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Piston valve help

Posted: Mon Apr 16, 2007 7:51 pm
by super spuder
i went into the hardware store today and bought a 3 inch T, a 3 inch addapter and a three inch cap. that is going to be the shell of my piston valve. but then i went to get some 2 1/2 inch pipe to go inside as the piston. but the problem is, no one in my area carys 2 1/2 inch pipe abs or pvc. so i gues what i am asking is what can i make a piston out of. i was thinking of making it out of wood with a couple o rings on it, cause i have acces to quite a few wood tools. but i was wondering if anyone else had any better ideas.

Posted: Mon Apr 16, 2007 7:52 pm
by pyromaniac
You can make a hot glue piston.

Posted: Mon Apr 16, 2007 7:56 pm
by super spuder
can you make a hot glue piston 5 inches long?

Posted: Mon Apr 16, 2007 8:05 pm
by Hotwired
If you've got enough glue :wink:

Posted: Mon Apr 16, 2007 8:07 pm
by Mr.Russ
only thing is, it would be heavy.

You could always scale it up or down, say to a 4" T 3 1/2" pipe or 2" T with 1 1/2" pipe

Posted: Mon Apr 16, 2007 8:11 pm
by homedepotpro
you can do it, make it hollow with some sort of pvc capsule. id make sure you have good lube for it because hot glue pistons are tight fitting

Posted: Mon Apr 16, 2007 8:13 pm
by hi
yes you can make it out of hot glue, but it will take forever to get it out of the mold, wood would work A LOT better. i just finished a valve with a 1.5'' porting in a 2'' tee and used wood as a piston, it works very very well and i didnt use O rings. Why does everybody think that a piston needs O rings, they work just as well without them if they fit well.

also a thing to consider is that ( just assume) that it doesn't seal, or that it doesn't actuate, how will you get the piston out? what I'm trying to say is, instead of a end cap, use a threaded plug that way you can get it out if you have to.

Ps- i think i used ash as the wood, we just cut down an ash tree, so i have infinite wood, but any hard wood will work.

Posted: Mon Apr 16, 2007 8:19 pm
by super spuder
so wood will seal with out an O ring. that is sweet. and the cap is threaded

Posted: Mon Apr 16, 2007 8:21 pm
by hi
yes it will seal, but it needs to be a good fit, it it wiggles at all you need some tape around it.

Posted: Mon Apr 16, 2007 8:24 pm
by goathunter
hi, If that ash is still wet your piston is going to warp and crack in the next month or so.

Super Spuder, I've made a piston using plywood inside a PVC pipe.Works good. Although that doesn't really help since you don't have any 2 1/2" pipe. Just a thought. Go with the wood and drill out the inside to cut down on weight.Varnish the outside to make it slick and then lube it and go.

Posted: Mon Apr 16, 2007 8:26 pm
by super spuder
ok. thanks. i will see what i can do in the school wood shop tomoro. goathunter when you say drill out the inside do the men make an indent in each end of the piston?

Posted: Mon Apr 16, 2007 8:40 pm
by goathunter
No just the back, but leave a sufficient buffer so your piston won't break.Think of a cup.All you want to do is reduce the weight.

Posted: Mon Apr 16, 2007 8:48 pm
by super spuder
ok. thanks. i will let you know it goes tomoro after school

Posted: Mon Apr 16, 2007 8:57 pm
by hi
goathunter wrote:hi, If that ash is still wet your piston is going to warp and crack in the next month or so.
i never thought of that :oops: i guess we will have to wait and see, the tree was dead when we cut it, but oh well.

Posted: Wed Apr 18, 2007 11:55 am
by meatballs
when making a piston out of wood you might want to use some sort of sealant, like polyurethane, since the wood is naturally porous. that would make it seal better and protect from water damaging the wood. ad o-rings and you're all set.