Aluminum Work

[ReQuieM]

Hi guys

About to embark on a biggish project using aluminum fabrication and I need to know a few things. First off I know you can cut aluminum with a jigsaw as long as its lubricated with a bit o WD40 (from the strut brace thread). Can I just use a standard mitre 'drop' saw to cut alum. tubing, rather then a angle grider style cut off drop saw? I'm ask cos there is a 50 buck and restricted angle difference. I know that you can buy an aluminum blade for a mitre saw but thats like 100 just for the blade! Yes i'm trying to do it cheap-ish but I dont need a metal only saw if i can have a tool i will definatly use again then awesome!

The other thing is can some one run through oxi aluminum welding? it was touched on lightly on in the old forums but not in depth. I think i've got enough aluminum to waste on teaching my self plus i have a mate who can weld steel to help guid as well... so please help!

[cri_ag]

you can use tungsten tipped circular saw blades ( i think all are now any way) for alluminium, we have cut a fair bit of small angle etc in the past (im a carpenter) but never never bigger stuff like tube. dont be shocked @ $100 bucks for a blade, thats what a decent blade is worth (timber or alluminium). actualy come to think of it the guy who does our alluminium handrails uses the cheapy dropsaws for all his alluminium work.

[ra_28]

Um Alloy would have to be the hardest type of welding you can do you need to learn how to weld steel first then attack alloy also it's not something you can pick up over night.

There are alot of factors involved in welding alloy like the heat to much heat you work turns up in a pile on the floor not enough heat the weld dosen't bond correctly very hard unless you a gifted welder then you will have no problem. If you friend can weld alloy let him do it and keep trying to weld alloy in the mean time.

[jeffro ra28]

To cut alum with a standard drop saw use an abrasive type disc intended for cutting cement or pavers. I chopped a whole cylinder head in half a few times using this method.

Lube or coolant is always good tho, the alum tends to melt into the pores of the disc which causes the disc to loose its abrasive effect. Even a steady flow from a garden hose will help.

Aluminium welding, TIG welding is more difficult then any of the others because it reqiures more co-ordination. The welder has to control the amps with his foot, the torch with his hand and also control the welding rod with his other hand.

A good practice for beginner tig welders is to heat the workpeice on an oven till its around 200F. Just make sure you cant pick it up with your bare hands anyway! This makes it easier to weld and is also used by experienced welders when doing things wich may have a risk of distortion or cracking due to un even heat distribution.

[YelloRolla]

Aluminium can be welded using oxy acetylene. Do a search on google, I think that there was an article done in Hi Performance build ups (or some such publication a while back).
I tried with limited success (mainly because I didn't think that I would be able to). I much prefer TIG welding.
I use the Jig saw and WD40 for cutting aluminium all of the time - it is quite slow on the thicker (10 - 12mm) stuff.

[takai]

Yeah, if you are having issues with cutting straight lines, then i would reccomend going back to the good old days and breaking out the hacksaw. I still do most of my alloy fab work with a hacksaw.

Also as others have mentioned you can use a standard ceramic disc for cutting alloy but it gets clogged up, but one way of getting around this is to be constantly blowing air on the cut to cool the surface.

While im here i may as well add another few tips. When bending alloy and you want a hard edge the easy way to do it is with a piece of angle iron supporting the bend and then a wooden block. Basically you start the bend with your hands and then continue with the piece of wood and a large hammer. Normally i use a piece of 2x4 and a small sledge hammer. Creates nice hard folded edges.

[EldarO]

We cut Aluminium at work using a Drop saw, we have the tungsten tipped blade, i have to say, it makes life a hellavalot easier.

Door and window frames go up in less than a tenth of the time!

Eldar.O.

[Ben Wilson]

I bought a cheap circular saw which I use exclusively for aluminium. No sign of any balde damage which I can see. I worked on the theory that aluminium is softer than a lot of wood.

You can weld aluminium with an oxy, but it is hard. You need a flux to stop oxidation and that flux flashes bright orange then you can't see the weld. You can get special goggles to see through the orange flare, but they are over $100...

