OT: Oxy Propane cutting

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
R

Rich

Guest
Hi to one and all, could any of the experienced people out there help me
with a little problem, using Oxygen and Propane, and a proper cutting gun
what sort of pressures should be used, and what thickness of steel would it
be capable of cutting

Rich
--
To reply remove " spam "


 
Rich wrote:
> Hi to one and all, could any of the experienced people out there help me
> with a little problem, using Oxygen and Propane, and a proper cutting gun
> what sort of pressures should be used, and what thickness of steel would it
> be capable of cutting
>

Cutting tip size controls the pressures needed and the thickness that
can be cut. If you give me some idea of what you intend cutting I'll
see if I can give you an accurate answer.


--
EMB
 
no more than 50psi oxygen and about 4-7psi propane.

make sure you have a single stage 2 gauge oxy regulator that goes to at
least 80psi [ie cutting reg] .

no real need for dual stage reg plus they are more expensive

note that propane or acetylene regulator will not show a great amount
of bottle pressure if using propane , so in other words you might think
bottle is empty when it actually isnt, its just that none of the gauges
available show much bottle pressure with either fuel gas even on a new
bottle .

1/16" PNM nozzle will cut up to 6" thick but i doubt youll go that
thick , realistically youll only need 1/16" nozzles for almost
everything .

if you want to heat materials there are heater nozzles available for
propane use but not for acetylene .

get decent quality nozzles for best performance ie OERLIKON , or use
PARWELD slightly cheaper .

if you are just cutting flat plate and want decent quality edge of
straight lines etc then you may like to look at an EVOLUTION CIRCULAR
SAW at 140 quid , this is like a normal wood type circular saw but can
cut mild steel up to 10mm thick and also can cut aluminium and
stainless steel with different TCT blades.
each blade is 18 quid and will cut 80m length of material before
resharp or new blade is reqd .

it will cut plate at almost same speed as you cut wood with similar
machine .

hope this helps

 
Probably only steel sheet, tube/box some RSJ's so a max of about 10mm thick,
I will find out what the gun is and tip size as well.

Rich

--
To reply remove " spam "
"EMB" <[email protected]> wrote in message
news:[email protected]...
> Rich wrote:
> > Hi to one and all, could any of the experienced people out there help me
> > with a little problem, using Oxygen and Propane, and a proper cutting
gun
> > what sort of pressures should be used, and what thickness of steel would
it
> > be capable of cutting
> >
>
> Cutting tip size controls the pressures needed and the thickness that
> can be cut. If you give me some idea of what you intend cutting I'll
> see if I can give you an accurate answer.
>
>
> --
> EMB


 
Rich wrote:
> Probably only steel sheet, tube/box some RSJ's so a max of about 10mm thick,
> I will find out what the gun is and tip size as well.

I've just dug out the specs sheet that arrived with a couple of new
tips. The recommendations are below (pressures in bar)

Tip Size Cut thickness Oxy Press Propane Press

00P 0-6 1.0-2.0 0.35
0P 6-13 1.5-2.5 0.35
1P 13-25 2.0-3.5 0.35
2P 25-75 3.0-4.5 0.35


The only thing to watch out for is that you can get a high enough oxygen
flow through your regulator - many that are designed for welding won't
cope with the flow needed for cutting, although as you're only looking
to cut 10mm it shouldn't be a problem.

It's ages since I've done any gas cutting - my little plasma cutter at
home will cut to 12mm cleanly and for heavier stuff I use the one at
work that's reasonable to about 40mm thick.


--
EMB
 
EMB wrote:

> It's ages since I've done any gas cutting - my little plasma cutter at
> home will cut to 12mm cleanly and for heavier stuff I use the one at
> work that's reasonable to about 40mm thick.

Bloody hell, you use a different definition of "little" to me ! Mine
tops out on 7mm, and its single phase. Your "little" one is three phase ?

Steve
 
Steve wrote:
> EMB wrote:
>
>> It's ages since I've done any gas cutting - my little plasma cutter at
>> home will cut to 12mm cleanly and for heavier stuff I use the one at
>> work that's reasonable to about 40mm thick.
>
>
> Bloody hell, you use a different definition of "little" to me ! Mine
> tops out on 7mm, and its single phase. Your "little" one is three phase ?
>
Single phase, 20A circuit. If I had 3 phase at home I'd be ecstatic but
it'll cost me about 2 months wages to get the cables run so I'll pass on
that.

--
EMB
 
EMB wrote:
> Single phase, 20A circuit.

That's what my tiddler runs on too. 12mm ? What's the difference I wonder.

