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1200rpm
01-11-2013, 10:47 AM
i`m just getting into using surface plates- got by with just my mill table until now.

any tips,tricks, etc, in the usage and care other than just keep it clean?

probably covered before...so apologies in advance if it`s a stale subject. :)

FWIW- i have a 12x18 grade A import plate

Void
01-11-2013, 11:24 AM
I have an 18" X 24" and a 24" X 36". I made covers for my two granite surface plates out of wood with Lexan top panels. When the covers are placed over the surface plates the Lexan tops clear the surface by about 1/8". I used Lexan because it reminds me (and my students) that it is not a hammering surface but objects may be placed on top of the cover gently.

A surface plate is a precision gaging surface and must be kept spotlessly clean as much as is practicable. I bought a gallon of Starrett surface plate cleaner and still have more than half a gallon after 5 years of use. If you leave clean your surface plate and leave it uncovered for a day or two (or even less) then wipe your hand over it you will feel the dust that has accumulated even if you can not see it. I use a soft 'draftsmans brush' to whisk off any dust before and after each use.

Wash all the oil off of parts and instrument before using them on the plate.
Do not use the uncovered plate as a dumping ground or storage area for parts and instruments.
Just as you wouldn't use a micrometer as a C-clamp or your calipers as a spanner... don't use your surface plate as a workbench. It is for gaging (or spotting if you do scraping.)

-DU-

jhe.1973
01-11-2013, 03:36 PM
Hi Everyone,

In the last shop I worked we used 'Windex' or equivalent glass cleaner with clean paper towels, often using several towels until they came up as clean appearing as they were before wiping.

It was felt that the paper did a better job than rags of attracting/trapping dust particles & using clean ones each time stopped any tendency to 'just grab the closest rag'.

We did a lot of UHV chamber work including the repair/maintenance of electron microscopes and this procedure worked well for us.

dian
01-11-2013, 03:46 PM
make sure you support it correctly.

loose nut
01-11-2013, 06:49 PM
we used 'Windex' .

Starret surface plate cleaner would be better. Cleans well and evaporates.

J Tiers
01-11-2013, 09:08 PM
oddly, even after cleaning with whatever, one can often find additional crud with the hand......

Cringe all you want....... I find that wiping my hand over the part and the flat as a final step does a fine job. I often find crud, even after cleaning with supposedly lint-free stuff.....

Scottike
01-11-2013, 09:32 PM
I find that wiping my hand over the part and the flat as a final step does a fine job. I often find crud, even after cleaning with supposedly lint-free stuff.....

It's amazing that the human hand is as sensitive as it is..

John Garner
01-11-2013, 11:05 PM
When it comes to cleaning precision stoneware, the best advise I can give you today is what I wrote on the Practical Machinist board a half-dozen years ago:

The best commercial surface plate cleaner I ever tried was sold by Rahn. It was a soft, cream-colored paste in a screw-top tin can that sold for US$ 5 a pound twenty-five-plus years ago. Funny thing was that it looked, smelled, felt, and tasted just like . . . um, I've forgotten . . . DL, Go-Jo, Lan-Lin or one of the other national brands of waterless hand cleaner that the local fast-food auto supply stores offered for 1/10 the price in their weekly ads.

Because of the striking similarity between the Rahn cleaner and waterless hand cleaner, I tried the waterless hand cleaner as a surface table cleaner.

BINGO! For the past twenty-five years I've been using one or another brand of non-ammoniated waterless hand cleaner without pumice to clean precision stoneware. (The can I'm using now is Go-Jo Original from Ace Hardware's August Sale; US$ 1 for a big can.)

Scoop a bit out of the can, spread it over the surface to be cleaned, scrub as necessary with a "ok for Teflon" kitchen scrubbie, and sop up the mess with paper towels or shop rags. Works wonderfully well!

One word of caution: The name of the product is "waterless hand cleaner", but most of them are fundamentally oil-and-water emulsions. To avoid rusting you'll need to allow several minutes for the residual water to evaporate after cleaning your granite flat.

