I have to second this. I took a Vo-tech welding course nearly 20 years ago, and it was definitely worth the time.

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

Yeah, don't let the doom and gloom stop you. Just "think safe" and definitely get someone to teach you.

I would also suggest if your rusty go get some scrap metal and practice before you work on anything important.

I was taught to arc weld by expert welders. They could weld a 10" pipe with 6" of room to work with without even looking. Any position anywhere, no leaks. Now that's welding!

Danny

__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination

oxy/fuel is a very versatile combination. You can even blow glass if you run oxy-propane.

That said, I got my first chance to play with a plasma cutter yesterday.. I'm fabricating a 'tall' bicycle (double decker), and had to seriously modify a few existing frames to get their parts. I was all ready to use the hacksaw for some delicate cuts that I didn't want to warp the hell out of with the oxyfuel cutting torch when my friend suggested we go use his plasma cutter. I'm glad I did, because the damn thing goes through metal like it isn't even there. No need to clean off rust or paint, and it handles any electrically conductive metal. Most will even cut up to 1/2" without complaint. Dead easy to use, too, just hook it up to the air compressor (with an inline drier), turn it on, and go.

Even though they are spendy, if I had to do a lot of cutting I'd throw away my hand saws and oxyfuel torch and hug a brand new plasma cutter.

If you have a few gas shops in town visit them and see what they can do for you for good deals on tanks or rentals. We've got a shop in town (CeeKay) which is really responsive and easy to work with, and they're good to hobbiests, I never feel bad asking them for advice since I'm confident they'll steer me in the right direction.

peace,
sam

__________________
"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

It helped a lot for me to just watch someone else do it before I jumped into it. Having someone around to give little tips is very helpful! However, if its just you, look into the Haynes welding manual, which goes over several welding and cutting processes, all from an automotive perspective. As usual with Haynes, it isn't the most complete reference, but it'll get you going with all the basic processes, and the automotive focus is handy, since thats the application you'll be working with a lot (I assume).

Also, spend a lot of time on the Lincoln and Miller welding sites, they have a lot of good articles and tech tips for different welding applications.

Peace,
sam

__________________
"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

"You can even blow glass "

Yes, but the dang protective glasses cost like $240 and you have to know which type glass you are going to be dealing with to choose the right ones....

Never open Acetylene tanks more than ONE FULL TURN of the handle...
Oxygen opens all the way....

Also remember acetylene and grease dont mix

Comments about recent postings here that are wrong.

1. Acetylene is dangerous at pressures above 15psig outside the tank. In the tank it is kept about 150 to 200 psig. The thing is that 99.99% of users never use acet. above 5 to 7 psig. You can cut 1" thick steel with 7psig so to say that acet. will explode is thechnically true but is not something that most people need to worry about. If you are running a large rose bud tip off of manifolded acet. bottles then you might want to watch your manifold pressure but in the average shop or industrial setting it is no big conscern.

2. As a hobbiest you can lay acet. bottles on their side and use them in this position until the cows come home and nothing will happen. Don't try this if you are running a large rose bud tip that requires a large flow from the bottle.

The reason that acet. can be stored in the bottle at 150-200psig is that the gas is suspended in acetone which in turn is suspended in usually something like cotten seed hulls. Tap on an oxy tank and then on an acet. tank. The dull sound on the acet. tank comes from being filled with hulls or some such material. I don't know what they use nowadays but years ago it was cotten seed hulls.

By running a tip that requires a very large flow rate you will draw the acetone out along with the acet. Mostly there is no reason to use an acet. bottle on its side but it can be done if you don't draw on it too heavily.

3. Grease and oil doesn't bother acet. It will not cause it to explode. Don't try this with oxy though. Oil on oxy regulator threads is under compression in an oxy rich atmosphere much as Diesel fuel is in an engine. It can go boom but it is very unlikely that the entire cyl. will go up since there is no fuel for it to burn. Oxy cyls. have blow out disks in the valve. If they are over heated such as in a fire the disk with rupture and if you are near by you will really wish that you were someplace else.

The most common accident that happens with oxy cyls. is that the neck is shapped off when they fall over. There are mega stories about this happening and the cyls. goiing through all sorts of concrete walls, cars, etc. The tv show Mythbusters demonstrated this by knocking the valve off a cyl and as I remember not a lot happened. Still you have about 3K psig worth of gas comiing out of a fairly small hole and aside from the noise you could probably get some damage but I doubt that it will be anything like what urban legend has it. This is as good a reason as any to be sure that you secure your bottles in the upright position.

