How do I cut 19mm aluminum?

[pwe]

Hi all,

So I've got a project coming up that will require me to cut some 19mm thick aluminium to make a shape. My initial plan was to use an angle grinder, however, from what I've read on the internet and the tight inside corner I'd need to cut, I don't thick that's a great idea.

Now, I'm stuck trying to work out the best way to do it.

I thought about milling it, but don't own a mill nor do I really want one for a one-off project. I thought about using a cnc router of some kind, but apparently that's not a great idea. I've thought about using a plasma cutter but the hobby ones I've found only seem to be able to do a "severance cut" (not really sure what that means) of 12mm.

How would you guys go about doing it?

Before one of you inevitably asks, yes it does have to be 19mm (3/4 inch) unfortunately. Yes, I have thought about having it done by an outside shop (particularly by laser/waterjet cut) but the cheapest quote I've had is from a Chinese factory at $600 excluding shipping and import tax; which is insane for a part that's less that 6 inches long and 4 inches wide.

Not that I know anything about plasma cutting, but is it possible to do multiple "passes" with the plasma cutter, like 3 passes as if I'm cutting 1/4 inch material, let it cool down between passes to minimize warpage (I think there's inevitably going to be some, but these aren't precision parts so I'm not bothered if they aren't mill flat.

Any help would be greatly appreciated!

 

[Hood]

All depends on the shape.
Vertical bandsaw would likely work, a mill would likely work, a big enough plasma would work.
Regarding multiple passes with a small plasma, nope that would just make a mess and mess up your nozzle after 10mm of cutting on the first pass. A plasma needs to cut right through the material to work.

 

[hotponyshoes]

No, you can't really do multiple passes with a plasma, you'll struggle to do 19mm thick alloy with most hand-held shop plasmas I'd think.

For a home solution I'd be using a jigsaw if you have one?

Or find someone with a band saw?

If it's just a 90deg internal corner then an angle grinder for most of it, finishing up with a hacksaw then clean up with a big file/old farriers rasp

At 6"x4" you could blue it up and pop it in the post to someone easily enough!

 

[Hitch]

What sort of shape are we talking?

A good Jigsaw with a coarse progressor metal blade will work but a touch slow.

 

[pwe]

What sort of shape are we talking?

A good Jigsaw with a coarse progressor metal blade will work but a touch slow.

It's like a star shape (almost) - it has five points going out, but of different lengths. If you remember the old laser symbol, it kind of looks like that.

With the jigsaw, do you recommend taping the aluminium to avoid splitting/chipping the metal like you do with wood (to be honest, it's been a while since I pulled my dad's old jigsaw out)?

 

[finyuk2005]

a normal wood circular saw works amazingly well on aluminium, it might work to get the rough shape as long as its all straight lines

 

[optima21]

might be able to do it with a hacksaw and file or two

 

[Hitch]

It's like a star shape (almost) - it has five points going out, but of different lengths. If you remember the old laser symbol, it kind of looks like that.

With the jigsaw, do you recommend taping the aluminium to avoid splitting/chipping the metal like you do with wood (to be honest, it's been a while since I pulled my dad's old jigsaw out)?

Clogging will be the biggest issue, plenty of cutting fluid to stop it sticking. It'll need some truing up with a file or two just like any other method.

 

[minimutly]

Find someone with a coarse metal cutting bandsaw, it will be a cinch.

 

[Screwdriver]

You wanna oneothese:

Look at those chips! Perfect!

 

[CaptainPugwash]

Do both pieces need to be to a certain dimension, or just one?
Are you keeping the piece on the outside of any radius?

Can this not be done with hand tools?
A dreadnought file won't clog up as bad as a normal bastard double cut file with ali.
A drawing or sketch might reveal that a bit of chain drilling and sawing could help with getting this to an easily file-able situation as a one off?

 

[gaz1]

if you use a jigsaw and you support the long blade it becomes something else similar to a scroll saw

 

[Barking Mat]

My experience with plasma cutting aluminium is you you don't get a very clean cut, will need much sanding / filing / grinding.

 

[sako243]

Jigsaw with wood cutting blade for straight edges, or maybe table saw for the majority of it.

Could use a die grinder and burr to finish up.

 

[Morrisman]

What sort of shape are we talking?

A good Jigsaw with a coarse progressor metal blade will work but a touch slow.

I’ve cut 3/4” aluminium with a jig saw, using a new sharp HSS wood saw blade. It’s slow, but with plenty of wd40 it made steady progress.

The 1/2” ally engine plates and the 3/4” ” rear brake caliper mount were all done with me trusty old Black and Decker jigsaw.

 

[RichardM]

I've done it with a jigsaw before, really depends on what size it is as it will be a slow job. Masking tape with the design marked on it, if you need protect the surface, although it will be ruined by the WD40 which would be better as a cutting fluid as you can direct it onto the blade with the red tube easier.

 

[oldbikedavey]

I'd fire up my Startrite 18-V-10.....

 

[Agroshield]

...although it will be ruined by the WD40...

A liquid lube when sawing aluminium is not always the best. To be useful, you need to use it as a flood, to sluice the chips away. Dampness just makes a messy slurry of liquid and aluminium dust. There is not really a good halfway house: either cut dry and blow the chips away, use a wax lubricant (candle rubbed along cut line from above and below) or cut properly wet.

A variable speed jigsaw on a low setting is good for aluminium. Clamp a straight edge to the piece and use it to guide the jigsaw.

No-one has mentioned that for metal cutting, you need to switch off the pendulum action.

 

[Hood]

My experience with plasma cutting aluminium is you you don't get a very clean cut, will need much sanding / filing / grinding.

It is not too bad, this is straight off the plasma, not a nice smooth surface like steel but still acceptable.

 

[Melvyn Best]

I once made an inlet manifold using 12mm ally plate that I cut using a woodworking coping saw with plenty of cutting lube. Worked surprisingly well.