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hwingo
10-05-2007, 09:55 AM
Hi guys,

I have a new lathe and it's been necessary for me to turn a backing plate for a new collet-closure chuck. The backing plate is made from cast metal. In general, cast metal is dirty containing sand and other harmful materails.

I attempted to take care by covering various parts of the lathe with paper but harmful materials still "peppered" the machine. What is the best way to clean the lathe after truning cast metal so as to assure that grit is not present to cause parts and surface wear?

Harold

gzig5
10-05-2007, 10:26 AM
Vacuum cleaner and clean rags. Don't get an air hose near it.

A.K. Boomer
10-05-2007, 10:34 AM
Yes I believe if you have crude sand castings that are holding sand that this can indeed be a recipe for wear, I would say get it as clean as you can the obvious ways and then lube the hell out of it and run it back and forth and lube the hell out of it and so on,,,

This is an interesting topic as Iv heard my friend describe cast iron as one of the best things to machine because its self lubricating, and in fact its loaded with graphite, but even so its also loaded with silicon, I get confused with this as silicon is an ingrediant in sand (silica)

I dont know but I went to wikipedia and copied this;

" Silicon is essential to making of grey cast iron as opposed to white cast iron. When silicon is alloyed with ferrite and carbon in amounts of about 2 percent, the carbide of iron becomes unstable. Silicon causes the carbon to rapidly come out of solution as graphite, leaving a matrix of relatively pure, soft iron. Weak bonding between planes of graphite lead to a high activation energy for growth in that direction, resulting in thin, round flakes. This structure has several useful properties.

The metal expands slightly on solidifying as the graphite precipitates, resulting in sharp castings. The graphite content also offers good corrosion resistance.

Graphite acts as a lubricant, improving wear resistance."





Keep in mind that this is "grey" cast and white and ductile are a whole nuther ball game...

By the way, yes I did try to find out some stuff in the archives but had no luck whatsoever so lets hear it from the guys that know cuz I sure the hell dont...

Mcgyver
10-05-2007, 10:53 AM
I agree protect the machine if its sand cast as bits of sand are embedded in the outlayer. However if its Durabar (continuous cast) it shouldn't be a problem. Also, castings like the Stuart Turner line should be fine - I'm guessing they are die cast or something as there is no sand.

I've never understood the aversion some have toward CI, machines beautifully and I don't find it that messy....then again, while it try to keep it tidy, my shop is not one of the operating theaters I see in the Mill thread :D

easiest way is to clean is to keep it out of bearing surfaces to start with. Paper towels (never a rag) held down with pot magnets works for me.

hwingo
10-05-2007, 10:54 AM
Boomer and gzig5,

Thanks for your replies. Both are valuable.

Since the lathe was new, it was coated in cosmoline requiring that I clean parts and surfaces with naphtha. Afterward, I well lubricated the screw, ways, and other surfaces.

Would it be prudent to remove all turned material with vac (as suggested), wipe down with clean rags (as was suggested), and then clean a oils from the surfaces and screw again, and then re-lub everything.

The reason I ask, is it possible that naphtha will drive grit into "nooks & crannies"? By the same token, if oil is not removed from the surface, particulate grit will surely be trapped in the oil leading to wear.

Any thoughts on this?
Harold

hwingo
10-05-2007, 10:59 AM
McGyver,

Your post beat mine so I don't want you to feel left out on gratitude so thanks for responding.

How would I know if the casting is "gray" or "white" or one I shouldn't concern myself with? The casting came surface ground so I know little of its history.

Harold

A.K. Boomer
10-05-2007, 11:18 AM
I think iv heard some guys say that because its self lubricating they dont use coolant or oil and duct tape thier shop vac right at the tool post, its catches everything if mounted right and thier is no worries...


I'll tell you whats about the worst thing I can think of machining, fiberglass...

lazlo
10-05-2007, 01:19 PM
How would I know if the casting is "gray" or "white" or one I shouldn't concern myself with?