And for what it's worth, the old Rahn Granite was bought by Tru-Stone, which was in turn bought by Starrett. Starrett Tru-Stone still sells the Rahn paste cleaner, and the MSDS reveals that it's made for them by one of the major makers of waterless hand cleaner, Stockhausen if I remember right. [Note that the current MSDS, dated April 12, 2010, no longer includes a manufacturer's name.]

Here's a link to the Starrett Tru-Stone website page showing the Rahn cleaner: http://www.tru-stone.com/pages/smp.asp#clean

And the MSDS: http://www.tru-stone.com/pdf/rahn_msds.pdf

John

Paul Alciatore
01-11-2013, 11:51 PM
Hey, granite is like, well, err, granite. It is hard to harm except with sharp blows, sharp edges, or abrasive. You can probably clean it with almost any mild soap or NON ABRASIVE cleaner. Do avoid harsh stuff, like bleach or ammonia. I am sure the cleaners made for surface plates are excellent.

If you use the hand cleaners as suggested above, do avoid the ones with abrasive in them.

Do keep it covered when not in use.

I like a soft rag made from old undershirts for wiping it clean for use. I seem to be hard on clothes and have a lot of them. Between old undershirts and other old clothing, I never have to buy shop rags.

Forrest Addy
01-12-2013, 02:17 AM
Gotta watch what's in any solution used to clean granite. Granite is a natural product of considerable variability Its constituant minerals may be subject to attack from chemicals in common water based cleners.

I've used waterless hand cleaners and specific purpose surface plate cleaners sold by Starrett etc but I wasn't too happy with the effort required (try a gelled or "putty" plate cleaner on a 4 x 8 granite flat) or the dead time needed for residues to evaporate. In the end I fall back on lighter fluid to remove tramp oil and skin grease left by my hands and elbows, then a mist with ammonia-less Windex followed by a wipe from clean twhite towels repeating to where the plate is smudge-free and the towels no longer smut.

Different strokes of course. The above is my preference and works well even on very large surface plates. YMMV

loply
01-12-2013, 05:18 AM
I always found brake cleaner works really well.

I keep it in a spray bottle in my shop and it lifts bluing right off.

I spray the plate then wipe down with a paper towel, it evaporates almost immediately, repeat until no bluing or suchlike shows, then wipe with your hand.

JoeLee
01-12-2013, 11:19 AM
The tech people at Starrett told me that regular rubbing alcohol is just fine and very close to the surface plate cleaner they sell.

JL................

oldtiffie
01-12-2013, 05:42 PM
+1

From the Starrett web site:
http://www.starrett.com/metrology/metrology-products/precision-granite/stands-covers-cleaner/cleaner

Surface plates are very durable - just use a bit of care - no need to "baby" or "molly-coddle" them. If you scratch them or put a "ding" in them they will still work OK.

http://www.google.com.au/#hl=en&tbo=d&output=search&sclient=psy-ab&q=Federal+Specification+GGG-P-463c+&rlz=1R2IRFC_enAU360&oq=Federal+Specification+GGG-P-463c+&gs_l=hp.12..0i30j0i5i30.4243.4243.0.11144.1.1.0.0. 0.0.278.278.2-1.1.0.les%3B..0.0...1c.2.fv_V3h001wo&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&bvm=bv.1357700187,d.dGI&fp=62de6c98bf44ccb6&biw=1920&bih=818

Grind Hard
01-13-2013, 01:12 AM
NO.

GODDAMN.

HAMMERING.

ON.

THE.

SURFACE.

PLATE.

I caught someone hammering on a surface plate once. Just gentile taps with a plastic hammer to seat an assembly. That's when they discovered that I do know how to swear... and at a level that would cause a sailor to object. Trick to scaring the ever-loving daylights out of people is only detonate when absolutely necessary. :D

Promise you this though: Neither that person or anyone within a 5 mile radius will hammer on a surface-plate again.

oldtiffie
01-13-2013, 01:37 AM
Realistically, in many if not most cases if the surface of a surface plate looked like that of some mill table tops it should be made OK the same way - just "stone" the high spots off with a good caurse/fine carpenters oil stone - they are very flat when new - (just as you might do when scraping (a surface plate??)).

