do any of you have recommendations on where to buy a nice piece of float glass for sharpening? either online or local stores, i live in Minneapolis. thanks, Dan.
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Replies
Dan,
Practically any glass you can buy is "float" glass. Some tool vendors charge a premium for the stuff. Don't fall for it. Any hardware store or glass supply store is fine.
Rich
My understanding is that float glass derives it flatness from being "floated" in a molten state, on tin. I don't think standard window glass is manufactured to this tolerance. Whether standard window glass is "flat enough" for sharpening - I can't say. I do know that the float glass that I bought from Lee Valley was thicker than most of what is available in hardware stores, and thus less likely to break with repeated use. It was also not that expensive.Just my 2p,Glaucon
If you don't think too good, then don't think too much...
Glaucon,
I believe 90% of glass available today, including ordinary sheet window glass is float glass. Lee Valley sells glass that's thicker than standard window glass for use as a sharpening bed. I wasn't referring to them regarding being expensive. They are pretty reasonable. I remember seeing prices for the stuff in a Garrett Wade catalog a few years ago that was really high.
Rich
Interesting... I hadn't realized that about window glass.Glaucon
If you don't think too good, then don't think too much...
I have to second Rich. When I went to a local glazier, he told me everything in his shop was float glass. He had a broken corner that was 3 " thick. roughly 16" by 8". For $5 he smoothed the rough edge, and away I went.
PPG has a window glass plant in Mount Holly Springs PA. It's a Float glass process.
Stewpot,
Where is the plant in or near Mt Holly Springs?
Alan
From Rt 34 east on Mill St. till it becomes Park Drive. My phone book shows the address is 400 Park Drive.
Thanks Stewpot67.
Alan - planesaw
Rich14
Do you need it for the scary sharp method of sharping? If so I've used a sheet of regular glass now for over 5 years I get such sharp edges on my tools that they can slice a thought lengthwise.
Dan,
Try a commercial glass shop. Often, they will have off-cuts of thick glass from jobs that they will sell very cheaply or even give to you. A little fire polishing of the edges, and you're ready to go (sometimes they'll even polish the edges for you for free or a small fee).
Beste Wünschen auf ein glückliches und wohlbehaltenes Neues Jahr!
Tschüß!
Mit freundlichen holzbearbeitungischen Grüßen aus dem Land der Rio Grande!!
James
Not what you want, but I have found that polished porcelain tiles are amazingly flat, and I have an offical certified granite flat to test them.
Porcelein not ceramic.
I use one for sharpening and it works great.
Edited 1/10/2007 1:52 pm ET by Piccioni
After buying Mike Dunbar's video on sandpaper sharpening, I went to a glass shop and bought a piece of glass 3/8" thick, 30" long and 7" wide. I can adhere enough PSA sandpaper to it for all the grits necessary to sharpen my tools. I put it on my bench between dogs and it works great. Tom
Like other posts, I went to a local glass shop and picked up a piece of glass. Cost was extremely high since it was a broken odd shaped piece from the junk pile -- free!
I did not polish the edges but a little work with a torch to flame polish it would have also been free.
When I was in Ann Arbor, MI, I got quotes from about six different glass companies in the local area. The size was about 6x16 inches and 1/4" thick, with polished edges. The prices quoted ranged from 9 dollars to 65. I recommend doing the same and going with the low bidder. Also, I recommend at least 3/8" thick instead of 1/4".
Was the $65 dollar place selling you tempered glass?
Speaking of that being as we are all concerned about safety here and I know that no one expects to break the glass but.... is it not dangerous to us untempered glass for this?
Doug Meyer
"is it not dangerous to us untempered glass for this?"
Nah. I've never broken a piece used as a sharpening bed. I've done it using newspaper as a "cushion" and resting right on the surface of a bench.
Of course, if the glass is on an uneven surface and you lean on it far more than you ever would need to while sharpening, I guess you could break it.
Rich
I didn't ask for tempered glass, so I don't think that is was. Plus, I had other quotes that came in between 20 and 40.My glass broke in shipping. I wouldn't expect it to break through normal use, as I used it for a couple years, but a thicker slab provides piece of mind.Todd
I think it would be safer to use untempered glass in this application. Tempered glass is very unforgiving when dinged with a pointed object or when hit on an edge. I'd rather clean up big pieces than all the little bits. Tempered goes off like a gunshot when it breaks and I've seen more than one person go to the ER to have little pieces removed from their eyes.------------------------------------
The ultimate result of shielding men from the effects of folly is to fill the world with fools. -- Herbert Spencer (1891)
I don't know if any one else has tried this, but I got a 3 cm granite sink cut-out that works beautifully. Very flat. Best part is you can get these for next to nothing at a counter top shop.
-Sean
An easily-procured alternative is a granite floor tile. They're typically 12"x12", and polished so well that you can see your reflection in the surface. They cost a buck or so at any big-box.
You can also buy small granite slabs from Grizzly, Enco and many other machinist supply places. Grizzly sells a 9" x 12" x 2" for $20 plus shipping at .0001" tolerance. Any thick glass will work as well. I don't believe most woodworkers should fret over .005". Too many articles tell about stuff you don't really need to do good work. 200 years ago they didn't have a fraction of what folks have today. Most folks don't realize many tools are cheaper today and more plentiful than they were 30 years ago. Spend money wisely.
