Circular saw blades can last a long time with the proper care and maintenance. In order to preserve the integrity of the metal and the safety of the blade, be sure to never use any abrasive substance which could destroy the metal. This includes stiff wire brushes, corrosive chemicals, or filing to remove scum and gunk. The saw blades are under enormous stress and pressure so any weakness can become highly dangerous during use. After all cleanings, rinse thoroughly with water, dry, and give a light spray of WD-40 before returning to the saw.
Step 1 - Soaking
Place the saw blade into the flat pan and fill it with either Simple Green cleaning solution. If Simple Green is not available, kerosene will work just as well. Soak the blade overnight, flipping it once during the process. Be careful when handling the saw blade. Even when the blades are dull upon wood, they can easily cut skin. Frequent cleanings will make the soaking much quicker.
Step 2 - Plastic Scraper
The plastic scraper is a great tool for removing gunky build up from pitch, sap, and resin within the wood. This buildup can be difficult to removed if it is not dealt with in a timely fashion. If the plastic scrapper cannot remove the gunky build up, return the blade to the simple green or kerosene for another day.
Step 3 - Brass Bristled Brush
The brass bristled brush is used because the brass is soft enough not to harm the integrity of the metal. For areas where the build up has been sitting a long time, use the brass bristled brush the second day of soaking. Going in the opposite direction of the tooth angle can help break up the build up enough to remove it.
Step 4 - Coated Blades
Newer blades on the market can be purchased with a coating which helps to reduce friction and keep blades sharper, longer. In instances such as this, soap and water can clean most build up, but kerosene works well too in difficult areas. However, do not use the brass bristled brush. The brush may not harm the metal, but it will definitely scratch the coating. Purchase a plastic scrubber from the kitchen cleaning aisle at the grocery store. The plastic scrubber should be Teflon safe, meaning that it will remove residue but not harm similar coatings on pots and pans.
Step 5 - Resin Remover
If the wood used frequently leaves the blade highly dirty, purchase a resin remover from a local woodworking shop. Rather than using spray on blade cleaners which include highly caustic materials and could harm the metal, the resin cleaner merely debonds the gunk without the need for scrubbing. Dilute the cleaner in water, soak the blade for 15 minutes and rinse clean. This is a bit overkill for the average cleaning, but works wonders on pine and other highly resinous materials.