Cutting aluminum for dummies

[pgray007]

I’ve never cut aluminum beyond one-off jobs with a hacksaw. I’m installing metal railing on my deck, and will need to cut several of the posts and rail sections to size.

I have a standard miter saw and have seen conflicting reports on whether the tool can be used, and whether or not I need a special blade. Ideally I’d like to use the miter since I’ll need to make lots of consistent cuts, and would like to keep them nice and square versus the hacksaw or sawzall.

I’ve also seen conflicting reports on whether I need to apply anything (paint, rustoleum, “touch up marker”) to the cut AL ends.

Any tips/tricks/different tools?

Thanks!


Sent from my iPad using Tapatalk

 

[Leaflessshadetree]

I cut some aluminum extrusions with my miter saw. I used a carbide tipped blade with a high tooth count (previously used for finish trim). I did lower the blade slowly as I cut but it went through it fine.
No need to paint the ends other than cosmetic.

 

[The Cobbler]

there are special blades for aluminum, but a regular carbide blade is fine.
a fine tooth blade, feed slowly . don't start the blade with it on the metal.
a spray of wd40 on the blade sides is good lubrication

 

[PugetDude]

Post 13 for what NOT to do:
https://www.garagejournal.com/forum/showthread.php?t=451386

 

[Dumber than lumber]

I have some cheap *** B&D Firestorm combination blades. They work better on my table saw than anything else i have tried. I primarily use it on aluminum angle. I use my precision miter gauge to get 45 degrees.

 

[jeepinerdeep]

I'd use the miter no problem. I would get a purpose built blade just so you get maximum quality and minimum aggravation.

If it's some residential handrail extrusion, I imagine 99.9% of that installed in the world today was cut on some general contractors miter saw.

 

[PCustoms]

Cheap high tooth blade, squirt of wd40 or a wax stick and ear/eye protection.

It will scream and throw sharp chips, but cuts nice and clean.

 

[InDaRed2]

I've also used a high tooth carbide blade no problem on some 80/20 extrusion. A little squirt of WD40 and you're good to go. Makes a freaking mess though with the chips!

 

[m32825]

Post 13 for what NOT to do:
https://www.garagejournal.com/forum/showthread.php?t=451386

Wow, bet that hurt! Reminds me of ET's finger...

 

[VR6ix]

...
I have a standard miter saw and have seen conflicting reports on whether the tool can be used, and whether or not I need a special blade....

I’ve also seen conflicting reports on whether I need to apply anything (paint, rustoleum, “touch up marker”) to the cut AL ends.

Consider the hierarchy of metals: anything harder and tougher than aluminium is going to work fine to cut aluminium. The cheapest carbide blade you can find will work great, as everyone else has stated: hearing protection is key, clamp the work, feed gently and don't let the blade grab the work, WD40 as needed, and the chips will go EVERYWHERE lol! Check the teeth between cuts, sticky chips are normal but if it's gumming-up and making a mess you need to clean the blade and use more lube and way less feed rate to stop the chips from melting.

Absolutely no need to "treat" the fresh cut ends. Aluminium will naturally form an oxide layer which protects the base metal from further corrosion. Just deburr the cut ends for safe handling and carry on.

Easy-peasy, just give 'er!

 

[JJohns3WG]

One of the times that I will grab a face shield instead of squinting, long sleeve shirt or sweatshirt and gloves if I have much to do. I use whatever half worn out carbide blade that's in the saw and plan on putting the new one in afterwords.

 

[Kevin54]

Like stated above.....face shield and safety glasses or goggles. Long sleeve shirt, a wax stick, and a carbide blade. You WILL have chips all over you. Best to have a hat on also.

At work, we used to cut 1" aluminum plate in a table saw, and smaller stuff in a miter saw on a daily basis. The thicker the aluminum, the slower you have to go. Just be safe. And if you don't have good eye protection, spend a couple of bucks and get some. A warm sharp aluminum chip in the eye is not a good thing. Believe me on that one.

 

[pgray007]

Thanks for all these tips. Incredibly helpful! I got a “real” AL blade and should be cutting later today...


Sent from my iPad using Tapatalk

 

[dr_clyde]

I used to make a product for a company that involved cross cutting corrugated aluminum sheeting, 11ga thick. We used an aluminum blade in a worm drive Skilsaw. Cut great. We could get maybe a few hundred linear feet of life out of a blade before aluminum would start to build up on the blade and cause binding. Since these were welded in a fussy fashion, we didn't want to be adding any sort of lubricant that could mess with the weld.

In general, a squirt of WD-40 or some stick wax works wonders for blade life and chip release.

Just about any woodworking tool will cut aluminum if it has a carbide blade. HSS will do it too, just not as well or for as long.

