Lubricant choices

Potatoes last one shot, so build reusable! Discuss ammo designs and ideas. Tough to find cannon part or questions? Ask here!
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Hotwired
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Sat Aug 01, 2009 5:29 pm

jimmy101 wrote:You could probably just use SAE30W motor oil. Yes it'll burn to some extent but even in a full-auto 15x hybrid it doesn't burn that much.
Weelll, a full auto 15x hybrid doesn't seal its pistons with o-rings, piston rings work well enough mind you.

I'd check the o-rings after a few shots whatever you use to make sure they're not getting too charred.
Mishkan
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Sun Aug 02, 2009 1:50 am

For a lot of my viton on metal contact I use 90 WT Silicon Oil (you might see as shock oil) you can get it for dead cheap on Ebay. Its often used for RC cars etc. Honestly haven't tried it in any uber high heat situations though.
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jimmy101
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Mon Aug 03, 2009 1:18 pm

Hotwired wrote:
jimmy101 wrote:You could probably just use SAE30W motor oil. Yes it'll burn to some extent but even in a full-auto 15x hybrid it doesn't burn that much.
Weelll, a full auto 15x hybrid doesn't seal its pistons with o-rings, piston rings work well enough mind you.

I'd check the o-rings after a few shots whatever you use to make sure they're not getting too charred.
True, but a thin coat of oil on the O-ring will go a long way towards keeping them from charring. 30W SAE automotive oil isn't going to burn to any significant degree even in a 15X hybrid. Besides, in the "full auto 15X hybrid" the "gun" is firing thousands of times per second, and has a useable life time measured in the hundreds of millions of cycles, without significant oil consumption. Transfer that to a hybrid that'll probably get fired less than 100 times in a couple years ... the oil will last the life of the gun, as should the O-rings. The thing that'll kill the O-rings is the roughness of the cylinder.

If the O-ring doesn't atually seal against the barrel, and ammo, then blowby probably will lead to premature O-ring failure.
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Technician1002
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Mon Aug 03, 2009 2:17 pm

jimmy101 wrote:
Hotwired wrote:
jimmy101 wrote:You could probably just use SAE30W motor oil. Yes it'll burn to some extent but even in a full-auto 15x hybrid it doesn't burn that much.
Weelll, a full auto 15x hybrid doesn't seal its pistons with o-rings, piston rings work well enough mind you.

I'd check the o-rings after a few shots whatever you use to make sure they're not getting too charred.
True, but a thin coat of oil on the O-ring will go a long way towards keeping them from charring. 30W SAE automotive oil isn't going to burn to any significant degree even in a 15X hybrid. Besides, in the "full auto 15X hybrid" the "gun" is firing thousands of times per second, and has a useable life time measured in the hundreds of millions of cycles, without significant oil consumption. Transfer that to a hybrid that'll probably get fired less than 100 times in a couple years ... the oil will last the life of the gun, as should the O-rings. The thing that'll kill the O-rings is the roughness of the cylinder.

If the O-ring doesn't atually seal against the barrel, and ammo, then blowby probably will lead to premature O-ring failure.
In a hybrid one of the things that prevents burnt oil is the oxygen is consumed in the combustion that caused the pressure spike. There is combustion and compression heating, but by that time very little oxygen remains.
spencetron
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Sat Sep 26, 2009 6:23 pm

For plastics: white lithium grease
For rubbers: light silicone oil
For metals: Militec-1 (synthetic weapons lube, love the stuff)
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