Not that I have much call for 12mm plate cutting, but you never know.

Steve
 
During stardate Thu, 13 Oct 2005 22:29:21 +0100, Steve
<[email protected]> uttered the imortal words:

>EMB wrote:
>> Single phase, 20A circuit.
>
>That's what my tiddler runs on too. 12mm ? What's the difference I wonder.
>
>Not that I have much call for 12mm plate cutting, but you never know.
>
>Steve

My 35 Amp feed Plasma tops at 10mm if my memory served me right.
Single phase.

Clarke one.

Lee D
--
Success is going from failure to failure without a loss of enthusiam.
Winston Churchill

www.lrproject.com
'76 101 Camper
'64 88" IIa V8 Auto
'97 Disco ES Auto LPG'd
'01 Laguna
 
Steve wrote:
> EMB wrote:
>
>> Single phase, 20A circuit.
>
>
> That's what my tiddler runs on too. 12mm ? What's the difference I wonder.

I don't know. It's an inverter rather than transformer supplied one.
And it's a no name Chinese made machine that claimed a 12mm clean cut
when I bought it - and I was really surprised to find that it lives up
to that claim.


--
EMB
 
Ah, someone else with a plasma cutter, I have a little one 25A 240v will cut
about 5 to 6mm but eats tips is this a common thing ? like the plasma cutter
quick and clean, never used gas cutting so I am giving it a go like the fact
it is just the torch that you need to use and very self contained just the
bottles and no mains or compressors etc:

Thanks for the replies keep it coming and I will see how it goes

Rich

--
To reply remove " spam "
"Steve" <[email protected]> wrote in message
news:[email protected]...
> EMB wrote:
>
> > It's ages since I've done any gas cutting - my little plasma cutter at
> > home will cut to 12mm cleanly and for heavier stuff I use the one at
> > work that's reasonable to about 40mm thick.
>
> Bloody hell, you use a different definition of "little" to me ! Mine
> tops out on 7mm, and its single phase. Your "little" one is three phase ?
>
> Steve


 
Got mine from Machine Mart the Clarke plasma king 25, no pilot arc you have
a sprung tip which starts the arc and its a heavy transformer type ( might
be more robust, less electronics to go wrong ) and I think it is good for
about 5 mm as they say in the instructions not a very good duty cycle though
it soon cuts out on over heat so I try to give it a good rest to stop that
hapening

Rich


 
Rich wrote:
> Ah, someone else with a plasma cutter, I have a little one 25A 240v will cut
> about 5 to 6mm but eats tips is this a common thing ?

Just where do you put the tip ? It should be against the stock being cut
? A little gap lets plasma at the tip bottom surface and I think that
stuffs 'em.

Do you run the tip on a piece of sandpaper too ? I keep it very clean
and I am some 35 feet of cutting 6mm through a single tip.

Steve
 
Rich wrote:
> Got mine from Machine Mart the Clarke plasma king 25, no pilot arc you have
> a sprung tip which starts the arc and its a heavy transformer type ( might
> be more robust, less electronics to go wrong ) and I think it is good for
> about 5 mm as they say in the instructions not a very good duty cycle though
> it soon cuts out on over heat so I try to give it a good rest to stop that
> hapening

Yes, my SIP has the same problems. The lack of a pilot arc is a bugger.

Steve
 

"Lee_D" <[email protected]> wrote in message
news:[email protected]...
> During stardate Thu, 13 Oct 2005 22:29:21 +0100, Steve
> <[email protected]> uttered the imortal words:
>
> >EMB wrote:
> >> Single phase, 20A circuit.
> >
> >That's what my tiddler runs on too. 12mm ? What's the difference I
wonder.
> >
> >Not that I have much call for 12mm plate cutting, but you never
know.
> >
> >Steve
>
> My 35 Amp feed Plasma tops at 10mm if my memory served me right.
> Single phase.
>
> Clarke one.
>
> Lee D
> --
> Success is going from failure to failure without a loss of
enthusiam.
> Winston Churchill
>

Pah - just toys ! My Hypertherm 900 will cut 22mm cleanly and sever
29mm off 230v single phase (but 55 amps!) My model is the one they
sold in the US so does use single or three phase. The 'CE' marked one
for Europe only does three phase which is a pain.

AWEM


 
Yes thanks for the advise, I do try and keep the tip on the work, have not
thought of keeping the tip clean with sandpaper though will give it a try,
thanks

What sort of air pressure do you use?