If in doubt, run a good level over the plate as the base of a good level is very flat and will soon "catch" any defects for further remedial action.

If there are any "burrs" etc. running the palm of your hand over the plate surface will soon find any/or most "stick-ups"/defects.

Providing that what you are using on a surface plate spans any defects, "dings", bruises or even holes ther will be no adverse effect.

Surface plates don't need cotton gloves and cotton wool nor do they need to be stored in a tabernacle with insence burning near-by.

A Grade "D" (the least accurate) has been used as the reference in work-shops, tool-rooms and some "inspection" (metrology?) rooms for many years.

1200rpm
01-13-2013, 05:26 AM
thanks for the replies, i don`t feel bad about using windex and paper towels now. :)

willmac
01-13-2013, 07:40 AM
Realistically, in many if not most cases if the surface of a surface plate looked like that of some mill table tops it should be made OK the same way - just "stone" the high spots off with a good caurse/fine carpenters oil stone - they are very flat when new - (just as you might do when scraping (a surface plate??)).


I can't think of reason ever to 'stone' a granite surface plate, unless you are re-calibrating it and that requires equipment and skill well beyond typical workshop level. Granite plates should never get raised burrs - that is one of their chief advantages. Sure, you would take chunks out of them if you drop something on them, but even then it should not raise a burr. No stoning of granite surface plates!

loose nut
01-13-2013, 02:04 PM
Tiffie is referring to a cast iron surface plate not granite. In that context he is quite right in what he is saying.

oldtiffie
01-13-2013, 05:33 PM
Originally Posted by oldtiffie

Realistically, in many if not most cases if the surface of a surface plate looked like that of some mill table tops it should be made OK the same way - just "stone" the high spots off with a good caurse/fine carpenters oil stone - they are very flat when new - (just as you might do when scraping (a surface plate??)).



I can't think of reason ever to 'stone' a granite surface plate, unless you are re-calibrating it and that requires equipment and skill well beyond typical workshop level. Granite plates should never get raised burrs - that is one of their chief advantages. Sure, you would take chunks out of them if you drop something on them, but even then it should not raise a burr. No stoning of granite surface plates!

While it is true that granite surface plate should not (but may) "raise burrs" and if it came to a case of removing the "up--satand" with a fine carpenters oil stome or binning anf getting a new plate for no good reason I would not hesitate to "stone" the granite plate I have.

If the oil stone if kept flat and used with care it should not cause any significant damage.

Even at worst case if my Grade AA plate was down-graded to A or B or D it would still be more than adequate for most shop purposes - but if the plate was only lightly scraped/scratched it would still function as an AA plate.

It is quite often that plates get "dinged" with the corner of what ever hits them but granite is very durable and resistant to damage.

oldtiffie
01-13-2013, 05:36 PM
Tiffie is referring to a cast iron surface plate not granite. In that context he is quite right in what he is saying.

That is very true - especially for cast iron plates but in the unlikely event that it happens to a granite plate it applies to a granite plate too.

I don't think that too many would "bin" an otherwise perfectly serviceable plate that had a "ding" or a "burr" or a "scrape/groove" on it.

willmac
01-13-2013, 07:16 PM
This whole thread is about granite surface plates. Some people reading the thread may not have appreciated that the stoning advice referred to cast iron plates ONLY.

.RC.
01-13-2013, 08:06 PM
I don't think that too many would "bin" an otherwise perfectly serviceable plate that had a "ding" or a "burr" or a "scrape/groove" on it.

You said you were binning all your equipment sometime in the future, serviceable or not...

ietech
01-13-2013, 09:11 PM
NO.

GODDAMN.

HAMMERING.

ON.

THE.

SURFACE.

PLATE.

