When to sharpen a table saw blade?

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New Jersey
Thanks to Scott I ordered a second Woodworker II blade from Amazon yesterday at a great price. My old blade is about 3-4 months old, how can you tell when a blade needs sharpening? Do you send it back to the maker for sharpening?
Thanks
Dennis
 
If somebody has a nice scientific way then I would love to hear it. I work on the principle that if you start wondering whether the blade needs sharpening, it almost certainly does. It obviously depends on how you use the saw. Sometimes mine will sit on the saw for a month or so, sometimes I change it twice in a week. Depends how much timber and what type of timber it has had to deal with.

I am lucky enough to have a sharpening service that calls once a week and they do a good job. Look in the yellow pages under "saw doctor" maybe. Or even better ask a local cabinet shop who they use.
 
Not all blades are created equal. I ran my first woodworker II blade for several years. It cut fine, but I was feeling so guilty... like I hadn't seen it degrade over time... that I sent it back to Forrest with a note to please check how badly it needed sharpening before they did it. They called to ask why I had sent it in... it didn't need sharpening at all.

I have slid my riving knife into the blade (it wasn't tight enough, and I shoved a sheet of something back and hit the knife which pushed it into the blade). That blade has been sharpened.

I had a jig with some metal in it that slipped and hit the blade. That blade has been sharpened.

Other than the really dumb things above, I watch for an increase in chipping and rough edges. But if someone invents a way to test... I would love it!
 
Thanks to Scott I ordered a second Woodworker II blade from Amazon yesterday at a great price. My old blade is about 3-4 months old, how can you tell when a blade needs sharpening? Do you send it back to the maker for sharpening?
Thanks
Dennis

I have a blade that is well over a year old and is not ready. I have a blade that I ran for a couple months and is wayyyy ready. Generally if it is not cutting like it used to, its time. The teeth should feel very sharp at the points. As Steve said, they should snag your skin if just brushed with the finger tip. If your finger tip slides right over is with no catch, I'd say sharpen 'em.

As to where . .. the eternal question. I am lucky enough to have a carbide product manufacturer that does work for many of the large names as well as market their own line right near by. I believe several folks use a guy in Arizona and there's Forrest back east (I'm in California . . . Las Vegas is back east from my perspective) who sharpen other makers blades as well as their own. I tend to ask folks or shops (window shops, cabinet shops, lumber yards) I'm in where they have their stuff done. This gives me sources plus opinions on the quality.
 
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For me I have a local guy that does a exellent job at a low price. As far as blade sharpening, when I notice it leaveing fuzzy stuff on the cut board. It will also depend on the wood as already mentioned.
 
To add to the good advice, you also need to watch for a build up of stuff on the blade, some timbers leave a lot of residue on the blade, and if this builds up, you blade will seem dull, if you clean it off, the blade can be as good as new.

I use the lid from a 20 litre pail, and some simple green kind of stuff from Costco, I let is soak a few hours and then I have a stiff bristle nylon brush to give it a good scrub, comes our shiny!

Cheers!
 
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I use the lid from a 20 litre pail, and some simple green kind of stuff from Costco, I let is soak a few hours and then I have a stiff bristle nylon brush to give it a good scrub, comes our shiny!

Cheers!

If it is the "Simple Green" brand solvent, the vendor says to NOT soak blades in it, because it can attack the brazing - only use it for cleaning without soaking.

When the FAA "outlawed" Simple Green in aircraft, the company came out with "Simple Green Extreme" which sounds worse, but does not attack metal, and can be used to soak blades and other things. I couldn't find the extreme version in most stores, but finally found it at Sams Club, the equivalent to Costco.
 
If the feedrate has slowed, burning increases, and cut isn't as good, it's a good indicator it's time to resharpen. Always important to keep the teeth clean for best results and wear.
 
If it is the "Simple Green" brand solvent, the vendor says to NOT soak blades in it, because it can attack the brazing - only use it for cleaning without soaking.

When the FAA "outlawed" Simple Green in aircraft, the company came out with "Simple Green Extreme" which sounds worse, but does not attack metal, and can be used to soak blades and other things. I couldn't find the extreme version in most stores, but finally found it at Sams Club, the equivalent to Costco.

Sorry Charlie, this is a general purpose cleaner that Costco sells, and it says nothing on the label about steel and or blades... :dunno:

Cheers!
 
Maybe a small insight - maybe not. Today I cut about 4500 linear ft of 1in European Oak (similar to AWO) from fresh blade to blade needing to be replaced because the extra effort was costing more than the resharpening cost. The blade (CMT 40T combo) was still cutting fine but there was an extra workload from pushing harder and experience (the expensive kind) tells me that this is not friendly to the motor on the saw. This sharpening interval may be a bit shorter because of the heat build up from a continuous run but probably not much.
 
If you look at a tooth of a sharp blade, you see a very fine line along the top edge. A dull blades tooth will have a wider, shiny line where it's rounding over. The scratch test is good if you're careful! This works for planer and jointer blades too . After checking my jointer, I noticed two blades revealed a shiny line and one was fine, which I found out was too low and never did cut anything. Still sharp as the day I replaced the set! LOL! Oh, you need real good eyes or a magnifying glass for this test:eek:
 
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