Thread: Workking with Aluminium

Bob, with the price of aluminium extrusions I'm not sure that I'd bother modifying something. However, you know about ginding wheels and ally will choke a file in nothing flat. Sorry I cant be a bit more positive on this matter.

Gday Bob, & welcome aboard!

Aluminium can be cut with a hacksaw (less tpi the better, fine teeth will clog) or using a power saw (ie. mitre saw) with a carbide tipped blade. WARNING - aluminium cutting blades usually have negative rake teeth, different to wood blades; however if you only have a few cuts to make you CAN cut Al. with a wood cutting blade provided you take it fairly slowly and carefully. I have done this successfully with my mitre saw & it went OK for me. Read a tip suggesting you put duct tape where the cut will be prior to cutting, haven't tried it but it apparently made a huge difference to the amount of swarf on the exit side of the material.

Al can be filed, but will need to chalk the file first (as it reads, rub chalk into the teeth on the file), this will prevent clogging. If you get some clogging anyway, use a file card to clean the file, and the corner of a bit of sheetmetal to push out any stubborn bits (a clogged file is called a "pinned" file BTW.)

If the al. is oxidised there are a number of compounds to polish it up, one of the best is Autosol paste, brings al. up a treat.

Good luck mate...........cheers.............Sean the heavily oxidised

Originally Posted by BobS

I know from harsh experience not to go near the grinding wheel !!

I've heard all sorts of things about people who have been incinerated by explosions grinding steel after some idiot has ground al on the same wheel, but always believed them to be urban myths.

What DO you know about grinding aluminium from harsh experience?

Cheers,

P :confused:

As well as cutting aluminium with power saws you can also use a router on aluminium just so long it is securely clamped. I have cut it with my mitre saw as well as on the Triton saw bench. As Scooter says there are proper aluminum blades made for it Irwin make them, a 10" 80 to 100 tooth blade for about $160.

Thanks for the feedback

Bitingmidge - sorry no explosions but I do have an old Aluminium Oxide grinding wheel that now resembles a lamington.

I was particularly interested in what I could use to remove (grind off) a 1mm lip from one side of the profile.

Bob S

You probably need to dress it up with a dressing wheel either hardened steel or diamond. Try Carbatec.

Originally Posted by bitingmidge

I've heard all sorts of things about people who have been incinerated by explosions grinding steel after some idiot has ground al on the same wheel, but always believed them to be urban myths.

What DO you know about grinding aluminium from harsh experience?

Cheers,

P :confused:

Well, as a young sprog I had my **** kicked by a foreman for grinding aluminium. He told me that the pores in the wheel clog and the heat cannot dissipate. So when steel is ground the wheel can heat up to the point where it can't expand, then it cracks. Since it is spinning so fast people claim it explodes. In reality it is just a very sudden release of energy and high velocity particles flying around the work area (hang on, that sounds like a ....).

As Barry White mentioned earlier, the Irwin blades do a good job cutting aluminium (although you can cut it with any blade with a large amount of teeth - 100+ on my 10" Irwin blade). Just make sure to spray the blade with some CRC Cutting Oil or equivalent to ensure the aluminium doesn't stick to the blade. It's a royal pain to get off if you don't, and the cut quality will suffer markedly too.

Oh yes, and prepare yourself for an unbelievable mess. I cut aluminium on my SCMS and found the workshop looked surreal when I had finished. Everything glittered like tinsel. Recommend you wear eye and respiratory protection - and a hat.

Originally Posted by Groggy

Well, as a young sprog I had my **** kicked by a foreman for grinding aluminium. He told me that the pores in the wheel clog and the heat cannot dissipate. So when steel is ground the wheel can heat up to the point where it can't expand, then it cracks. Since it is spinning so fast people claim it explodes. In reality it is just a very sudden release of energy and high velocity particles flying around the work area (hang on, that sounds like a ....).

Yes second that from experience, have seen results of wheel that had (initially) a large chunk break away and culminated in a guard case full of wheel sections.
Unfortunately for the individual using it at the time he stopped the 10% that wasn't contained from injuring his mates.

Cause: grinding of Brass and sharpening of Pencils, supervisor got a rocket for not controlling use and monitoring state of equipment.

A good guide for detecting a wheel that is clogged is a need to apply more pressure to obtain a cut, unfortunately this need can creep up on you.

There is no real problem with files & aluminium you just have to clean them regularly.
It works quickly & relatively cleanly with a file.
It machines well with normal carbide wood working tools but it makes a lot of noise & mess and you must have very very firm controll of the job and the tool.
A good wax or liquid lubricant is a must for any power cutting.

Its also quite cheap if you buy it in the right place.

Rub chalk on the file before filing aluminium, it slows the clogging.

Dan

Originally Posted by scooter

Gday Bob, & welcome aboard!


If the al. is oxidised there are a number of compounds to polish it up, one of the best is Autosol paste, brings al. up a treat.

Good luck mate...........cheers.............Sean the heavily oxidised

I came across something I think is better than autosol. Mothers aluminium and mag wheel polish, Comes in a tub (supercheap sell it here in perth). I found it works alot easier and the black stuff (not sure what that is caused by exactly) all rubs off easier. it is also good for stainless.

One, why bother polishing the aluminum? Won't make the table any better. Time better served working. Two, Use a hand 4 or 5 inch grinding wheel on a hand grinder. Three, They do make wheels for the bench grinder just for aluminum. Four, do you have a way to weld the aluminum? you can do it with a torch and special rod. You can use a regular wire welder with aluminum wire. You will need to use a little larger orfice so it will not hold up and you must keep your lead streight. You can weld in one inch lengths with no problem I do it all the time. Finaly make the thing out of plywood or MDF. You can make a great protable router table from a half sheet. I have made many of them. I can make two in an hour. No give, no warp I do have two comercial router tables. one has a cast top and a sliding table. I have used my wood ones for 25 years. They are great for the job site when needing to make special little moldings on site. My tables have a 24 by 30 inch top. I make them big because it supports the work so much better. I work with a private school shop that runs on a budget. I made 6 of the tables for them years ago and they are like new. They are used every week.

Yes, regular wheels can explode from build up. I was a tool and die maker before I became an Architect and contractor. I have seen them explode.
Another safty note for welders. Do not keep a disposible lighter on your person. Sparks can burn through and blow the lighter up. I have seen pictures of a man who blew his leg off from having a lighter in his pocket while welding.

Originally Posted by sailingamerican

Do not keep a disposible lighter on your person. Sparks can burn through and blow the lighter up. I have seen pictures of a man who blew his leg off from having a lighter in his pocket while welding.

Richard,

Still use a zippo lighter to this day for that exact reason. Found one of my plastics one day with a bit of spatter burnt into the side of it :eek:

Dan

Maybe migrating here was a mistake, I should have gone where the knowhow is! LOL.