aluminum cutting help please

[speedingredline]

Well after some hours of working with a piece of aluminum I have nothing to show for my efforts. I was simply trying to cut a "perfect" rectangle of about 10,2"x7", with a jigsaw. Probably my first mistake. but even using a guide the lines were not straight. or the aluminum would bend at the end of cut. So what are the techniques to working with aluminum. I went out and bought a nibbler today. I'm thinking manual labor may be my best option. Thanks for helping a newb

[dutchcedar]

How thick is it?

Personally, I like to cut outside of the line a bit, even on a bandsaw, then sand it to the line on a belt sander. :thumb:

[lbreevesii]

yup, it always helps to cut outside(or inside the line for cutouts) the line. it can also help to score the line with a dremel or some other tool to give whatever you use something to follow.

[speedingredline]

thinkness is .040, I tried the approach of cutting outside the lines,then filing and grinding down the edge but was unable to achieve a straight edge.

[mnpctech]

Bandsaw would be optimal, but if you must use a jigsaw/nibbler... C-clamp that sheet to edge of a table or workbench first. No less factor to worry about. I agree w/ everyone, cut outside the line... Then place the sheet in a bench vise for hand filing your cuts.. And another thing, edge some masking tape over your cut line, it can help you monitor your progression as you file. I recall squinting a lot to find my cut line :blink:

Straight lines by hand are very difficult. Von Dutch was famous for his precision hand pinstriping and metal crafting/engraving, but you can tell it was all done by hand.

[Hal]

also make sure the saw blade is for the right thickness, i have found that out the hard way a few times. if it is not right, the teeth with bite and catch on the metal.

[mnpctech]

Good call HAL, use a metal cutting blade with a minimum of 18 teeth.

[fillip]

Good call HAL, use a metal cutting blade with a minimum of 18 teeth.

Is it a general rule of thumb that more teeth = smoother cutting? http://wizdforums.co.uk/images/smilies/huh.gif

[flacowboy]

thats the rule you can also clamp a piece of wood to the alu. and use that as a guide fence the the jigsaw rides up against like on a table saw just make sure your wood is straght

[ỒĊBłůē]

Is it a general rule of thumb that more teeth = smoother cutting? http://wizdforums.co.uk/images/smilies/huh.gifPretty much, but you have to be careful with ali as it can clog between the blade teeth.

Same with your files - aluminium clogs those too. I've always had a wire brush to hand to clear it, although I've heard that applying chalk to the file beforehand works too. Anyone tried that?

[flacowboy]

yeah the chalk works learned that in metals class in high school

[speedingredline]

also make sure the saw blade is for the right thickness, i have found that out the hard way a few times. if it is not right, the teeth with bite and catch on the metal.

good to know, I will go home depot or lowes today and get some new blades. The blades I have are metal blades, forget how many teeth though, may or may not be acceptable.

I had the aluminum clamped to a wood base, but when I got to the end of the cut thats where I had most of the problems. I'm assuming the blade got jammed up and just bent the aluminum to all heck. I also tried the guide thing, I think maybe the clamps I am/was using may not be holding the materials solid enough and moving around during the cut. My

My wife and father-in-law were looking at my failures last night, and perhaps I am being to anal about this. The one piece is probably salvagable, I will have to be very careful about finishing the edges. I will take some pics, and at it to my progress in the chop shop section.

[speedingredline]

How thick is it?

Personally, I like to cut outside of the line a bit, even on a bandsaw, then sand it to the line on a belt sander. :thumb:

thanks dutch, I will have to steel my father-in-laws belt/disc sander. and his scroll saw too!

[Hal]

good to know, I will go home depot or lowes today and get some new blades. The blades I have are metal blades, forget how many teeth though, may or may not be acceptable.

I had the aluminum clamped to a wood base, but when I got to the end of the cut thats where I had most of the problems. I'm assuming the blade got jammed up and just bent the aluminum to all heck. I also tried the guide thing, I think maybe the clamps I am/was using may not be holding the materials solid enough and moving around during the cut. My

My wife and father-in-law were looking at my failures last night, and perhaps I am being to anal about this. The one piece is probably salvagable, I will have to be very careful about finishing the edges. I will take some pics, and at it to my progress in the chop shop section.

yeah i have found that the saw teeth will really catch and fubar the metal if it is too large for the metal.

