Category Archives: Tool Cleaning

Acceptable Tech Level

Today was a great day. I got up early to head out to the Saratoga Fire Station to take my Amateure radio Extra class exam. I am happy to report that I can now use the temporary callsign KK6GXG/AE, for those not in Ham radio, that means I passed. Needless to say I was stoked to reach this, the highest level of amateure radio licence. Lots of plans are piling up for radio projects on my desk/bench so there will be reports on those to come, this post however, is not about radio.

Water Grinder & MotorAfter the test the wife and I went to the De Anza College Flea Market. I found something I have been looking for for a long time, a sharpening stone (wet stone) grinding wheel. What I had been looking for was a manual, or hand-crank type that can be easily adapted to a foot-treadle or bow-spring drive. The one that I found was attached to a motor via a reduction pulley-and-belt system, though in honesty I didn’t realize how low the reduction was at first.

My initial reaction was to remove the motor and adapt the wet-grinder to a manual power source right off the bat. After looking up the patent info on the motor and seeing what it was originally intended for a story began to emerge on the origins of this particular assemblage.

The board everything is mounted on does not appear to be that old. The dimensions are modern, making the mounting 2 x 12, at oldest, from the 60s. The mounting hardware is a mix of 50s and contemporary. The casting and markings of the wet-grinder suggest that it was cast in the 1920s to 1930s. The patent date of the motor is from 1926. This particular 1/4 HP motor was designed for washing machines of the 20s and 30s. A newer motor was produced after the war and the model and frame numbers on the data plate suggest that this motor was produced in the 30s.

20140607_191708The story I have come up with is that these parts were cobbled together in their current configuration some time the 70s from parts and used regularly for a significant time as such and eventually shelved in a shed where they had been sitting for at least a decade.
I ended up doing a mechanical teardown tonight. I was planning on getting started with the electrical teardown and testing tomorrow. For the most part this was an inspection teardown. I didn’t do any “repair” although I did fill the water reservoir with a rust remover to begin prepping it, and to see if it still holds fluid. I didn’t detect any leaks and we will see if it develops any overnight.

20140607_191718The plan is to deal with the mechanical and electrical as completely separate restorations. The mechanical is the primary because I can still set it up as a manual wet-grinder and begin using it.
I have a number of sharpening projects that need to get done soon and this would be a big help in speeding things up. Once rust is abated I think a couple of coats of iron oxide primer followed up with a couple of coats of oil-based paint should provide a sufficient level of protection.

Once the mechanicals are all taken care of I will spend some time on the electrical motor. At this time I have no information on the motor other than what’s on the data plate.

20140607_114338So why the title “Acceptable Tech Level”? one of the reasons I wanted a manual grinder was to further the off-grid hand tool goals I have been trying to work with. With this particular configuration I can easily swing it over to manual and with the motor most likely being from the 20s-30s it falls into my era of interest in aircraft and is also from around the same time as several of my inherited and acquired hand tools meaning it fits right in with many of my vintage tools. The important part is that it CAN be used with manual power.

Until next time…

☮ ♥ ✈ & 73,
~FlyBoyJon / KK6GXG

Air Tool Dos & Don’ts

Welcome back to Dad’s Workshop! I wanted to cover a couple of related subjects, They are all about pneumatics; air tools and compressors to be specific.

In some people’s minds these amazing tools are mystical magical apparatuses that somehow convert moving air into another form of energy. When it all comes down to it, most air tools function in one of two ways: they are ether a windmill or an over-pressure valve. They’re that simple.

How Air Tools Work

Take an air drill for example: a small cylinder that has maybe five or six slits along the long axis, and the same number of fins set into the slits. That assembly is then slid into another cylinder with very close tolerances between the edge of the fins and the outside cylinder. Air is introduced into the cylinder perpendicular to the fins causing them to rotate the inner cylinder in the direction of airflow. The more air, the faster the inner cylinder spins.

Those mechanically-minded types are already thinking about all kinds of stuff much more advanced than I am going to discuss here, like forward-reverse switching, variable speed valves and so forth. There are more parts in making something like an air dill work, of course; valves, gears, gaskets, seals, o-rings, and the like, but the basics are those concentric cylinders and the fins at the heart of it all.


