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Is this ok?
Posted: Sun Dec 30, 2007 7:35 pm
by elitesniper
Hey guys , i just posted this topic to ask you guys if im doing my piston right so here are pics .
Posted: Sun Dec 30, 2007 7:44 pm
by ALIHISGREAT
well the hollow piston could be a problem, how thick are the walls... if you are not cofident they are thick enough to holdback the pressure you will use you should fill it with epoxy or something.
Posted: Sun Dec 30, 2007 7:47 pm
by jrrdw
There is only one way to find out if any piston is going to work. Try it. It looks good so far.
Posted: Sun Dec 30, 2007 7:47 pm
by elitesniper
well there thick enough that i cant bend it with my fingers.

and one more thing home depot sells 1/4 female threaded tees right?
Posted: Sun Dec 30, 2007 7:50 pm
by mark.f
Drill holes into the hollow piston to prevent collapsing from compressed air on the outside.
Also, you may have problems with the sealing face. If the rubber foam is open-cell construction, air will leak through it.
Posted: Sun Dec 30, 2007 7:53 pm
by Hotwired
Nothing wrong with a hollow piston, the lighter the better as long as it can take the pressure you're using and only one way to find out with a medicine bottle

Posted: Sun Dec 30, 2007 8:19 pm
by elitesniper
well its the pepto bismol one

seems prety sturdy so ill just try it. it should take the pressure if not ill just fill it with expanding foam or somthing, can i make it serviceable by using a threaded end cap in the back of the piston?
Posted: Sun Dec 30, 2007 8:53 pm
by mark.f
Just make sure it's a pressure rated plug, not a cleanout cap.
Or, you could use screws and a gasket, like this:
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The gasket is between the green 2" SCH-40 and the bushing.
Posted: Sun Dec 30, 2007 9:19 pm
by elitesniper
thanks but my piston isnt that short im guna put a threaded coupler thingy behind with a threded plug so i just unscreaw it to service it. :DWAIT and a blow gun will be enough to pilot the piston? since its very light.
Posted: Sun Dec 30, 2007 9:23 pm
by MrCrowley
elitesniper wrote:thanks but my piston isnt that short im guna put a threaded coupler thingy behind with a threded plug so i just unscreaw it to service it. :DWAIT and a blow gun will be enough to pilot the piston? since its very light.
<A HREF="
http://www.spudfiles.com/forums/the-tru ... tml">Don't forget the bumper, or else.</a>
A blow gun should, if your piston is made well. Though I would recommend a 1/4" or 3/8" ball valve for best performance.
Posted: Sun Dec 30, 2007 9:27 pm
by elitesniper
ouch thats gotta hurt MrCrowley

, but yea you can see the bumper behind the piston its epoxyed on there tight, its those cushiony things from drum symbols
Posted: Sun Dec 30, 2007 9:32 pm
by MrCrowley
Yeah that's where I got mine from too
Just make sure the piston isn't small enough to get jammed in the threaded adapter like mine did
On a side note, the SGA is back up and running with a sprinkler valve for pilot.
Posted: Sun Dec 30, 2007 9:35 pm
by elitesniper
haha congrats MrCrowley

i thought she wouldnt make it

. haha
and how much of a differnce did the sprinkler make?
Posted: Sun Dec 30, 2007 9:41 pm
by MrCrowley
A LOT! Well in sound anyway, it's incredible at just 50psi, i've had people hear it as far away as the beach, which is over 300m away.
Posted: Sun Dec 30, 2007 9:45 pm
by elitesniper
wow thats louder then my burst disk
