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Saw Blade Sharpening/Washing4/11
So I'm back in the 'working for someone else' mode (couldn't resist the challenge?!) and have a going debate with a few of the woodworkers on the floor....
When I got here a few months ago I was given a few departments to run, one is estimating (my main charge) but the finish department and blade sharpening are also on my plate.
In the past, I've been a huge proponent of washing my blades a few times before I sharpen them. I've found the blades usually don't need sharpening as much as you think and washing them typically gives me another 'round' or three of use out of them. I was taught this by an old and very experienced 'blade person' who manufactured and sharpened blades for more than 50 years.
Eventually, there are diminishing returns, and I ALWAYS replace teeth and sharpen when I see it's needed BUT I have researched this for years and don't see any serious disadvantage to this. Sure, you can't do this forever, you need to sharpen on a regular basis and I'm not arguing that, but washing a blade even twice in between sharpenings will give you 2-3 TIMES the blade life!
Any way I look into this, whether under a microscope (seriously, I did) to just 'feeling' the edges, it seems to come up positive for a cleaning program and less sharpening.
Most woodworkers tend to agree once they utilize the system too. Some don't and there lies the rub.
Does anyone have any feedback on this? Any written material anyone knows of that I can pass around? Anyone have any 'offhand rules' on how many times you clean before sharpening (I tend to just LOOK and FEEL the blades, but some folks are comforted by rules) or any other observations?
I thought for SURE I'd find something on this in the knowledge base, but I couldn't. Am I crazy, or am I a genius?
Thanks in advance
Yes its a good idea to wash the blades if they get gummed up. How much they get gummed up depends upon what you are cutting. The primary reason to clean them is to prevent overheating which could damage the teeth. Sometimes you can cut a scrap piece of melamine and it will clean the blade. Depends on what's on it.
The extra heat might warp the plate as well.
Jeff, What do you use to wash your blades in?
How much production time do you loose from a production employee washing blades? How many times do they chip a tooth or some other 'mistake' that has to be dealt with, while doing so? Figure the real dollar and cents of washing, vs just handing them off to be washed and sharpened by someone else.
Carbide's primary mode of failure (loosing sharpness) is heat, not abrasion. So washing could be of real value if your blades get a lot of pitch, and the math works out.
I often have to clean a blade in the shop BEFORE I can use it. I guess nobody is interested in using the right tool for the job anymore because I often witness coworkers using the hi atb mel blade for ripping 2x on a bevel, then wondering why they have to wrestle it past the blade. "must be dull!" and into the sharpening pile it goes.
I endeavor to examine the blade first and make sure there is no damage done already from overheating, then if it's good I'll give it a soak using a 5 gallon bucket lid (perfect!) and a some straight simple green. I've read that some solvents can degrade the carbide or the brazing, but I cant think that the short time that is necessary is going to have a discernible effect. Soak for 5-10 minutes and wipe clean with a rag. Occasionally I'll have to use an old toothbrush if the gullets are gummed up and the rag doesn't like to play. It's pretty effective and doesn't break the bank, or take unnecessary time.
I usually also check the blade body where the arbor plates press against it, during frequent changes, dust will sometimes get packed on and cause some runnout which can make the cut "feel" dull.
That's how I roll, just 2 cents.
All good thoughts, and to each his own, but....
15 mins a week washing blades is $1,300/yr in our shop. And that is only the washing, not the demounting, remounting and interruptions. That will make an argument for disposable blades.
How sharp is sharp? How dull is dull? How can anyone tell, beside the obvious?
I had one employee that liked to trip up the foreman by taking a dull blade, cleaning it up a bit, and putting the rubber wax protectorate on it so it looked fresh from the sharpening service. He'd take the freshly sharpened blade and run 100 ' of pine and hand it to the foreman and ask if it is dull. The foreman would say yes, since most blades were run well past their due. The employee then hand the foreman the dull blade - dressed up to look sharp - and ask if that was a good sharp one to use. The foreman would reply yes, and the employee spent the rest of the day telling his coworkers how dumb the foreman was.
I did track hours on a M-J gang rip with thin blades so as to try to equalize the life and maximize the cut between sharpening that were more expensive than regular ripsaws. Marginal or questionable savings was the only outcome I came up with.
A carbide blade will glaze many times before becoming dull, so in my opinion it is important to keep them clean. When a blade becomes glazed simply soak it in a bath of formula 409 or similar cleaner for several minutes (while using a spare blade). Dry with a paper towel, the buildup will come off without effort, so no time is wasted. Cheap and effective and will prolong the time between sharpening. 409 will rust the body if left overnight however. Weinig has a product called cutter guard which is an industrial soap that will not promote rust if you want to try that, but 409 works fine.
I use simple green. I set them in a round deep pan, come back after a while and make a couple of passes with a scrub brush, if there's any muck that didn't come off I'll let them soak a while longer. I'd be surprised if I spent more than 5 minutes cleaning a couple of blades.
Why don't you ask your boss? As owner of a shop and having a hefty monthly grinding bill, I think I would tell you to pull the blade and send it in to be sharpened.
Could cleaning help....maybe. Do I want my foreman changing blades, washing them, and then hoping the results are improved over why the decision to change the blade in the first place was made? Definitely not.