Because of the close tolerances any debris or binding will cause catastrophic failure. Most of the time the fins are made from fiberglass or something similar, carbon fiber is common too. Even though the materials are strong, the parts are small and thin, they are also spinning very fast. The fins are lightweight and the cylinder is comparatively heavy so the rotation builds up a lot of inertia. If a small sand-sized particle gets into the chamber, pieces of fin can and most likely will impact them and bits will break off, adding more loose material and causing a cascading failure. This can also happen with binding. If a fin hangs on the wall of the chamber for some reason, like gummy oil or a moisture build up, it drags the fin weakening it until it breaks, leading us back into another type of cascading failure.

This might make air tools sound a little too touchy for the average tool user, and they can be. The biggest part of taking care of air tools is in understanding them; how they work and what causes problems. Take the time to read all the paperwork and look closely at the diagrams and parts list. We have already covered several of the potential problems. Air tools that are susceptible to particulate damage usually have a small screen filter to help, but you can do a lot by keeping particulates out of your air hose. Hook up a blower tip and just blow out the hose before attaching it to a tool; that will go a long way in preserving your air tools right there.

Air Pressure and Air Tools

Another tip for keeping your air tools in good shape is to pay attention to the manufacturers pressure specifications. If the specs give you a pressure range, say 30 psi to 70 psi, stay in that range. If you are dialing in your pressure for a nail gun, start on the low end. The pusher should drive the nail just below the surface for finish nails or flush to the surface for head nails. If you are using another kind of tool start in the mid range, say 45 or 50 psi in that 30-70 range. If you need more oomph, kick it up a little. If it can be dialed down, then dial it down a little. Never exceed the maximum pressure specified! This will only degrade the tools performance and will likely damage something the key here is RTFM.

Air Tool Oil

O-rings and seals in air tools are at very close tolerances. Too much air flow will blow them out causing metal-on-metal stresses that will damage the tool. Some people think that by applying a lot of oil to their air tools they are helping them work better, smoothing things out. In truth, they are damaging them. An over-oiled tool is more likely to blow out seals and rings. An over oiled tool builds up more pressure than it should and may unseat seals and rings causing them to dislodge. Either way it is not good for the tool. Here is another RTFM moment. If the manufacturer says two drops of oil in the air inlet after 4 hours of work, they mean TWO drops after FOUR HOURS. Not a squirt, or “I’ll get it later.” This is very important.

The problem arises for most people when they don’t understand what that means. In a consumer-grade tool, follow the directions and don’t use the tool in a construction environment. In a construction-grade tool used in a consumer environment you need to pay a little more attention. A roofing nailer that says “four drops of oil at the beginning of the day” means a full day of continuous use like a roofer would. If you are roofing a dog-house, dial it back a bit. If in doubt, many manufacturers have customer support lines, give them a call and tell the service department you have a question about oiling, make sure to tell them how much you are actually using the tool. They should be able to help.

Most air tools that need oil come with a small squeeze-bottle of air tool oil. Read the manual for specifics about what oils are safe in that particular tool. If not specified, a generic air tool oil can be used. Only use oil specifically designated for use in air tools. A little side note: That tiny bottle of oil, if used properly, it will usually last a lot longer than you might think. Again RTFM.


This brings me to automatic oilers. For the average consumer tool user they are a waste of money. They are designed for shop use at a work station, one tool, same air pressure, all day. If you change tools or change the pressure you need to re-calibrate the oiler. Another consideration is that not all tools use the same oil. Most do, but the few that don’t, really don’t. It really is more of a pain than just putting in a drop of oil before stowing the tool. Another consideration often forgotten is that oilers put oil into your air line as well, and some tools don’t need, or can’t have, oil run through them. Clean dry air is all you want in your air lines and in your compressor tank. Oily air attracts particulates that build up. Eventually a clump of oily crud may find its way into your air tool, and for some reason it’s always the new expensive tool you just got that gets hit with the crud-clump. Save yourself the headache and the money.

