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Tool Corner

All about tools for the stone carver.

Tool Column: Quiet Your Dust July/Aug 2004

While attending the Camp Brotherhood symposium last year, I admired not only the work, but also noted the tools other sculptors were using. Like others, I became enthralled with Tom Small and his beautiful detail work in basalt using electric die grinders. One of his grinders was variable speed and did not have the screaming intensity that I associate with die grinders. Always willing to share information, Tom obligingly doffed his dust mask and answered my questions regarding the tool: variable speed die grinder by Metabo, 6.2 amps, 7000-27000 rpm, and electronic speed control. Tom was also using diamond, silicon carbide stones and tungsten carbide burrs to carve and smooth the facets in his basalt pieces.

 

Tool catalogs and the web disclosed two Metabo VS models: GE700, 7000 - 27000 rpm rated for 2” wheel at 6.2A, and the heavy duty GE900 Plus, 2500 – 6000 rpm rated for 3” wheel at 7.5A. I would suggest you carefully hide all credit cards and checkbooks before you plug one in for a test ride.  I chose the model GE900 Plus:  its lower rpm and smoothness delivered quiet power to the stone with very little dust thrown up. I have other grinders, single speed electric and air, but generally have to move away from everyone else due to the enormous amount of dust and noise. Goggles quickly cloud over even with antistatic, respirator elements clog, and the sun is in eclipse for several hours. Exhausted, half deaf, and numb, I had avoided die grinders whenever possible.

 

Now, however, grinding at slower rpm, neither tools nor stone seem to heat as quickly. I have noticed less fatigue from vibration, noise and dust. I frequently just grab this grinder and lose track of time and whatever else was going on. My smile has returned. This grinder comes with a torsional stabilizer handle that fits on the barrel, similar to those on beefy drills, keeping the grinder from twisting out of control. Using the stabilizer, I have chucked a 3” SA type sanding disc and reached deep to smooth and polish out cavities inaccessible with other sanders. The tool has a built in spindle lock on the ¼” collet, so only one wrench is needed to tighten or remove attachments. Needless to say, I am delighted with the grinder and seldom reach for another of the multitude of similar tools in my studio.

Bottom line, well, if those credit cards happen to surface after all, consider it $300 well spent!

 

Hold it!  Late breaking news flash: I was about to disclaim putting a manufacturer’s name in this column, because I considered Metabo a “single source” manufacturer for this particular tool. As luck would have it, I was at a wholesale house in Seattle (my first visit, honest) that is frequented by many members of this association, and between conversations with Kirk McLean, noticed a competing tool in the showcase. Yes, yes, a little web activity Googled out Makita’s brand new GD0810C, variable speed ¼” die grinder. Most of the stats are similar, but without a collet lock, the Makita requires two wrenches to add or remove attachments. Power is slightly less on the Makita at 6.6A vs. 7.5A on the Metabo. The Makita runs 1800 – 7000 rpm, compared to 2500 – 6000 rpm. Both use similar electronic control to maintain constant speed under varying load.  Metabo is a little bulkier and heavier at 2kg (4.4 lbs), compared to 3.7 lbs for the competition. As unreliable as the web is, current street price was about $40 less for the Makita. Choices, choices, what would we do without choices?

 

I’m sure that, by the time you read this, our esteemed Mr. Urban, the toolman of Brotherhood, will have had some enchanting dialogue to offer us this summer during the power tool segments of instruction.

Tool Column: In Hot Water March/Apr 2004

February in our Northwest is pretty predictable: sun, clouds, wind, rain, maybe all in the same day or hour. Temperature, too, is all over the place, generally hanging around 40F somewhere. I usually bundle up in raingear, working out under the trees rather than abusing my privileges in the garage.  Once the gloves, goggles, respirator and earmuffs are on, it is easy to get lost in the stone world and forget about the weather.  There does come a time in the process for sanding and finishing, usually with water to lubricate and clear away particulates.


Maybe I’m getting soft or lacking passion, but for whatever reason, the water seems colder these days.  It generally comes out the tap around 45-50F degrees. After about 15 minutes in that environment the imagination gives way to reality and fingers don’t function like they should.  Gloves are generally cumbersome and sweaty, but sometimes the disposable blue nitrile’s give a little protection from abrasion without much loss in sensitivity.  They don’t keep hands warm. I recall talking with Stu Jacobsen about this in the past; he installed a hot water tank in his studio to reduce pain and suffering.  Unfortunately, my outdoor studio doesn’t have a secure space for the tank, nor the electrical capacity for heating.  The garage is 75 ft away, so temperature losses would be too great to install the tank there.


I followed Dave Haslett’s example and brought a small piece down to the house and sanded in the kitchen sink.  Warm,? Yes. Inconvenient and destructive to sink and countertop finishes? Yes. Provoke outbursts of disapproval from householders not obsessed with the joy of stone sculpture? Yes.  You get the idea?  I quickly shut off my fantasy of plunging a rather large sculpture into the hot tub for a somewhat lengthy period of hand sanding.


