I am looking for a source for reasonably priced “float Glass”. I tried my local glass dealers and they want $48.00 for a 1/2″ thick piece 4 inches by twelve. Garret Wade is about $29.00 for an 11″ piece. I need 3 or 4 pieces 12″x 4″ or more–1/2 thick. Does anyone have any sources for this glass at reasonable prices. I know that Float Glass requires special manufacturing techniques. I plan to use this for a Scary Sharp sharpening system. I appreciate all of your assistence.
Ken & Patti
Replies
Ken & Patti -
I have found that 1/4" aluminum plate works just as well. Tempered aluminum plate will be very flat. I buy pieces occasionally on Ebay. You can also cut it using a band saw.
PlaneWood by Mike_in_Katy
PlaneWood
If you a search using the word "float", backing the parameters to the beginning of time, you can pick up a few threads concerning float glass, what the term means and if it really matters for we woodworkers who like to use abrasive sheets on glass. In the end, I think a piece of glass cut to your preferences from your local glass shop will do the trick quite nicely. It has done so for me.
Cheers,
Greg
Patti and Ken, have you seen the December 2002 issue of Fine Woodworking? In a similar method of sharpening, one contributor uses a 9"x12" granite surface plate. He also uses wet/dry sandpaper dipped in water, as opposed to the adhesive-backed sandpaper mentioned in the article you read. The water holds the sandpaper in place and provides lubrication.
The granite surface place costs only about $20 at Harbor Freight, although I would expect shipping costs to be significant.
How about a local place that sells gravestones? Gravestones cost a lot, but you could ask what they do with the ones that arrive damaged or broken. Maybe they'll give it to you for nothing.
Another thought: A kitchen renovation business. They might have cut-outs leftover from installing sinks into kitchen counters.
Edited 10/26/2002 3:03:44 PM ET by DWREAD
You can get a 9" x 12" x 2" granite surface plate from Grizzly that's plus or minus .0001" for $17.95. The aluminum plate idea sounds worthwhile checking out. Did you consider starting out with some used plate glass and have it cut to size. Do you think you'd really notice the difference especially if you are just starting out with a new technique in sharpening. Just checked my Enco sale catalog and they have it for $14.95.
Rick
Edited 10/26/2002 3:03:20 PM ET by rsl
Edited 10/26/2002 8:08:10 PM ET by rsl
I bought a 18x24 granite plate from Grizzly for around 48bucks, Picked it up at one of the stores because i was around there. Allows me to have several grits afixed. and plenty of room for fettling planes too.
I spent some of my early years in the employ of Pittsburgh Plate Glass, now called PPG. In the early 1950's, Pilkington Glass of England developed a revolutionary method of making plate glass in which the molten material floated on a surface of what, as I recall from 50 years later was mercury. I believe that all plate glass is now made in this manner. (Don't know if they still use mercury, due to environmental requirements.) Therefore, any plate glass should serve your purpose.
I use 3/8" plate that I got from a local glass supplier. I didn't order a particular size for a particular purpose, but knowing that glass dealers have a scrap barrel just like woodworkers, asked if I might look through the scrap barrel for something I might use. I got six pieces for $5.00. Don't worry too much about the thickness. Glass this small is not very flexible, and if it's on a fairly rigid surface, it won't flex at all.
Because of my interest in the Ultraviolet light transmission of various types of glass I did considerable research into "glass" in general.
Mr. Robert Heithoff, a technical expert in "glasses," employed by Pittsburgh Plate Glass Industries, aided me very substantially. Here's a direct quotation from Mr. Heithoff
A brief tutorial on glass types: Before 1962 there were two basic categories of flat glass for windows. "PLATE GLASS" was formed by metering it through water cooled rolls link washing machine ringer rolls, but with a gap equal to the thickness of glass made. The rolls have a rough surface which leaves an impression in the glass. The surface is then ground an polished to a mirror finish. This glass was used in architectural glazing and high quality mirrors.
"SHEET GLASS" is formed by drawing it upward from a tank of molten glass. The sheet is cooled as it rises (gripped by rollers)--drawing more glass behind it. Sheet glass was used for many low quality or thin glass applications. Sheet glass was often called "window" glass.
In the 60's the "FLOAT" process was developed. This glass is formed by "floating" it on molten tin. The tin remains liquid as the continuous ribbon of glass changes form a free flowing liquid to solid glass that can be conveyed on rollers. Today essentially all common flat glass is float glass. However, it is still common for hardware stores to refer to the glass as window glass. Furthermore, "window glass" from a hardware store is the same as what float glass manufacturers refer to in their literature as "CLEAR" glass, or "CLEAR WINDOW GLASS." And it would almost certainly be float glass. I think that glass shops, the kind that a customer would go to to repair a "plate" glass store front window would have other colors of glass.
