Abrasives, Cut Off Wheels, and Burr Bits

How to weld metal art scrap art sculpture necklace fine art craftsmanship.jpg

I'm obsessed with texture, how it looks, how it feels, how it makes me feel; I experience texture with my soul.

~Barbie The Welder
;

Cutting Metal

Cut-off disks are a go to for the metal sculptor when cutting metal. They come in a variety of sizes to cut a variety of metals and have flat or a recessed center for flush cutting. The thickness of your cut off wheel will determine the speed of your cut and how much material it takes with it as it cuts. I prefer thin cut off wheels for most cutting but I do keep some thicker ones that I lightly grind/sculpt with. (More on that later)

When purchasing cut off wheels make sure the center hole size is correct for your grinder. (7/8" arbor (center hole) is the most common.

Grinding, Sanding & Smoothing Metal

Hard stones are exactly what they sound like, a hard stone. A hard stone is used in removing a lot of metal at once. They are aggressive and wonderful in sculpting metal when you're adding and removing large amounts of material. In a metal fabrication setting a hard stone would be used first to remove a large portion of material, then a sanding disk would be used to smooth the material and take out the metal, then a scotch brite pad, like a sink scrubby but for a grinder, would be used to get a clean, mirror like finish. Hard stones are not necessary for welding art but I use them extensively in sculpting.

Sanding disks are one layer of sandpaper made for a angle grinder and are used with a rubber backing pad and held on with a large nut. (The backing pad is a separate purchase. Most angle grinders will come with a hard stone, a tool to change the nut, the nut, and the grinder.) Disks come in a variety of grits however 36, 60, & 80 grit are the three I recommend for both the welding artist and sculpting artist.

Sanding disks are used to smooth metal and can also be used to texture metal if you are sculpting. The lower the number the courser the grit, 36 being a more aggressive grit than 80.

Flap disks are flaps of sanding paper glued to a disk, it's like a hard stone and sanding disks had a smooth baby! They work more aggressively like a hard stone but with the smooth finish of a sanding disk. They are wonderful for both the welding and sculpting artist.

Sculpting Metal

Burr bits, also known as carbide burrs, die grinder bits, or rotary files, are cutting tools used to shape, grind, and cut a variety of materials, are used extensively in sculpting metal.

Burr bits are designed to remove material or rough edges from a workpiece with precision while maintaining a smooth surface finish. They come in a variety of shapes and sizes, and the size of the burr affects its speed.

Carbide Burrs Come in Several Cuts; Single Cut, Double Cut, and Non-Ferrous
Single cut (one flute) carbide burrs have a right handed (Up cut) spiral flute. These tend to be used with stainless steel, hardened steel, copper, cast iron, and ferrous metals and will remove material quickly with a smooth finish.

Double cut carbide burrs tend to be used on steel and other ferrous metals, soft steel and also for all non-metal materials such as plastics and wood. They have more cutting edges and will remove material faster. Use for medium-light stock removal, deburring, finishing and cleaning. A double cut carbide burr is the most popular cut and will see you through most applications and the ones I use exclusively.

Burr bits come in 1/4" and 1/8" and the size you will use depends on the size of the sculptures you're creating. The smaller the details you desire to create the smaller the burrs need to be.

In creating the Tradesman I used a oval shaped 1/4" burr to sculpt much of the details on this 6 foot tall sculpture. The texture the burr creates is beautiful to me and totally worth the hundreds of hours it took.