Flame cutting cast iron

[dgfoster]

You can't ignite the cast iron the way you can steel. You can kind of melt your way through but it will be uglier than butt ugly.

I spent 10 years as a shipfitter where a torch was my #1 tool. I have done severing cuts on cast iron. Clean torch cuts are not possible. If you try, you will use a huge amount of fuel gas too.

What you are saying dovetails nicely with Scottl’s report on burning steel bolts out of CI cylinders.

As far as butt ugly cuts are concerned, when I worked in “raw stock“ at Link Belt, my O/A cuts in steel were butt ugly! I remember well gnawing on 6 and 8” bars of alloy steel trying to learn as I went. The company would have been money ahead had the foreman shown me a thing or two. But then, I was summer help and summer help was known to be hopeless.

On the other hand, I did have the privilege of watching a master torch man who was so good that he was the only one allowed among several hundred workers to do certain torch bevels and other fancy work. Every operation on a part was named but his torch cuts were the only ones that had a worker‘s name specified on the prints. Sadly, he was not eager to teach summer help scum.

Denis

 

[moonlight machine]

What you are saying dovetails nicely with Scottl’s report on burning steel bolts out of CI cylinders.

As far as butt ugly cuts are concerned, when I worked in “raw stock“ at Link Belt, my O/A cuts in steel were butt ugly! I remember well gnawing on 6 and 8” bars of alloy steel trying to learn as I went. The company would have been money ahead had the foreman shown me a thing or two. But then, I was summer help and summer help was known to be hopeless.

On the other hand, I did have the privilege of watching a master torch man who was so good that he was the only one allowed among several hundred workers to do certain torch bevels and other fancy work. Every operation on a part was named but his torch cuts were the only ones that had a worker‘s name specified on the prints. Sadly, he was not eager to teach summer help scum.

Denis

I don't have the time of day for assholes that won't teach the youngsters, I love passing on what I know, we aren't going to be around forever and after we take the dirt nap things will need to carry on.

 

[TGTool]

What you are saying dovetails nicely with Scottl’s report on burning steel bolts out of CI cylinders.

As far as butt ugly cuts are concerned, when I worked in “raw stock“ at Link Belt, my O/A cuts in steel were butt ugly! I remember well gnawing on 6 and 8” bars of alloy steel trying to learn as I went. The company would have been money ahead had the foreman shown me a thing or two. But then, I was summer help and summer help was known to be hopeless.

On the other hand, I did have the privilege of watching a master torch man who was so good that he was the only one allowed among several hundred workers to do certain torch bevels and other fancy work. Every operation on a part was named but his torch cuts were the only ones that had a worker‘s name specified on the prints. Sadly, he was not eager to teach summer help scum.

Denis

I don't know where all Link Belt had plants, but I used to drive by the Cedar Rapids plant frequently and knew a guy who worked there.

 

[dgfoster]

I don't know where all Link Belt had plants, but I used to drive by the Cedar Rapids plant frequently and knew a guy who worked there.

That was their sole power crane and excavator plant back in the late 60’s when my dad, uncle, and brother were full-time. And that is when I worked there. Prior to the “Speeder” shovel/ cranes was the locally owned factory and was purchased by LB to become Link Belt Speeder. It eventually was moved down south. Driving by the empty yard and hulk of an empty building always was a bit painful. Stood empty for ?10? years.

Denis

 

[TGTool]

When I was in a local machinist program we had a tour there since they hired some from the program and one memory stands out for ingenuity.

There was a splined shaft that they wanted hardened on just the splines. To do it, in production, the shafts were hung end-on from a conveyor with electromagnets. The shafts then moved between induction heating coils that brought the ends up to the transformation temperature. At that point they were no longer magnetic and dropped off the conveyor into the quench tank below.

Later I worked in the toolroom at Square D just up the road.

 

[crickets]

I was thinking maybe we'd get some other responses to my questions. But, none seem forthcoming.

So, I did do some searching for answers. It looks like 2" is about the max a common several thousand dollar Hypertherm can do. They do make industrial machines intended for CNC applications requiring 480V 3-phase 80KW power supplies that can cut up to 6 inches. Hypertherm says that plasma is a good option up to 2 inches but O/A is preferred over that for most situations.

It does look like plasma cutters also produce a very hard surface on CI. That is due to nitriding as a result of atmospheric nitrogen coming in contact with the super-heated surface of the cut metal. That might be mitigated by using an inert cover gas like argon.

Powermax 85 is the largest single phase machine they make, it's rated to cut up to 1-1/4" mild steel. Next model is Powermax 105, which is 3ph only, and it's rated to 1-1/2" mild steel. Given cast iron has a lower melting temp, I wonder if a significantly thicker material can be cut on the same machines.

 

[dkmc]

Thank you all. I have an old Universal HBM that needs way too much work. Buying it was a failed experiment with an on-line auction.

You didn't happen to buy that at Lagoe Oswego Corp did you? There were a number of them there.

 

[john.k]

AS mentioned ,you actually melt the iron with the torch,and use the oxygen to blow the melted iron away......which is not economic,but does Get 'r'Dun...............arc gouging is far the cheapest ......you can buy a diesel Lincoln 400AS nowdays for $500,and thats the ideal powersource for arc gouging

 

[Luke Rickert]

As mentioned before scoring and breaking is an option. I know a guy who cut up an old metal lathe for reuse (so very similar application) using an angle grinder to score/cut and breaking what you can with a hammer. It is still a mess and a pain in the rear and you need a really big powerful angle grinder.

