how to clean/refresh glazed oilstone

[Stewie Simpson]

Mike; pm sent.

[Rob Young]

Silicon Carbide -- SiC

Various grits available as loose powder. All kinds of grinding applications. Cheap and cheerful method, if a bit messy.

[bridger berdel]

Stewie can you enlighten me, what is sic powder? I have a piece of granite. It is a scrap from a counter top would that work as a flat reference surface?

he's talking about lapping the stone with silicon carbide powder. this works great, though it will be very slow on a carborundum stone. it will also abrade the lapping surface, so your granite slab won't be flat anymore when you're done. however, a cheap piece of glass laid on top of the granite will present a sacrificial surface.

[Stewie Simpson]

As always; there is plenty of advice offered within the realms of an open forum. How best to go about flattening and deglazing a Norton Hard Silicon Carbide (Carborundum) Stone, being no exception. I did send Mike Kees a 1/2 page pm on the information he requested, covering all that I could think of to assist him with the issues he faced with his Norton Stone. That information included a copy of the thread I posted back in 7/7/2016 on the very subject, how much was needed during each flattening process, even down to how best to clean up the loose sic slurry when your finished working with it.

Since forwarding that pm, there has been some additional comments forwarded by members, that I felt needed some further clarification. Moving on.


The Norton Carborundum Stone I use in the workshop was last flattened on the 7/7/2016. That's 7 months ago. Its the 1st stone I use after a new edge has been hollow ground and needs to be worked on a fast cutting stone to change the primary bevel from hollow to flat. Its a double sided 2 grit stone of fine and medium cut. The medium cut being the only surface I work with. This stone also represents the only man made stone I use within my sharpening regime, the rest being naturals.

To check how much out of flat the Norton Stone surface was after 7 months of high use, I tested its surface this morning on 180 grit wet and dry, adhered to an 11" x 4 1/2" x 1/2" laminated glass. That's what I would personally regard as a tight enough tolerance to be checking the flatness of any sharpening stone surface. As you will see from the photo, the amount of wear over that period of time is hardly a concern. Why so little out of flat you may ask. Because I make sure I use the whole surface of the stone when working the bevels and flats on my plane irons and chisels.



For the sake of the exercise, I am moving onto a larger 50" x 12" x 1/2" laminated glass. 1 primary surface of the glass is dedicated to loose sic work, the other for flat sanding work. The side dedicated for loose sic work has had a hell of a work out since I purchased it 7 months ago. Its worked both primary flats on at least 12 different type of stones. imo it has lost little of its original flat surface over that time period. Why. Because I make sure I work the whole surface of the glass to minimise the chance of any uneven wear patterns. The sic powder being used on this occasion is 150 grit. Within 3 minutes of working the surface of the Norton Stone in a figure 8 pattern, changing the direction at equal time intervals, the pencil highlights have disappeared, suggesting the stone surface is within a tight range of flatness.



How tight a tolerance. Well its back to testing its surface on the 180 grit adhered float glass. Giving the tighter tolerance of testing, that surface in my opinion is good enough to stop at.



To finish up, Norton Stone is then washed down in a bucket of clean water to remove any traces of loose sediment, coated with some honing oil, and then packed away ready for its next use.



So what of the mess created by the loose sic slurry. My advise, wait until the slurry starts to harden up, then use a paint scraper to scrape the slurry remains into a neat little pile and dump it in the bin. Then wipe the glass surface down with a damp rag, and its ready to be used next time its needed.



Stewie;

[Mike Kees]

Thanks for the help Stewie. I will give it a go once I round up apiece of glass and SiC powder.

[Stewie Simpson]

Your most welcome Mike; if you require any additional info just forward me a pm.

regards Stewie;