Ideal Piston Valve Lubricants

Potatoes last one shot, so build reusable! Discuss ammo designs and ideas. Tough to find cannon part or questions? Ask here!
kamranalig314
Recruit
Recruit
Posts: 1
Joined: Mon Nov 29, 2010 9:17 pm

Mon Nov 29, 2010 9:36 pm

Hey everybody
New to the forum, just wanted to say hi to ya'll. I've been a spudder a while now, but I have been taking a long break up until recently, and that is because I have finally decided to return to finish my most epic cannon yet. I did my best to search around the whole entire interwebs for an answer, and I still have yet to see any discussions on what types of lubricants are ideal for piston valves.

Currently I have designed and built a 4" wide barrel-sealing piston valve for my final air cannon, with the rest of the body complete and only the support-frame to finalize construction. It is magnificent, highly dangerous, and yet it will mean nothing if I dont find a lubricant that suits such a seal for the behemoth of a piston. I need a lubricant for a simple rubber to PVC seal with a VERY low friction coefficient but still capable of withstanding over 160 psi.

spudfiles will you help?
I hope this is enough information, please ask any further questions if it helps!

my sincere gratitude,
Kamran
Selador
Specialist 2
Specialist 2
Posts: 213
Joined: Wed Nov 03, 2010 9:44 pm

Mon Nov 29, 2010 9:45 pm

Plumber's silicone grease.

You'll find it in the plumbing section at Lowes.
If you can't fix it, you don't own it.
User avatar
saefroch
Staff Sergeant 2
Staff Sergeant 2
Posts: 1679
Joined: Mon Jun 08, 2009 8:47 am
Location: U.S.A.- See Map

Mon Nov 29, 2010 9:47 pm

If you can't find silicone grease (which is highly recommended) engine oil will work just fine. That's what I use, since I'm too lazy to go find silicone grease and there was a big container of it in my garage.
User avatar
mark.f
Sergeant Major 4
Sergeant Major 4
Eritrea
Posts: 3627
Joined: Sat May 06, 2006 11:18 am
Location: The Big Steezy
Has thanked: 52 times
Been thanked: 53 times
Contact:

Donating Members

Mon Nov 29, 2010 10:19 pm

I'm sure silicone grease would work fine (I haven't tried it). I usually use white lithium grease (the kind that comes in a squeeze tube that could sink a ship but only costs about two bucks) with my pistons and haven't had a problem with corrosion. Before that I used petroleum jelly with my early piston valves (duct tape > PVC interaction) but I found the valves needed lubrication more often and the duct tape wore away pretty quickly.

Just keep in mind that lubricant wears away fairly quickly on a piston valve. How accessible is your piston?
Selador
Specialist 2
Specialist 2
Posts: 213
Joined: Wed Nov 03, 2010 9:44 pm

Mon Nov 29, 2010 10:30 pm

Silicone grease has no petroleum distillates.

Withstands extreme heat without melting or burning.

And it will last a long time, without 'wearing away'...

:D
If you can't fix it, you don't own it.
User avatar
mark.f
Sergeant Major 4
Sergeant Major 4
Eritrea
Posts: 3627
Joined: Sat May 06, 2006 11:18 am
Location: The Big Steezy
Has thanked: 52 times
Been thanked: 53 times
Contact:

Donating Members

Mon Nov 29, 2010 10:37 pm

Well, by 'wear away', I don't so much mean 'wear away' as 'being blown out of the barrel port by 125 PSI of compressed air.' :roll:
Selador
Specialist 2
Specialist 2
Posts: 213
Joined: Wed Nov 03, 2010 9:44 pm

Mon Nov 29, 2010 10:43 pm

mark.f wrote:Well, by 'wear away', I don't so much mean 'wear away' as 'being blown out of the barrel port by 125 PSI of compressed air.' :roll:
I can guarantee that the silicone grease, (plumber's variety, at least), will withstand a lot more of -that-, than the motor oil, lithium, or vaseline, will, as well.

