liam.mccaffrey
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| posted on 17/8/06 at 10:25 AM |
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grinding aluminium
as above can you grind aluminium with a nrmal disc? I've heard they load up quite bad and you need special discs.
I've also heard you can use soap on the disc to prevent loading.
can anyone confirm or deny the above
cheers
liam mac
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graememk
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| posted on 17/8/06 at 10:35 AM |
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when i was cutting out pannels in 2mm i used them skinny disks the thickness of a cs with ni probs
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iank
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| posted on 17/8/06 at 10:39 AM |
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Screfix sell aluminium cutting discs for ok money.
http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100159&ts=10835&id=48992
You aren't supposed to use normal discs, but many have got away with it.
Isn't the worry that they can fail when loaded up, I personally wouldn't risk it.
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mookaloid
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| posted on 17/8/06 at 10:53 AM |
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I think I was told in metalwork at school - a very long time ago!
discs are supposed to wear away as you use them as happens when you grind steel, ally is not hard enough to wear the disc an it forces it's way
into the voids in the disc - which can cause the disc to fail (explode)
so I don't think you are supposed to grind ally at all with a regular disc.
Someone will no doubt be along to give us the full version
Cheers
Mark
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omega 24 v6
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| posted on 17/8/06 at 11:26 AM |
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Basically it's a big NO NO as already explained by Mookaloid. Once the alloy is in the wheel it expands through heat and causes the disc to
fail/explode
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SteveH
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| posted on 17/8/06 at 11:29 AM |
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If your going to be doing a lot of ally grinding, get the proper disks...
If you only need to do the odd job there is a work around (Below)... if it's sheet work of 5mm & less use a Jigsaw with metal blades &
use paraffin to lubricate the blade as you cut.....
If you need to grind Ally & you cant get a proper disk ...SMALL... jobs can be done with a disk designed for steel.
You will need to unload the wheel often!!!
It's important to use light pressure & take your time.... ALL Guards should be in place...
For unloading a surface disk:- stop the grinder & unplug... securely hold the grinder.
Using a steel wire brush... brush from the outside towards the middle to remove as much of the deposited Ally as possible.
Start the grinder in a safe manner & in such a way that should the disk fragment the parts will fly in the safest direction. Using an old scrap
metal cutting disk that is securely held in a vice (NOT in your hand!!!) dress the cutting surface of your working disk against the fixed disk... stop
the grinder & inspect to see if the majority of Ally particles have gone. If not repeat the process.
If the imbedded particles are starting to form a continuous ring & cannot be removed A heavy application onto a piece of scrap steel will usually
remove this layer.
You can use the same technique but excluding the wire brushing process on a cutting disk, but be aware they load up much quicker.
This works for me... I recommend that you get a proper ally disk if at all possible it will be safer & quicker.....
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liam.mccaffrey
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| posted on 17/8/06 at 11:51 AM |
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rest easy i've bought some ali cutting discs
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graememk
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| posted on 17/8/06 at 11:52 AM |
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oh dear looks like i was lucky then
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John Bonnett
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| posted on 17/8/06 at 01:07 PM |
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grinding aluminium
The original question was as above but the replies talked about cutting and cutting discs. I would have thought it unsusual to want to cut aluminium
with a cutting disc. Depending on the thickness it can be sheered, cut with snips or with a jigsaw. If you are using a jigsaw you should use a coarse
blade. A fine blade will clog.
Flapper discs are excellent for sanding aluminium either on the surface or on an edge. They are available in different grades according to the finish
needed. In fact, I have stopped using grinding discs altogether in favour of flapper discs because they last longer, are less agressive and much less
messy. They are also excellent on both mild steel and stainless.
John
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liam.mccaffrey
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| posted on 17/8/06 at 01:27 PM |
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what i wanted to do was to cut the plenum chamber off of my ali inlet manifold. too awkward for a hacksaw, jig saw or tinsnips.
sanding back after will be with sanding disc as suggested
i will then get it milled back true if required
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John Bonnett
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| posted on 17/8/06 at 01:58 PM |
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I'm intrigued how everyone else knew you meant cutting rather than grinding.
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iank
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| posted on 17/8/06 at 02:08 PM |
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We didn't My reply mentioned cutting only in that you can get the discs cheap.
Re-reading my reply it wasn't clear my comment applies to both cutting and grinding discs.
Guess graememk is just psycic
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SteveH
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| posted on 17/8/06 at 03:02 PM |
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quote:
Originally posted by liam.mccaffrey
what i wanted to do was to cut the plenum chamber off of my ali inlet manifold. too awkward for a hacksaw, jig saw or tinsnips.
sanding back after will be with sanding disc as suggested
i will then get it milled back true if required
I made myself a chunky Hacksaw to do that job...
 
Description
It's an old Bow saw frame, had to put a new bend in it... only needed a little propane heat & a vice... the blade is from a Powered
"Cutoff" saw...
Took about 20 minuets to do this...
 
Description
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oliwb
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| posted on 17/8/06 at 04:15 PM |
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Broke a grinding disc once cutting a PVC barrel in two.....it was a very loud and scary experience and I hope not to be present when it happens again!
Tres lucky! Oli.
If your not living life on the edge you're taking up too much room!
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liam.mccaffrey
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| posted on 17/8/06 at 04:16 PM |
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when you posted your chunky hacksaw,
i had a lightbulb above head moment, specifically about when i made that exact same tool about 3 years ago but i completely forgot about it.
anyway just fished it out and broke it as soon as i picked it up. snapped the tensioning bolt. will fix it tomorrow.
just for giggles i cut the 2 end runners with normal hacksaw took maybe 5 mins, i can't get to the innner 2 without said chunky saw though
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