Preheat from the under side, heat rises, after heating good and hot you can make the pierce from the top or bottom. OxyPropane is not very good for piercing heavy plate, ArcAir is quicker and cheaper if you have it. Once you have a hole you can use the torch to make a clean sided hole.
Your BIL may want to keep a bolt in the hole to prevent wear when loading dirt or gravel.
My BIL wanted me to cut a hole in the front of his front end loader to mount a trailer ball to manipulate trailers. Simple, I think at first.
Then I notice there's two layers there. Ohhhh.
Now I'm using propane instead of acetylene. I fire it up, and blow a hole in the top layer, about 3/16" thick. The molten metal looks like silver globules. It blows upward and outward like a drop of milk in a saucer of milk.
I heat and heat and heat the bottom layer until I fry the copper jacket on my cutting tip. I change tips, this time keeping it farther away and waiting for the proper color before hitting the oxygen. I penetrated the lower layer, about 3/8" thick. I made a couple of circular passes to round out the hole, but still saw a couple of the silver looking globules form on the edge.
I know that any time you flame cut layered materials, it gets interesting.
But what was the silver coloration? Was it perhaps a different grade of steel used on a bucket like that? Maybe hardened or different metallurgy?
Ended up getting a nice round hole, ground it to look nice, ball fit, and BIL was happy. All's well that ends well.
Any suggestions on what I could have done different except drill a starter hole with a conventional drill or MagDrill?
Steve
Presumably "Brother In Law"
Forgive me. What is BIL?
-- As Iron Sharpens Iron, So One Man Sharpens Another. Proverbs 27:17
I dont know the size of this bucket but lots of the larger buckets can have a high manganese/nickel alloy steel edge for wear. from my experiences it doesnt behave like most other steels , especially after being work hardened
A year or two ago I was watching a fellow cut up some European machinery for scrap metal. Some of the rollers were of a very hard material and had to be cut quite differently than the way one normally would. I don't recall the exact procedure but he didn't wait for the right color as in cutting mild steel. I think the "secret" to it was to apply the oxygen as soon as you see the little "droplets" start to form.
Brother In Law
That was the final key. But, as private stated, were I to do another, I'd go through the thick bottom sheet first, and blow upward. Yeah, when the color is right and when the metal just starts to bubble tiny bubbles, that's when I hit the O2.
Steve
I thought after I'd posted earlier that we were comparing apples and oranges. You were having to blast through a second layer with air, etc. in between to allow blow back. The situation I witnessed was an open roller so he already had a rounded edge to get started on. Don't know what he'd have done had he had to blow a hole through that hardened roller.
Al
When I'm having trouble getting the metal hot enough to start a cut, and if the configuration allows, I drill a hole. It's a lot easier to the the edge of a hole hot enough to start the cut, and the hole gives the slag someplace to go.
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