[GodsUnicorn]

What you must do is use a sharp blade that is designed for the material you intend to cut, and set your saw to an appropriate speed, if it has a pendulum setting, turn it off (thats mostly for wood) also make sure your work area is free from debris.
Wear saftey goggles and clamp the work piece down securely and make sure the power cord is away from the blade.

Start by drilling a hole that is big enough for the saw blade to sit in without touching the sides, place the blade in the hole before you pull the trigger and then holding the saw with both hands gentley move it forwards, using a gentle, steady pressure.
You should aim to stay just to the waste side of your line (remember, a jigsaw is not a finishing tool, you will have to dress the job with a file when you are done) as you get more confident you will be able to cut closer to your line and therefore have less finishing to do.

When you finish your cut back the saw off a little, release the trigger and allow the motor to stop before you remove the blade from the workpiece.

I would suggest that you take another piece of metal and practice on it, the only way to get good at it is to do it.

As for using a straight edge or a guide fence, well they aren't too effective unless you have a good quality jigsaw as the blades tend to wander a bit as they cut.

But remember the saftey side of the job, as it will be hard to finish your mod with missing fingers or a patch over your eye.


Always use sharp well maintained tools, weather they be power tools or hand tools, more accidendts and knackered jobs result from people trying to force a blunt tool to do what it does not want to.

Have fun.

[speedingredline]

thanks for all the tips and info, I wont have an opportunity to work on it again till sunday.

[flacowboy]

some thing else you can try to is clamp a piece of wood under the metel and cut both at the same time may help save the end from bending

[speedingredline]

that was going to be my next step, but I was going to sandwich the aluminum between to pieces of thin plywood.

[GodsUnicorn]

that was going to be my next step, but I was going to sandwich the aluminum between to pieces of thin plywood.

Probably a better idea, as jigsaws cut on the up-stroke.

[ỒĊBłůē]

...unless you get a downward cutting (e.g. laminate) blade ;-)

[Anabolic_OMEN]

hello,
i have sheet of aluminium 1mm thick would it be best to cut it with them super scissors or jigsaw ?

[GodsUnicorn]

hello,
i have sheet of aluminium 1mm thick would it be best to cut it with them super scissors or jigsaw ?

Try it and see is the best way, shears will distort the metal as you cut and they are a bit harder than a jigsaw to do curves.
But try both on a piece of scrap and see which you are more comfortable with.

Good luck, and welcome BTW

[ỒĊBłůē]

I don't think I'd try a jigsaw on alu that thin - I'd expect it to keep bouncing and bending all over the place unless you can really pin it down, and support it underneath; very close to the cut-line.

Is it a straight line you're cutting or something more intricate?

[Anabolic_OMEN]

something in the shape of the white paper
http://img133.imageshack.us/img133/6520/dsc02742mb5.jpg

[ỒĊBłůē]

So you're just needing to cut the two bays at the top?

[Anabolic_OMEN]

the white you see is paper and i need to cut aluminium 1mm thick in that shape including the 2 bays in top

[ỒĊBłůē]

Ah, I think I understand.

Cutting around the outside of the paper template with a jigsaw shouldn't be a problem, as it looks like the edge of the alu is bevelled - so this will help support it.

Check a few worklogs around here and you'll see most folks cover the entire surface of any aluminium they're cutting with masking tape to prevent scratches from the baseplate of their jigsaw or shears.

Make sure you also support it underneath with a decent sized scrap piece of wood or something - clamp it so that it's no more than 5mm away from the line you're cutting; as it'll be hard to support on both sides of those cuts with that bevelled edge.

Ensure everything is clamped down firmly - the aluminium and the wood you're supporting it on; you don't want anything to move. A stable working surface is also essential here.

Only do one cut at a time, then reposition your piece for the next one.

I'd go for the drive bay cuts first; clamped and supported as already mentioned, then the long outside cuts and finally the ends - in this order I think you'll make the best use of the support that bevelled edge gives you :thumb:

Remember you don't have to cut exactly on the lines you are after - you can always cut a couple of mm away and file the remainder down - thin aluminium files very quickly and easily (sometimes too quickly and easily - be careful!)

Choose a jigsaw blade suitable for the job, select the right speed, make sure you're happy about cutting and take your time over the cuts - don't rush them.

^ Just my tuppenceworth - good luck with it ^_^

[Fibbles]

A high quality French nibbler?

I used mine to cut a 120mm hole in my 2mm thick side panel. Very smooth and effective.