[WallyB]

I have a Hitachi 10" sliding miter saw spinning a Freud 80 tooth finish blade. This has been working well for quite a while but recently I've encountered a couple problems. If working from the left side of the blade (which I normally do since I'm right handed), I've started to get tearout, burning, and even gouging by the trailing edge of the blade. If I switch sides and work from the right of the blade, I get very little of this.
Does this sound like a saw alignment problem or a failing blade problem? I've removed, cleaned, and reset the blade, but nothing changes. It's not a new blade, but I've certainly not put it through as much use as any pro would. And there is no apparent tooth damage.
I contacted Hitachi about alignment procedures and they just sent me a link to find a repair facility. :thumbdown:
Any ideas or thoughts would be appreciated.

Thanks,
Wally

 

[sawdustfactory]

You might have a slightly bent tooth. Has the saw gotten noisier lately?

 

[cabinetman]

How do you cut...plunge down and pull forward, or, pull out, lower blade and push back?

.

 

[knotscott]

If the blade is clean, I'd suspect that it may be dull. Technique could also be a contributor as Cabinetman pointed out, and then there's always the fact that some materials are just more prone to tearout than others. I'd consider having the blade resharpened or replaced if you don't find any other smoking guns.

 

[rrich]

You might have a slightly bent tooth. Has the saw gotten noisier lately?

+1

The best way to cut is through the back against the fence, raise and score the top to the front of the work piece, lower, cutting through the front edge and push back finishing the cut.

 

[WallyB]

sawdustfactory - I don't see a bent tooth, and there hasn't been any noise increase that I've noticed. I'll pull the blade and look at it more closely.

cabinetman - I pull forward, lower the blade, and push back. I have to admit I never even considered plunging and pulling. I do plunge if the item is narrow enough for that, and I only see minor burning when I do that.

knotscott - I guess I didn't think it was dull since it hasn't had THAT much wear and it looks/feels sharp enough. I'm not sure paying to have a $40 blade sharpened is worth it. It may be time for me to spring for an upgrade and save this one for rough work.

rrich - Are you saying to score the top of the board with a shallow pull and then cut it through with a full depth push? Does this also apply when you've doing something with a full-over bevel setting?

Thanks for all the input guys,
Wally

 

[knotscott]

....knotscott - I guess I didn't think it was dull since it hasn't had THAT much wear and it looks/feels sharp enough. I'm not sure paying to have a $40 blade sharpened is worth it. It may be time for me to spring for an upgrade and save this one for rough work.

All of Freud's blades are worth sharpening IMO. Whether or not that particular blade is the appropriate blade for the task, I can't say. A Hi-ATB will have the least tearout of any grind, but also has the shortest edge life. A triple chip grind (TCG) will have more tearout, but the longest edge life. A standard ATB grind is a decent compromise.

Dynamic Saw Sharpening is a top notch outfit that charges $13.50 to sharpen an 80T blade, plus s/h...prolly ~ $30 round trip, but sending more than one blade maximizes the shipping costs.

In case you pursue a new blade, here's a list of some decent blade bargains.

 

[rrich]

...rrich - Are you saying to score the top of the board with a shallow pull and then cut it through with a full depth push? Does this also apply when you've doing something with a full-over bevel setting?

Yeah. What you are trying to do is to have the teeth pull into the kerf. If you just pull straight through the top side of the cut has the teeth pulling chips and dust into the kerf while the bottom side is being pulled out of the kerf. You get rough edges when the blade breaks the wood out of the kerf.

I watched a finish carpenter cut the molding for around windows and that was the way that he made every cut. I couldn't figure it out and had to ask. He laughed and explained. He said that none of his apprentices ever bothered to ask.

 

[rrich]

I'll start another thread on how to check for bent teeth.

 

[DannyT]

over the years i noticed that the left side of the miter saw blade would dull first. when I needed to shave a little off of a board the board is always to the left of the blade since I am right handed so the left side of the blade got more use then the right edge did.

 

[rrich]

There is one other thing. The RAS people will bear me out on this one. If the blade is not parallel to the path of the cut, the rear of the blade will drag and cause a rough cut.

This problem would happen all the time on my old RAS until I discovered the problem.

"Thou shalt not put threads into aluminum and expect torque to hold."

 

[WallyB]

Thanks, knotscott. I'm really getting educated on blades. Your info and links really help. I guess I'm in no great hurry, so some studying is in order.

 

[WallyB]

DannyT - that makes so much sense that I'm embarrassed I didn't even consider it. I guess I'll start working left handed.

rrich - I gave that cutting method a try and it wasn't as hard as I thought. I didn't do it on a high bevel angle yet, but next time I have one to cut I'll try it. Also, I understand about the parallel blade. That was my first thought and that's what I was contacting Hitachi about but they didn't help. I've done checks with the various measuring tools I have and everything seems good. If a different blade doesn't fix it I'll know I have an alignment problem.

Thanks everyone for the great help!

 

[DannyT]

it took me a while before i figured it out.