Maybe the best option is to look around for someone local with a large sliding table band saw, that would make short work of this sort of task.
There are also some really massive cutoff band saws as well that could work (vertical movement rather than hinged).
There are metal cutting circular saws but I don't think any of them run slow enough to be anything other than toys designed to sell new carbide blades (as they run at 10x the max surface speed of carbide cutting steel)

Luke

 

[marka12161]

You didn't happen to buy that at Lagoe Oswego Corp did you? There were a number of them there.

Nope. That would have made too much sense. Came out of a shop in Arkansas.

 

[marka12161]

As mentioned before scoring and breaking is an option. I know a guy who cut up an old metal lathe for reuse (so very similar application) using an angle grinder to score/cut and breaking what you can with a hammer. It is still a mess and a pain in the rear and you need a really big powerful angle grinder.

Maybe the best option is to look around for someone local with a large sliding table band saw, that would make short work of this sort of task.
There are also some really massive cutoff band saws as well that could work (vertical movement rather than hinged).
There are metal cutting circular saws but I don't think any of them run slow enough to be anything other than toys designed to sell new carbide blades (as they run at 10x the max surface speed of carbide cutting steel)

Luke

I'll make a value judgement on how hard i want to work. It may be more trouble than it's worth.

 

[dgfoster]

I'll make a value judgement on how hard i want to work. It may be more trouble than it's worth.

What dimensions are you working with?

Denis

 

[Tyrone Shoelaces]

I remember trying to snap a big planer bed in half. It was about 30 ft long and we wanted to send it to the scrap yard in two halves to save on transport expense. The guys were gouging it, trying to burst it with hydraulic jacks, grinding it, hitting it with sledge hammers ! The thing wouldn’t break. Finally we lifted one end on the overhead crane and dropped the bed from a fair height onto a length of 10” dia steel bar set up roughly where the middle of the bed was ! The cumulative efforts finally paid off.

Regards Tyrone.

 

[john.k]

there is cast iron and there is cast iron........years ago times were bad ,and I decided to scrap the pile of big old electric motors I had .........about half the motors broke quite easily,but the rest it was 14lb hammer blows until I was stuffed.

 

[wildo]

My girlfriend does all the torching at the local scrap yard. She hates cast. They break it with an excavator.
Last year she scrapped a locomotive with a 645 EMD in it. All the ol boys at the grain terminal were pretty shocked when she took off her respirator!

 

[dgfoster]

there is cast iron and there is cast iron........years ago times were bad ,and I decided to scrap the pile of big old electric motors I had .........about half the motors broke quite easily,but the rest it was 14lb hammer blows until I was stuffed.

Was some of that cast iron bending some before it finally broke? Makes me think you were bashing ductile or malleable iron with the 14 lb hammer. Ductile is very difficult to break with a hammer. Grey takes some work, but it is doable. The first time I picked up some foundry returns with ductile mixed with the grey it took me a few minutes to tumble to the fact that they had given me some ductile. It just did not want to break no matter how hard I hit it. I "break" ductile with my 7" angle grinder.

Denis

 

[john.k]

I learnt a long time ago to cut scrap with an air arc ...saves the horrible blowbacks you get that shower you in slag and melted sand .....horrible sticky stuff ,not to mention being red hot.

 

[DDoug]

Might try a Quicky saw.....

 

[marka12161]

What dimensions are you working with?

Denis

What dimensions are you working with?

Denis

Table is 32 x 58 so saddle is a bit smaller than that. Having said that, there are some overhanging pieces tha t i can probably cut off pretty easily with a porta-band. Resulting cut-offs will probably be in the 10" x 3" x 6" range. Easy enough to do and definitely worth it for my purposes. The rest of the saddle is pretty beefy. Not sure wrestling with it makes much sense but i'll know once i get the table off.

 

[dgfoster]

Table is 32 x 58 so saddle is a bit smaller than that. Having said that, there are some overhanging pieces tha t i can probably cut off pretty easily with a porta-band. Resulting cut-offs will probably be in the 10" x 3" x 6" range. Easy enough to do and definitely worth it for my purposes. The rest of the saddle is pretty beefy. Not sure wrestling with it makes much sense but i'll know once i get the table off.

That should be pretty easy to score and break. Just score a 10X3" piece a half inch or so top and bottom where you'd like it to break. After scoring I'd prop the scored end on a solid support of some sort and strike hitting the table on the waste side of the score. That will mininmize bruising of the work piece and minimize chances of accidentally cracking the work piece. A few good licks with an 8 or 10 pound maul will crack it pretty cleanly at the score lines if this is ordinary grey iron. Just for interest, note the crystal pattern on the broken piece. You should clearly see much larger crystals near the center (slower freezing after the initial pour) and progressively finer crystals toward the surfaces.

Then take the pieces to a horizontal band saw and clean them up for milling and finishing.

If you are scraping the work pieces, I'd stress relieve them at 1150F in a standard pottery kiln or equivalent for maybe 3 hours for 3" thick iron. That will be plenty. Ramp up 400 deg per hour. Hold 3 hrs. Turn off the kiln and let it cool to 400F before removing it. Stress relief will make a very thin oxide layer easily wire brushed off. But no scaling will occur.

Denis