Long straight cuts in 9mm plate

[discotroll]

Hi -

I hope I've put this is the right section but if not hopefully admin will see it put in the right place.

I'm working on a one-off project and I need to cut out a couple of long lengths of steel plate - plate is approx. 9mm thick and each cut is roughly 18m in length. I need these cuts to be as straight as possible so although I'd normally immediately think of plasma I have also seen some online vids of people using a cicular saw (run along a piece of angle) to give a super-straight and clean cut.

As this is a bit of a one-off project I'd be interested in the thoughts of the experienced forum regulars and hopefully get steered in the right direction regarding the best cutting method.

Thanks in advance,

DT.

 

[Hitch]

What are you cutting thats 18m long would be my first question...not splitting beams into t sections?


I'd be inclined to use a laser line and centre punch every few metres, then use a bit of wide flat bar 3-4 metres long as a straight edge guide and simpy run the torch along the edge.

 

[discotroll]

What are you cutting thats 18m long would be my first question...not splitting beams into t sections?

Working on an old Thames barge - hence the length....

 

[dannyp]

i think you'd get a better cut with a plasma, tho even if it meant hireing a machene in id want one thats well on top of the job like a 70 - 100 amp machene

get some thign like 130 - 150 x10 , laser it to be sure it's straight tack it down and run down it

 

[discotroll]

Thanks dannyp - as a single job I was thinking that hiring a bigger machine was probably the smartest way to go.

As you and Hitch say, I'll be using the laser to get a dead-straight line and then put down some angle to run along...

 

[Brad93]

We've cut sheets with a slugger metal saw.
It's loud, vibrates a tonne and hard to keep straight. You get a lovely cut though. I wouldn't want to cut 18m with one though.

I would set up a track with oxyacetylene or use a plasma with a drag tipped a piece of aluminium extrusion.

 

[fizzy]

Looking at Youtube videos I was surprised how well a circular saw works even on thick steel. Looks a much better cut than I get with my Plasma.

 

[nickk]

You might relieve sufficient stress in the bar to cause it to taper,select a blank that means you remove the least.good luck.

 

[discotroll]

Looking at Youtube videos I was surprised how well a circular saw works even on thick steel. Looks a much better cut than I get with my Plasma.

Yeah - they certainly make for a neat cut but you do wonder just how long a blade is going to last going through thick steel....