Tank Rot

Which brings me to Tank Rot. Compressors are susceptible to tank rot in part because they are rarely kept in environmentally-controlled places. This means that the temperature will range widely, especially when the compressor has been in use. The wide temperature fluctuations tend to cause condensation in the tank which leads to rust, commonly referred to as tank rot. A good water separator on you main tank outlet will spare your lines, hoses, and tools, but it can’t help the tank itself. You shouldn’t put oil in the tank to prevent rust because it will end up in the air, then the lines, hoses and tools. Oil can get past some of the water separators and will clog others, so you are better off not doing that.

I have seen some success from people who removed everything from the tank and poured some oil-based paint inside and rolled the tank around slowly for a couple of hours making sure that the entire tank interior was covered then draining off the excess. This is a difficult process though. It requires an acid cleaning in the tank, thorough rinsing and drying at least cycle. I have seen it need two or three cycles of prep work before the tank was ready for paint. This all needs to be done on a new tank, it really doesn’t work well on old tanks. All in all I don’t think it is worth the trouble. The bad part is that you have introduced potential particulates and cracks in the paint become moisture reservoirs and end up accelerating tank rot not stopping it.

The best way to combat tank rot is to discharge all of the lines and the tank at the end of the day through the bottom valve and leave the valve open until you are ready to use the compressor again. If you think it will be a long time before it will be used, a rubber band or string and a piece of cotton cloth tied over the opening will allow air and moisture through but not critters. When the air in the tank is able to contract and expand with the outside air it is less likely to have condensation.

Wrap Up

So the basics are:

  • Look at the diagram or breakdown that came with the tool and see how it works and what the failing points are likely to be so you can prevent them.
  • Only clean dry air should go from the tank to the tool.
  • Use only the specified pressure range.
  • Use only air tool oil and use it the specified quantities.
  • Discharge the entire air system when not in use

See you next time,


Clean Tools are Happy Tools

I have several topics I want to cover in September, but I did want to get a quick post in about cleaning tools before the end of the month.

I have been down in the shop several times over the last week, but that time has been devoted to getting stuff back in order after remodeling my shop space. As I am going through all of the stuff (I say stuff but what I really mean in many cases is crap) that was filling my workshop, I am finding that I have been holding on to things I know I don’t need. One such category is Telco materials. Yes, I also worked for Pacific Bell for a while as a repair tech. I have accumulated lots of miscellaneous connectors and even some communications tools that I will most likely never use again, not that I’ll get rid of the tools.

While reminiscing over this accumulation I discovered something else… I have been neglecting some of my tools! I felt so guilty about it that I had to stop, clean them and make sure they were is good working order. Many of the communications and networking tools like toners, amplifiers, and meters just needed fresh batteries, but some tools like screw clamps needed a full cleaning; digging out debris from the threads and a good scrubbing with some Scotch Brite. A few things needed a full tear-down so I could clean them properly.

One tool that needed the full treatment was an old Black & Decker 7″ circular saw I inherited from my great uncle when he passed away in 1989. I figure he bought it around 1979 or thereabouts, so this saw has been in service for 30+ years. This tool, like any other, deserves my respect and attention. It was an in expensive saw back in the day but that doesn’t change the fact that it still does its job without complaint.

My tear-down consisted of removing the blade of course, the guard and and clamping rings. This is when I cringed; there was a thick build-up of debris and oil behind the guard. I am embarrass to say it, but I don’t think I have removed that blade in 5 years, maybe more. I cleaned off the mess and wiped the area clean. The disassembly continued by separating the housing and inspecting the inside of the body and handle. Here is where I was pleasantly surprised. It was mostly clean in here, a little compressed air and a wipe-down and all was well. The commutator and brushes looked good, as did the wiring and switch.

The gear section was opened to check the gear case grease which was also in good condition. I was about to bolt everything back together when I noticed a nick in the power cord. Not really bad, no copper showing, but I could see the white shielding of the neutral wire in the two conductor cable. I don’t have any extra power cord or plug ends on hand, and the damage wasn’t at the point that it would be a structural hazard so I decided to heat shrink that section of the cord. I disconnected it from the switch, slipped on some heat shrink and got it nice and snug, then reconnected everything.

After getting the saw back together and buttoned up I gave it a short test drive on some 1/4″ ply. She sounded happy to have had some time at Dad’s Tool Spa.

More shop and tool cleaning on my schedule for September.

Till next time,