[ReQuieM]

Awesome, thanx for all the replies guys! didn't expect so muh help and so fast!

First off, Ben is the blade you use just a standard 'toothed' blade? How is the cut? Is it clean or does it need a fair bit of filing? How thick can you go with the 'standard' blade?

Can you get an abrasive disc for 'wood' drop saws at normal hardware joints like bunnings? Also how much? I'll grab one to be safe if I can other wise I might try my luck. Simply because as i said the drop saws have much more adjustability then the metal cutter ones. The metal ones just go straight down, you just move the item your cuting to suit.


Now to the welding, My mate knows how to 'Arc' weld (his words) he thinks thats probably the same as tig welding? not sure, but he's only done it with steel. So he'll help but not be that much of a help if you catch my drift.

I figured with an oxy it would be basicaly like soldering but in a big scale? heat surface and junk alum bar and sought join them. Am i close or way off?

Is it safe to heat aluminum in the oven? I've herd that aluminum is toxic when burnt/melted/whatever? Plus last time I did it I smoked out the BBQ!

Thanx again for the help guys!

[YelloRolla]

Arc welding is nothing like TIG welding. The motion of TIG welding much more represents that of oxy, BUT, it uses a tungsten electrode that is shielded by Argon gas. You need much better co-ordination with TIG than with gas as the electrode needs to be kept close to the parent metal WITHOUT touching.
Welding anything (and especially Alum) is nothing like soldering. I would heat alumium in the oven without problem, as most of my parents cookware when I was growing up was aluminium. Just make sure that the aluminium is clean - I like to use an atomiser with some methylated spirits to clean off any impurities on the surface.

[Ben Wilson]

First off, Ben is the blade you use just a standard 'toothed' blade? How is the cut? Is it clean or does it need a fair bit of filing? How thick can you go with the 'standard' blade?

I wandered around Bunnings until I found a cheap saw with a fairly fine toothed blade. It is the standard wood blade which came with the saw.

I've cut 4mm wall thickness extruded box with it and had no problems. The cut is very nice, the cut edge looks almost polished. The edges are sharp, but not jagged.

Obviously, the saw isn't designed for this, so be very careful...

[acmtt]

Just cut slowly, with the saw. An Aluminium blade will have lots of teeth so the saw doesn't grab the material and in the case of thin wall stuff twist and tear it.

Make sure its held securley while you are cutting and wear goggles/glasses and cut slowly.

[cri_ag]

why dont you go to your local tafe and enrole in a welding course, i did last year, basicaly i spent the first half of the course learning and practising tig and the then the latter doing my own jobs. i found my tafe teachers more than happy to help me out with my projects and not only do you get the use of decent tig welders but the rest of the facilites as well, grinders, bench press drills, etc. best $150 i ever spent! only prob is now i want my own tig.

[Xistant]

Arc welding is nothing like TIG welding. The motion of TIG welding much more represents that of oxy, BUT, it uses a tungsten electrode that is shielded by Argon gas. You need much better co-ordination with TIG than with gas as the electrode needs to be kept close to the parent metal WITHOUT touching.
Welding anything (and especially Alum) is nothing like soldering. I would heat alumium in the oven without problem, as most of my parents cookware when I was growing up was aluminium. Just make sure that the aluminium is clean - I like to use an atomiser with some methylated spirits to clean off any impurities on the surface.

And god has spoken

good info there thats for sure

[ReQuieM]

why dont you go to your local tafe and enrole in a welding course, i did last year, basicaly i spent the first half of the course learning and practising tig and the then the latter doing my own jobs. i found my tafe teachers more than happy to help me out with my projects and not only do you get the use of decent tig welders but the rest of the facilites as well, grinders, bench press drills, etc. best $150 i ever spent! only prob is now i want my own tig.

Yeah that was my plan hit the tafe and learn but i think they wanted some thing like 450 in melb for a short course! Thought that was a might rich. I;ll have to investigate again, maybe theres a cheaper one out there.