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Neil Jones
02-27-2009, 11:45 PM
Using a surface grinder that does not have a flood coolant system. Can I get a better finish on the cast iron part I'm grinding if I coat the part with a lubricant like say kerosene or WD-40?

Mcgyver
02-27-2009, 11:56 PM
duplicate

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Mcgyver
02-27-2009, 11:57 PM
in my experience cast iron will take a very finie finish with dry grinding....finish will depend on the grinder and wheel

Neil Jones
02-28-2009, 12:11 AM
Using a Norton 32A46-J8VBE grinding wheel. I think the finish could be a lot better.

wierdscience
02-28-2009, 12:27 AM
I use WD-40 when surfacing cast on a grinder without coolant.I find it helps keep the wheel from loading and also helps control dust.

Finish will have more to do with the dressing job you do on the wheel and the condition of the grinder itself.

moldmonkey
02-28-2009, 08:59 AM
I'll add that finish will be greatly helped by taking smaller DOC and crossover steps as you get to size. I"ll drop to .0005" DOC and .050" step. Then down to .0002-3 and maybe drop again to .0001". I like to also do at least 2 spark out passes. All done dry so far, I may have to try the WD40 trick. Another thing about grinding dry is taking breaks so the part doesn't get warm and grow that can lead to burn marks and worse.

The Fixer
02-28-2009, 10:08 AM
the function of the 'coolant' is as much to cool as it is for machine finish and stone clogging! I find that the cast iron s very prone to warpage if not cooled esp if the part is not a substantial size. Even if the part is substantial in size you can impose significant stress into it which can result in part failure in service.

jmho
al

Spin Doctor
02-28-2009, 11:24 AM
Using a surface grinder that does not have a flood coolant system. Can I get a better finish on the cast iron part I'm grinding if I coat the part with a lubricant like say kerosene or WD-40? If you can rig up some sort of mist coolant using compressed air it will help alot. But as SGs make a mess in terms of fine swarf you will most likely need to run a vacuum to suck up as much of the swarf and mist as possible. Also most SGs are designed to allow for a wet coolant system to be used whether they were equiped at the factory or not.. A small pump and a gallon bucket would be more than enough for a 6x12 grinder

Neil Jones
02-28-2009, 12:15 PM
"If you can rig up some sort of mist coolant using compressed air it will help alot"

I'll try this. Thanks.

Peter N
02-28-2009, 01:30 PM
Small depth of cut and small feed, together with the right wheel should give a reasonably good finish grinding dry on cast iron.

The picture below shows grinding a piece of unhardened mild steel. Soft steels always give a worse finish than harder steels, which tend to 'cut' more cleanly, as the softer stuff can microscopically 'smear' a bit,
Depth of cut is 0.0005", and cross feed is in 0.015" increments. The wheel is a plain vanilla Norton 38A white alumdum, 46J grit/hardness.


http://www.btinternet.com/~p.neill/Grinding_Finish.jpg


I tend to cut everything dry, as I hate the mess that coolant makes, either on a manual lathe, mill, or grinder.

Peter

Oldbrock
02-28-2009, 03:43 PM
Neil, you should be using a 37C wheel for cast iron not 32A. Peter

Neil Jones
02-28-2009, 04:00 PM
Neil, you should be using a 37C wheel for cast iron not 32A. Peter

I'm curious to know where you get this from?

I used this Norton chart;

http://www.ind.nortonabrasives.com/media/documents/S0000000000000001035/Toolroom%20Selection%20Chart%207505.pdf

Oldbrock
02-28-2009, 08:50 PM
Third column moderate to light and non ferrous lists 37C . I have never seen alundum used for cast iron before. I guess I went by the old Norton information but must look in my grinding handbook again. I know I always use silicon carbide hones on my Sunnen for honing cylinders, sure are expensive. I find the esso exxcut a lot cheaper than Sunnen honing oil. Have surface ground cast iron with 32A before because I was too lazy to change the wheel.:eek: Peter

Len
04-14-2009, 12:32 AM
I bought a ceramic wheel on E Bay for cheap called the company (Norton which has changed hands). I was informed by Norton that these wheels will grind most anything wet or dry. I asked about the finish they give on meanite which is a good grade of iron, was told they do a great job. After it arrived I tried it on all sorts of material; worked just like I was told and the finish on every piece is really fine. I use this wheel to regrind special cutters for meat.
Regards
Len

Spin Doctor
04-14-2009, 07:41 AM
the function of the 'coolant' is as much to cool as it is for machine finish and stone clogging! I find that the cast iron s very prone to warpage if not cooled esp if the part is not a substantial size. Even if the part is substantial in size you can impose significant stress into it which can result in part failure in service.

jmho
al

Think CI is bad, try grinding Ampco. We had a boss that loved having gibs made out of Ampco (don't ask me why). Youd get it just about cleaned up on one side and there it would go.