4. There are stories and stories of acet. cyls exploding because of flash back from the torch to the tank. I have been messing with oxy/acet for about 50 years, most of which was in industry, and have yet to see this. I have seen these cyls. catch on fire but never explode. There is not enough oxy present around or in an acet. cyl. to cause an explosion. It does make a very interesting fire though with a LOT of soot.

It is easy to have a blow back into the torch. If you don't shut off BOTH the oxy and acet. the torch will melt and the fire can travel back up the acet. hose and set the acet. regulator on fire. If left unattended I am sure that the regulator will melt and perhaps you will get a very noticeable fire, but the cyl. will not explode. The fire will not race up the hose since there is no oxy in the hose to support combustion. It will slowly burn the hose and eventually get to the regulator. Pleanty of time for you to walk over calmly and turn off the bottle.

What you might look at instead of acetylene is a new gas called Mapgas. It is a combination of acet. and propane. It is much cheaper and a lot safer than acet. The tips are different than acet. and it takes a bit longer to heat the metal before cutting but once you get used to it its no big deal. If you go this route be sure to get someone to show you how to use Mapgas. It takes a bit more oxy to run.

Was that the bell? Of, welding 101 is dismissed.

ps. Whatever system you use remember to turn off your bottles after use. I turn off mine after every use unless I know that I am going to use them again in a few moments. A small leak over time can cost you a $40 bottle of acet. Plus you will be out of gas on a Sat. afternoon just after the stores have closed and right when you need it the most.

Hmmmm...I was always told that the surface area exposed in the acetylene tank when layed over would overpressure the tank and rupture it...

Was told that by my metal shop teacher...and by a few others...and one rental shop refused to let me carry them home horrizontal......guess that was a popular urban legend...

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

The world, and vo-tec classes, are full of urban legend. How can laying over the tank over pressure it? Where is the pressure coming from? There is no outside source of heat to cause pressure to build up. There is also nothing inside the tank for the acet. to react with in the horizontal position that is not in contack with the acet. in the vert. position. I used to load acet. bottles onto supply boats in the Middle East. We used to roll these tanks down the wharf and down the deck of the supply boat. All this in the noon day sun. Never had a problem.

Think about it. Would gas companies that supply highly explosive gas to industry make a product that would explode if mearly rotated 90deg.? Not likely. You are dealing with industry that employes many workers that are, how would you say, not really the brightest bulb in the fixture. When is the last time that you read about an acet. bottle exploding in one of your local plants and killing 5 people? Hasn't happened.

I live along the Texas coast. The area from here, Corpus Christi, to Baton Rouge, La has probably 75% of the oil refineries in the States. I have never heard of an acet. cyl. exploding in all the years I have lived here. Now the refineries themselves go up every once in a while, like yesterday in Texas City, but on the whole they are very safe considering the product they handle. I can't believe that if acet. bottles exploded when turned on their side that there refineries would allow them into the plant.

Turn an acet. bottle up on its valve end. Let it stand for a few minutes and then crack the valve open just a bit. You will usually get some gas and liquid out of the bottle. The liquid is acetone. They might use some other chemical nowadays but they have to use something to suppend the acet. since acet. will explode easily over 15 psig.

Don't doubt your word.....not backed up with your experience..

it was always explained to be absorbed into the Acetone...verticle the surface area is minimal....horizontal it was great...never understood the physics behind that so just took them at their word.

So its nice to know its really a non issue and an urban legend.

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
---------------------
Section 609 MVAC Certified
---------------------
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

Ok guys...to debunk some myths...

1) Laying a bottle of Acetylene on its side will not cause it to rupture...
2) You cannot use a bottle of acetylene whilst it is laying horizontally...no matter the size

The reason that you don't lay acetylene bottles on their side is because the acetone inside it will seep into the regulator and clog the tips on your torch... making them dangerous

The rule of thumb is to put the bottle back vertically and not use it for twice the amount of time it was laying down

Trust me...I do this stuff at OIT everyday

__________________
Nick
*****
2002 Sprinter 2500 140" High Roof :

There have been fatal accidents when sparks fell into shirt pockets containing BIC lighters...

http://www.snopes.com/horrors/techno/lighters.htm