Gray cast iron has graphite flakes in it which act as a lubricant, chipbreaker, and vibration damper. When you mill gray cast iron, you can see the graphite flakes in the cut.

White cast iron is unique in that it is the only member of the cast iron family where carbon is present only as carbide. Due to the absence of graphite, it has a light appearance (hence the name).

By the way, I mill a lot of cast iron, and I suck it all up with a Shop Vac, then meticulously clean all the machine ways with solvent and re-lube.

Forrest Addy
10-05-2007, 02:10 PM
I believe a stout shop vac is a real asset to have near the lathe and the mill. It should be used for no other purpose than clean up on and around the machine tools. It's very quick and convenient. It simply slurps up the chips and they disappear into the vac cannister.

If you sweep up the chips by hand you have to gather them into a small pile, sweep them into a dust pan, and transfer them into the chip container.

A powerful shop vac also teaches you to keep allen wrenches, thread wires, carbide inserts, and small tools in a place separate from where the chips accumulate; get the nozzle anywhere near then and Schlup! they dissappear. Snarly chips however are better handled by hand.

The vac should be an 8 amp or larger equipped with a 2" hose. The chip pick-up tool of choice is a crevice tool but the two extension wands and the floor tool are handy for the general area.

If the material you're cutting is particularly abrasive, arrange a bracket to support the vac nozzle near the cutting tool.

Never use the shop vac for dust pick-up. The dust will clog the filter and halve if not quarter the available suction volume. Obtain a separate vac for that. By the way, 16 gallons of chips is HEAVY. Emply the vac frequently.

Moving on to machine cleaning, use rags towels etc for general wipe down. Move the machine slide a quarter inch or so and clean up any crumbs lurking there.

I can't stress this enough. The wipers are a service point. Once a month or oftener they should be removed cleaned and inspected, the felts replaced if necessary, oiled, and the axis moved a bit at a time to coax debris from between the ways and the way bearings. Then the wipers should be installed and checked to make sure there is a compressive seal between wiper and way. This simple act of faithful maintenence combined with cleanliness will result in a machine lasting literally a lifetime.

Story about clean well kept machine tools: In the early 70's I went to an auction in Portland. I got to talking to a misty eyed older fellow who was standing by a beautifully kept B&S Universal mill. On pallets nearby was every attachment and knick knack ever made for that machine all serialised to it. There was even a rack cutting attachment with an indexing attachment for the table lead screw. The older guy used to run it. He was a tool room machinist and he ran that machine from the time it was new until the company went broke, maybe 20 years. He oiled and babied it every day. Compressed air, he declared, had never been used on it.

While the machine had been heavily used there was only slight wear; you could see that it was superbly cared for. I exercised it. It was still tight and had only moderate wear in the lead screws. It was a sad story: an older guy mooning over "his" machine about to go on the block. He wanted to bid on it but the machine started at $500 or so and went up to nearly $5,000 as I recall. That was in 1971 when $5,000 was the price of a new Cadillac.

Rich Carlstedt
10-05-2007, 10:41 PM
When doing cast iron, I place a plastic shopping bag over the ways,under the chuck,and on top of the cross-slide. Then on top of that, I place a dampened
paper towel (s). The chips and dust will stick to the towel, and yet the plastic keeps them from going through. The weight of the wet towel helps keep it stable
If many chips are made, then I may recover several times.
This setup allows me too grab most of the chips, by gathering the edges of the plastic (by the way, keep the plastic away from the leadscrew !) and tossing it in the scrap pail.
When done, a complete vacumn job is done (NEVER air ) and then oiling and wiping, oiling and wiping, until I get a clean oily cloth or towel when wiping.
Included is removal of the way felts, AND loosening the tailstock, and sliding it over a clean towel several times...again oiling between.
Lots of work..Right... but so is scraping a new way surface
Rich

Although I have never done it, I saw a guy who cut out a big "C" shaped piece
of cardboard that he inserted between the headstock and the tailstock which wedged in the total distance. The "C" section was where the tool post traveled, and the cardboard sloped to dump all the chips in the rear and keep the ways covered.