Tips for Carving Monumental Stone (i.e. Granite) Home

The following describes some of the equipment, tools and techniques I utilize to carve monumental stone (granite and dolomite) sculpture. Remember these are the methods that work best for me in my applications. They may or may not apply to the way you work.

With respect to carving granite, don’t be afraid to tackle a project in this material just because it is hard. You may want to experiment with small pieces before moving up to monumental sculpture. This will help you to develop your working techniques and self confidence. Personally enjoy the resistance and response of granite. It is a great material to work in. I normally carve field stone (granite & dolomite) mainly because of it’s availability in my part of the world. It can be very interesting/surprising to deal with due to its impurities and faults. If you have an opportunity to carve good quality quarried stone, enjoy.

Saws:

The picture below shows the two saws I mainly utilize for monumental work. On the yellow grinder I run a 9” blade whereas on the green grinder I run a 4.5” to 5” blade. I use the 5” grinder for more detailed work and the 9” grinder for roughing.

With respect to the larger 9” saw (yellow unit) this is a basic industrial grinder. It is not specifically a stone saw. You may wish to purchase a unit that is specifically rated for stone. To date I have not done so due to initial cost and functional factors. The 9” grinder I am currently using is a Dewalt Model D28499 and meets all my requirements at this time. The 5” grinder is a Bosh 1348. Again these are my current preferences and you will need to investigate what fits your needs.

Things to consider when purchasing as saw:

• RPM - for the 9” saw do not exceed 6000 rpm. 9” blades are normally rated at 6000 rpm maximum. If you are using blades with a lower maximum rpm rating then you will have to purchase a saw rpm rating accordingly.
• Locked trigger – I have noticed some European grinders have removed this feature for safety reasons. For me it is necessary to lock the saw on due to the length of time it takes to complete a cut. Yes this is a dangerous situation, so caution must be exercised. I can guarantee you will jamb the blade at some time (more often when 1^st using this tool). When this happens you have to be ready to stall the saw, so be ready to hang on. What this really means is that you must be constantly aware and be ready for a jammed/locked blade situation. This is probably the most dangerous part of using a diamond stone saw freehand. If you are not comfortable with locking your saw on or do not have sufficient strength to stall your saw, then I would recommend that you DO NOT lock the saw on. Again this is a personal working preference.
• Weight – Saws come in various weights. A few ounces can make a significant difference when working long hours. My current unit is heavier than previous units, but I have found that the extra weight to be a benefit when cutting. That is I use the weight to my advantage. In the end this is a personal preference that will vary in regard to your application and work experience.
• Brushes: - Make sure the brushes can be inspected and removed easily and quickly. This will help facilitate the frequent checking of brushes. When I am running a dry diamond blade (which is the majority of the time) I check the brushes once a week for wear. Some grinders incorporate a feature that automatically stops the grinder when the brushes reach end of life. I would still recommend pulling the brushes once a week since this helps facilitate cleaning the brush holder which could cause brush hang up, resulting in premature motor commutator failure.
• Softstart: - A nice feature but not necessary. I have owned grinders that start with a jerk and I don’t particularly like this since in my opinion it is hard on the drive gear train when running a 9” blade and also causes the saw to jump in your hands. The unit I currently use doesn’t have a softstart feature but starts gently. Therefore you may want to actually try the unit out with a 9” blade attached before purchasing.
• Handle Length: - The total length from the front to the back handle is important. Get the longest length you can find. I have found the longer the length the higher the cost of the unit. Why is length important – because it gives you extra leverage on a blade jam?
• Rotating Rear Handle – The unit I have has a back handle than can be rotated 360 degrees at the press of a release switch which is built into the handle. Notice the current position of the handle. Grinders with fixed handles point to the side instead of to the bottom. This is very uncomfortable with extended use. Also the rotating handle is useful when you need to reposition it for specific cuts. Normally I leave it in the current position. If you cut left handed you would adjust it to the up position and the front handle would be placed on the other side.
• Blade Guard – The blade guard should have a built in quick release mechanism, so you can quickly adjust the guard position. I find this useful to achieve maximum safety, viewability and dust dispersal
• Cutting: Cut from the top down rather than across whenever possible. It will save your back and saw blades. When cutting vertically the blade will wear more evenly on the sides. As a novice expect to go through more blades. It takes some time to get used to handling the saw. The deeper the cut will allow you to increase the spread of the kerf cuts. This means less cutting of kerfs. I try to cut at least 2 inches deep and 2 inches wide for roughing purposes. As you get closer to finishing reduce the depth and width accordingly.
• Daily Maintenance - The unit should be cleaned with compressed air daily to remove dust that passes into the unit. Blowing the unit out will prolong the life of the brushes and internal electrics by reducing wear and heat buildup. With my current unit I can quickly remove the brush covers and blow out the brush area daily. Run the unit after applying compressed air. This should remove more loose debris.