Rich
To reply remove " spam "



"Steve" <[email protected]> wrote in message
news:[email protected]...
> Rich wrote:
> > Ah, someone else with a plasma cutter, I have a little one 25A 240v will
cut
> > about 5 to 6mm but eats tips is this a common thing ?
>
> Just where do you put the tip ? It should be against the stock being cut
> ? A little gap lets plasma at the tip bottom surface and I think that
> stuffs 'em.
>
> Do you run the tip on a piece of sandpaper too ? I keep it very clean
> and I am some 35 feet of cutting 6mm through a single tip.
>
> Steve


 
Rich wrote:

> What sort of air pressure do you use?

About 70psi (which is much the same as every plasma cutter I've used).


--
EMB
 
Have seen one of these saws at work, have not played with it though, are
they noisy. I have got a Clarke plasma cutter at home which is great for
sheet and land rover type stuff, just wanted to give the gas thing a try.

Problem which seems to occur with me cutting thin sheet ( 2mm ) is the cut
gap fills up after the cutting torch has passed and then I have to go back
over it and this makes the cut much wider !!!

Rich

To reply remove " spam "




"m0bcg" <[email protected]> wrote in message
news:[email protected]...
> no more than 50psi oxygen and about 4-7psi propane.
>
> make sure you have a single stage 2 gauge oxy regulator that goes to at
> least 80psi [ie cutting reg] .
>
> no real need for dual stage reg plus they are more expensive
>
> note that propane or acetylene regulator will not show a great amount
> of bottle pressure if using propane , so in other words you might think
> bottle is empty when it actually isnt, its just that none of the gauges
> available show much bottle pressure with either fuel gas even on a new
> bottle .
>
> 1/16" PNM nozzle will cut up to 6" thick but i doubt youll go that
> thick , realistically youll only need 1/16" nozzles for almost
> everything .
>
> if you want to heat materials there are heater nozzles available for
> propane use but not for acetylene .
>
> get decent quality nozzles for best performance ie OERLIKON , or use
> PARWELD slightly cheaper .
>
> if you are just cutting flat plate and want decent quality edge of
> straight lines etc then you may like to look at an EVOLUTION CIRCULAR
> SAW at 140 quid , this is like a normal wood type circular saw but can
> cut mild steel up to 10mm thick and also can cut aluminium and
> stainless steel with different TCT blades.
> each blade is 18 quid and will cut 80m length of material before
> resharp or new blade is reqd .
>
> it will cut plate at almost same speed as you cut wood with similar
> machine .
>
> hope this helps
>


 
Rich wrote:
> Have seen one of these saws at work, have not played with it though, are
> they noisy. I have got a Clarke plasma cutter at home which is great for
> sheet and land rover type stuff, just wanted to give the gas thing a try.
>
> Problem which seems to occur with me cutting thin sheet ( 2mm ) is the cut
> gap fills up after the cutting torch has passed and then I have to go back
> over it and this makes the cut much wider !!!

Smaller cutting tip needed for starters. And secondly don't hold the
torch perpendicular to the sheet - you want it pointing at a 45 degree
angle with the flame aiming in the direction you are cutting. And
moving fast helps keep the cut clear.

--
EMB
 
Ah ok I have found that angling the torch helps will look for size of tip
and let you know

Rich

"EMB" <[email protected]> wrote in message
news:[email protected]...
> Rich wrote:
> > Have seen one of these saws at work, have not played with it though, are
> > they noisy. I have got a Clarke plasma cutter at home which is great for
> > sheet and land rover type stuff, just wanted to give the gas thing a
try.
> >
> > Problem which seems to occur with me cutting thin sheet ( 2mm ) is the
cut
> > gap fills up after the cutting torch has passed and then I have to go
back
> > over it and this makes the cut much wider !!!
>
> Smaller cutting tip needed for starters. And secondly don't hold the
> torch perpendicular to the sheet - you want it pointing at a 45 degree
> angle with the flame aiming in the direction you are cutting. And
> moving fast helps keep the cut clear.
>
> --
> EMB


 
You must log in or register to reply here.

Similar threads

codfather79
Series 3 Lower dashboard rebuild
Replies
6
Views
550
codfather79
codfather79
A
Engine cutting out 2.25 petrol
Replies
3
Views
2K
Tony Monsantoe
Tony Monsantoe
Hammer'n'tongs
Tyres wearing unevenly:- Axle ends out of alignment
Replies
9
Views
2K
Hammer'n'tongs
Hammer'n'tongs
VikingRider
1974 series 3 dashboard retrim advise
Replies
3
Views
2K
Bobsticle
Bobsticle
xDParis64
Freelander 1 Converting from wasted spark to distributor (or Visa Versa)
Replies
0
Views
796
xDParis64
xDParis64
Back
Top