Reclaiming the Lost Art of Benching

When starting a career in polishing years ago, shop owners would always ask the same question, "Are you a graver?" These men wanted the right answer because they knew that a polisher is a polisher, but a polisher who could engrave by hand or bench any contour or any shape on any block and prove it was a true find. This has always been the most important qualification of a polisher and its need has never gone away, only the teachers have. Following are several tips, techniques and practices that will help define real benching and engraving by hand.

Types of Tools Used for Scraping

Most engravers used to utilize a collection of Swiss files that they developed throughout the years - different jobs demanded different shapes and so their collections grew. Seeing an engraver with a hundred or more different scrapers only attested to his skill and long years of patient work.

Why so many different shapes? Different jobs demand different approaches. For example, let's say that you have a core and it requires a .030" radius on all molding corners. The veteran already knows that pulling a scraper toward himself will be 10 times faster than pushing one away from himself. Why? Because for some reason the human hand has more natural "depth control" pressure when it pulls than when it pushes. Today many polishers simply grind or blitz radii. Some are quite good at maintaining perfect size and consistency - which is good - but the next time they get an electrode that cannot be ground or a contour that requires dimensions to be benched into the steel and those dimensions must be held, blitzing may not be the best option.

Carbide blanks have become an extremely useful tool in the benching and engraving tool box - blanks of 3/16" and 1/4" diameter are a perfect fit to most people's hands and the polisher can retain a good feel without his fingers cramping or getting sore. Feel is the secret to engraving.

The Secret to Benching

The secret to benching is that the tool is the boss and not the polisher. Take any piece of scrap steel, sharpen an old Swiss file into a three-pointed scraper, and practice different pushing and dragging moves. You'll immediately find that the tool works better one way than the other.

Now change the angle at which you are holding the file to the steel from perpendicular to a 45-degree angle. Notice that when you push forward that same scraper gets a lot more aggressive and probably will bury itself into the steel and stop, which is a complete disaster and should always be avoided - no contour will come out looking professional with uncontrolled nicks and gouges in the steel.

Try rotating the scraper - like a doorknob - forward and backward a few degrees. Some strokes will produce a smooth cut while others will not cut at all or bury into the steel. The desired result is always a smooth, easy stroke. It's far better to take several easy strokes that all produce a consistent chip, than one big ugly gouging crash into the steel.

Only experimentation will demonstrate to you how a scraper will cut. This is because each one of us naturally uses a different amount of speed in our stroke, uses a different amount of pressure with our hands and holds the scraper at a different angle.

However, the true way to learn which combination is best is to try the following:

• Scrape away from your body as fast as you can (exactly like peeling a potato) using a light pressure.
• Look at the size and type of the chips that you are producing.
• Try to produce an exact pile of chips that are all the same.

This is the beginning of control. Learn how your hand feels as you are doing the work. Go for a consistent feeling in your hand and you'll get a consistent result every time. Next, after you have been "peeling the potato" for a while, roll right in and change something in your stroke. Change the angle from perpendicular to 10 degrees forward or backward, but keep your speed, pressure and stroke speed the same.

What differences do you see in the chips? Make two piles side by side to compare the differences. The results are your greatest teacher - results never lie and results never vary from day to day. That is what a professional engraver/ polisher is all about - a knowledge of an exact result.

 

Engraving by Hand

After you have experimented with scraping and feel comfortable with your new skill, start practicing engraving by hand. This is where we really separate the veterans from the apprentices. A key to engraving is staying inside the line. What does that mean? Picture a smooth steel finish - maybe 600-grit or even diamond - and along comes a polisher with a really sharp scraper and he is going to start cutting on this surface freehand.

How does he keep from slipping? By staying inside the line. The engraver sees the pattern, letter or shape he wants to put into the steel and either sketches it on the steel with a pencil, copies it from a drawing or sees it only in his mind. Then he begins by lightly "sketching" this letter or shape into the steel - possibly using tape to keep a straight line as he travels along. Once that shape is sketched in, he uses light pressure and goes back to do it again - over and over using the exact same light pressure until he is at a comfortable depth into the steel.

Comfortable for what? Slowly increasing his downward pressure. The secret of staying inside the line is the deeper the line, the slightly harder you can press down on the tool because the depth of the scratch helps "guide" the scraper as it starts cutting faster and faster. The trick is to never press down hard enough to bury the cutter or to make it "skip" out of the line. Engravers are the masters of knowing how much pressure they can put on a type of scraper and not skip out of the existing line.

Beginner's Practice

Take a block of soft steel and put a 600-grit or finer finish on it - cold-rolled steel is fine - then lightly stamp a letter into the steel using any pre-made letter or number stamp, sharpen a Swiss file or carbide blank into a diamond-shaped chisel point and begin lightly "drawing" in the lines you just stamped.

It's exactly like drawing with a pencil or crayon. Experiment with different angles at which to hold your scraper. Each angle will produce completely different cutting results. Remember that you want consistency and a low enough downward hand pressure to keep the scraper from jumping out of the lines.

Use your fingers to feel how the steel is cutting - your fingers should become your eyes when you polish. With time, practice and a little "hand education" you will discover new skills that you never knew you had that will improve your polishing speed and quality.