Life Cycle of Patch Lube

[roundball]

TONIGHTS QUESTION:

Does the raging inferno immediately liquify patch lube, and is liquid lube then forced forward up around a projectile by gas pressure?

 

[jtmattison]

Yes. No. Maybe. :youcrazy:

Huntin Dawg

 

[Stumpkiller]

Well, I tried to see and lost an eyebrow peeking in the vent hole. :nono: I think you asked that on purpose 'cause you knew we'd try lookin. :cursing:

I imagine it squeezes out the oils just before they're partially vaporized as the powder gives way to the explosion. The oils that have snuck into pores may stick around and help keep the fouling soft. Something remains as it sure makes a difference if you try to use too little. :hmm:

 

[rabbit03]

NO!

Not for me and ol' John L. anway. We use a tight enough patch and ball combo that ther is no way it could ever get past ours.

rabbit03

ps Pound the Bejesus out of em' :rotf:

 

[riarcher]

,,,, and the wife says I analyze too much? :shake:
But I don't think so unless your burning / blowing patches.

 

[mike alexandre]

Interesting question which at best we can only theorise without some very expensive lab tests ( could always ask NASA). If I look at part of the end result ie the patch, it tells me that the outer bit which was above the ball in the barrel when seated is still pretty much the same as when it went in. So it looks like no flame or temp got above the ball as the ball was moving fast enough to keep ahead of it. I've recently read an interesting write up on exactly where the fouling occurs in a barrel and in short some 90% of it occurs in the first 4 or 5 inches above the ball seated area, so it seems that most of what happened to the lube is there as well. The next bit is guess work !! and based on the fact that everything burns given the right conditions. As the powder ignites the lube must burn as well whatever it is. Its the chemical reaction that takes place between the lube and burn powder afterwards that presumably decides whether the fouling stays soft enough to be able to reseat the next ball in the same place and not produce the verticle stringing affect that shows unless a barrel wipe is done. The ring fouling that I've come across seems to be in the first 1" at most above the ball seat area.
So in my opinion the answer to your question is that that lube below the circle where the ball/patch is touching the barrel is that it has probably done its job within the first couple of inches of its travel. The lube in the patch above the circle of contact is the bit thats providing the lub as it travels up the barrel. Hope this is not prattle or "teaching Grandma". :hmm:

 

[pondoro]

First I will discuss a spit or water-lubed patch. The patch in back of the ball is exposed to the flame and is heated by convection and radiation. The layer of water nearest the flame will vaporize. So the very back surface of the patch is full of steam, the rest of the patch is still soaked in water. Steam is a poor conductor so the convection of heat into the patch almost stops at this thin layer of steam. Radiation from the flame will penetrate the layer of steam somewhat. As the patch travels down the bore the layer of patch that is filled with steam gets thicker and the layer of patch that is soaked with water gets thinner as the water vaporizes. One (desperate)way to escape a burning building is to wrap yourself in a wet blanket - but you'd best get out before it dries, and it will dry quickly! The thin area around the ball where the patch squeezes into the lands/groves is another story. If there is much leakage then the hot gas will race through the gap at a few hundred miles per hour. This will dry the patch out fast and cut it as well. Racing hot gas will cut things in short order, and is how the first space shuttle disaster started, with a small leak of hot gas around an o-ring. This is why the right combination of patch and ball will help eliminate cutting and burning.

So if the patch is tight enough only the back half "sees" much hot gas, and if there is enough water for the short trip down the barrel the patch never "runs dry".

Oils are different than water. They are a mixture of light and heavy hyrocarbons. They do not have a fixed boiling point like water. At certain temperatures the lighter hydrocarbons boil off, then at higher temperatures the next lightest ones boil of, etc. So with a pure oil lube the various hydrocarbons are boiling all along the barrel. Some of the heavy ones can form "coke" or "sludge", a thick crud, but at high enough temperatures even that burns off. It would be impossible to analyze exactly what a given oil would do in the short violent trip down the barrel, you would need tests and pictures and temperature measurements. (Trust me I have tried to predict temperatures in various industrial devices for many years, including boiling hydrocarbons in long tubes).

A mixture of oil and water? Even harder to predict!

Moose snot? Forget even wondering about it, just try it and see if it works for you!

I suspect the best mixtures loose oil/grease from the patch in a way that deposits them mostly on the barrel, and the worst mixtures loose the oil and grease in a manner that is conducive to them burning or solidifying in a hard crud.

Another idea that I had is that the high pressure behind the ball might actually force the liquids forward through the patch between the ball and rifling. Imagine a lubed ball stationary in the barrel. If you blew (hard) from behind the pressure might make the oils/water wick through the patch and out the othe side. So maybe the patch acts as a wick and allows the vaporized grease and water to replenish the thin layer between the ball and the barrel.

This is truly an area where an enlightened experimenter can be generations ahead of a scientific analyzer.

 

[Birddog6]

And Who Said this was not rocket science ??? :rotf: :thumbsup:

 

[mike alexandre]

Liked your story untill the last paragraph. This ball and patch is moving so fast and the area behind the ball so big in comparison to the ring area where the ball is seated that I can only believe what the patch is telling me - ie there is no leak past a well fitted ball/patch combo
PS. this could end up like Molder and Scully in the X files and before you ask - I'm Molder -or is it Scully

 

[rabbit03]

:rotf: too funny, yall crack me up. Hey by the way what is an X file :hmm: and will it cut forward and backward?

rabbit03