I caught someone hammering on a surface plate once. Just gentile taps with a plastic hammer to seat an assembly. That's when they discovered that I do know how to swear... and at a level that would cause a sailor to object. Trick to scaring the ever-loving daylights out of people is only detonate when absolutely necessary. :D

Promise you this though: Neither that person or anyone within a 5 mile radius will hammer on a surface-plate again.



WELLL If I were the person You are talking about and I was doing something stupid like you describe -- I would take a polite and strong correction and agree --- I would refrain from making the same mistake again.

BUUUUUTTT If you were to speak to me like you, so egotistically, just described. I WOULD DECK YOU ON THE SPOT --- and surely be looking for another job after I got out of jail. Your behavior in speaking the way you decscribe is just as STUPID as pounding on a precision surface. Better lighten up dude --- You Just might YELL at the wrong person on a bad day ---- Good Luck to you. You probably have many talent and skills --- but this is not one of them. As a matter of fact the organization I work for now would fire you on the spot for yelling like you describe at another employee.

oldtiffie
01-13-2013, 09:54 PM
Originally Posted by oldtiffie
I don't think that too many would "bin" an otherwise perfectly serviceable plate that had a "ding" or a "burr" or a "scrape/groove" on it.




You said you were binning all your equipment sometime in the future, serviceable or not...


True - and that still stands - as soon as I neither can not want to use or keep it.

At my age - 76 - that can happen any day now - death, stroke etc. etc. - you name it - but it might be a while yet too - but in any case there is no need for anyone to hope for any of the action when it happens - what ever it is.

But in the meantime I will make what ever use of it I want to.

Peter.
01-13-2013, 10:07 PM
You should definately take care of your surface plates but I'm not so sure about feeding them - you don't want them growing a belly :)

oldtiffie
01-14-2013, 01:27 AM
I mentioned previously that if my Grade AA surface plate were to be down-graded to A or B or D it would be no drama as Grade D ("Shop" grade) was pretty well the sole grade of (cast iron in them days) Grade availabe in Shops, Tool Rooms, and "Inspection" (metrology?), so let's see how that statement stans up for say Shars/com granite plates:

Grade AA, 24" x 36" Black Granite Surface Plate: Accuracy: 0.000042" (0.4 "tenths") - $380.00.
http://www.shars.com/products/view/2358/Grade_AA_24quot_x_36quot_Black_Granite_Surface_Pla te

Grade A, 24" x 36" Black Granite Surface Plate: . Accuracy: .0001" (1.0 "tenths") - $264.95
http://www.shars.com/products/view/2343/Grade_A_24quot_x_36quot_Black_Granite_Surface_Plat e

Grade B, 24" x 36" Black Granite Surface Plate: . Accuracy: .0002" (2.0 "tenths") - $195.95
http://www.shars.com/products/view/2344/Grade_B_24quot_x_36quot_Black_Granite_Surface_Plat e

With a price difference between the AA and B grade plates of $380.00 and an accuracy difference of (0.000042" - 0.0002" = 0.00016" say 1.6 "tenths").

It is very hard to justify the difference in cost and accuracy of a Grade AA plate in a HSM shop - so why do it?

It also shows why the "B" plate was the default plate (even in the days of cast iron).

So any plate will take a fair amount of abuse without really and functionall affecting its accuracy.

Note too that Shars provides a:
- provides Certificate of Accuracy; and
- meets or exceeds Federal Specification GGG-P-463C

And that is (all?) the Starrett provides.

I think that some need to re-consider their "need" (as opposed to "want") as regards surface plates in general and granite surface plates in particular.

oldtiffie
01-14-2013, 01:29 AM
You should definately take care of your surface plates but I'm not so sure about feeding them - you don't want them growing a belly :)

Peter,

perhaps its not a case of being over-fed perhaps but that the plate might be pregnant 'cos some "effed" it - well and truly.

No?

Grind Hard
01-14-2013, 03:21 AM
WELLL If I were the person You are talking about and I was doing something stupid like you describe -- I would take a polite and strong correction and agree --- I would refrain from making the same mistake again.

