What you will read below is a conversation that took place between me and a reader of mine via e-mail. I am publishing it here after doing some minor editing to make it more presentable for a website format.
When circular saw blades are used to cut green lumber or particularly resinous woods, these gums and resins can accumulate on the blade surfaces. This can cause rough cutting and dull the blade more quickly because of unnecessary overheating.
A quick remedy for this condition, which can be performed easily by any woodworker, is as follows:
Dissolve common household lye in water according to the manufacturer’s instructions. Soak gummed-up blades for about 20-30 minutes. Then rinse thoroughly in clear running water, using a stiff-bristled brush to help remove the gums and resins.
Caution: Lye is very caustic! Be sure to follow the manufacturer’s precautions carefully, and think about those youngsters around the house who “don’t know any better.” Think FOR them.
I have found that instead of soaking blades for 20-30 minutes in lye solution, it is much easier to dip an old toothbrush into a can of lacquer thinner and scrub the resins off with that. It’s faster, and lacquer thinner is less caustic and more likely to be on hand than lye.
With no criticism to your blade-cleaning method, let me make just a few more comments. First, the use of lacquer thinner does have some inherent dangers that home woodworkers need to be aware of. The vapors from the thinner are harmful if used in unventilated areas, let alone the fire hazard presented when an “unthinking” woodworker starts cleaning blades near his water heater in the garage. In some cases, it may even be necessary to have a special permit from the Fire Marshal to use lacquer or lacquer thinner.
Second, your toothbrush method is fine for one or two blades, but a large shop may have several blades that must be cleaned. I sharpened saws professionally for a time, and would have needed to hire someone just to clean blades all day long with a toothbrush. My method (learned from an old-timer) was much more productive. I used ordinary household drain opener and diluted it to a weak solution. No fire hazard, no fume problem. Of course, I had to wear rubber gloves to handle the blades during this procedure.
The diluted solution was used in an old, circular auto oil-drain pan and stored in a gallon glass jug until I deemed it too dirty and made a new solution. No disposal problem either, since it helped clean out our household drains at the same time. A 20-30 minute wait was no problem because it enabled me to get on with other jobs while I was waiting for the pitch to soften. Then, a quick rinse and brushing with a stiff-bristled brush gave me 10-12 nice, shining blades ready for the sharpener. In the diluted formula, you could even leave the saw blades in the solution for days without adverse effects. In fact — they just become more shiny.
Thank you for the valuable info mate!