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Up Topic Welding Industry / General Welding Discussion / Acetylene Availability?
- - By MBSims (****) Date 04-03-2011 16:29
We got a letter from our gas supplier last week that says due to the calcium carbide plant fire in Lexington, KY, acetylene supplies may be limited for awhile.  One of the ways acetylene is manufactured is by reaction of calcium carbide with water to form acetylene.  Based on what I've read so far, acetylene is mostly produced from methane gas in the U.S. with only about 20% coming from the calcium carbide process.  The fire affected a plant that supplies 50% of the calcium carbide, so this would suggest about 10% of the U.S. supply would be affected.  Anybody have any better information on this?
Parent - - By hillbilly (**) Date 04-03-2011 22:14
The local Airgas will be affected, according to them. The other LWS I do business, Volunteer Welding says they do not get theirs out of the affected plant.
Parent - - By thewelder (***) Date 04-03-2011 22:50
here on so cali tri-star gas a welder supply store send me a letter last week. the acetylene price will be treeple on the next month or so because of the plant fire and airgas said wil be no less then double on the next 3 to 4 weeks that was friday, i just waithing to see the final ''price''.
Parent - - By Lawrence (*****) Date 04-04-2011 02:19
Propylene
Parent - - By DaveBoyer (*****) Date 04-04-2011 02:53
Since You mentioned it... I know it should only be used with Grade "T" hose, and that there are different cutting tips for it, but how about single flame tips? They are "just a hole", do they need to be made special for Propylene? I know they make rosebuds for propylene, but will acetylene rosebuds work with it?
Parent - By Tommyjoking (****) Date 04-06-2011 00:52
Dave someone told me there was a brazing tip for Propylene  but I have not seen one yet.   You need different rosebuds too....the tips are entirely different.  My friend has a small bottle of it at his shop (125-150CF I think) and he is on his fourth oxygen to that same Propelyne he got two months ago:eek:...and the Propylene was a few dollars cheaper!   My LWS does not stock anything but grade T, I just bought 100ft and it was not bad at all.
Parent - - By MBSims (****) Date 04-04-2011 13:30
Lawrence,

How do you like the performance of propylene vs. acetylene for cutting, scarfing and preheating?  When you changed over, did you keep any acetylene rigs?  I know we need new tips, hoses and regulators.  Did you have any issues keeping the propylene equipment from getting intermingled with acetylene equipment?  Any issues retraining folks on how to set the flame?

To change our entire fleet of plants over to propylene would be a major undertaking, "if" we decided to go that route.  We weathered the last acetylene "shortage" when Katrina hit the Gulf coast fairly well.  Any info you could provide on making the transition smooth would be helpful. I'm not convinced the "shortage" is of the magnitude being conveyed by the sales people.  I'm thinking there are a number of gas suppliers out there that purchased calcium carbide from the KY plant to make their own using acetylene generators, and those are the ones most affected.  There are others that obtain acetylene as a by-product of oil and natural gas refining that will not have their supply affected, but their demand will rise due to the calcium carbide shortage for their competitors that use acetylene generators.  Air-plasma is looking better every day.:grin:
Parent - - By Lawrence (*****) Date 04-04-2011 14:22
Marty.

Honestly I think for manual oxy-fuel cutting and scarfing, track burners too... I can see no difference between the two... Both work well and I like em.

I do keep a couple of Acetylene carts on hand for several reasons. Most of our cutting work is run through manifolded hard lines that carry Propylene.
1. to show contrast between the two gasses
2. Mapp/Propylene will not gas weld
3. Acetylene makes that nice smoke that covers aluminum for hack level annealing.
4. Unwlling to throw away perfectly good rigs.

The danger comes when acetylene is burned with a mapp/propylene tip,, Not so much the other way around.  I made this mistake once and had a backflash/tip fire... Ruined the tip and put a little scare in me... Learned my lesson quick.

Some hoses/regulators are interchangable, some are not... Research required.
Parent - - By Skaggydog (**) Date 04-04-2011 16:48
How come when I say "scarfing", people say, " Scarfing!, What is scarfing?  Don't you know how to Talk?"
But you guys are acting like you know what scarfing is.
Parent - By Lawrence (*****) Date 04-04-2011 17:47 Edited 04-04-2011 17:49
Ok you got me there.

Actually AWS 3.0 defines "Scarf" this way:

"A nonstandard term for bevel"

We use the term (incorrectly) generally to communicate the notion of metal removal with a cutting torch or plasma cutter... Things like backing bars etc.

Also for  unauthroized consuming of the can of beans cooking in the rod oven   :)

I'm surprised Al or Joe Kane haven't set us straight already.
Parent - By welderbrent (*****) Date 04-04-2011 18:50
In my more than likely misled education 'scarfing' referred to flame gouging.  Use of a flame to 'wash' welds, remove material in a seam to give the weld some depth, can also be used to remove heads on rivets, bolts, etc.  Originally used more on castings and billets but used by a lot of boilermakers to accomplish tasks without an air arc or grinder handy or at times because it is just the better process for the job.