BUUUUUTTT If you were to speak to me like you, so egotistically, just described. I WOULD DECK YOU ON THE SPOT --- and surely be looking for another job after I got out of jail. Your behavior in speaking the way you decscribe is just as STUPID as pounding on a precision surface. Better lighten up dude --- You Just might YELL at the wrong person on a bad day ---- Good Luck to you. You probably have many talent and skills --- but this is not one of them. As a matter of fact the organization I work for now would fire you on the spot for yelling like you describe at another employee.

Actually, I wasn't the only one to unload on 'im, and he lasted only a short time beyond that --- he was fired for a general lack of shop sense. Which is funny because he claimed a decade of "precision work." Hammering on the stone plate, using mics to tap fixtures, put a nice burr on my good pair of calipers, was an aggressive consumer of taps as well. EDM guy loved him, EDM guy got lots of overtime burning taps out of holes. :D



Anyway. Cast iron surface plates. This caught my eye. All surface plates I've ever known have been stone. What are the advantages/disadvantages of an iron plate over a stone plate or even the other way around?

oldtiffie
01-14-2013, 04:12 AM
There are practically none as granite is superior in all respects.

http://www.tru-stone.com/pages/benefits.asp

Cast iron plates were manaul or machine-scraped - and were very expensive.

Granite is machine lapped and calibrated.

Greg Q
01-14-2013, 04:56 AM
You can scrape a flat surface in cast iron using three square plates to spot each other. Doing something similar with granite would require different processes.

A small granite surface plate can be used to spot square machine elements for scraping, as can a stone, but the cast tool will be lighter.

Cast iron craters when dinged, with a raised rim. Stone does not. Cast iron flats can be restored by scraping against a known good master. Stone does not have corrosion or heat growth problems. Stone has been stress relieved for millions of years, cast not so much.

Greg

JCHannum
01-14-2013, 08:21 AM
There are practically none as granite is superior in all respects.

http://www.tru-stone.com/pages/benefits.asp

Cast iron plates were manaul or machine-scraped - and were very expensive.

Granite is machine lapped and calibrated.

You talk as though cast iron surface plates are no longer available. That is not the case, they are. They are available either ground or hand scraped.

As far as one being superior to the other, that all depends on the application. They are not inexpensive compared to import granite, but each has its uses and advantages.

http://machining.buschprecision.com/viewitems/surface-and-bench-plates/cast-iron-surface-plates-1000-series

http://www.newmantools.com/busch/1000.htm

Void
01-14-2013, 09:37 AM
What are the advantages/disadvantages of an iron plate over a stone plate or even the other way around?

The main advantage to cast iron is one can re-condition it ones self (given enough time, patience, and an extra two reference surfaces) with simple hand tools. But that is not so much of an advantage any more as it is far easier and cheaper to just buy a granite plate.

What is NOT so easy to do with granite is to make custom shapes such as angled straight edges for dovetails, precision angle plates, and last but not least being able to easily drill and tap the surface plates for custom fixturing. All of which can be done with granite but it is far more difficult in the home shop and/or more expensive to buy custom granite equivalents.

Starrett will happily make just about any shape and size of granite fixture you care to imagine... complete with grooves, V ways, dovetails, drilled holes with threaded inserts or whatever. They will charge you accordingly.

Cast iron is also easy to use magnetic bases on. This can also be very handy.

If you need to make a custom precision setup it does not have to be a cast iron surface plate per se... you can also use old table saw, milling table, drill press, band saw, etc... cast iron tables. Scrape them to the desired precision (using your cheap granite plate as the reference) and create the fixtures as needed.

-DU-

oldtiffie
01-14-2013, 06:04 PM
Originally Posted by oldtiffie

There are practically none as granite is superior in all respects.

http://www.tru-stone.com/pages/benefits.asp

Cast iron plates were manaul or machine-scraped - and were very expensive.

Granite is machine lapped and calibrated.




You talk as though cast iron surface plates are no longer available. That is not the case, they are. They are available either ground or hand scraped.