Insight occurred during a stroll through the local homeowners warehouse store.  Still dreaming about the hot tub no doubt, I wandered down the aisle where the water heaters lived.  There sat this cute little white cylinder about a foot and a half tall, with a standard three-prong power cord coming out the side.  A two and a half gallon Point Of Service water heater is meant for remote bathrooms, where there is not a demand for large quantities of hot water, i.e., no tub or shower and there would be significant heat loss running the normal hot water system that distance.  The POS heater uses 115 vac, at about 12 amps.  This means it could be plugged into a standard 12 AWG extension cord without overloading the circuit.  Flash, flash, buy it. I did for $130.


I used ½ inch pipefittings with a female hose coupling to the inlet (cold water) side and a standard ½ inch hose bib faucet to the outlet (hot water). I also put ¾ inch pipe on the blow off valve to divert any discharge downward.  Hook up a garden hose to the inlet, plug it in, warm water comes out the hose bib.  A flag raised, questioning what occurs if someone plugs in the unit before it fills with water.  There is a thermostat that automatically controls the heater element, but the tank needs to be full of water for that to work properly.  I installed a low-pressure cutout switch ($30) on the inlet side and wired the power cord in series. These are standard controls for water pumps, meant to shut off a pump when a well runs dry, and prevent burning up pumps.  Now the heater will not come on until the tank fills and there is 20 lbs water pressure on the supply hose.


I set the thermostat as low as it would go, 90F.  Use a long hose on the supply side to bring the tank out to the work site.  Then use a short 10 ft hose on the hot water side to reduce heat loss (it is not a very efficient space heater).  Plug in the extension cord.  It takes me about fifteen minutes to gather and haul tools from the garage to the studio area.  The water is usually hot by this time. The 2 ½ gallon unit is adequate for one person hand sanding or using small power tools with center water feed or side jets.


The wind still howls and the rain still comes in sideways.  Turn on the water. Start sanding. Tropical 90F water flowing over the fingers, maybe some slack key playing through the headphones...ahh, stone sculptor reverie, where will it take me next?


Some simple calculations for the numbers enthusiasts:


Heater output is 1440watts x .0569 Btu/min watt = 82 Btu/min.

Energy needed to raise the temperature of 1 gallon of water  from 48 to 90F is 1gal x 8.34 lb/gal x (90F-48F) = 350 Btu/gal

Energy required for a tank full of water is 2.5 gal x 350 Btu/gal = 875 Btu

Time to heat tank of water is 875 Btu / 82 Btu/min = 11 min.

Maintainable flow through tank at 90F is 82 Btu/min / 350 Btu/gal = .23 gal/min (roughly 1 qt per min)


Using water at a rate greater than this would cause the water to slowly get cooler because the heater can’t add enough energy to the cold water.  I measured start and stop temperatures and timed the duration of the startup heat cycle.  It was within 10% of calculated, way close for studio work

Jacks or Better - Sept/Oct 2003

 

It was a bright sunny day; the air was warm but not uncomfortable. There seemed to be little chance for rain to dampen my enjoyment of my first Stone Carvers’ Symposium at Camp B. Feeling in good spirits, I had just finished setting up my work bench when suddenly I looked up and was shocked to see a rabble of 30 or 40 persons bearing down on me. This unruly mob appeared to be led by a wild-looking woman riding a strange motorized vehicle! As they drew nearer I became aware that many of them were carrying rocks and various other threatening objects. Then, as I cowered further back under my shade canopy, they charged in, pelting me and my work bench with the rocks and dust and such while ranting all manner of strange incantations! But, I get ahead of myself.


I had been carving in clay for some years when I heard of the Symposium and decided it was time to try a new medium. Unfortunately, I knew only two things about sculpting in rock: 1) Rock is hard, and 2) Rock is heavy.


I couldn’t do much about the first, but I assumed I should be prepared for the second. So, I set out to construct a work stand.


It is easy to build a sturdy, fixed stand, but I also knew that one often needs to change one’s perspective (angle of attack) and that the simple, center-pole apparatus used with the light clay pieces wouldn’t work with a heavy stone. Hmmm, what to do?


The answer magically appeared in the Sunday ads: Schuck’s Auto Store was selling an ATV jack for $69.99. The thing could lift 1200 pounds a full twelve inches. (I have seen Michelangelo’s  David  and, although I suspect that it is heavier than 1200 lbs, I didn’t think I’d be working on a piece that big. Well, not at first.) So, off to the store I went.


Once I got the jack home I realized there was one small problem; it was designed to sit on the garage floor. I am not. So, I needed to lift the lifter. A trip to Lowe’s and a few saw cuts got me the necessary ingredients which I list at right with a drawing of the lifter table.


First, I removed the wheels from the jack, no need for those things. But then the basic question was: how high? I initially made the legs 36” long, giving me enough height to occasionally sit on a stool and work. I also knew I could easily shorten them later if necessary.


