Vacuum Pumping 101

I have noticed something interesting related to discoloration recently.

I follow a 2 days on/1 days off routine, with 2 PE sessions on my excersize days. I do manual stretches, followed by 30 minutes of pumping at 5 inches of Hg (6 sets of 5 minutes), followed by 200 wet jelqs.

I have noticed that my first session gives me the worst discoloration, and that each following session the spotting on my shaft grows less. By the time I do my fourth and final session, I see almost no spotting. Any explanations? Is this related to lymph build up? The discoloration at the end of the first session seems to be a little worse each time, which is bothering me, but as it all goes away before I start the next cycle I am not too worried yet.

I have also been measuring in the tube. If I look at the measurements at the very end of my session in the tube, I see about 0.5-1.0cm difference between the first session and the fourth.

I did an extended session the other day to see if more time would give me more stretch. I went from 30 to 45 minutes (9 sets of 5 minutes instead of 6). I measured in the tube at the 30 minute mark and the 45 minute mark, no difference.

You would think that…but I think that it may have something to do with a vertical column of air perpenticular to the surface.

It appears that there is some effect when the vertical column of air above a surface is too small, it diminishes the force exerted on that surface…to some minimum required height.

Thats my theory anyway. Heres what I know experientially;

When I water pump, with less vacuum force, my unit gets expanded further to the sides of the tube than with air pumping.

There is a certain amount of optical distortion, but I eliminate that my moving the tube and seeing if the skin is pinned to the tube walls or not.

When it is pushed up against the tube wall, it moves with the tube…if it isn’t…it doesn’t.

I can see when I pump with water I get much more skin and further up my unit getting pushed against the sides.

And its not even close with air. In my new 2.25 in tube, there is no way my penis touches the walls (thats over 7” girth!), with water it does.

I don’t think a 1/4 in column of air perpendicular to the sides of my unit can generate the same vacuum force as a 2 in column perpendicular to my glans. The force vectors involved with the air at the end of the tube cannot generate the same force perpendicular to the sides of the penis as a vertical column can.

Water, because of the non compressibility seems to need very little area about the surface to generate the same forces it does with larger areas.

You can argue with me…but I suggest to try it yourself and see, just don’t get any water in your pump…it can ruin it!

Discoloration and spotting are usually referring to two separate things.

Spotting usually refers to small red spots which are burst capillaries.

Discoloration usually means a brown pigment that begins to build up in the skin.

By discoloration what do you mean? What do you mean by spotting?

As far as measurements in the tube…good observations. I suggest if you see no further expansion, than it will merely add to recovery time and not growth…so find out your last productive set and stay with that for a while, and experiment occasionally to see if the additional set/sets will be productive.

I think that with time, some toughening can occur, which may require additional sets to get the expansion that came sooner in a non toughened state.

Always try to find the minimum force needed to get the job done…in the long run it will reduce the toughening process to a minimum.

I must agree with HalfRusski. Pressure is simply Force per unit area, be it water or air. No difference at all. Guaranteed.

If there’s an advantage with water, it would have to do with it’s larger heat capacity, which would make it easier to maintain a stable temparature. With air, it takes time to heat up through glass (if you use an IR lamp), then suddently, it gets to hot, you need to move away a few inches; now you’re uncomfortable; pain in the butt… If you put warm water in there (or better, sit in a bathtub at the right temperature, you solve the heat problem.

ll

It is a lot like saying what weighs more, a ton of feathers or a ton of rocks…obviously a ton is a ton.

But what if you don’t have room for the ton of feathers in your container…then you will not have a ton.

My point is that due to the volumn constraints in a tube, you may not have enough space above a surface to generate the perpendicular force with air that you can with water.

I have consistently noted greater girth expansion in water than in air…always! And like I said, that is accounting for visual distortion.

Sparky,

I think we are dancing around some other reason why water is working better than air for you. I haven’t had the time, and will not for a while, to try it myself. I beleive what you are seeing and feeling, but the explanation you give is not consistent by the basic physics of forces exerted by pressure in a fluid medium. So something else is going on.

