What Kind of Steel Pipe Do I Have?

[Hilbilly]

It is definitely not stainless. This stuff is the same thickness as Sched 40 pipe but is a different material. I think it is gas pipe and the coating is not paint.

I'm making a forge based on the Whitlock design and I'm using this pipe for the internal air flow selector. I used the unfinished forge to heat up the pipe to burn off any chemicals or coatings on the pipe but was amazed that the coating burnt but still did not flake off even at around 1600* F. I couldn't even scrape it off after that much heat. I will end up having to use the grinder to get it off.

I've used the forge a few times already without the air flow selector but I think it will be better with one. I'm in the process of making my first set of tongs using my newly completed anvil. Man anvil making is time consuming. If I remember I'll get a pic of the anvil and forge tomorrow.

 

[Tractor Seabee]

My guess w/o further info is that it is either malleable, ductile, or cast iron pipe. Malleable pipe is not any more but fittings are. Ductile is more common 3" and larger; it is used in the utility industry. They all leave few yellow sparks when grinding (high carbon content), resist sawing, are coated black. Cast iron is the hardest, it is normally cut by scoring and breaking. Ductile by cut off saw using carborundum wheels or diamond grit blades. Look for a mold line on opposite sides and the finish is rough and not perfectly round; it is probably cast. Ductile is spun cast so there is no mold line. None of these weld in production work, they are joined by mechanical gasketed means.

Old Pipefitter, Ron

 

[Hilbilly]

I believe the winner is cast iron. After I finished cutting the slots in the pipe, heating it to get rid of the coating and grinding it smooth, it fell off the table, hit the floor and broke into 3 pieces. Looks like I need to make another one. I think I will use something else this time.

So for the next question. The only other piece of pipe I have that is close to the right diameter is some old rusty pipe with remnants of what appears to be galvanized coating on the outside. So the question is; if I grind off what is left of the outside coating will it be safe to weld or is the inside also galvanized? Can't tell by looking because it is heavily rusted on the inside.

Here are pics of the anvil and forge. The anvil is made up of pieces of 1 1/2" mild steel plate welded together, with a 3/4" piece of AR500 for the top plate / face.

 

[dragoneggs]

Since I was wrong in the first one I won't venture to guess but I sure do like your anvil! Nice job.

 

[CNC Dan]

The zinc coating on galvanized pipe isn't that bad.
If you are stick welding it (or flux core), use a fan to pull or push the smoke away, and work outside or by an open door. If using MIG, use a fan to pull the fumes away, but from far enough away/above so you don't lose your shielding gas coverage. As before, try to aim the fan out a door or window. There are good and affordable respirators that will allow you to work in an area with less than good ventilation too.

 

[dragoneggs]

I would definitely wear a respirator such as one of these 3M guys with the pink replaceable filters. They are lightweight and surprisingly comfortable. Mine is an older version similar to this...

3M 6000 Series Half Facepiece Respirator, Medium - Papr Safety Respirators - Amazon.com

 

[ch1ch2]

Galvanized pipe fumes can make you sick. If you do breath them and feel sick, drink a glass of milk. Sounds funny but I was taught that in welding school and I have experienced it first hand.

 

[Hilbilly]

Thanks guys.

I just finished welding some legs on the forge and a set of wheels on an axle. Now it's time to get back to making the air flow pipe. I'll use the galvanized pipe and grind off the outside coating. I know what you mean about feeling sick inhaling welding smoke. I get a similar thing from inhaling MDF dust. I got really sick from that stuff a few years ago and now use a respirator most of the time when I'm welding or doing woodwork. I've got 2 types, one that fits under the welding helmet and I've already gone through 2 filters on that one. I also starting using a fan a about a week ago just so I could l see the puddle when welding. That has helped a lot. Most of the time I am welding in my shop and have to open the bay door to get rid of the smoke. Sometimes I leave the door open while I'm working but it gets cold in the shop even with the wood stove going. So I usually open the door to vent the fumes by turning on my ceiling mounted air filter fan and when the air is clear I close the door and repeat the process.

Dragoneggs, thanks for the compliment on the anvil. When I started making it I thought it wouldn't take long. Man was I wrong. But I'm happy with the way it turned out. It's pretty heavy at 155 Lbs I don't want to move it around any more than needed. Going to have to make permanent base for it. The wooden bench it's sitting on now moves around when I'm hammering on it.

 

[Big Barn]

Hilbilly your anvil looks awesome! Nice work.

Terry

 

[STx]

I weld galvanized material almost every day, just stay up wind and don't inhale the smoke and you'll be fine. If you inhale it, it's supposed to make your muscles really ache but I've never had any problems working with it but, I've also never inhaled the smoke. Actually, I generally avoid inhaling any smoke when welding, whether it's from galvanized material or not.