I use the same thing only mine was from woodcraft. Downside, it aint light!!!!!Government's view of the economy could be summed up in a few short phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
i'll ring in here too. i bought some glass at my local glass company and it's been more than adequate for the sharpening. before that i was using quarter inch mirror and that worked very well too. i truely believe that good ole locally bought glass is fine.
Lee Valley has a safety-glass lapping plate (8-1/2" x 14" x 1/4") that is guaranteed to be flat.
http://www.leevalley.com/wood/page.aspx?c=2&cat=1,43072,33017&p=33017
Life is what happens to you when you're making other plans .
Edited 1/11/2007 8:31 am ET by JerryPacMan
JerryPacMan and All
Safety glass is OK but I do not recommend tempered glass, not because it breaks into little pieces, but because the tempering process makes it imperfect. It is not as flat as what people here are looking for. Safety glass is float glass that is laminated, with a sheet of material (usually plastic) between the two pieces of glass to insure that if it ever breaks it will not fall apart and leave dangerous edges. JL
I found a piece of 3/8" glass intended for shelving at our local Menards in Mankato. I think it was $5-6. Size works great for 4 healthy sized pieces of sandpaper.
Thew
I salvage a 1/2" thick piece of glass from a coffee table leg a long time ago, The table had four legs I kept one and tossed the others. If I would of know better I would have saved them and given them to other scary sharp acolates. Anyway check out the second hand shops you should not have to pay much for the glass especially if it is scrap.
Troy
You can find 3/8" glass shelves fairly easily. I use a piece of
12 x 12 polished stone tile, you can get from any flooring place.
I worked in the glass industry for 12 years. most of the advise given so far is correct and some of it incorrect.
Call your local glass company, I would recommed 3/8" with seamed edges which means they will hit the edge with a wet belt sander to take off the sharp edges, you don't need the edges polished. Any thing thinner than 3/8" you'll need to make sure the surface below the glass is flat. All clear glass today is float glass with out going into the history of plate glass that was was ground flat, float glass is floated out on a molted bed of tin and comes out flat.
I would not use tempered glass one because of cost and if you bump the corner it can explode and shatter into a million small peices and when making tempered glass it is heated up and cool air is blasted on it, so often it's no longer truely flat.
I would not try to flame polishing the edge, (they flame polish plexiglas not glass.) Glass softens at about 1150 degrees and turns to a liquid around 1200 to 1300 degrees. you would have to heat the entire glass in a kiln to ensure even heating otherwise it will crack or explode it's not worth the trouble.
Sorry about going on and on.
Again go to the local glass shop and show them some of your wood working pictures and tell them what your doing and you might get a free peice of glass. You can seam the edges with a belt sander and a grease stick but why mess up your belt sander with grease all over it.
Don
Don: One question about float glass: Do both faces come out equally flat? Duke"... Buy the best and only cry once.........
dukeone
yes both surfaces are flat when floating on the tin it's self leveling.
Don
Why is float glass so important? I picked up a piece of stone left over from a kitchen job -- polished, flat, 4 inches wide by 31 inches long for $5. Seems to me a stone yard is a good deal and not as breakable as glass.Dan Carroll
You are right, so long as it's FLAT, you're good to go. It's not so much the glass that's important, as it is the flatness of the surface. Glass is 'usually' flat to a tolerance that is well within what's needed to sharpen woodworking chisels and plane irons, so most folks use glass of some kind for sharpening their tools.I was using a 12" X 12" polished granite floor tile I paid a couple of dollars for at one of the big box stores. That worked fine too and the price was right. I just recently upgraded to a 9" X 12" X 2" granite surface plate for my sharpening surface and let me tell ya, that's deeeelux...Jeff
It's not that it is so important as that it is flat and readily easy to get.
Alan - planesaw
If you haven't found one yet, I use a piece of glass from a louver window. You know the old style ones with the 5" wide slats you could open and close like a shutter. I have a stack of them I rescued from the trash, some 30" and some 40". If you were closer (NY) I would say drive over and you can have one. They are about 1/4" thick and work really well mounted on a piece of ply.
I went to a commercial glass dealer and was told that most current production, theirs included was "float" glasss. I have a small plate that I have used for block plains and blades. I bought a piece 1/2 thick by 44" X 8" for bigger planes. Klingspor has stick on wetdry paper in rolls. I have flattened a 4 and 4 1/2 on this plate. This large piece came with very finely beveled corners - per the dealer as a precaution. Ted
I didn't read the whole thread, but if somebody hasn't suggested it, you might try Brin Northwestern. I buy all my glass from them, but I don't know if they carry float glass:
http://www.bringlass.com/
********************************************************
"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
I've been using a 12" X 12" granite floor tile, it's dead flat and worked fine. HOWEVER, I just bought a 9" X 12" X 2" granite surface plate (always wanted one anyway) from Grizzly for about $25.00 (shipping included in that price). It's certified flat to a tolerance far greater than required for woodworking. I've been looking for a granite surface plate for a long time, and shipping has always been more expensive than the plate inself. Grizzly doesn't charge a premium for the shipping so it's a heck of a deal.
The mass of this rock makes it ideal for sharpening my chisels and plane irons with sandpaper, I LOVE IT. Couldn't be happier. Cost was significantly more than the floor tile, but lifes short and it's what I wanted. SCARY sharp baaaaby. Ya can't go wrong, I'd take this over glass any day.
Jeff
Edited 1/28/2007 2:34 am by jeff100
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