:D
If you can't fix it, you don't own it.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Mon Nov 29, 2010 11:31 pm

Be careful that whatever you use, it doesn't get absorbed by the rubber seal and deform it. A safe bet would be KY Jelly or any similar water-based lubricant.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Selador
Specialist 2
Specialist 2
Posts: 213
Joined: Wed Nov 03, 2010 9:44 pm

Mon Nov 29, 2010 11:37 pm

jackssmirkingrevenge wrote:Be careful that whatever you use, it doesn't get absorbed by the rubber seal and deform it. A safe bet would be KY Jelly or any similar water-based lubricant.
Plumber's silicone will not do that, either.

All the above are pretty much reasons why they MAKE plumber's silicone, in the first place.

Trust me. Once you have used plumber's silicone grease, you'll never use anything else.
If you can't fix it, you don't own it.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Mon Nov 29, 2010 11:46 pm

Oxbreath wrote:Once you have used plumber's silicone grease, you'll never use anything else.
I bet the wife finds that comforting :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
Selador
Specialist 2
Specialist 2
Posts: 213
Joined: Wed Nov 03, 2010 9:44 pm

Mon Nov 29, 2010 11:55 pm

jackssmirkingrevenge wrote:
Oxbreath wrote:Once you have used plumber's silicone grease, you'll never use anything else.
I bet the wife finds that comforting :D
ROFLOL

There ARE some things that a water-based lubricant is better for.

But I thought we were talking about librication for a piston in an airgun...
If you can't fix it, you don't own it.
User avatar
Gippeto
First Sergeant 3
First Sergeant 3
Venezuela
Posts: 2503
Joined: Sat Jan 19, 2008 10:14 am
Location: Soon to be socialist shit hole.
Has thanked: 2 times
Been thanked: 17 times

Donating Members

Tue Nov 30, 2010 12:35 am

Silicone grease is good stuff. Started out using lithium based whited grease..didn't last as long as I liked.

Silicone grease can be found in many places. Dielectric grease in the automotive isle, some "brake" parts grease is silicone based, divers grease, and yes...even plumbers grease. :wink:

Currently using Dow Molykote 55 o-ring lube...slippery as goose shite.
"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Technician1002
Captain
Captain
Posts: 5189
Joined: Sat Apr 04, 2009 11:10 am

Tue Nov 30, 2010 3:24 am

I found plumber grease is good for sealing minor leakage, but due to the viscosity, it moves like molassis. I have settled on White lithium grease. It does not bother the rubber o rings, is slippery, and doesn't attract too much grit, so cleaning and re-greasing is less often than with plumbers grease which tends to stick to everything. The QDV's are easier to pull under pressure with the Lithium grease.
Selador
Specialist 2
Specialist 2
Posts: 213
Joined: Wed Nov 03, 2010 9:44 pm

Tue Nov 30, 2010 3:35 am

Technician1002 wrote:I found plumber grease is good for sealing minor leakage, but due to the viscosity, it moves like molassis. I have settled on White lithium grease. It does not bother the rubber o rings, is slippery, and doesn't attract too much grit, so cleaning and re-greasing is less often than with plumbers grease which tends to stick to everything. The QDV's are easier to pull under pressure with the Lithium grease.
I actually like the plumbers grease for the same reason.

Put it on, wipe to a really thin film, and it sticks and stays forever.

It will withstand being blown out, for the same reason.

If you prefer a thinner viscosity, then use the silicone dielectric grease from the auto parts store. It's more like the viscosity of lithium grease.
If you can't fix it, you don't own it.
User avatar
saefroch
Staff Sergeant 2
Staff Sergeant 2
Posts: 1679
Joined: Mon Jun 08, 2009 8:47 am
Location: U.S.A.- See Map

Tue Nov 30, 2010 7:48 am

Oxbreath wrote:I can guarantee that the silicone grease, (plumber's variety, at least), will withstand a lot more of -that-, than the motor oil, lithium, or vaseline, will, as well.
Not too sure about that statement, I still haven't yet re-greased my piston valve after 5 shots at 1,000psi using motor oil, and that's a lot of "wear" from airflow. I also haven't had a problem with it burning, naturally... or being absorbed into o-rings.
Post Reply