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Best blade for cutting aluminum?

Posted by californian (My Page) on
Wed, Sep 12, 07 at 1:34

I am replacing some aluminum framed windows and doors and have two jobs to do as part of it.
1. Cutting the door frames in pieces so I can demolish them without damaging the stucco or drywall. First I used a 7 inch plywood blade in my wormdrive skillsaw but quickly wore it out when the teeth hit the stucco. Then I switched to 7 inch abrasive wheels and they worked better. Someone suggested using a 40 or 60 tooth carbide blade instead.
2. The windows have about a half inch drip edge protruding past the stucco which has to be cutoff flush with the stucco before installing the replacement vinyl windows. I tried the seven inch abrasive wheel in the skillsaw but it was too hard to control and couldn't reach the corners. So I went and bought a cheap 4 1/2 inch wheel Ryobi hand grinder for $39.99 which burnt out after about 20 minutes use using 1/8 inch abrasive wheels. The 5.5 amp motor just couldn't hack it. So I bought a Firestorm 4.5 inch grinder which was rated 8.5 amps for the same price, and switched to thinner 1/16 inch thick blades which I couldn't use in the Ryobi because it wouldn't clamp down enough on them. The thinner blades worked like a champ, only trouble is they wear out so fast, wore this one out just cutting off 3 feet of aluminum. At this rate I would use 6 blades up on one window, and they cost $1.98 each. I think part of the problem is there is some stucco touching the aluminum which eats the metal cutting blades up. Maybe I should use masonary blades instead? I don't guess a diamond blade would work on aluminum. Do they make a 4.5 inch carbide blade that would work in a hand grinder?
3. Some people have recommended I use my sawsall reciprocating saw, but I am thinking the thin layer of stucco on the aluminum would wear the blades out in about 30 seconds.
4. I do have a portaband saw but again I think the stucco would chew up the bandsaw blades so I can't use that, plus it couldn't get into the corners.

Follow-Up Postings:

RE: Best blade for cutting aluminum?

Aluminum is very sticky, and rather than dulling the blade, you will see bits of aluminum welded to the teeth. A carbide tipped saw specifically made for cutting aluminum is best. You can buy a stick wax lubricant for grinding aluminum, and Crisco works, too. For sawing and drilling, WD-40 or kerosene works pretty well at preventing chip welding. I've cut plenty of steel with a sawzall; aluminum is much softer/easier, if you can prevent chip welding.

RE: Best blade for cutting aluminum?

You are right about aluminum being sticky. It seems the abrasive blades are melting their way through the aluminum rather than cutting it. The metal retainer ring that is used to clamp the blades onto the spindle accidently touched the aluminum while I was cutting it and got a coating of aluminum welded to it that I had to scrape off. I went through five .045 inch thick abrasive blades and five 1/8 inch thick blades just cutting off the drip edges on three windows. Maybe I can find a 4.5 inch carbide toothed blade with a 7/8 inch arbor hole in it if I ever have to do this again. But can you spin a carbide blade safely at 10 or 11 thousand RPM?

RE: Best blade for cutting aluminum?

My experience with aluminum is that you need to clamp the work firmly especially with a carbide tipped blade.

The "stickiness" of the material makes the saw catch and if your not careful, fire aluminum shrapnel into your face.

The stick wax helps a lot, you also have to make sure your blade is sharp. Most aluminum contractors have several spare blades in case one gets dull.

I buy my carbide tipped aluminum cutting blades from B.C. Saw in Mississauga, Ontario. Theres bound to be specialty saw blade companys close to you who service the contractor and industrial market. B.C. Saw sells the blades and will sharpen them as well.

My 8" aluminum cutting blade for my miter box cost me about $90.00. I'm sure you could find a smaller blade.

Smaller blades are often used in automatic miter box saws used by window manufacturers.

CR Laurence is huge California based window shop supply house, you might call them and see who sells their saw blades to the public locally. Just Google their name.

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