunk the end in a bucket of water of charge up the shot but hey

Does anyone have any tips for attaching fizzy drinks bottles to A) plastic pipe (for the PC) and B) normal hosepipe (for the backpack reservoirs)?

Silence · Post by **Silence** » Wed May 09, 2007 9:51 pm

Nice! Do you have any pictures?

I believe, with Teflon tape, soda bottles screwed into some size of PVC or CPVC fitting. I'll have to check that though, so don't take my word for it. Epoxy is always an option - epoxy the bottle to a threaded fitting and screw that fitting into a port in the water gun if you want a removable PC.

K.o.R · Post by **K.o.R** » Wed May 09, 2007 10:25 pm

No pictures of it firing, but I have a couple of it in its new configuration (those more expensive pipe fittings are awesome - they're designed for mains water pressure yet can be disconnected and swapped round in no time)

Nozzle and extended pump
Back end with temporary PC
The temporary PC (all my spare 15mm tubing!)
The pump handle disassembled, and yes, that is a 13mm masonry drill bit

A spare bit of 15mm tubing and cap over the end and you'd never know!
A Coke bottle with 22mm tubing in the neck - this is actually fairly snug, but it still needs something to seal it.

Apologies for my cruddy phone camera, I seem to have misplaced my normal one.