Yet another Saw Stop Question

[jeffss]

This could be a silly question but here goes. I was ripping quiet a few board that had Polyurethaned a few days ago. Did I run the risk of gumming up my blade and undermine its safety?  thanks 

[Bill_de]

(11-22-2020, 08:54 PM)jeffss Wrote: This could be a silly question but here goes. I was ripping quiet a few board that had Polyurethaned a few days ago. Did I run the risk of gumming up my blade and undermine its safety?  thanks 

Shouldn't be a problem, but to be sure just pull the blade and clean it.

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[JohnnyEgo]

I do not believe you will have a problem. I have the unfortunate first-hand experience (pun intended) of having a blade embedded in a standard cartridge on my bookshelf here in the shop. Thought about making a clock out of it or something. I've also tested the dado cartridge with a hidden staple. The spring is pretty stout and drives up fast and with significant force. In both of my experiences, the blade was well-buried in the aluminum block. Power also gets cut to the motor right away, so the blade is only going in with the momentum it is carrying with it. I can't imagine your gummy polyurethane would provide sufficient lubrication to make that much of a difference in the speed of capture, should it fire.

I'd be more worried about the messy gunk on the blade or in the cabinet than I would about it stopping safely.

[iclark]

(11-22-2020, 08:54 PM)jeffss Wrote: This could be a silly question but here goes. I was ripping quiet a few board that had Polyurethaned a few days ago. Did I run the risk of gumming up my blade and undermine its safety?  thanks 

Are you asking whether or not the polyurethane has enough electrical conductivity to trip the SS sensor (like cutting some wet pressure-treated wood might)?

[EightFingers]

Either that or increase the electrical resistance, possibly not allowing the saw to “see” flesh contact?

[kroll]

I bet running little oak across that blade will help clean it up. I think that when cutting/ripping pine is a problem due to sap pockets.

[jeffss]

(11-23-2020, 01:05 AM)iclark Wrote: Are you asking whether or not the polyurethane has enough electrical conductivity to trip the SS sensor (like cutting some wet pressure-treated wood might)?

I was more worried that the blade becomes "coated" and will not trigger if need be.

[iclark]

(11-23-2020, 09:26 AM)jeffss Wrote: I was more worried that the blade becomes "coated" and will not trigger if need be.

I can understand that concern, but I have trouble imagining any significant build up of a finish on the blade tips (unless the blade is both negative rake and horribly dull).

I would expect the cutting action to continuously clean the blade tip as it slices through wood.

As long as the tips are clean, the safety circuit should be good to go.

If you start getting a lot of sap or finish build up on the blade/spindle area, just be sure that you do a good job of cleaning that area when you change blades. That is important for both the electrical connection and the blade run-out.

[stoli]

(11-23-2020, 09:26 AM)jeffss Wrote: I was more worried that the blade becomes "coated" and will not trigger if need be.

You can test this yourself, to varying degrees of completeness/safety.

With the saw on BUT NOT RUNNING, grab a screwdriver (or something else conductive) and touch the blade.  I believe this should be enough to trigger the lights to show a triggering condition, but since the saw is not running, it will not actually trip the mechanism.  Maybe you have an INCRA or other aluminum fence around to use instead.

You could also try the same thing with a hot dog in your hand, to avoid the question of the "sharp" contact caused by the screwdriver.

Finally, and not totally recommended, you could directly touch the blade.  This is the best test to see if the blade would still sense skin, but also the most dangerous since the saw is still on, and best practice is to UNPLUG, not just turn off, the saw before you get your hand close to the blade.