Summing up: Any glass which you buy today at a glass shop as "Clear Window Glass" is FLOAT Glass.
Any glass that you buy today manufactured in recent years is flat enough to use as a base for the "scary sharp" sharpening system.
Furthermore, for the substrate upon which to affix your sandpaper in the various grit sizes, MDF can be used, also. So can your jointer table or your table saw's cast iron ground surface.
FWIW
WilliamI make something, sometimes twice, each year.
These days you have to pay more for glass that *isn't* perfectly flat!
I'm with you 100%
Bob
Great post William! Too many woodworkers get sucked into buying things they think they need that will make them better woodworkers. When I startd woodworking you either bought a PM 66 saw, Unisaw or a Craftsman. The only alternative fence was the Bies which had just come on the market. Interesting how people buy all the gizmos so they can make things like the old masters who had far less than we do now which shows it's not so much the tools but the folks using the tools. Think any one looking at an old classic can tell if they used a Marples or Buck Brothers chisel. So does it really make a difference if the chisel was sharpened on a piece of MDF or a piece of $48 dollar "float glass" from Garrett Wade?
Rick
I got mine from a large glass company, it was left overs from building a big aquarium. I got it for about $5, and it was 1/2 an inch thick.
Did the same a couple of years later in a different city, and got 2 pieces for a few dollars, same thickness. I went in and asked for offcuts/scrap. The second time around he actually fished it out of the scrap bin.
I also went to a place that sold headstones. As said above, my bits were from a broken one and were in a pile in the yard. The guy there was only too happy for me to take whatever I wanted. As it was flat and polished smooth, I was pleased to oblige.
Wood Hoon
So basically what you are saying is that for your materials you sort through garbage or rob the dead?
Maybe where you come from. :)
The broken headstone was a manufacturing dud, I doubt the remaining bits were used for a funeral. If the glass outfits want to sell me usable glass for little then fine by me........
Wood Hoon
Hi.
I bought two 8" X 12" pieces of float glass for less than $15 at Binswanger Glass in Dallas..I think it's a chain of glass places...do auto glass, mirrors, windows, etc. They had it in several thicknesses and, for an extra charge, will even bevel it for you. I see very expensive prices for float glass and don't know what that is about....
As an FYI (I'm a glass guy...smile) float glass is manufactured by floating molten glass on liquid as it anneals (cools and tempers). They used to float it on Mercury..and may still. The liquid is so level (think about it, liquid may be the most level of "tables") that the glass is flatter than regular "plate" glass, which is poured out onto a flat metal table and annealed.
I've used "Scary Sharp" methods..very good system...I'm not convinced that one needs float glass-flatness.....but it's a good method.
Good Luck
lp
Larry, sorry, but I think we need to lay the mercury story to rest. They have been using molten tin for as long as I have known of the proces,..since the '50s. Molten tin is going to look like mercury so the misunderstanding is reasonable. Mercury has a surprisingly high vapor pressure at room temperature and at glass manufacturing temps it would be extreemly poisinous, a fact that was well understood when the process was develpoed. I would hazard a guess that if used in float glass manufacture, mercury would distill off and the vapor that was not inhaled by the workers would condense as mercury droplets all over the factory.
I don't suppose it matters in a woodworking forum but you never know when some idiot will pick up some gem of information gleaned from the forum and invent some use for it. Idiots are so ingenious. Not the folks who post here, of course, but you never know who's lurking. LOL
BJGardening, cooking and woodworking in Southern Maryland
There is also a decorative treatment in which a silvery coating is applied to one side of glass to make mirrors and ornaments. It has always been called "mercury glass" for its looks, even though mercury has never been a component. No doubt this misnomer contributes to the myth of mercury being used in glass products.
If mirrors were made with mecury, we'd all be mad as hatters. ;)
Just so there's no confusion, I'm a different "Bart". Guess I'll have to change my screen name.
Anyway, a year or so ago my wife wanted a granite dough board for making pastries. I found one of the local stone suppliers who piles all of their offcuts (nicely polished on one side) on pallets in the parking lot. You have your pick of the litter for something like $0.05 per square inch, and that's before you haggle. I never thought of getting a piece for sharpening, but I am now......
I stand corrected. Don't want anyone poisoning themselves.
lp
I use the glass out of an old photocopier, it is a nice size so I can put different grits of sand paper on it at the same time, the edges are finished and best of all it was free. Any copier dealer is likely to have a boat load of junkers in the back somewhere and should not have any problem giving the glass away out of one of them.
Just a suggestion
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