Replacing the Pad Protector of my Mirka CEROS

I bought my Mirka CEROS (Compact Electric Random Orbit Sander) 18 months ago.  I didn’t use it much for the first couple of months, but have been using it a lot more, especially on sculpted shapes, including Ash Table and Relationship Study.

The CEROS utilizes a Pad Protector, a thin disc of material with hooks on one side and loops on the other (think Velcro).  When abrasive discs are applied or removed from the sander, the hooks of the Pad Protector take the wear instead of the sander’s pad.  This prolongs the life of the hooks on the pad.  When the sandpaper no longer sticks, you only need to replace the Pad Protector.

This video shows the simple replacement of the Pad Protector and I demonstrate the difference between a worn hook pad and a new one.  (Duration – 1:15)

Flat-Top Ripping Blade is King

Freud’s 24-tooth Heavy Duty Rip Blade (LM72M010) is what is installed in my table saw 90% of the time.  The blade has 24 teeth 0.126″ wide, ground flat on the top and pitched forwards at 20 degrees.  These characteristics make it the most versatile and most used saw blade in my shop.

Heavy Duty Rip Blade - Technical Specifications (from FreudTools.com) K= Kerf; P= Plate Thickness

As you would expect, this blade excels at ripping.  The 20-degree forward (positive) hook angle makes feeding stock past the blade easier and the blade leaves two clean surfaces requiring little, if any, further clean-up.  This blade also does a formidable job with cross-cuts too, especially when freshly sharpened.  (When I need a super-clean crosscut, I take the time to switch to a dedicated crosscut blade.)

For a 10″ circular saw, 24 teeth is not very many (they may have as few as four or as many as 90).  Having few teeth allows quicker, more aggressive cutting.  The trade-off is that the blade will tend to leave a rougher cut than a blade with more teeth.  In some cases, using a slower feed rate increases the quality of cut.  In other cases it only causes burning.

Freud Heavy Duty Rip Blade

The flat-top blade is useful for joinery.  Non-through cuts have square shoulders and flat bottoms, making cleanup unnecessary.  The blade has a regular kerf that is 0.126″ wide, just a little over 1/8″ (1/8″=0.125″).  This is 20% thicker than a thin-kerf blade which typically removes 3/32″ (0.09375″).  While a thicker kerf means it turns more wood into sawdust and requires more power to spin, it also means that only three passes are required to cut a 3/8″ wide groove versus four with a thin-kerf blade.

In addition to making joinery more convenient to cut, set-up is also quicker and easier.  Because each tooth is the same, the top or edge of any tooth can be referenced for accurate set-ups.  Another benefit to the tooth shape, which distributes the cutting duty over a wider surface, is that the teeth are also very durable and as a result, I need to have the blade sharpened less often.

There is a lot more information on saw blades on the Carbide Processors Inc. website.

Sharpening a Card Scraper

Of all the techniques related to woodworking, this sharpening a card scraper tends to generate the most interest. This is my method:

  1. Remove the old burr if necessary by rubbing the face of the scraper on a stone. I use my diamond stone as not to scar my water stones.
  2. Clamp the scraper in a vise with the edge you are working on exposed by about 3/4-1″ (enough room for your knuckles, but not so much that the scraper flexes too much) and mill the edge square by holding a mill file parallel to the edge and taking passes until the edge is flat. If you get the right angle, you can tell that the edge is straight by how it reflects light. Be careful not to create a rounded edge.
  3. Refine the edge with a water stone. I usually go up to 1200x, but you can go as fine as you like. At this point, I will have a burr on the edge of the blade which will actually turn up shavings. However, the burr is not nearly as durable as a hook, so I proceed.
  4. Start to roll the hook by taking 2-3 passes with the burnisher square to the edge. Use steady, controlled pressure. If you have any fear of slipping and hurting yourself, you are using too much force! At this point, the scraper is ready for very fine scraping. For a more aggressive cut…
  5. Roll over the hook by taking another 2-3 passes with the burnisher tilted slightly, using the same force as before. A five-degree angle is great for fine work, fifteen degrees is very aggressive and takes work to push! I usually aim for about five degrees.