Cutting disc help please

[Peloquin]

I've got to cut down the legs from a large, heavy, machine at work this weekend.
We were gong to use a plasma cutter but cost/logistics have ruled that out so I'm just going to chop them down with the 9" grinder.
The steel I'm cutting is 6mm and 8mm and needs to be done accurately and neat do that plates can be welded on after.
I'm looking for advice on the discs to get. There's 8 large legs, think girder standing vertical on a girder laid horizontal and welded. About 8 of these plus some smaller gauge struts.
The discs need to be decent and easy to get hold of as I want to make a start straight from work tomorrow.
Any preferences?
I'm thinking thinner the better really but not sure on a decent make.
Cheers folks

 

[Wendelspanswick]

I've got to cut down the legs from a large, heavy, machine at work this weekend.
We were gong to use a plasma cutter but cost/logistics have ruled that out so I'm just going to chop them down with the 9" grinder.
The steel I'm cutting is 6mm and 8mm and needs to be done accurately and neat do that plates can be welded on after.
I'm looking for advice on the discs to get. There's 8 large legs, think girder standing vertical on a girder laid horizontal and welded. About 8 of these plus some smaller gauge struts.
The discs need to be decent and easy to get hold of as I want to make a start straight from work tomorrow.
Any preferences?
I'm thinking thinner the better really but not sure on a decent make.
Cheers folks

I've been using the Erbauer 2mm discs from Screwfix, £10.39 for 5, a fast cut and they don't disappear in an instant!
They do flex a bit though, slightly disconcerting when you spin one up for the first time.
http://m.screwfix.com/p/erbauer-metal-cutting-discs-230-x-2-x-22-23mm-pack-of-5/33315

 

[Peloquin]

Cheers, that's one I was looking at. They are supposed to be a decent make.
Work are buying them so I'm not over bothered about the price, I'm trying to not fall into the "get the most expensive I've cause it'll be better" trap.

 

[Badger1bear]

How are you supporting this heavy machine whilst your cutting the legs off ?

 

[Peloquin]

Fork lift trucks either end. It has lifting eyes.

 

[BrokenBiker]

another vote for erbauer discs. i use the 1mm 115mm discs and the 2mm 230mm discs and they are both good discs

 

[Peloquin]

Cheers.
They'll do then.
Thank you gents.

 

[evobilly666]

Be careful, it can be difficult to know how much tension you have with a forklift. I'm sure you know how a 9" grinder can be if the disc grabs. I try not to cut anything that may be in tenson or compression without really thinking what way to cut. Is there no way to oxy cut it and then clean up after?

 

[Woody.v8]

Why not use oxy fuel? Snizzle off and a quick flick with the grinder to knock the dross off and George is your tranny uncle.

 

[Shedendman]

Also remember what you cut out you lose,i know it may be 2mm but you'll have to cut each leg spot on,still bet the chances are one leg wont match up right to weld back on.
cutting horizontal accurately isn't easy with any size grinder

 

[Peloquin]

The plan is lift the machine about 10mm then cut the join on the 2 girders. Once all are cut I'll lower machine onto plates, line plates up with a tapper (bfh) and rule then put a load of tacks to ensure plates don't warp/move. Lift the lot up again and weld it all up properly.
I would have liked to weld it all on the flour but it's concrete so won't risk it.
I don't have access to any oxy and never used it so I wouldn't be confident trying it.
I pick things up pretty quickly so would have liked to try this option but there was no chance so angry grinder and care it is.
I'll try get a load of pics anyway of the whole process.
Thanks for the tips etc...

 

[Peloquin]

Well, went to make a start on it...this is the machine...

We raised it, marked where it needs the legs cutting and out came the 9" grinder.
Touched it to one leg and...


Bloody painful that.

I ended up ringing the boss and saying no chance. Oxy or plasma, don't care which but not using discs.
A load of ringing round and I'm picking up some oxy cutting gear tomorrow.
Haha, now I just need a crash course in using it.
Any tips?

 

[balmerchris]

Lighter touch maybe?

 

[Peloquin]

Possibly. I only scratched the metal really so not sure. Oh well. Not the first time I've had a disc splode and I dare say another will at some point.
Loads of ppe though so nowhere near as bad as I could have been.

 

[Rocketman]

I'm not being funny but if you are doing professional stuff you should be at least using something like Dronco discs.

 

[fixerupper]

Well that's well weird , what sort of discs are they ,not standard cutting discs ?...is it some kind of weird hardened steel ? hope you're not hurt ..If it were me I'd use sommat like these ..jeff...

 

[Peloquin]

Well I used this make of disc before just not the 9"ones and as I said, hardly made a cut into metal, it just went bang so I give up right away,wasn't going to try another.
I thought it was just bog standard steel, boss didn't know, just bought the machine.
I'm suspecting it was a Crap disc but oxy acetylene will cut it easy enough, it's only 6.5mm at the thickest point.

 

[marlinspike]

We use the Rhodius discs too, from Tool Station. They seem good quality, though only used them on up to about 2mm thick.

 

[fixerupper]

I just looked back over this thread,one thing .... I would'nt use a 2mm disc for 6mm 8mm stock ....I see those thinner discs for stock that is 1mm up to 4 mm or 5mm .On a nine inch grinder the 2mm disc flex and distort ...jeff...

 

[Sarto]

On these thicknesses, at work, they use 3,2mm discs, if no other option is available.
With curse mode on at full power, by the way.