Search the Community

During the past few years, I have tried several methods of fossil preparation, including manual prepping with needles and pin vises as well as some chemical techniques. Earlier this year, I decided to try pneumatic scribes and I purchased two of the Hardy Winkler models. Before deciding on these two scribes, I was informed by the helpful comments of others on the Forum. I am now submitting my comments in the hope of adding to those reviews. Since scribes must be selected with specific purposes in mind, I will state that I am a hobbyist (not a professional) and collect relatively small fossils (ranging from couple of millimeters to a few centimeters in their longest dimensions). Also, most of the fossils I find are partially embedded in limestones, mudstones, shales, and phosphate nodules. I do nearly all of my preparation under a stereo microscope. Since my fossils are mostly small, I wanted scribes with a range of uses from very fine micro work up to moderate matrix removal. I also wanted scribes that impart minimal vibration to protect delicate fossils (as well as my own nerves and blood vessels). Finally, I wanted scribes that operate at relatively low air pressures and air volumes so I would not have to replace my 30-year-old compressor. Based on reviews in the Forum (and other sources), I decided to try the highly-adjustable HW-322 and HW-70. Skipping to the punch line, I am very happy with both scribes. They complement each other well enough to cover the entire range of my needs. For those who may be considering these scribes, the following comments will provide some pros and cons of the two models. HW-322. This scribe operates with a pointed chisel that floats in a removable head. The chisel is driven by a piston. The movement of the piston is affected by air pressure from an external regulator, a tuning adjustment in the body of the device, the actions of o-rings, and a spring. Here is an overview of how the tool’s action can be adjusted to fit the work: 1. The HW-322 typically comes with two different springs: A soft spring and a hard spring. Use the soft spring for intricate cleaning of delicate fossils. Switch to the hard spring for chiseling away somewhat larger amounts of matrix. 2. Two types of pointed 1.3 mm needles are available: Use the fine-tip needle for delicate work. Use the standard needle for less-fine uses. 3. You can vary the air pressure with the supplied regulator: For fine work with the soft spring, you can set the pressure anywhere in the range of about 0.5-1.4 bar (7-20 psi). For less-fine work with the hard spring, you can operate in the range of 0.9-1.8 bar (13-26 psi). At 1.0 bar of pressure, air consumption with the soft spring is about 17 liters per minute (0.6 cfm). With the hard spring at 1.4 bar of pressure, air consumption is about 20 liters per minute (0.7 cfm). 4. The twist-to-tune feature in the body adjusts the depth of stroke through a range of movement from a nearly imperceptible vibration of the needle to full engagement of the needle with the piston. With all of these adjustments, the tool can be configured for a range of work so broad that it’s almost like two or more scribes in one. With the soft spring and fine needle, this tool handles all of my needs for ultra-fine work. With the hard spring and standard needle, I can use the tool will remove matrix to a depth of a few millimeters over areas of a few square centimeters. Negatives/cons. As with all tools, there are some limitations. My main complaint relates to the difficulty of finding consistent technical information and instructions for the user. Some retailers offer their own pdf summary sheets and videos with use and care tips; however, there are occasional discrepancies in the advice, and I have yet to find a definitive user’s manual from the actual manufacturer. As another negative, the scribe is designed to be used only in a forward bulldozing motion. Sweeping the scribe from side to side is discouraged because side movement may cause abnormal wear to the nylon head bushing. This means you may not be able to use the scribe to sweep away tool tool marks (I am currently removing my scribe marks manually, with a hobby-type razor tool). Finally, due to limited manufacturing, retailers are often out of stock, and waiting lists are sometimes long. Most retailers sell the HW-322 in a package with one tip, both springs, a 0-4 bar air regulator with fittings, and an air hose. Mine came with European fittings, so I had to order a global-style high-flow quick connect socket (which I could not get at the local hardware stores). HW-70. The HW-70 can be adjusted for a range of uses from borderline-fine work to moderate matrix removal. Adjustments in the action of the tool are affected by the many needle sizes/styles and by varying the air pressure from the regulator, as follows: 1. Three sizes of pointed heads/needles are available (1.3 mm, 2.0 mm, and 3.0 mm). In addition, some needles are also available with chisel or hybrid tips. With the 1.3 mm pointed tip, it is possible to work relatively close to many fossils. With the larger needles in different styles, you can remove rather significant amounts of matrix in short order. 2. The overall aggressiveness of the tool is controlled by adjusting the operating pressure at the regulator. The HW-70 works well at a range of pressures from about 0.3-2.0 bar (4-29 psi). Air consumption at 2 bar is about 20 liters per minute (0.7 cfm). At low pressures with the thinnest needle, the HW-70 seems to pick up where the HW-322 leaves off. Although I always do my finish work with the HW-322, I’m happy I have the HW-70 for quicker matrix removal in the harder and larger rocks. Negatives/cons. On the negative side, the same cons apply as already mentioned for the HW-322: A disappointing lack of documentation from the manufacturer, the inability to use the scribe in a side-to-side sweeping motion, and limited availability. Concluding comments. If you are looking for high-quality scribes with minimal air supply requirements, one or both of these models may be worth considering. Before buying any scribe, I recommend you search for other reviews on this Forum. When searching for reviews, keep in mind that some members include the dash in the model numbers and others do not. Therefore, you may find more reviews if you try separate searches for HW-322 and HW322. Also try separate searches for HW-70 and HW70. If you are new to preparation work, you’ll also want to study the many informative forum posts regarding fossil repair, consolidation, and general prepping techniques. It may be worth noting that I decided to try pneumatic scribes because I tend to damage fossils when I push too hard with manual pin vises and needles. I do not have this problem with pneumatic scribes because the scribes do all the work and remove matrix with very little pushing. In fact, the HW-322 will often remove the last remaining bits of matrix from delicate fossils when the tool is held perfectly still with the needle just barely touching the matrix. There are some items you’ll need that are not provided by the manufacturer, including an air compressor, an air filter, a hose from the compressor to the filter, and all of the fittings between the compressor and the quick-connect fitting that is provided with the regulator. If you are working on small fossils, you will also benefit greatly from a stereo microscope. All of this can be expensive (not bass-boat expensive, but it may still require some time to save up). As with any scribe, the standard warnings apply: wear eye protection (unless your eyes are pressed against a pair of microscope lenses), wear respiratory protection such as a NIOSH-approved N-95 or P-100 respirator as protection against crystalline silica ( https://www.cdc.gov/niosh/topics/silica/ ), and if you use a scribe frequently or in cold environments be sure to learn about hand-arm vibration syndrome ( https://www.cdc.gov/niosh/topics/ergonomics/default.html#vib ). Best wishes.