I’ve found these two types of safety glasses to be indispensable. The clear set I use all the time, whether it be for grinding or melting. The dark set I use primarily when using a flame that incorporates both propane and oxygen.

I have been experimenting with these simple hand-held torches to see if they can effectively replace the old-timer’s blowpipe. Preliminary tests indicate that the propane torch does a great job. I’ve tried the tiny propane torches and found them wanting.

This picture illustrates some of my experimental contraptions for blowpipe tests. There are 2 typical bent brass jeweler’s blowpipes, 1 copper tube connected to a glass pipette, a battery powered air pump connected to a glass pipette, a plastic tube attached to an glass pipette and bottles containing fuel for a flame source.

The pictured glass lamps have advantages and disadvantages. The one at far right with an adjustable wick and can be purchased for about $15.00, while the other requires the fingers to constantly be pulling up the wick, but is only about $7.00. I have been using denatured alcohol for the adjustable wick and kerosene in the other bottle. Currently, my opinion is that neither of these two lamps are suitable, because the flame does not get tall or thick enough and the wicks burn too fast, as well as the kerosene often produces too much soot and the alcohol is consumed too fast. Another reason I don’t like the alcohol is that when not in use the fumes can become an explosive hazard and I am forced to keep this lamp outside. The smallest lamp, with an unknown oil I got at Wal-Mart for $1.50. It works ok, but it too constantly requires the fingers to get burnt pulling-up the wick as it burns and does not produce a suitable flame. My plans are to get a lamp that has a much larger wick for a large broad flame that the air exiting the blowpipe can direct downward onto the rock fragment.

There are many ways to produce a flame, but most are not worth the effort. I’ve tried using the propane torch flame with and without the air nozzle, but this turned out to be an exercise in futility. The old books indicate using a Bunsen burner, but I have not yet purchased this tool.

The two brass blowpipes with bent ends are referred to as jewelers blowpipes, which I find to be too short and someday may extend them with additional copper tubing, or, more likely keep them as artifacts.

The battery operated air pump connected to a soft plastic tube and glass pipette works reasonably well, but am not at all happy with not being able to regulate the amount of air exiting the pipette.

The straight copper tube with an attached glass pipette works well when there is a suitable flame, but, although there’s flexibility it needs considerable improvement, as well as making this large diameter tubing comfortable in the mouth.

When I 1st began playing around with the blowpipe a few years ago I used just about any conceivable tool within grasp. Of course none worked worth a darn, primarily due to the size of the hole where the air exits. Fortunately, I stumbled upon using glass pipettes, because the nozzle end is tapered to a very small opening that allows for a strong steady blast of air to enter the flame and direct it to the rock chip that rests upon a plaster or charcoal tablet. In addition the flame does not bother the glass and the glass does not contribute any contaminates.

From what little I can piece together the old-timer’s employed several different types of blowpipes. Some were long and others short, with and without a bent end. However, it appears that the preferred blowpipe was close to 2 foot long and had a right angle extended air exit. Apparently, this right angle extension is to be able to see and direct the flame better, as well as allow for a way to capture the accumulating saliva that the breath produces. I finally got around to making something similar that preliminary efforts seem to verify that this design does indeed have merit.

The below image illustrates how I made a replica of the old timer’s blowpipe. Pictured is a glass tube cutter, a glass pipette and one pipette that have been cut, as well as a ¼” inside diameter copper tube and joints that make up the completed functional blowpipe. All the joints are silver soldered except where the glass pipette is inserted, which I merely put a little duct tape on to acquire an air tight connection. Plus, should I accidentally break a pipette I can quickly replace it with another. Also, by removing the pipette I can wash-out the copper tubing of any accumulated saliva whereas the old-timer’s used threaded joints. I have not, as yet made a place to put my lips against to make it easier to maintain distended cheeks while blowing through the tube. So far, even though the straight tube is a little tiring for the lip muscles it works good enough.

The following pictures show me using my home-made blowpipes. The stand is normally used for chemical glassware, but I found it to be practical, because each ring is adjustable up and down, side to side and supports the lamp and Plaster of Paris or the charcoal tablets that the crushed rock fragments rest upon.

Please keep in mind that by taking my own pictures there was inadequate time to click the auto time delayed shutter, rush back, sit down and try to show a flame before the shutter would activate. So, no attempt was made to actually demonstrate the flame being placed upon an actual sample. Nevertheless, these images should allow the reader to visualize the sequence of events and provide clues how to make and improve upon what is presented herein.

This image shows the air pump attached to one of the jeweler’s blowpipes and somewhat describes the flexibility of using an air pump. Once I have this system perfected I may like it because of the flexibility and not having to blow through the mouth.

Normally the flame source would be positioned to allow the sample to be very close to the directed flame. But, due to circumstances trying to blow and direct the flame was a timing challenge and the primary purpose was to demonstrate how the flame is manipulated. So far I find my long, straight homemade blowpipe to be the easiest to use, because there is good line of sight and is the most comfortable to use.

This image demonstrates that only the glass pipette can be used, but I find that I am bent over, too close to my work and not at all comfortable, plus I have difficulty in watching the tip of pipette the flame and the flame being directed upon the rock chip.

The above image was the best I could get considering that a gentle breeze kept blowing the flame. Normally, when practicing this art I am in an enclosed room, sitting on a stool with the stand on a bench and adjusted to comfortable heights, which allows the blowpipe to function without extraneous distracting circumstances.

I have found that the old books although indispensable do not and cannot teach every aspect of this art. Learning how to manipulate the air from the mouth to the target takes considerable patience and practice. Often the blowpipe books insinuate that the prospector, geologist or mineralogist is in the field conducting these blowpipe tests. Although this may be accurate some of the time I have trouble believing this is the normal situation because any wind will deflect the flame and create insurmountable troubles, unless of course a portable windshield is also carried along with the blowpipe kit that houses the various chemical reagents necessary to complete a semi-qualitative/quantitative analysis. Therefore, it seems logical to me that the prospector who will use this methodology ought to bring home the collected rocks and test them in an area free of drafts, but well ventilated to obtain the best results.

Assuming that the blowpipe books provided have been at least scanned proceed to the next section relating to Plaster of Paris and Charcoal tablets.