Est. 1998 — 27 years of woodworking knowledge
Glass for flattening waterstones
Wes Billups
>I called around to some local glass suppliers yesterday and asked for float glass and they acted like I didn't know what I was talking about. On the last call, I told the guy that I wanted it to use with wet-dry sandpaper to flatten waterstones. He said that 1/4" plate glass would be plenty flat and stable. What do you guys think? I am a little worried about it flexing if I don't have it setting on a perfectly flat surface.
Thanks,
Wes
Re: Glass for flattening waterstones
Tim of Livermore
>1/4 inch should be fine. I used 1/4 inch prior to "discovering" waterstones. You should not be applying much pressure to the glass. I find that the harder down I press while sharpening or lapping, the poorer the results. It is difficult for me to press down hard and maintain the bevel or back or sole in a level and flat position throughout the sharpening stroke(s)
From one that just recently switched - truly consider Shapton stones. I just got some Hippos and they cut unbelievably fast. I had a pink 220 grit stone and the 1000 Hippo cuts as fast, if not faster (take that with the grain of salt that I cannot do a direct comparison as the pink stone is no longer in my shop). The 5000 Hippo makes my 1000 grit King stone seem lethargic and the 5000 leaves a polish good enough for most chiseling and planing work. Woodcraft now sells Shaptons and today (Thursday) is a 10% sale.....I'll get some Professionals to round out my 1, 5 and 12K Hippos. At this price range, you should also consider a motorized scary sharp system - I've read that $400 will set you up very well with the Veritas system and $800 to get you the LapSharp. I've yet to hear someone who is unhappy with either. They have their limits but seem to be a very quick method of sharpening.
One of the disappointments for me when I tried scary sharp was the requirement for a guide. I could never free hand sharpen without gouging the papers....and I've found that my chisels and irons don't like to be clamped in a guide (I've got the Veritas) reproducibly.
Tim
Re: Glass for flattening waterstones
Wes Billups
>Tim, thanks for the reply. I am not going to be using the glass for sharpening but for flattening my waterstones. Do you think 1/4" plate glass would be acceptable for this?
Wes
Re: Glass for flattening waterstones
Tim of Livermore
>Yes.
It will dish over time though. It isn't that effective (IME). You get a slurry build up in the middle of the stone and you'll have to be constantly washing that away and adding new abrasive grit. Might want to consider a flattening plate/stone or diamond "stone" for flattening.
Re: Glass for flattening waterstones
Wes Billups
>If I use wet-dry sandpaper on top of the glass, how will it dish over time? Or are you saying it will dish due to sagging.
How do you flatten your stones? I am trying to keep from spending $80 on something just for flattening my stones.
Thanks for your help,
Wes
Re: Glass for flattening waterstones
Todd Stock
>Bed, Bath and beyond was selling 1/2" glass curring boards (got to wonder) for $15. About 10" x 13", and flat to under .001 based on the three that I picked up. An option if you can't find float glass. I get peppered with 20% off coupons, so $12 out the door.
Also - no dish if the wet-or-dry, film, whatever is used on the glass.
Re: Glass for flattening waterstones
Thomas Williams Columbus, Ohio
>I have recently been using an 8" concrete block to flatten my stones. Works quicker than paper on glass and they are just as flat. Of course it does take up more room to store.
Re: Glass for flattening waterstones
Tony - Memphis
>I use some 1/4 glass from the glass store (not sure what kid it is). I add 220 grit wet/dry to that and flatten away. Very simple and quick. I do the finest stone first and work my way down.
Tony
I like granite better
Steve Elliott
>I went through two 3/8" glass plates before I bought a cheap granite lapping plate (from Lee Valley) and it's much better.
My first glass plate got pretty scratched and chipped, so I had my second one tempered to see if that would be more durable. The tempering distorted the glass slightly, so that one side was slightly convex, the other concave. The granite is flat and it's not fragile like glass.
I also have a 12" square polished granite tile that has such a good surface I think it would be fine for flattening stones, too.
Re: I like granite better
John Meikrantz
>I have used granite floor tiles in the past with no problems. I also have a Rubbermaid glass shelf from Menard's that is 3/8" thick that I use as a flat surface for sharpening, etc. I got tired of the hassle of sandpaper (not that much hassle, I'm lazy) and bought a Norton coarse crystolon stone for $13 at the local woodworking show. It was recommended by a Norton rep there for flattening waterstones. It works great! Just work the stones against each other under running water.
John
Re: Glass for flattening waterstones
Frank D. in Montreal
>Hi Wes,
Just to add to what's been said, plate glass is the same thing as float glass. My local glass store knew what float glass was but said that no one called it that. I got some 1/2" leftovers from him. 1/4" might work but it can flex quite a bit. It won't wear out if you use sandpaper, only if you flatten directly on it with carborundum or similar powder grit.
Frank
Some people...
Ted Owen, Pittsburgh
>who use powder rather than sandpaper apply laminate to the glass with contact cement. Can change the laminate as necessary--which is more often than you might guess.
Don't think you need to restrict yourself to float glass.
Best, Ted
Float glass
Wiley Horne
>Wes,
It's my understanding (and I can provide links) that virtually all the commercial sheet glass sold in the US is float glass. That is how it is manufactured.
This is just from my reading. Perhaps there is an expert among us who can differentiate ordinary architectural glass from what is marketed occasionally as 'float glass'.
I also agree with Steve Elliott about granite plates--for what Grizzly charges for delivered granite surface plates, that's the way to go. It'll change your workshop life.
Wiley
Re: Float glass *LINK*
John Meikrantz
>Here is a great link that has info on float glass. Process was invented in 1959, and today 90+% of all flat glass is actually float glass.
Glassontheweb
Re: Glass for flattening waterstones
Alan Hamilton
>Wes,
I guess I agree that 1/4" glass might work; but if you're the type that worries about such things, thicker glass is available. On the cheap, too!
I went to my local, friendly glazier and ask if I could rummage in their scrap barrel. I found a piece of 3/8" (3/8" IIRC) plate glass that's about 12" or so wide, and 24" or more long. My local, friendly glazier squared up a slightly off end, ground the edges smooth and rounded them over a little.
The cost? My local, friendly glazier charged me all of five dollars!
I'm pretty sure even my 3/8" glass must flex some if it's not on a flat surface--but not enough that I worry about it. According to my primitive measuring tools, it gets my stones flat--or flat enough.
Alan
Tried that...
Mark Harrison -- in Sydney, Australia
>I now use a cement block though I don't use the sides of the block as the cutting medium. I use a sheet of 280 or 320 over the block to actually flatten the stone.