# float glass, granite for flattening planes and waterstones?



## Millo (Jan 19, 2010)

Hey all,

I got some price quotes for float glass to be cut for sharpening and flattening purposes: 3/16" 6.50 per sq. ft., 1/4" was something like $13. I was thinking of going the granite route and in the future build a little cabinet to use it as a top, essentially building a small flattening/sharpening desk/table…. was thinking of something like 12"x24" or so…. Anyhow, reading one of David Charlesworth's books he recommends 1/2" float glass. OF COURSE, FOR THE MOMENT I SHOULD TRY TO GET SCRAPS-I will make a field trip tomorrow, and/or on Wednesday. I have NOT gotten around to researching this idea too much. STILL, I WAS WONDERING:

-What are average prices of granite and float glass per sq. ft. in your area?

-What thickness in both materials would you recommend for reliable service?

Thanks!


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## drewnahant (Dec 10, 2009)

not sure about glass, but I got a piece of polished granite from a countertop shop. they sold me a double sink cutout for $5, it's basically scrap to them. seems like the best deal to me, and though Im sure it isnt quite as flat as float glass, but it has worked great for my sharpening.


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## 33706 (Mar 5, 2008)

I use a 16" X 28" tempered glass, in an aluminum frame, from a salvaged aluminum storm door. I bought it from Habitat 4 Humanity Re-store for $5, because I needed the hinge rail for the worn-out one on my back door. So the glass was a bonus. They got dozens of 'em here. It's probably 1/4" thick for the heavy-duty use in a swing door.


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## bigike (May 25, 2009)

http://www.leevalley.com/US/wood/page.aspx?p=32526&cat=1,43513,51657
http://grizzly.com/products/searchresults.aspx?q=granite%20surface%20plate&new=1
Anyone of these should help also what I did was go to a place where they do counter tops 
granite of course and other stone and asked for a small piece about 2" wide by 24" long and about 1-2"thick 
they gave me a piece fro free I guess it was cut offs cuz the edges weren't finished smooth but the top was and that is most important anyway I still have it today and use it for planes and blades. GOOD LUCK!
I'm going with the grizzly site to get my next one cuz they have good prices as far as I can tell plus I want one that just looks good that's all.


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## mchuray (Mar 11, 2010)

Check out Grizzly. They have thick granite plates for very reasonable prices and are very thick and stable.
Mark


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## ksSlim (Jun 27, 2010)

In my area, granite cut offs are $25$/sq ft. most are 24"X??X,1 1/4 thick cut to your use.
These pieces make "workable" pieces for a sharpening bench.
They are not AAA flat (<.002") but are workable.


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## Millo (Jan 19, 2010)

Thanks for your replies.

The only issue I can think of w/ the mail-order route is that shipping can be as much or more than the granite itself, and then it is placed in danger as well-it being hard and brittle. I was thinking about his, though, because eventually when/if I build the sharpening table I'd like it to be comfortable and obviously not have too many sharp/dangerous edges and the countertop stores might be cost-prohibitive or such a small project.

bigike, that piece is a very good size.

ksSlim… that sound like a good price and pretty much something I'd like to get. So, there are grades for flatness, huh? So they usually tell you at the countertop shop about these degrees of flatness? Will they look at me funny if I bring a straightedge with me (in any case, I don't know if the straightedge is straight/flat LOL!)?


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## TheWoodNerd (Aug 30, 2009)

You really don't need lab-quality flatness or even good machinist-grade for sharpening. Some people have had perfectly fine results with polished granite tiles from their local home center.

If you have a WoodCraft in your area, they often have their granite surface plates on sale for $20. I have one, it's fine but very heavy. If the granite tiles work for you, that'd be a lot more convenient.


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## KentS (May 27, 2009)

I know a guy who works for Xerox, reparing copiers. He has given me several pieces of 1/4" glass he has removed from old machines. You can't beat free!


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## woodspark (May 8, 2010)

I'm not that fussy, normal 1/4 glass works well for me. Working 2 stones against each other is an easy way to get both flat!


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## woodspark (May 8, 2010)

Hey CessnaBarry
I should mention that I use oilstones which are harder than waterstones. I have always worked stones of similar grit together; maybe I have too many stones! I use kerosene as a lubricant and flush the stones well afterwards.
Another method I've used was to work the stone on a flat piece of glass with automotive valve grinding compound as cutting agent. Flushing the stone well afterwards, I had no problems with grit. Maybe you didn't wash the stones well afterwards, maybe it was because it was softer waterstones?

Don't fly too close too the sun, don't want your wings to melt!


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## Tedstor (Mar 12, 2011)

I bought a 12×12x5/8 granite tile from a restore for $4. According to my straightedge, its flat. And its big enough to accomodate three strips of various grade sandpaper. My results have been 100% satisfactory. 
I'm not sure if the thickness of the material is even an important factor. As long as its thick enough to resist the force applied to it without flexing/breaking, I'd guess its thick enough. I mean how would a chisel know if its being rubbed against a 1/2" plate vs a 2" plate? But I freely admit to being a hack, so take my thoughts with a grain of salt.


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## Dcase (Jul 7, 2010)

I was using a thin piece of plate glass until I dropped a tool on it and shattered it 

Rather then getting another piece of glass I did as some others have said and got a piece of granite tile from Home Depot. The tile was 4.94 and its the perfect size. I also checked the tile and its perfectly flat and I have no complaints.


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## 33706 (Mar 5, 2008)

Remember though, if you ARE using glass, it should be tempered glass. Regular window glass is not sufficient for this procedure.


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## Millo (Jan 19, 2010)

Cool, guys… thanks for your accounts and tips! I essentially wanted to lap a #7 plane on a large piece of granite or glass, although the smaller tile size works for the waterstones, so thanks for the tip!


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## coloradotrout (Nov 30, 2012)

I may be able to pickup a 12" x 36" x 3/8" thick piece of glass intended for shelving. Any idea how to tell if this is float glass or not? I suppose I can check with my starret straight edge. If it's flat not sure much else matters. I have a smaller piece of 1/4", but the larger piece will flatten hand plane soles.


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## jjbuzard (Oct 30, 2012)

I went to a local granitecounter topcutter and they not only gave me a cut off piece for free they cut it to size for nothing.


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## smitdog (Aug 20, 2012)

I found a stash of granite sink cut-outs and counter cut-offs out back of the house I bought a couple years back. Score! One man's trash is another's treasure as they say! Thought about getting one square of float glass that I can use for the highest grit paper for that super fine edge, but I doubt I'll be able to tell any difference myself, but I could be wrong… It's been known to happen occasionally…


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## alohafromberkeley (Oct 26, 2011)

Got a granite sink cut out through "Freecycle"- it's a yahoo group that people can offer stuff they don't need/want to the community. No trades/sales allowed. The idea is to keep stuff out of the land fill and into the hands of people who can use it. Also got a synthesizer, papercutter, lots of free wood items. I look for solid wood items that are dilapidated for scavenging- I have passed up tables, chairs etc that are useable. Couldn't see taking apart a solid wood cherry dining table just for the wood. There are Freecycle groups around the world. An important idea, IMHO.


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