Making a Protective Case for Your Hydrometer

The hydrometer is an important instrument in a few trades.

This is the glass tube you see the Maple Syrup makers use to test the syrup for sugar content when they are making syrup. I have note syrup with a hydrometer so I am not sure how this technique works. When the color is right for me I take it off the fire. You can't sell the stuff without a license anymore so it is all personal taste. Dark, dark caramel for me please.

By the way I got the idea from one of these hardcore syrup makers and didn't see it here so I am passing it on.

The hydrometer is used by by spirit makers to judge the amount of sugar content in a mash, and to used the beginning and end readings to estimate the alcohol content. The reading is taken at the start of the ferment ( say 15%). The reading is taken at the end of the ferment, or during (say 5%) these readings are subtracted to get the estimated alcohol content of the mash (fermenting mixture) 15 - 5 = 10% alcohol - Approximately.

Hydrometers are used by seafarers to test the density of the water they are floating in. This is very important to them, as when a ship travels from fresh sea water (more dense - more buoyant) to fresh water (less dense - less buoyant) the ship will sink further into the water, changing the draft of the vessel ( the vertical distance of the ship's hull under water). The name of the game is to carry the maximum amount of cargo without going over the maximum allowable draft. So if you test the water and it is a little fresh, and you know the density of the water will be greater at the place where you have a set draft ( say a lock). You know you can load a little deep, because the ship will rise up. There are many calculations unique to every ship that must be used to figure it out. Once you know what you are doing it is easy, like everything. Mistakes can cost you your job though as penalties for going over are high (sometimes in the 6 digits) causing big losses in profit for the company. You don't want to screw up too many times.

Anyway, this is an Instructable on how to make a very sturdy case to protect this fine instrument.

A hey you can do it with old recycled copper pipe - Another contest entry. Whooo Whooo

Step 1: Collect the Parts

What you will need.

11" piece of 3/4" copper pipe.
Two 3/4" end caps.
Half a 1 1/2" thick sponge. ( or similar)
Little solder
Small torch.

Crawl under the house and locate the pipes that run the that bathroom you tore out last year. Make sure you find the right pipes and cut an 11" piece length of pipe out of a section. It might be better to get a bigger piece and fine cut it in the shop. You will have more pipe to play with later for other projects.

The end caps I picked up at the local store.

I elected to buy new sponge also as the old stuff I had was well used and I didn't want to take the chance of contamination of any food stuffs.

Others I had.

Step 2: Putting Together the Pipe.

First take the pipe and end caps to the sink. Use the scouring pad to shine the pieces up inside and out. This may take a bit of work if the build up is great on the inside of the used pipe but it should not be. If it is, you may want to look into your water supply, as something is very wrong.

Test fit the pieces. The end caps should go on easily, but a tight fit is good. choose the tightest cap for the tightest end and set it aside.

Place the loosest cap on the loosest end and set it up with the torch as I have in the photos. I do not have a vise here, so I used the slightly sticky side of a roll of Duck tape to keep the pipe from rolling away on me.

Heat the CAP of the pipe. The solder will run to the hottest area. If you heat the seam the solder will stay at the seam. You desire the solder to run under the cap for the best hold. Leak proof is not important here, but this is the same technique to get the best leak-proof connection.

As I said leak-proof is not important here, so I only soldered a small portion.

When you can handle the pipe run it to the sink and run cold water over it to cool the pipe.

Use the scouring pad to clean it up, file it smooth to your satisfaction, and scour again.

Finished with that end.

Place the other end in front of your torch this time with no cap in place. What you are going to do is place a very small, thin bead of solder on the edge of this end to make the cap even tighter a fit then before.

Near the end heat the pipe hot. Apply some solder and what for the solder to spread out. This is not thin enough. Tap the pipe on the counter to spread the solder even thinner. Take the pipe to the sink and cool it. Test the cap on the pipe - chances are you will have to file the spot of solder even thinner. When done take to the sink again and scour clean.

Finished with that part.

Step 3: The Safety Cushion.

Cutting the sponge for the inside of the tube which used to be called a pipe.

Cut some sections off your sponge. Square or whatever. Then pinch remove the corners of the sponge so you end with a rough cylinder of sponge 1 1/2" tall and roughly 3/4" in diameter. the thing you want here is an insert for the tube that is not too tight. It wil compress when the hydrometer is inserted into the tube but when you remove the hydrometer you want the sponge to expand. If the sponge is too tight in the tube it will hang up on the side, and not expand due to friction. So, not too tight - just right is best.

Place two of these in the tube then place the hyrometer in the tube. You will have to experiment with this as sponges come in diderent forms. I ended up using three in the bottom and a tight fitting piece at the top. A tight piece at the top is OK as you can pull it out with your fingers and it will re-expand. The ones on the bottom - if you wish to remove them you will require a rod, with a bent hook on the end, to dig them out.

Looks good. Feels good. Must be Good.

Your should hear no noise when you shake the sealed tube. I would not throw it at the wall, but it should survive a drop on a steel deck, or a summer in the tool box of your truck.

Take care.

P.S. If I win the Zing I'll etch a photo of a hyrometer on the outside of the tube and a seal on the caps.