As far as one being superior to the other, that all depends on the application. They are not inexpensive compared to import granite, but each has its uses and advantages.

http://machining.buschprecision.com/viewitems/surface-and-bench-plates/cast-iron-surface-plates-1000-series

http://www.newmantools.com/busch/1000.htm

I concede that I do/did talk as if there were no cast iron plates - but I was careful not to say that there were no cast iron plates - which there clearly are - new and used.

I rarely if ever see cast iron plates advertised in a HSM forum/BBS as I guess price rules and cast iron (new) is pretty well priced out of consideration.

A magnetic base for a dial indicator or what-ever can be attached to a magnetic (steel/iron) base mounted on a granite surface plate will meet the requirements of a magnetic base on an granite surface plate. If the base is heavy enough it should not move - but care is needed.

Greg Q
01-14-2013, 06:33 PM
There are vacuum bases for dial indicators. I have a Swiss one that works very well indeed.

oldtiffie
01-14-2013, 07:22 PM
A good solution Greg.

But people need to be adaptable and improvise - as some do and others less so.

My pedestal drill table is pretty flat and has t-slots in it which is good enough most times - as are the tables (with t-slots) on my mills (HF-45 and Sieg X3) - same with the ground top (where the magnetic chuck goes) on my surface and T&C grinders. The magnetic chuck ground faces make good reference surfaces with a choice of whether the magnets are switched on or off.

Not all stuff requires accuracy to even that of a Class B surface plate and its not hard to find steel plates or structural members that can be milled pretty flat - a fine file and a good carpenters (very flat) oil stone and perhaps some "wet and dry" "cutting paper" after milling (fly-cutting?) will all help improve the surface with no significant loss of accuracy - to provide a surface for a magnetic base.

Or surface grind the face for the magnetic base.

Grind Hard
01-14-2013, 08:14 PM
Thank you for explaining cast-iron surface plates.

oldtiffie
01-14-2013, 08:48 PM
I not only mentioned cast-iron surface plates but also practical (cast iron) alternatives to it (press drill table, mill tables, surface grinder top faces, magnetic chuck (on or off)) - all of which are cast iron and none of which are granite but all are attracted by a magnet.

Often times if a surface plate (granite or cast iron) was only used when it was really necessary it would spend a lot more time covered up (idle) than it does uncovered for work that really needs it.

While it definitely is not magnetic, I often prefer to use sheets of toughened "float" plate glass (which is very flat) mounted (usually but not always) on painters masking tape at about 4" spacing on my mill table - works very well too.

http://i200.photobucket.com/albums/aa294/oldtiffie/measuring/Dig_Ht_Gg1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/measuring/Surfaceguage4.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/measuring/Surfaceguage3.jpg


Float glass is a sheet of glass made by floating molten glass on a bed of molten metal, typically tin, although lead and various low melting point alloys were used in the past. This method gives the sheet uniform thickness and very flat surfaces. Modern windows are made from float glass. Most float glass is soda-lime glass, but relatively minor quantities of specialty borosilicate[1] and flat panel display glass are also produced using the float glass process.[2] The float glass process is also known as the Pilkington process, named after the British glass manufacturer Pilkington, which pioneered the technique (invented by Sir Alastair Pilkington) in the 1950s.

From:
http://en.wikipedia.org/wiki/Float_glass


Glass has several strong points concerning optical properties:
- It can be produced in large and homogeneous panes
- Its optical properties are not affected by ageing
- It is produced with perfectly flat and parallel surfaces

From:
http://www.saint-gobain-sekurit.com/fr/?nav1=GC&fn=intro_glass_pro.html

http://www.google.com.au/#hl=en&tbo=d&rlz=1R2IRFC_enAU360&sclient=psy-ab&q=float+glass+properties&rlz=1R2IRFC_enAU360&oq=float+glass&gs_l=hp.1.1.0l4.0.0.1.2830.0.0.0.0.0.0.0.0..0.0.le s%3B..0.0...1c.fRdHC_qeiHQ&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&bvm=bv.1357700187,d.dGY&fp=62de6c98bf44ccb6&biw=1280&bih=545