Next I built a frame for the jack to sit down into. The inside of the frame is just a scant 1/8” longer and wider than the jack’s footprint, so I could lift the jack out if need be. (I had to cut down the rear cross piece a bit to allow for a lifting handle on the jack.) The long side supports are dropped down 1-1/4” below the top of the legs and end supports to keep the jack in place.


I added four more support pieces half way down to give the legs stability and to hold up a half-inch plywood utility shelf.


Finally, I added 2” x 6” outriggers to give the stand stability in its narrow axis. I attached the outriggers to the legs with lag screws for easy removal.  I also cut a 2” x 12” step to set across the outriggers giving me seven more inches of attitude adjustment. (19” total.) I cut the step so it barely fits between the vertical legs. This tends to keep it in place but allows me to slide it to the other side or tuck it under the bench as needed.


The jack’s lifting surface is made up of two rubber-covered feet with a lug at the toe and heel to keep your ATV from sliding off.  This arrangement makes a rough 12” x 12” platform but it really isn’t suitable to hold a stone, so I cut a 21” x 21” work-top from 3/4” plywood. I needed half-inch deep groves in the bottom of the plywood to fit over the lugs so the top would sit flat on the jack’s feet. The lugs keep the top from shifting.  Finally, I screwed ‘L’-shaped pieces of angle-iron along the perimeter of the work-top to keep my piece from sliding off.


I built a second, Lazy Susan work-top using a TV-rotator set between a pre-cut 18” round table top I found at Lowe’s and another plywood base. (The base is the same diameter as the table-top and also has the lug groves to keep it in place.) I arrest the Lazy Susan’s rotation by dropping a carriage bolt down through a hole drilled in the top into one of several holes drilled along the perimeter of the base piece.

The three-foot long pump handle that comes with the jack was just too ungainly, so I drilled a hole in a wooden hammer handle to fit over the pump stud instead.


For transportation the whole thing can be broken down into easily managed parts by unscrewing the outriggers and lifting the jack out of the stand.


There are several bells and whistles you might want to add: a small grinder on the utility shelf, a drawer for chisels, pegs for hammers, a power bar for electrical tools, a swivel light, a drink-of-choice holder, etc.


Now, where is that pesky rock?


The author makes the following disclaimer. Caution! If you build one of these things, do not casually mention to Verna Dee Dice that you would like for her to ‘bless’ it or else you may suddenly look across the field at Camp B and see a gaggle of people advancing upon you with rocks and stones and dust and flower petals in their hands.


Stuart is retired and lives in Warm Beach, WA with his wife and two young daughters. He would be glad to answer any questions on this project.  Phone: (360) 652-1897 or  e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..


Specifications


Lumber

4 - 2” x 3” x 36” for legs

4 - 2” x3” x 31 - 1/4” for side supports

4 - 2” x3” x 19” for end supports

2 - 2” x 6” x 37”  for outriggers

1 - 2” x 12” x 26” for step

1 - 13” x 34 - 1/4” 1/2” plywood for utility shelf

1 - 21” x 21” - 3/4” plywood for work top

1 - 18” rd. - 3/4” plywood for Lazy Susan base

1 - 18” rd. end table top (pre-cut, ready-to-finish)


 

Hardware

36 - #10 wood screws 3” long

8 - 3/8” lag screws 3” long

1 heavy duty Lazy Susan turn-table

4 - L shaped pieces of angle iron 12” long for stops

1 wooden replacement handle for a hammer

1 - 3/8” carriage bolt 2-1/2” long for Lazy-Susan stop


Note:  I used the unusual 2” x 3” sized lumber because 2” x 2” seemed too weak and the more traditional 2” x 4” seemed too clunky. The dimensions in this drawing reflect the actual finished size of 1.5” x 2.5”.

 

 


 

The Tool Column - Oil That Hammer - July/Aug 2003

My first “power tool” for sculpting was an angle grinder fitted up with a masonry grinding disc. It seemed an amazing step from the serenity of hand tools to the dust and noise of machinery, and yet the allure of power had touched me.


At a Camp Brotherhood Symposium workshop, I learned about fret cutting and bought a turbo diamond blade that still seems so indispensable for roughing out forms. I also watched the figurative carvers dance their carbide chisels in and out of tight spaces on voluptuous marble forms.


In another arena, granite gods and goddesses with bushing tools were contouring, texturing and anointing salt and pepper obelisks and spires. Maybe it was the beauty of the sculpture, or perhaps the romantic notion of historic production (air hammers have been around for over a century) that coaxed me over to the demo booth. I nervously plugged a pneumatic hammer into the air hose and attacked a piece of white marble with a 3/4 inch, 3 tooth chisel. Plug in your earplugs, suck the straps down on the goggles and snap some new filters into the respirator; I am hooked! Of course I bought one - a big one. And yes, quite a few chisels too.

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