Cutting Aluminum

I wanted to get some input on cutting aluminum with circular saws using carbide tipped blades [tips, techniques,etc.].I picked up a 10" Freud non ferrous blade for my mitre saw today [for cutting extrusions],but was more interested in what worked best on 7 1/4" circular saws.I have ripped 20 ft.
sheets of 1/8" before with good success using 24 tooth blades but was wondering if a 40 tooth finishing blade would work better for cutting curves?
What has been your experience?I have heard of guys pulling skillsaws backwards [in an attempt,from what I understand,to utilize the negative rake on the back side of the blade] but have not tried it myself.Also, regarding lubricants,the "expensive 10 blade "I bought today recommends using wd 40
and not a wax which concerns me do to the silicone content and potential for
weld contamination.I would like to hear your comments and suggestions on this subject,and any horror stories are O.K. too...

Regards, dick stave

 

I rip 1/2" alluminum all the time with a circular saw and never bothered with what sort of blade was on it.but you better ware glasses that thing will throw some stuff in your face.I think my saw just has a good wood blade probably carbide.When something has to be rounded i use the angle grinder "GO GRAB MY MAKITA"..And the sawzall.I don't use any lube at all mayby i should try some.It cuts fast and easy as it is though.

 

I cut out my 3/16" bottom plate this morning with a 40 tooth 7 1/4" finishing blade.
There was no problem making the 11 ft. radius dry cutting.The new boat is underway.
thanks, dick stave.

 

ready for this...

I build fuel tanks all the time and sometimes from 1/4 inch sheet.
Recently i bought from Sears a 5 1/2" circular saw and a set of ultra thin carbide blades. I can cut a scribe line perfectly streight without a guide.
Don't push hard on this one you can easily break the belt.
I hear Porter Cable has a 5 1/2" worm drive circular saw. Im all over that thing if i can find one. Oh and i use wax not WD 40.

 

I Cut everything with just a plain cheap blade. Don't get the real cheap ones but i build houses with the same saw and blade.. But i did buy a $35 skill just for the boat. The old one gave up when i was doing the 1/2" keel plate. The new one has built the boat to almost done stage. It still seems to run pretty good. Put on some cotton gloves and glasses with a face shield.. Its a painful process, The NOISE is incredible, so ear plugs are a must.. I have some special lube i bought 20 years ago and use it sparingly. But wax, wd40, is good too. Even if you don't use anything will work, it just loads up the side of the blade.
I use my band saws a lot too. HAPPY CUTTING. don't forget the lacquer thinner or acetone.. I like the smell of lacquer thinnner much better.
Gary

 

Soft metals are always cut with teeth that have offset teeth wider than the blade body. SHARP, wood blades work fine. SHARP carbides work fine. Key word in soft grabby metals is SHARP. Blade has to punch out those triangular chips without heating the metal to much or it starts to stick to the dull heat producing teeth. Same for the plastics in MOST cases.------------------------------There is no difference between a vertical band saw blades teeth and those of the circular saw.

 

A 7-1/4" skillsaw is the standard cutting tool here. I like 24 tooth blades but they dont hold up as well as the 40 tooth.
A few comments:
NEVER pull a skillsaw backwards.
With a little experience you can clean up imperfections with the "back" of the blade.
A standard carbide tipped "wood" blade works fine, but blades made by Matushita(about 49 bucks) and others are more durable. The blades I use are custom made by Cal- Ore Carbide here in Medford. They cost around $100 but will withstand 6 months of 10 hours a day cutting before sharpening.
WD 40 is not a lubricant!(personal pet peeve
A9 aluminum cutting fluid is ok, I prefer Cosmoline Non- ferrous metal lubricant. Comes in aerosol and 5 gallon cans

 

Blade effectiveness in aluminum

The key to cuttin aluminum with a circular saw is a blade where the carbine insert is 'revealed' a small distance (like 1 mm) outside the turning profile of the blank. The speed of rotation versus the speed of travel through the material exposes a constant amount of cutting edge carbide to the material being cut. So if the blade is an open gore wood blade that exposes a large surface of the carbide insert's face then impact will eventually tear the silver solder braze of the insert off the blank. On the other hand 'nail cutting blades' which have a very small gore (gap in front of the tooth insert) and therefore 'meter' the carbide, or regulate the exposure to cutting, into the aluminum will last much longer than conventional wood cutting blades.

Also food frying pan prep spray will keep the cut lubricated and will vaporize as a much lower temperature than petroleum based producs so "pam" is better as a release agent on cutting edges than oil. Blades with slightly dulled carbide from over agressvise bight in metal, will heat the aluminum and pick up melted shavings which "coat" the blade tips and make a dull or worn cut. The 'pam' spray acts to release these particles before they melt into a coating on the carbide insert on the blade and keeps the carbide edge available to 'scoop' or chisel a fresh shaving each revolution. Some low vapor point lubricants will work but are often more costly than generic "pan spay".

 

A worm drive saw is definately the best for torque and control of a straight cut.

The nonferrous blades I use have varying tooth profile, i.e., left, right, square or cupped,square. These configurations make for a much cooler and efficient cut.

The best lube is Boelube, developed and mfg. by Boeing Aircraft. (I think they've got a bit of experience working with aluminum.)

 

Ever see a Boeing worker cut aluminum with a circular saw?? Maybe once while he WAS employed.

 

Can't say I've ever been to Boeing so I can't say I've ever seen them drill, tap, ream, counterbore, file, finish, debur, sand, punch, rout, mill, turn, press, hammer, roll or break a single piece of aluminum. Oh, I forgot saw.
Just trying to be helpful with a bit of input Cyclops.

 

It was not taken in any other way, Mareng. Thank you, Rich.

 

There are circular saws special for metal.

Like the others, I have used common wood saws and blades with great luck. I've cut 1/8 to 1/2 aluminum with them - no problem. I do use carbide and it cuts 1/8 width.
I bought a Evolution saw - special for metal and cut my first aluminum with it last week - 3/16th and 1/4. It was the best of all the wood saw.
It cost more than I liked - $400.00 / blades are $50.00 U.S. in Alaska.
Wood saws will do it for a long time and are easier to handle.
I would not buy the Evolution if I had to do it over, but it does cut a smaller path and catches the cuttings in a special compartment.

 

Found the best blade for cutting sheet

I will never use a wood saw blade again for cutting aluminum! I stumbled on a company when surfing the internet that makes THE BEST carbide tipped aluminum saw blade. I have to cut a lot of 1/8" - 1/4" aluminum sheet metal and the wood blades just werent cutting the mustard. I need a really clean edge that I can weld and all of the not-so-cheap wood blades I bought from Home Depot were leaving burrs that I had to then file. (That is when they weren't throwing teeth).
Solution: I bought an 8" General Saw, thin kerf, saw blade, and MAN, it is like cutting butter. I must have destroyed 5 blades before I found ONE that is my MVP now. This guy named Roman told me that a wood blade will throw teeth because there is too much hook. I am a believer now.

 

I've never tried using my Skilsaw on aluminum plate.... borrowing a plasma cutter is so much easier and quieter ;-)
Having said that, I'd agree with Yachta's advice on using a carbide blade designed for aluminum. Some of you may have had luck with wood blades on sheet metal, but I'm a believer in using a tool designed for the job.