Blades:

• Granite or Marble Blades: - Purchase a true granite or marble blade. For my 9” blades I do not use concrete blades since there matrix is not designed for cutting granite or marble. You can try cheaper blades on granite – some work – some don’t. For safety sake check the segments for cracks daily as indicated below – especially when cutting curves or jamming the blade.
• Dry Cutting Blades: - I use dry cutting blades since I do not have water where I work. Besides water is messy and also dangerous when working with electric tools. Therefore I cut dry and allow the wind to remove the dust from my site. Cutting dry creates a fair amount of dust. Also the noise level can be quite annoying. Therefore it is not a good idea to cut with a diamond saw in your backyard. Your neighbors are sure to complain. Try to find a noisy industrial site instead.
• Blade Support – Back Plate – I run a metal blade back plate support. It helps to reduce the wobble or bending on the blade when your working a deep cut. It also limits the depth of the cut since the back plate is approx. 4 inches in diameter. You do not need to use the back plate. It is just a personal preference of mine. Back plates can be purchased as an option.
• Cutting: Let the blade do the cutting. Do not force the blade. It takes time to cut stone. Forcing the blade overheats the diamonds and causes premature wear of the blade. If the blade segments are turning blue then you are pushing the blade to hard. When the blade is at the end of its life do not push it since this may lead to blade/segment failure and jamming.
• Blade Check: Check your blade daily before starting work. Check for hairline cracks at the major segments. If cracks develop this can lead to failure of a segment causing break out. If the blade develops hairline cracks throw it away. If your cutting a lot of curves and you are not very stable with your saw or you are causing the blade to twist , premature failure may occur. Check, check, check.
• Caution: When a blade is at the end of it useful life it will tend to bind or jamb more readily than when the blade is sharp. If the diamonds are basically gone and the blade jambs repeatedly for no apparent reason it is spent – throw it away – safer to spend a few $ on a new one than get hurt. On a jamb situation the saw will try to eject itself from the cut groove so be constantly watchful and hang on if this happens. You don’t want the saw to jump out of your hands and hit you or a bystander. Do not day dream when cutting free hand with diamond blades.

Miscellaneous Tools:

• Hearing Protection: - Cutting with diamond saws and using a hammer/chisel is a very noisy proposition. Therefore wear excellent hearing protection. Buy the best since you will be wearing your hearing protection for most of the day. You will want maximum protection and comfort. I don’t use the standard over the head band unit. Instead I use the unit that I can fit my hardhat over. It has a spring wire that goes around the back of the neck and a thin nylon band (Velcro adjustable) over the top of the head. The over the head nylon band is so thin you will not notice it when wearing head gear.
• Eye Protection: - When I am roughing I do not wear my glasses. Therefore I can wear bullet or welder goggle style of safety eyewear. This is the only safety eyewear I have found that actually keeps flying debris out of my eyes. Other types of eyewear (i.e. over glasses enclosed goggles) always allow some stone to get in behind the goggle and glasses. I find this to be a real problem when roughing dolomite.
• Hard Hat. When roughing I wear a hard hat with a wire screen visor. Basically this saves the skin on my face. My hard hat has many deep scratches in it from flying stone. It probably wouldn’t meet safety standards anymore due to the deep cuts in the plastic.
• Stone Hammer: - I use a 3 lb. hammer for mass removal of stone. Last year I replaced the 10 inch handle with a 14 inch handle. This has made a huge difference in comfort and handling. It also increases the hitting radius to apply more force. Buy a good quality stone hammer (best quality steel) since you will be using it a lot and hard. I purchased my hammer from a retired stone mason. I have used it for years and the steel head is as good as new – no mushrooming as with cheaper hammers.
• Chisels: - I do not use carbide tipped chisels. I found that I kept breaking the carbide points out of the steel shank. Instead I use high quality steel chisels. I use a 12 inch chisel for most of the roughing and an 18 inch chisel to reach into deeper areas. Both these chisels have a 7/8 inch flat edge for setting the line on the stone and final takeout. I seldom use a pointed chisel. I find the 7/8 or ¾ inch flat is more efficient for the way I work. Also add a protective handle to your chisel. This may mean that you will have to find an inexpensive masonry chisel in a hardware store and adapt it’s handle. Since chisels come in various shank sizes you will need to find a protector that will fit your chisel. I have found that the protective handles are a must for the way I work. I have been sculpting stone for 20 years now and I still manage to miss the chisel from time to time. The protector makes a huge difference when I miss the chisel with a 3 lb. hammer at full swing. Considering I cut in all directions and on some occasions the hammer glances of an adjacent stone, no wonder I hit myself.

