Sharpen Those Dividers

Several months ago I decided on purchasing a set of dividers for laying out my projects.  I noticed immediately that very few manufacturers still produce dividers.  Those that do have them tucked away as either some form of machinist / engineering tool or they are with the turning tools, along with inside callipers, etc.

I got the second kind since they are reasonably priced at Lee Valley.  LV also sells the more expensive Starrett dividers, but from what I can tell they are different versions of the same type of tool - namely a spring divider. According to hand tool users these are the inferior types.  The good ones are friction dividers or "wing" dividers of old.  I can't find anyone who sells those, and I didn't feel like buying an old one on Ebay only to spend huge amounts of time fixing it up.

I bought two of the small 4" ones for dovetail layouts and small joinery, and have since purchased the larger 6" version (or is it 8"?  I can't remember.)  I have no point of reference since I never have owned a "wing" type divider, so in my opinion these are pretty good and accurate, and I have no problems with them.

The only criticism I have is when I purchased them originally I noticed that two of them (the small ones) had one leg that was slightly longer than the other, and that all of them seemed to have a burr from the milling process on the inside of the points.  The different length legs and the burr made for sloppy measurement at times since the dividers would rock on their tips.






I looked online for ways to sharpen dividers and was greeted to a 1945 US War Office document which indicated to use whetstones to sharpen the points.  Simply awesome in every way.

I set my dividers together and while holding them at 90 degrees to my stones I rubbed them back and forth until the tips were even. I started on my soft Arkansas (image left) but stepped down to my medium India stone when it was taking too long.  Fifteen to twenty strokes on the India stone got them all equal length quickly.








I sharpened the tips much like any plane blade or chisel.  These dividers have one flat edge meeting an angled edge.  I honed the outside bevel on my India Stone, then followed it up with the soft Arkansas.

I then turned the leg over and polished the inside point (the flat part.)  That got rid of the annoying burrs.  Now my dividers are super sharp and even more accurate.  Tuning up the dividers was a lot easier than I had expected.

I'm sure that there are better vintage dividers available out there, but for the money and ease of tuning them up, the LV dividers are so far a great buy in my books.

-Lucas in BC