[TheForge] Oxy/Propane reprise

[Paul N]

I guess I'll have to take a closer look at those adjustments. I was 
primarily playing with the lower "butt end" pair, and didn't fuss with 
the valve for the jet that much once I got it cutting.

Actually, once I established heat, and hit the O2 jet, things got 
quieter, and it cut pretty nicely until I'd get ahead of the heat and 
have to wait.

Also given what Andy has added, the fact that this plate was plenty 
rusty on both sides probably contributed to the difficulty I was having 
getting initial heat. But once I got a cut established, getting it 
re-established in the same kerf was a relative piece of cake.

But my thinking was that I figured the guys in the junk yards probably 
don't prep anything and just burn through. And the #2 tip should have 
been overkill.

That leaves just my gas control and technique to look at. I had better 
luck getting my primary cone close to the work for the pre-heat, and 
then once I started cutting, moving the torch off the work, and cutting 
with maybe 1/2" to 3/4" distance between the tip and the surface. Again, 
it was 3/8" plate, so while not hugely thick, it did require a bit of 
oomph (but thicker than anything I had cut with even acetylene in the 
past. I'm only a hobbyist, and my cutting experience was maybe 2 hrs in 
a Community College welding class last semester)

I really appreciate the help guys,
**Paul

Peter Fels & Phoebe Palmer wrote:
> Paul:
> Check all the O rings and make sure they are perfect.
> Make sure the seats of the cutting attachment tip are clean and smooth.
> It sorta sounds like you might not be opening up the oxy valve on the 
> torch butt wide enough before you adjust the oxy valve on the cutting 
> attachment.
> Check that the tip oxy jet is clear.
>   As soon as you can see a red surface, you should be able to start your 
> cuts. pf
> 
> Paul N wrote:
>> Well, I spent a couple hours messing around with oxy propane cutting 
>> today, probably ran through 40-60 cu ft of O2.
>>
>> It took me awhile to get the flame balance to where I could cut (Notice 
>> I didn't say "correct", as I'm not sure that term would be accurate).
>> I have a "clone" of a Victor r100 torch, and was using a #2 oxy/propane 
>> cutting tip. I was working outside, so there was some wind to contend 
>> with. I had the propane at about 6psi, O2 at about 25psi.
>>
>> I had to "ratchet" up to working settings on the torch. If I just turned 
>> up the propane at the torch, the flame moved away from the tip, and if I 
>> added O2 at that point until I got a nice clean cone, it wasn't hot 
>> enough, nor was there enough O2 flow to cut. So I had to alternate: add 
>> more propane, add some O2, etc. until I got a decent flame.
>>
>> I was cutting 3/8" plate (cutting a 30" circle to use for a base of a 
>> legvise mount I hope to build). It took several tries to get things 
>> acceptable, along with the tip to work distance. Even then, I got some 
>> occasional popping in the torch. I thought that would be an indication 
>> of excessive heat, but adding more O2 made it worse, and adding more 
>> propane made the flame "noisier", and had me thinking it was too high.
>>
>> It's obvious I need some more practice, and perhaps play around with the 
>> gas settings some more, as I had to move pretty slowly to maintain a 
>> steady cut.
>>
>> Still, every once in awhile, I'd move the torch in a way that would 
>> result in losing the cone, but not the flame, and I'd have to back off 
>> the pressure to re-establish the cone. So maybe I had it turned up too 
>> high. I'll have to spend a little more time with it to get more familiar 
>> with using propane. It's obviously different from acetylene.
>>
>> Next step will be "plunging" cut (not starting at an edge) I'm going to 
>> assume that there's some difference there too, as with acetylene, I had 
>> actually started to form a puddle before hitting the cutting O2.
>>
>> Comments and further advice is welcome.
>>
>> Thanks again everyone.
>> **Paul N.
>>
>> ______________________________________________________________
>> TheForge mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/theforge
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:TheForge at mailman.qth.net
>>
>> TheForge mail list group photo site is
>> http://www.photoaccess.com
>> Login: blacksmithblacksmith at hotmail.com
>> Password: anvil
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
> ______________________________________________________________
> TheForge mailing list
> Home: http://mailman.qth.net/mailman/listinfo/theforge
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:TheForge at mailman.qth.net
> 
> TheForge mail list group photo site is
> http://www.photoaccess.com
> Login: blacksmithblacksmith at hotmail.com
> Password: anvil
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>