Electrical

• Electrical Cords: - Purchase good quality industrial cords. I use a 50 foot #12 wire cord. The #12 cord reduces voltage drop and heat buildup in your electric saw, thus extending the life of the saw.
• GFI – If you are working in wet location or outdoors I would recommend that you utilize a GFI Ground Fault Protectors for your electrical equipment. Self electrocution is not a good thing.

Clothing

• Coveralls: - I cover up totally when roughing out granite or dolomite. The flying debris can be quite nasty and I have found that full coveralls work the best. They also give me freedom of movement and can be air condition by wetting them down.
• Safety Boots: - A must since you maybe dropping fairly substantial pieces of sharp stone ( i.e. sharp 20 lb pieces). The leather toes of my safety boots are cut up and torn from falling stone.
• Shin Protectors: - These metal protectors lace onto your safety boots just above the safety toes. When roughing on scaffolds these are definitely beneficial. For some reason falling stone seems to find a place to land behind your steel toe and yes it does hurt. The shin protectors will deflect the stone making your work much more comfortable and safe.
• Wrist & Elbow Support: - If you find your wrists or elbows are getting tired – wear expandable supports. Wrist supports also reduce the amount of debris cutting your wrists (especially when cutting dolomite).

Hand Stone Cutting

• After I kerf cut a line with the diamond saw I set the edge of the stone cut line with my hand hammer and chisel. The 1^st row is a pain but after removing the 1^st line of stone you can now easily set the line. After setting the line a couple of times the stone should start to pop loose. When setting the line you do need a fair amount force with the hammer. When swinging the hammer keep your arm at full length during the swing and reach back as far as comfortable and swing with a smooth motion. Let the hammer do the work. Once you become proficient at swinging the hammer the full swing motion should be become comfortable and relaxing.

Cutting Comfort

• Back – Save your back. I have found that cutting with the diamond saw for long periods of time (more than one 2 foot cut) kills my back and overheats the saw. Therefore make one cut – put down the saw (no matter how tempting it is to keep cutting) – pickup your hammer and chisel and remove the latest cut material – do over. In this way you can work for a 7 to 8 hour period quite comfortably.
• Tired – Rest – If you have been cutting with your diamond saw for a couple of hours and find yourself physically fatigued – Stop – Take a break. Do NOT operate your diamond saw when you are tired (beat-up) since this can lead to accidents. When I get to this stage I take a 15 to 20 minute break and lay down on a stone. At this point the stone feels awfully comfortable and besides messes with peoples heads when they see some fool lying on a stone.

Scaffold Work

• When working on scaffolds use high quality stable scaffolding.
• When I am standing on a platform that is more than 5 feet from the ground I use an approved fall protection safety harness and tether. The tether I use is an approved seat belt tether that will break a fall within 3 feet. You may want to opt for the bungy tether systems. If so make sure your purchase the correct tether arrest length for your application. The reasons (other than occupational safety) that I wear the fall arrest equipment is that it provides me with an added comfort level when working under windy conditions and in the event the saw jams. Either condition might cause me to loose my balance while working on a scaffold.

Note:

Don’t let me scare you with the safety issues. Use good common sense and things will go well.

And remember get some blood on the stone.

Let’s carve

Copywrite: Floyd H. Wanner Home