In my post on spotting and discoloration, I was specifically referring to spotting. I have not noticed any long term discoloration yet, but the spotting seems to get worse each time I start a new cycle.

I am taking a two week break from pumping right now and enjoying the fruits of my labors, so I will give an update in late October.

Spotting can be the difference of 1 in hg…try reducing slightly and see at what point it disappears, while still getting your desired result.

As far as the physics go…if the fluid medium is compressible (air) is there a force/unit measurement that is needed to generate the full force measured by the gauge?

For example if you only have 1 mm of space between the shaft of the penis and the cylinder wall, can that generate the same perpendicular force vector that 2 inches at the end of the tube generates on the pressure gauge?

IF it does, what is the minimum distance needed with air to generate that force?

Do you think 0.1 mm will also do it? Or at that point is most of the force vectors being generated longitudinally?

Sparky,

Thanks for the advice on pressure, I will try a lower pressure for my next session and see how that goes.

Pressure in a fluid medium, whether it is positive pressure or negative pressure, creates force perpindicular to the surface it is acting on. In a static situation, where you are just sitting there holding a certain pressure, it does not matter whether it is compressible or incompressible. The difference is that if you do something to change the pressure, like stroke your pump, the pressure will change faster with an incompressible fluid. A gas will “give” more, and the pressure will change less. This is not to say that there are not other positive effects of water pumping, but I have no experience, I am just trying to understand the physics.

The unit of measure you are looking for is area, as in how many square inches of penis skin are subjected to the pressure. In the cylinder, you can calculate a force acting to stretch your penis in the length direction easily - it is just the cross sectional area of your dick at the base times the vaccuum pressure, and you have to convert inches of Hg to pounds per square inch (divide by 2.04, i.e. one psi equals 2.04 inches of Hg).

In the girth direction, there is no single force to be calculated. If this was a piece of steel pipe we were talking about (and mine gets hard but not THAT hard) you could calculate the stress in the steel by this formula:

stress = (Pressure * diameter)/(2 * WallThickness)

but it just doesn’t mean the same for a dick, unfortunately, so I think it is best just to say how much pressure you are using.

The clearance does not matter - one mm versus 2 inches - so long as there IS clearance. If your dick is touching the sides, all bets are off. When my dick touches the sides of my cylinder all the way up, I will throw the damn thing away (the cylinder, not my dick) and do a very happy dance.

No, you will get greedy like the rest of us and get a bigger cylinder! :)

A millimeter is plenty, regardless of the fluid (compressible, incompressible, high-density, low density…). Pressure equalizes very quickly in the tiniest spaces.

ll

Thanks.

Ok, confession time.

I took my cylinder in the tub the other day, filled it with water, then put the cylinder UNDER water also…to keep it hot.

Well, the water in the tub completely corrected the distortion of the water in the cylinder and guess what….it looked EXACTLY like it does with air in the cylinder!

So, I’m an idiot…you guys were totally correct!

Hey, I was confused about pressure and forces in college. It took a few years to ripen in my brain.

I still think water pumping in a hot bath could have a great advantage for delivering heat. I have a problem with the IR lamp. It’s difficult to arrange it so all sides get heated by the right amount. Suddenly it’s too hot. Then not hot enough…

Which brings me to a question: I have a Kaplan pump. Can I use that in the bathtub? Anything that can break?

If you have a Kaplan pump, pump to the desired vacuum, then mark the cylinder where you glans is at that level.

Then just use your hose and apply suction by mouth to that level. Its not exact, but with practice you can get pretty good.

When you have it where you want it…just disconnect the hose, you will keep most of your vacuum. Just go a little over to compensate for the loss when you disconnect…works great.

Water in the pump can ruin it…no need to risk it.

Interesting technique. I suspect it will be a month before I have guaranteed bathtub privacy, but I’ll try it eventually. Can’t be in a rush to get to 6 inches…