Stone isn't flat - is it okay to sharpen?

[jisk]

I swung by a garage sale today, and one of the things I picked up was a sharpening stone. I think it's an oilstone, as it's black and kind of oily (I'm still learning this stuff!). One side also has a more fine grit than the other.

Now, I need to sharpen my planes for the first time (I just got them a few days ago). I've got heaps of info on how to sharpen them, so I'll be OK there. My stone does have a groove in both sides, though. Will it be okay to sharpen my plane blades, or do I have to do something about this first? I don't want to trash the blades.

Photos attached... help is very appreciated

[routermaniac]

Its best to flatten it first. Use some coarse wet and dry on a glass plate or fixed onto thick mdf or melamine.

BTW I maybe wrong but the stone looks like one of those chinese cheapie oil stones, I doubt you will get good results from that. I used to use them when I started and the results were disappointing.

regards

Marios

[RobTro]

I'm no pro and I use water stones but I think you should flatten the stone before using it on your new blades. Use glass (or granite) and some wet and dry sandpaper. Maybe with a bit of oil (if they are oil stones) to help or maybe someone else will give some advice. If they are really out of wack you could use a masonry block to get them close and then use the sand paper.

When I reconditioned my old water stones which were pretty dished I used a masonry block and lots of water and then I finished off with a diamond stone/plate to get them really flat. Now I just give a swipe over every now and again with the diamond stone to keep them as flat as I can.

The grooves in the stones if not too bad might dissapear with the above reconditioning but if they are not too wide and mainly just deep you should be OK using them still as long as you use the whole stone by changing directions a lot not just back and forth in one spot (that will probably transfer the stone defect to your blades)

Good luck.

Rob

[bitingmidge]

Another non-expert comment from me! :D

It took a long while for me to believe all those who were fanatical about keeping their stones flat. By golly it makes a difference!

Try grinding it flat on a concrete block. (Besser Block) they are a useful device for this sort of thing provided the stone isn't too hard, and cheap stones usually aren't.

The wet and dry and other stuff all takes too long for impatient little me!

Cheers,

P
:D

[Mirboo]

Here is a recent thread on the topic of flattening oil stones.

http://www.woodworkforums.ubeaut.com.au/showthread.php?t=19896

You really do need to have a flat stone.

[jisk]

Thanks guys.

After reading that other thread, I've shelved the secondhand oilstone for the mean time - no besser block handy and I don't want to ruin the new driveway.

I managed to pick up a honing stone from bunnings for 35 bucks - "Worksmith Diamond Honing set". It seems OK after using it, but I haven't used one before so have nothing to compare it with. Will this one work OK?