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My blowgun leaks...:(

Posted: Sat Nov 21, 2009 6:25 am
by Pookydarts
Does anyone know how to mod a blowgun to stop it leaking?
Yes, I searched and wiki'ed (...that took an extra hour mostly trapped in the humour section... :lol: ) but only found that others have had no probs up to 400psi!?!
My three all leak at +/-200psi
(Just had a lend of a 300psi shock pump! :P )
Have unscrewed the internals and checked for cleanliness.
Any tips from the old hands ?!? :?

Posted: Sat Nov 21, 2009 6:36 am
by john bunsenburner
How about telling us where it leaks? Also try teflon.

Posted: Sat Nov 21, 2009 6:41 am
by jrrdw
john bunsenburner wrote:How about telling us where it leaks? Also try teflon.
Ditto. If we don't know where the leak is we really can't help you. Other then, if it's coming from the threads use Teflon Tape like John mentioned. If it's leaking past the valve it's the seal or seat that the seal, seals against, or a crack in the valve body.

Posted: Sat Nov 21, 2009 6:44 am
by jackssmirkingrevenge
Can we see your internals? ;)

Posted: Sat Nov 21, 2009 6:49 am
by Pookydarts
Shit! Good point! It appears to be getting through to the normal exit port either between the steel shank and the rubber washer,

OR, between the rubber washer and the plastic sleeve with the transverse hole in it.

I spun up a brass replacement sleeve, fail.

chamfered the brass replacement sleeve and crushed an 'o' ring between the sleeve and the body. Also fail.

Then spun up a brass sleeve, with a 60 degree taper (giant schrader valve) and a steel valve with an '0' ring EPIC FAIL. :lol:

But the last fail was because of a combination of poor machining skils, rushing, and not having the correct size 'o' ring...

I suspect I can make it work with more time, but was hoping for "The easy way"

(Edit: Photo of internals added)

Posted: Sat Nov 21, 2009 6:50 am
by inonickname
I find them to usually be quite reliable. Unscrew the valve, check all the o-ring and seals. I find the only reason mine stop working is teflon tape becoming stuck in the valve seat.

Posted: Sat Nov 21, 2009 6:58 am
by Pookydarts
Teflon tape? Join to pipe-thread glue age! (Except for the wait time... :evil: )

Posted: Sat Nov 21, 2009 6:59 am
by POLAND_SPUD
I suspect it's mostly about the quality...
think about QEVs... have you ever heard of one leaking ?? I haven't... because they are so well made...

your blowguns were probably built using the cheapest materials possible...
the simplest solution is to buy one that works good

Posted: Sat Nov 21, 2009 7:03 am
by Pookydarts
...I think you might be onto something Poland Spud...

I do usually look for the cheapest blowguns I can find, and then wait 'til they're on special! :lol: :lol:

Posted: Sat Nov 21, 2009 8:01 am
by absinthe
i tend to get the slightly more expensive valves ($15), i have had to glue o-rings on though at 500+ psi, try doubling up the shaft o-ring, and give the whole thing a good grease up

Posted: Sat Nov 21, 2009 8:16 am
by inonickname
I posted a thread warning about them a while ago. I replaced the insides with the innards from another blowgun that had cracked threads.

Mine also leaked randomly, especially below 100-200 psi. I'd find another with metal internals.

Here's the thread.

I couldn't get a fix with the standard internals. The seals are basically plastic disks and useless. Making new internals or replacing them with ones from an older broken blowgun is the best bet.