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What are the necessary considerations for custom-making a showerhead? Specifically, what is the relationship between the number of holes and the water flow and such?

I'm about to begin a remodel project of my main floor bathroom. I'm on somewhat of a tight budget and I've already hit that without buying any fixtures so I'm looking for crafty alternatives to buying brand new kit. As part of the re-plumbing, i'll end tearing out about 20 feet of somewhat clean 3/4" rigid copper pipe. I was thinking of bending some of this into a tight coil and drilling holes, 1/16" or smaller, to turn it into a vertical downpour type showerhead. I have all the tools necessary for this kind of project.

If I use 1/16" holes, I would need to drill 256 of them to end up with almost exactly the same overall area as the cross-section of the 1/2" plumbing that is feeding the showerhead. Do I want fewer holes to increase the pressure? Or more holes?

William S.
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  • Technically, the pressure will drop along the length of the pipe, and you'll need every hole to be a different size. This is why showerheads usually have all the ports in a flattish plane. If you want, you could spend a few $ and buy (or recycle) a bunch of 'T' fittings, and reduce this problem significantly by arranging them in a T or H shape. Apart from that, if you have hard water, 1/16th holes will clog with minerals. – gbronner Dec 29 '14 at 20:39

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What you're going for is flow and velocity to make for a good feeling shower. There is absolutely no reason to assume that the cross-sectional area of the nozzle has to match that of the pipe, in fact you don't really want it to, you want the velocity coming out of the nozzle to be higher than that in the pipe, that's why you have a nozzle. At any rate, the pressure drop across 256 (shouldn't it be 64?) 1/16" holes is a lot different than that across one 1/2" hole.

Nozzle making is tricky because there's a lot more that goes in to it than just the pressure and velocity. There's friction, edge effects, and contraction at the holes. There's even, as gbronner says, pressure drop through the line, but in a 3/4" manifold, the drop should be very small. I'd say your best bet is to experiment. Start with a small number of holes and work your way up until it feels right. Looking at my own shower head, it has 45 holes which all look a bit smaller than 1/16th inch. So maybe I'd start with 30? The fewer

Your biggest problem will be getting them to point where you want them to go. That can be a bear and I'm not sure I know of any way to solve that other than to drill and deburr the holes very carefully and, again, experiment. Maybe even just start with a few. You may be surprised at where the water wants to go.

Joel Keene
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