Truing up a benchstone?

[Poncho65]

How would 1 go about truing up an old benchstone? My grandfather had an old benchstone that he used for years and it is very worn how do you return them back to a flat surface? After I get a few ideas I may give it a go and see how it turns out Not that I may use it much but I would love to bring it back to a usable condition

[Mike, Lord of the Spammers!]

You can grind them against a flat (harder) surface, but it takes absolutely ages mate

[Magnus]

belt sander?

either that or just rub it against a paving stone

[ringzero]

I too have an old benchstone inherited from a grandfather.

It's a black benchstone of unknown material, embedded in a hardwood base with a hardwood cover.

Must be at least a century old, because my grandfather said he got it from his father.

Mine is also somewhat worn down in the middle, but is still usable.

Think I'd just as soon leave it as a memento rather than mess with truing it up.

Doing it by hand would represent a prohibitive amount of hard labor.  Hiring it done by a machine shop would run the risk of messing up the hardwood base.

.

[skidoosh]

It depends how hard the stone is.  If you check some wood working shops they sometimes have diamond stones specifically for bringing stones back to true (its a problem with Japanese water stones).  If that doesn't work I'd get the thickest piece of glass you can find (ask for float glass) and then get some wet/dry sand paper- glue it to the glass and see if you can make any progress on the stone. 

[Poncho65]

I too have an old benchstone inherited from a grandfather.

It's a black benchstone of unknown material, embedded in a hardwood base with a hardwood cover.

Must be at least a century old, because my grandfather said he got it from his father.

Mine is also somewhat worn down in the middle, but is still usable.

Think I'd just as soon leave it as a memento rather than mess with truing it up.

Doing it by hand would represent a prohibitive amount of hard labor.  Hiring it done by a machine shop would run the risk of messing up the hardwood base.

.

I believe that he would have liked to have done it himself if he had thought of it so I won't feel bad about truing it up

Also thanks for the suggestions guys I will ponder on them and see what I can come up with

[Splat]

I've read of folks using DMT diamond stones for that.

[WhichDawg]

I just did this Poncho! it's easy.

we used a "single point hand held diamond dressing stick" (about 15 bucks depending on the size of your wheel)

we set up a jig to do a "double compound 10-15 degree angle" (for the diamond stick) sounds harder than it is lol
because you need too have the point of the rod (diamond) dragging 10-15 degrees left or right (never point into the wheel but DRAG across (or you'll wear out your diamond tip fast!) and 10-15 degrees downward.

do slow even passes about 1/2 to 1 inch per second swipes, little at a time and you will see the valleys and peaks disappearing!

watch edges of the wheel when you make your swipes, do not start in too much or else you will round-off the edges, go slow.

it's really not hard bro, wear good full faceshield (stuff flies at you) and your wheel will look like new!

after we used a "Friable" Silicon Carbide "Dressing Stick/stone" to clean out the gunk after each use (so you don't have to re-shape it later so often) when the wheel gets "shinny" or full of "stuff" it needs a cleaning,
I just press the dressing stone up against it to clean it out, works fast.

here is a site for you to see everything more accurate; http://www.diamondtooling.com/article_diamond_usage_01.html
Honest it was my first time and it came out great

safety tips:
-always let your grinding wheel spin for a minute or two with you and anyone/thing off to the side, clear of the front. If it is bad
it will usually spin the debris forward.

-watch for a level, even spinning wheel when you first start it, I spin it manually first to make sure before applying power.
if it is wobbly I won't use it, it is dangerous.

-always wear safety goggles or a faceshield!

-no loose clothing, gloves, long-hair, rings, chains, any jewelry near the spinning wheel! (you knew that )

-after long grinds, check to make sure your motor isn't too hot, allow to cool for better use and life.

-don't get your fingers too close to the spinning wheel while grinding! pay attention to what your doing and
remember buffing wheels seem to catch people off guard a lot! materials can get pulled into the cloth easy!
be careful.

-never grind on the side of a wheel (unless it is designed for that, most aren't!)

I made a couple of high-speed steel bits for our mini-lathe and they came out great! and you need a true wheel
to do it. It wasn't hard buddy.

Good Luck and be safe

[Poncho65]

Guess I need to update I actually went and looked at the stone (it was at my Dad's house) and the stone was in much better shape than I thought There were a few bad spots on the sides but nothing to affect sharpening I did see the stone I thought that this 1 was and it was a little worse for  wear but it's my Dad's stone and if he want's to fix it he can Also got a little more info on it as the stone I thought only belonged to my Grandfather (my Mom's dad) but it also belong to her Grandfather on her mom's side So The stone is much older than I thought Once again thanks everybody for the input and when I get the other rougher stone passed down to me I will surely fix it

[WhichDawg]

that is cool Poncho! I don't know why I was thinking bench grinder, sorry!

when you get it take pictures (before and after) it should be interesting