We use routers all the time to put radii and chamfers on aluminum bar and tube.

The rules are the same for any kind of metal cutting. Use appropriate feeds and speeds. Cut with lubricant or coolant of some kind if possible. Use sharp tools. Wear hearing and eye protection. Be prepared for the tool to grab and cause problems. Hold the work as well as possible.

 

[danielbuck]

woodworking power tools can be used suprisingly well on aluminum plate. I've used a table saw, chop saw, circular saw, router and even a scroll saw & jig for aluminum. (actually, I use a jig saw for steel fairly often too, with metal cutting blades though)

If you're going to be doing lots of it, it might be a good idea to get a dedicated blade meant for cutting aluminum, but a regular wood cutting blade will work. I would suggest using a blade with a high tooth count.

Just a fair warning, you will get small aluminum chips EVERYWHERE. haha Thickest I've cut is 3/8", thinnest is 1/8".

 

[toplessHO]

Post 13 for what NOT to do:
https://www.garagejournal.com/forum/showthread.php?t=451386

yikes ,missed that
Did you soak in cider to make the swelling go down?

 

[Farrier]

Not to be the safety police, but be sure not use a metal cutting blade that's rated for low RPM in a high RPM wood cutting tool

 

[Kevin54]

Not to be the safety police, but be sure not use a metal cutting blade that's rated for low RPM in a high RPM wood cutting tool

Ran carbide blades in a table saw for years and never had a problem. The only problem we did have was if you rushed the aluminum through, it would stall the motor. Then we'd have to wait on it to cool before the reset button would take.

 

[Monza Harry]

Not to be the safety police, but be sure not use a metal cutting blade that's rated for low RPM in a high RPM wood cutting tool

I think this is excellent advice!

I used to make a product for a company that involved cross cutting corrugated aluminum sheeting, 11ga thick. We used an aluminum blade in a worm drive Skilsaw. Cut great. We could get maybe a few hundred linear feet of life out of a blade before aluminum would start to build up on the blade and cause binding. Since these were welded in a fussy fashion, we didn't want to be adding any sort of lubricant that could mess with the weld.

In general, a squirt of WD-40 or some stick wax works wonders for blade life and chip release.

Just about any woodworking tool will cut aluminum if it has a carbide blade. HSS will do it too, just not as well or for as long.

We use routers all the time to put radii and chamfers on aluminum bar and tube.

The rules are the same for any kind of metal cutting. Use appropriate feeds and speeds. Cut with lubricant or coolant of some kind if possible. Use sharp tools. Wear hearing and eye protection. Be prepared for the tool to grab and cause problems. Hold the work as well as possible.

Hey Doc compressed air is an "Ok" lube/coolant more coolant than lube but has been used for years and years in the machine/tool shops I've worked in. [non-contaminating generally]
And as Kevin stated FACE SHIELD and non melt clothing ie: no polyester! Also cheap bar hand soap is an acceptable lube/anti-stick for this application, whatever you like at the dollar store, like Irish Spring, Ivory, etc. Harry

 

[pgray007]

Well I was having a great old time cutting AL thanks to everyone’s tips, then this happened:



Chopped up my rail pretty good jacked up my saw a little bit, and scared the **** out of me, but otherwise all’s well.




We’ll see if HD will honor the Diablo “lifetime” warranty since this guy probably only made a few dozen cuts.


Sent from my iPhone using Tapatalk

 

[The Cobbler]

you jammed the saw , did you start the saw with the blade depressed into the work, or try to cut to fast?

 

[PugetDude]

Well I was having a great old time cutting AL thanks to everyone’s tips, then this happened:



Chopped up my rail pretty good jacked up my saw a little bit, and scared the **** out of me, but otherwise all’s well.




We’ll see if HD will honor the Diablo “lifetime” warranty since this guy probably only made a few dozen cuts.


Sent from my iPhone using Tapatalk

That looks familiar. Check your fence carefully for cracks...and your spindle for runout if it bent the blade. I tossed my 30+ year old Ryobi miter saw due to these issues after a crash when I was cutting aluminum angle.

 

[JRC3]

Cut aluminum SLOWLY.

 

[pgray007]

That looks familiar. Check your fence carefully for cracks...and your spindle for runout if it bent the blade. I tossed my 30+ year old Ryobi miter saw due to these issues after a crash when I was cutting aluminum angle.

Blade doesn’t appear bent (just lost a couple teeth). Fence looks ok. How does one check the spindle?


Sent from my iPhone using Tapatalk

 

[pgray007]

you jammed the saw , did you start the saw with the blade depressed into the work, or try to cut to fast?

I’ve been cutting pretty darn slowly based on the tips here and this was a pretty thin piece (probably around or less than 1mm rail cover). Maybe I need to slow down even more or I just got ahead of myself...

