Preparing a granite surface plate

blue_luke

Registered
Registered
Joined
Sep 6, 2011
Messages
49
Hello all! :)
In the next few weeks I will buy a few more tools for my hobby machining shop and I intend to buy a granite surface plate.

I have been gathering informations about this subject and it seems that for my purpose I shall be happy with a 12"X18"X3" grade 'B' (tool room)
I intend to build a welded square tubing base for it and use a three point leveling system to set it perfectly level.

Funny enough I can't find much information about how to treat the surface initially when it's new, and then at routine maintenance intervals. Maybe since these are very simple devices there is simply not much to say about them? But without being maladively perfectionnist, I like to know and understand these basic things!
So the questions are:
- is there an initial treatment to be given to a new stone?
- Are there some products I should never touch the stone with?
- Other considerations I am ignorant of?

Thanks, Luc
 
I have a Starrett 24 x 36 x 4 plate. I watched youtube videos regarding "Bessel and Sperry points" which helps sort out your mounting. There are formulas online which I found helpfull. Too, I watched "Suburban Tool" and they suggest using "ammonia" to clean the plate. I went to Canadian Tire and got a $3 jug and it works amazingly, just make sure you ventilate the shop when you use it. I keep my plate covered when I am not using it with a vinyl Starrett cover. I am just a basement shop so I have not had the plate resurfaced or re-calibrated yet, but for you that won't be an issue. Good luck.


Sent from my iPhone using Tapatalk
 
well, I have never treated my plate. I clean it with simple green. Don't sand or file on it. Don't hammer on it.
Clean it, cover it with some tempered hardboard when not in use. It will protect it from the crap that normally winds up finding it's way to that surface.
 
Hi blue_luke,
a thorough cleaning is recommended for a new stone.
granite dust can create all kinds of scratches on the plate and instruments
i use straight dollar store ammonia, after seeing a great video by Don at Suburban Tool Co
Tom Lipton at Oxtool uses Starrett brand surface plate cleaner
i have heard of people treating their surface plates with lanolin, it is an acceptable practice and recommended by some
 
Hey Mike, does that apply to newly-reconditioned stones as well? Mine just got re-done, should it get a good clean with ammonia?
 
Hmmmmm....
That is exactly what I was suspecting. A new plate was probably fairly well cleaned after manufacturing but there must be still some dust, particles and whatnot on it.
So this has to go somehow. I did not know about using amonia on granite.

Also while on the subject, a 'B toolroom grade" plate is surfaced to 0,0002" which is is about twenty times better than my abbility at machining right now! I will buy one from a machine tool distributor, I 'need' the comfort of buying something certified, but just out of curiosity, how flat are the granite found at countertop or toombstone fabricator ?
Also, again out of curiosity, I had some belgian, french and austrian colleagues at one point or another in my career and contrary to us north-american as where we refer to a 'surface plate, or a 'granite', they refered to a 'marble plate' or simply a 'marble'
Is it just because granite is more common in America, and marble more comon in Europe, or this is just a semantic quirp?

Luc
 
In my opinion marble would make a poor surface plate, It is soft and porous. So my guess it's a case of translation.



Sent from my iPhone using Tapatalk
 
Granite is stable and long wearing against abrasion. Ammonia is a great choice for a cleaner. Some surface plate cleaners contain lanolin, which makes the rock look nice, but builds up a film that compromises the accuracy, which is the sole purpose of the plate. Your measuring tools should be be accurate to an order of magnitude higher than the work you want to calibrate with them. For some work a yard stick is close enough...
 
While watching some Vintage Machinery videos on YouTube. Richard King advised the guys in the class to use windex. I have Starrett surface plate and it seems to work well.
 
Last edited:
Hey Mike, does that apply to newly-reconditioned stones as well? Mine just got re-done, should it get a good clean with ammonia?
Yes,
I got quite a bit of diamond dust to come off onto the white rags when i cleaned mine after calibration

Ammonia will not compromise granite.

you can spend more money if it makes you feel warm and fuzzy, but there is no magic in other cleaners , rather only preference
 
Back
Top