I have a couple of torch tips that I was told were 'bulkhead or scarfing' tips.  They are curved and flat on one side and missing a couple of the preheat holes along the flattened side so you can get closer and at the proper angle instead of using a standard cutting tip.  I have often used the standard cutting tips but it takes a lot more care to keep from gouging too deep into your parent metal.

Scarfing is also used often, by those who don't understand proper usage, to describe air carbon arc gouging. 

I have used Propylene for near on 20 yrs.  Love it.  Usually set all my torches up with hoses that will run either Acet or Prop.  The tips are two part as opposed to the single part Acet tips.  I believe an acet rosebud will work for Propylene but you have to keep the pressure up.  I think that is the correct way, been a while since I have used one.  I have a rosebud made for Propylene.

I don't remember changing the regulators. 

Have a Great Day,  Brent
Parent - - By jpill (**) Date 04-04-2011 20:22
"3. Acetylene makes that nice smoke that covers aluminum for hack level annealing."

Don't know about annealing, but carbon smutting a heavy aluminum section with acetylene before welding was a standard industry practice to determine proper preheat temp prior to welding before the days of tempil sticks, and temp guns. Smut the section, adjust rosebud flame for heating, and heat till smut disappears, then start welding.
Parent - - By Lawrence (*****) Date 04-04-2011 20:32
Right.. 

The "smut" will burn off at 800 F.   This is also right about the transformation temp for 1100 and 3xxx series aluminum..

Just keep in mind that the temp to remove the smut is only 300 degrees from the melt point of the aluminum and that any heat treat condition that the alloy may have had is way past gone. Most aluminum preheats are 400 F. or less.

Apologies for the thread hijack... But its good info.
Parent - - By jpill (**) Date 04-04-2011 20:38
and that is the reason it was (key word) standard before tempil sticks and temp guns! Old methods are not always the best methods...lol.
Parent - - By jpill (**) Date 04-04-2011 20:53
Since we have hijacked the thread on matters of heating this reminds me of a discussion I had with a much older than me Morgan Worchester engineer once when I mounted a coupling on a piece of their equipment on a job. He asked how I was going to test the coupling heat before I mounted it, I told him I was going to spit on it and when the spit bounced off it was in the range of 250-300 F. He like to have had a cow, I told him to find me a 250 tempil stick, a heat gun, and some 30 weight oil. I oiled the coupling and started heating it with the rosebud, the whole time spitting ocasionally on the coupling when the spit bounced off the oil was smoking (30 weight smokes at 250). I then told him to wipe it with the tempil stick, it melted, then told him to shoot it with the temp gun....258 F. He said "I'll be damned, I learned something from a kid." He asked me how I learned all that I told him I had worked with some of the grumpiest old millwrights that had taken me under their wings. That was almost 15 years ago and I still try to learn something everyday.
Parent - - By welderbrent (*****) Date 04-04-2011 23:14
I'm just wondering how you could 'OFFICIALLY' calibrate that procedure??!!

Have a Great Day,  Brent
Parent - - By jpill (**) Date 04-05-2011 00:12
He was satisfied with the tempil sticks, and the heat gun (both traceable to a standard), but had never seen 30 weight smoke at 250 or the spit trick. You can also do it by sight in good light, bright steel takes on a yellowish straw color at around 250-275, but it all depends on the quality of the ambient light around you, I never trusted my eyes enough to do it by sight. To long with the torch and the steel goes blue when it cools which is a big no-no to the white hats that inspect and sign off as its a sure sign the heat treat has been affected. What a lot of people don't realize, on interferance fits on couplings or bearings is that at around 250 F. a part has grown to the max it is going to so there is no reason to keep heating past that point.
Parent - By J Hall (***) Date 04-05-2011 01:27
Finally, someone else that know the Spit trick. I learned that years ago from a very good welder mechanic.
But it doesn't work as good since I quit the Copenhagen.
Parent - - By DaveBoyer (*****) Date 04-05-2011 03:03
Acording to the American Machinist's Handbook, 420f is verry faint yellow, and 440f is light straw.

I have noticed a really pale yellow on tool steel that was tempered at 400f.

I remember something about using a small piece of pine wood to determint the temperature for annealing aluminum, but never did it that way.

Steel will continue to grow above 250f. 6.4 micro inches per inch per degree f is the proper coeficient at room temperature, but this does change with temperature.

We heated ball bearings in a deep fryer to 350f. This is about as far as You want to go, as they are tempered about 400f, and the 350f oil gives a little safety factor.
Parent - By jpill (**) Date 04-05-2011 13:02
I absolutely hate heating bearings in oil, some companies I did work for didn't want it any other way. No matter what heat gloves you wear you can't get enough of the oil off before seating without getting burned. Heat gloves wick hot oil like nobodys business!
Parent - By FixaLinc (****) Date 04-05-2011 17:45
I just got this today from Lincoln and Harris.

Alternate fuel options

http://email.lincolnelectric.com/track?t=v&mid=4313&msgid=4308&did=2200&edid=2200&sn=1245880827&eid=txfireman92@gmail.com&eeid=txfireman92@gmail.com&uid=18830&rid=18830&erid=18830&fl=0&mvid=0&extra=&&&2000&eu=100&&&VWP
Up Topic Welding Industry / General Welding Discussion / Acetylene Availability?

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