And no on starting in the work. Always start outside and let the saw come up to speed is what I was taught.


Sent from my iPhone using Tapatalk

 

[PugetDude]

Blade doesn’t appear bent (just lost a couple teeth). Fence looks ok. How does one check the spindle?


Sent from my iPhone using Tapatalk

Ideally you'd use a dial indicator, but you can use a piece of heavy wire and a set of feeler gauges in a pinch. You just need something rigid to keep the tip from moving when you're checking the runout.
UNPLUG the saw.
Put a new (high quality) on the spindle, tighten it down firmly and set up your indicator just inboard of the teeth, on a continuous part of the blade. Slowly rotate the blade by hand and note how far the blade moves away or toward the indicator. A dial indicator will give you a continuous readout; a fixed wire and a set of feeler gauges will give you an idea if there is excessive runout in your blade, say >,010". If there is, try spinning the blade 90 degrees and try your readings again.

A professional machinist would use a ground flat circular plate of known flatness, a precision dial indicator and give you an answer to 5 decimal places.

Good luck.

 

[Aaron_W]

Well I was having a great old time cutting AL thanks to everyone’s tips, then this happened:



Chopped up my rail pretty good jacked up my saw a little bit, and scared the **** out of me, but otherwise all’s well.




We’ll see if HD will honor the Diablo “lifetime” warranty since this guy probably only made a few dozen cuts.


Sent from my iPhone using Tapatalk

Were you using the Diablo blade made for laminates and non-ferrous metals or just a carbide wood blade?

Just wondering because I've been using their non-ferrous blade for a couple of years to cut brass and aluminum up to 1" bar on a 7-1/4" miter saw.

Tubing can be a problem, I cut a piece of 4" ABS pipe, a piece about 1/2" with my 12" miter saw. I had made several cuts on a longer piece, and this was just trimming the last piece to size of the rest.
That narrow piece of pipe twisted just right and caught in the blade, cracking the plastic insert in the saw table and scaring the piss out of me.

 

[PCustoms]

was the piece flat on the table, or flat against the fence?

 

[tyyost]

I’ve posted in these threads before, and you are on the right track. Aluminum extrusions, shapes, and profiles cut well in a common miter saw. When you get to thinner metal, you really need to consider the large gap at the fence and throat of the saw. There is a lot of force exerted to create chips cutting the metal and chatter(vibration of the part) can make many things go sideways.

Larger shapes are rigid enough to be forgiving of the lack of support close to the cut, but thin materials always benefit from a sacrificial fence/table on the main table. They provide close support and zero clearance for the blade and the work, and for small parts give you a place to clamp work.

 

[UglySign]

And as Kevin stated FACE SHIELD and non melt clothing ie: no polyester! Also cheap bar hand soap is an acceptable lube/anti-stick for this application, whatever you like at the dollar store, like Irish Spring, Ivory, etc. Harry

Dont forget a hat for those who sport the Moby look.
A coworker once got a few chips on his skull that were hot
and well let go and the fence busted. They can land on your neck too
so you might as well be in a bubble cutting.



Missing teeth in a blade is for the garbage can.


Sacrificial fences is your best bet as well as safely clamping the work piece if possible. Look ahead before you cut and imagine what could happen.


Bring blade to speed, cut, wait to slow down, release. Small pieces bind with the suction if released to soon.


Of course coolant/lubrication.

 

[zeug]

First of all, glad you are OK. I remember having a tool let go of the morse taper in my MFE class in college. Not only got my adrenaline going, but woke my teacher up rather quickly! I I quickly learned how to properly install a tapered tool and inspect for fit.

Can we see a picture of the end of that piece of metal? I would also like to know what direction you were cutting, orientation of the metal, and how far in the cut you were before it grabbed. This would help diagnose the cause of failure.

 

[sqznby]

The thinner material has to be cut extremely slow. Or what happened will happen again.
As you can see it will flex and bite yah.

 

[j p smith]

Helped a guy one time, he used a blade for wood and mounted the blade to run backwards with a worm drive skill saw

 

[garrettlee]

We've been using the blue Avanti blades from HD (40 tooth count) in our table saw at work and cut up to 3/8 aluminum for years just fine. I make sure to use plenty of WD-40 though.

 

[Terry D]

Well I was having a great old time cutting AL thanks to everyone’s tips, then this happened:



Chopped up my rail pretty good jacked up my saw a little bit, and scared the **** out of me, but otherwise all’s well.




We’ll see if HD will honor the Diablo “lifetime” warranty since this guy probably only made a few dozen cuts.


Sent from my iPhone using Tapatalk

What is the rated RPM of the blade compared to the saws RPM