Thread: Cutting Aluminum with a Router

The problem with using a V router cutter in aluminiun is that the cutting tip is very small and as a result the ali will tend to stick to the cutter and clog it up. Once that happens the rest of the cut is just generating heat and this will make the glogging worst.

I think you would get a better result making a jig that will accept and hold the 4" pipe so that a track saw can be used.

An expensive track saw option is the one that is specifically designed to cut a V groove in aluminiun.

http://www.festool.com.au/epages/too...roducts/575003

The dust collector will have no problems with the metal flakes but if you use a liquid lubricant it will in time oil up the inside of the hose and cause problems when used with wood. This would be solved by using a dry lub.

I've done a fair bit Al routing and cutting with WW gear, I got the idea from watching my BIL who is an Al boat builder and uses many WW power tools in his work.

Routing on edges is straightforward, rub hard wax onto the edge and use router as per usual.
The wax is essential or the Al will gall onto the edges and if left unchecked it will make a complete mess.
If a bit of galling appears the finish will not be as good but it will still keep working for a while.
I use a slow speed than 20,000 rpm, typically 15,000 rpm

Routing slots is somewhat trickier.
If the bit galls, even just a wee bit it, rattles the bit in the slot can then grab and shake the shyte out of the workpiece making the slot wider and rougher, and even breaking bits.
You'll need more force than cutting wood so you can't use really small bits unless they are brand new and then they only last for a few cuts before they need cleaning.
On a sediment core tube I could even envisage it grabbing the tube and cutting crooked.
If you did not want to risk the bit grabbing and cutting through the plastic you'd need think about the pros and cons of the bit type.
Up cut will dig in possibly penetrating the plastic, and down cut will spray the plastic with swarf, could even melt the plastic.

The way I would do this is with a Table saw with a negative raked toothed blade and set the TS up with a suitable stop high high enough above the blade so you could rotate the core tubes.
The blade I bought a few years ago was a Chinese Bosch blade ($69) and that is the blade I tend to leave on my TS, as well as Al it cuts brass and plastics and also wood - but very slowly.
The negative raked teeth are essential because they don't pull the work into the teeth but push the work away and scrape away the Al.
I would make and install a guard to completely cover the blade except for the depth of teeth needed to cut the Al tube.
Hard wax rubbed on the workpiece and blade teeth would reduce the likelihood of galling.

Whatever you use the savings are like little razor blades so full face protection is needed - my DC sweeps those from a TS away but using a router table is considerably less effective.
Also your tubes will get in the way of dust/swarf collection but you will have to live with that.

Meths is a fantastic lube for Al as it leaves no mess BUT you need to be careful and not have ANY sparks happening. to work properly you need to apply lots of it and thus you cannot use it for very long because it will fill the shed with vapour - i.e. flammable and can make you very sick. I use meths on Al, mainly on a DP, BS and metal lathe, especially with Forstner bits, and apply it with a hand pump spray pack. Wax works better on a TS and router.

I agree with Bohdan, a circular saw is probably a better option than a router

From a safety standpoint, I would use a table saw. Build a sled that can be clamped to the table. Make it a "V" to hold your plastic / aluminum. Raise the blade through the sled just enough to cut into the plastic sleeve. With the saw running, gently put the plastic / aluminum into the "V". Hold the left end with your left hand and press down with your right. Use your left hand to turn the plastic / aluminum in a clockwise direction.

Another thought that is even safer. Just use a pipe cutter, one of those hand operated ones with a couple of rollers to hold the pipe and a cutting wheel.

Originally Posted by rrich

Another thought that is even safer. Just use a pipe cutter, one of those hand operated ones with a couple of rollers to hold the pipe and a cutting wheel.

Unfortunately this won't help with the longitudinal cuts down either side of the tube.

How thick and long is the tube? A caustic bath will dissolve it pretty fast, but won't affect the plastic. Can you plug the ends and leave it in caustic overnight?

Originally Posted by RobbieB

How thick and long is the tube? A caustic bath will dissolve it pretty fast, but won't affect the plastic. Can you plug the ends and leave it in caustic overnight?

The caustic will get into the sediment cores so I doubt that is a practical solution.

Yeah, definitely no wax, caustic, etc. We're taking lots of samples which need to measure contaminants in parts per million, billion, and even trillion, so nothing can be added.

And I also found out today that I misunderstood my boss... The tubes are not Aluminum, they're Lexan plastic. This will cut like butter and likely without any problems. I almost feel bad buying Festool gear to do the job...

Almost

Anyway, thanks a lot for the insight. If I ever do need to cut metal I've got a much better understanding.

Cheers,
Luke

Originally Posted by Luke Maddux

Yeah, definitely no wax, caustic, etc. We're taking lots of samples which need to measure contaminants in parts per million, billion, and even trillion, so nothing can be added.

And I also found out today that I misunderstood my boss... The tubes are not Aluminum, they're Lexan plastic. This will cut like butter and likely without any problems. I almost feel bad buying Festool gear to do the job...

Are there now two plastic tubes?

Originally Posted by BobL

Are there now two plastic tubes?

There are dozens, maybe hundreds. I'm honestly not even sure. Each core comes in a tube, and we're collecting many hundreds of cores, but only a portion (of size unknown to me) come in the tubes which must be cut with power tools.

Originally Posted by Luke Maddux

There are dozens, maybe hundreds. I'm honestly not even sure. Each core comes in a tube, and we're collecting many hundreds of cores, but only a portion (of size unknown to me) come in the tubes which must be cut with power tools.

I meant are the Lexan plastic tubes over the top of an inner plastic tube?

Originally Posted by BobL

I meant are the Lexan plastic tubes over the top of an inner plastic tube?

Oh, sorry. No, it's just one tube around a core.

Another thought.

Use a table saw. Set the fence to half the diameter of the core Lexan thing and subtract half the saw kerf. Set the saw blade height to almost the thickness of the Lexan. Run the core in the Lexan through the saw. Roll the core 180° and cut again. Use a large flat blade screwdriver in a twisting movement to separate the Lexan tube.