3/4" Hose Barb Substitute?

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boyntonstu
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Thu Sep 10, 2009 2:35 pm

I have all the fittings for a 3/4" brass T piston valve, but I can't locate a hose barb for a 3/4" tee for the sealing surface.

Is there another way to make it?

BoyntonStu

Edit by jrrdw.
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Technician1002
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Thu Sep 10, 2009 2:51 pm

Maybe make it 1 inch and use a reducer to your desired barrel size. The reducer could be filled with body filler to make a nice transition zone for high flow efficiency.
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pizlo
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Thu Sep 10, 2009 8:43 pm

Wow, well yeah, a threaded bushing works with a nipple, just takes bit of sanding too. just look at a barb and think how can I make something similar to this? If you need more ideas spoofed to you look at some of the other piston guns or maybe Crowleys piston gun tutorial, just size down whatever he does.
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MrCrowley
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Thu Sep 10, 2009 8:51 pm

Assuming your tee is 3/4" with female threads, i'd find a 3/4" nipple, see if you can find any copper/metal/PVC pipe that will fit inside it. Once you've done that, cut it to the length so it goes inside the tee but doesn't extend out of the nipple on the barrel side, epoxy it in and then attach your barrel to the 3/4" nipple.

Assuming you have a small barrel or can't find pipe that will fit in a 3/4" nipple, you could try a 3/4"-1/2" bushing and try the same thing.

If you don't understand what I mean, i'll make a diagram. But it's pretty much what I do on a larger scale with my piston valves or when I use metal barrels that don't have threads (as I can't solder/weld).
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FORE!!!!
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Thu Sep 10, 2009 9:13 pm

Or you could just use a 3/4 nipple or 3/4 by 1/2" nipple depending on what size barrel you want to use. then find a kinco nut and olive to suit the barrel size and your away, with the compression fitting you can adjust the dept of the pipe extending into the tee
al-xg wrote:
I've used various things like cutting oil, silicone lubricant, even butter

jsr wrote:
This collection of containers on your bedside table must look very intimidating to any visiting young ladies

...but hey, lube shows you care;)
MRR
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Fri Sep 11, 2009 12:28 am

Hi Stu,
I've made this little tutorial a while ago ...Brass fitting piston valve.

It is very reliable but you should go with a lighter piston.

A good substitute for a hose barb would be a piece of threaded galvanize steel pipe (already tried that).
Basically I shortened the thread a little, cut the pipe to my needs and grinded away the sharp edges at the seat to have a smooth surface.
After that I used a little antirust protection to the cut areas.

Had some trouble to make it 100% airtight but in the end it worked with some epoxy.
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