Can't figure out why table saw is burning wood

[Trip]

==>I mean really.....years without a burn?

It really has been a very long time… If I see burning on well-behaved stock, then I start looking for problems... In 99% of the cases, it's a dull blade... That’s expected… I can get burning with wonky wood – that’s also expected… What I’m talking about is unexpected burning… You process a reasonably-sized well-behaved stick with a sharp blade -- no burning... Occasionally, I’m distracted and my technique’s off… That happens --- and I walk away with minor spot-burning...  Or maybe processing something really awkward (Roubo benchtop comes to mind and the occasional 4x8 sheet of BB) --- but I usually just stop ripping, reposition and continue without much issue… The last real burning I had was processing my Roubo's top, but that's an entertaining story for another day...

 

Until recently, it really has been many months (and probably more than one year) since I got unexpected burning… If it happens, I start troubleshooting… I have not had to readjust my alignment/setup in a very long time... Recently, I got some burning that couldn’t be attributed to a dull blade or wonky stock, so I checked and the fence was indeed a couple thou cast-in... Must have gotten banged somehow.... It happens, but not often… But I detected it on the first rip, stopped what I was doing to change blades, got the exact same burning on the next pass, so stopped to troubleshoot the issue... That's how rare burning should be: if I see it once, dull blade; twice, alignment issue...

 

My workflow also reduces problems at the tablesaw… Rough rips are performed at a bandsaw, and if the stick is wonky, continues at the bandsaw...

 

Having reasonable stock storage in the shop, forward planning and being a hobbyist contributes: Stock is picked and staged well before starting a project – my acclimation time is measured in months – sometimes many months… I can only get away with that because I’m a hobbyist – and my honey-do list is measured in years – probably lifetimes   By the time sticks are processed, they are very well behaved…

 

Using the right blade helps… I batch my operations… If I’m going to rip a bunch of 8/4 Hard Maple or 12/4 QS Padauk, I mount a dedicated rip blade… Going to process sheet goods, then it’s a plywood blade, etc.. I would not use a Hi-A/T blade to rip hardwood… That being said, I'm reasonably OCD, but not totally anal: a WW-II #6 grind (ATBR) is mounted about 80% of the time… I only switch blades when it's a batch operation, not the one-off cut...

 

Having a well-tuned and properly setup saw really helps (and having a Father-in-law who’s a Master pattern-maker setup the saw in the first place). If you like, you can try a couple of traditional pattern-maker’s tests: stand a nickel on edge on the saw’s table, start the saw, rip some stock, turn-off the saw --- the nickel should still be standing… And under no circumstances should anyone try this one -- ever: take a long well-behaved stick, rip it half way, leave the saw running while you go make some coffee (actually, I was told it was to take a leak, but this is a family-friendly forum), then return to continue the rip… Like I said, don’t try that one…

 

So yea, I don’t get burning all that often… And when I do, it's usually a dull blade, wonky wood or cockpit error...

[dwacker]

I agree with HHH everyone gets a burn here and there but it should not be a regular occurrence.

[AceHoleInOne]

Just looked at the specs on my riving knife and spreader:

Thickness: 2.3mm

Blade body range: 1.8-2.1mm

Kerf range: 2.35-3.5mm

The blade body on the Freud Premier Fusion is 2.6mm and almost as wide as the carbide. Could be this blade is a bad match with this saw. Maybe not. Could be a dull blade or bad splitter alignment. I got my first two saws tuned in and will get this one.

On the last cut the cutoff bowed into the board so probably contributed to burning.

ImageUploadedByTapatalk1424743385.997954.jpg

 

 

 

 

 

Yep I can see that. And you're cutting close to that flat grain, which if there is any tension. its typically found around there. Chances are, if cuts are going good then you have a board and it begins to pinch and hard to push. You found tension. 

 

-Ace-

[estesbubba]

Got my Premier Fusion blade sharpened, adjusted my riving knife, and made about 10 cuts with rift sawn red oak and all is well.

[wouldwurker]

Came in late here, maybe too late...

 

I was having burning problems as well - fence was at a perfect 90. 

 

Turned out my freud fusion general purpose blade was a hair wonky - could feel it when I laid it on a flat surface.  New blade and no problems.

[Trip]

I haven’t any experience with the blade in question… Did some fly-over research… On Amazon, the blade seems to have a polar review history… Some think its great and give it 5-stars and the others report burning with 1-star. Very little in-between... Makes you wonder if the blade is being miss-marketed as general purpose (which a Hi-AT grind is not) and/or they have QC issues…

[estesbubba]

I'm lucky to have a sharpening service that is 4 miles away and has some really good equipment. The sharpening instructions for the blade said not to take anything off the sides until sharpening #5. My guy said the double side grind that leaves a glass smooth finish also makes the blade pickier at times. He said my blade wasn't too dull but lightly hit it and also tweaked the side grind just a hair. My test cuts yesterday had smooth finishes on both rips and crosscuts and fed easily with no burning.