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  • OT - Glass cutter...

    I need to cut some 1/8" thick glass into 7.5-inch by 10-inch window panes. What is a good glass cutter to use? I'm thinking of getting one that has an oil reservoir. Any recommendations?


  • #2
    Red Devil, it ain't in the cutter, it's the person with the cutter in his/her hand.
    "four to tow, two to go"


    • #3
      Originally posted by speedsport
      Red Devil, it ain't in the cutter, it's the person with the cutter in his/her hand.
      I agree! I ran an antique furniture restoration business (learned that from my mother) for a few years. Cut a lot of glass to replace little panes found in fancy sideboard glassed doors etc.
      When I first tried it I sorta thought you had to almost press the cutter at least halfway through the glass That doesn't work!
      I bought every cutter I could get my hands on...stoopid things...none of them worked.
      Then I started taking my glass to a real glass guy to get it cut. I watched him...barely holding on to the cutter as it slide smoothly along the straight edge....a little tap on the table edge and Bingo...a nice piece of glass. Not like my shattered bits!
      Constant pressure is the answer. It doesn't have to be alot, just enough to score the glaze. I can cut glass pretty decent now with just a cheap cutter.
      I have tools I don't even know I own...


      • #4
        The glass cutter can be one of the cheaper hardware store types if it is new and clean. Don't press too hard, you just want to score it. Make sure the score goes from edge to edge. and don't rescore the glass, once is enough. Very clean glass cuts better and it should be warmed a little. Use a little light oil on the cutter.
        Good luck

        I would rather have tools that I never use, than not have a tool I need.
        Oregon Coast


        • #5
          does mirrored glass cut the same as regular glass? just wondering as i have a small piece of mirror that i need to cut a piece off of for a project. i'm debating if i should try it or just go to the glass shop and ask for a piece the size i need.

          andy b.
          The danger is not that computers will come to think like men - but that men will come to think like computers. - some guy on another forum not dedicated to machining


          • #6
            It's more technique than anything, but the carbide wheel with oil does a really nice fast job, much easier to use than the old steel wheel. You might find that a framing shop or glass shop will sell you the glass cut to size for less than it would cost to buy the tool and sheet glass and cut it yourself. Not that buying a new tool isn't worthwhile all by itself, of course.


            • #7
              I've got toyo's from doing stained glass a few years ago, but lately i can't find them so i just use a carbide tipped lathe bit. takes a bit of practice with the lathe bit though, you gotta have your pressure perfect so you dont overscore it.


              • #8
                As others have noted, do not put too much pressure. I find that it works better if the scoring is done lightly but evenly alongth the length. Also, avoid tapping to cut the glass after scoring. Instead use your hands and try to bend it up.

                I prefer the diamond point cutter over the wheel version and it seems to provide a more positive feedback during scoring.


                • #9
                  I watched a guy cut a hole in plate glass one day. Simple one movement 360 with an ordinary glass cutter, tap tap- out came the circle clean as a whistle. The hole became his handle to manipulate the piece of glass.

                  They did not use this method to instal the new glass.

                  I'm not in the business, but I've cut my share of glass, old and new. Having the glass clean is a big plus, and so it not dicking around with the cutter. One smooth score using a straight edge does it, and I've been using the same cutter I got probably more than 30 yrs ago.
                  I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-


                  • #10
                    Plain sheet glass

                    The discussion thus far is very good indeed - thanks.

                    It hasn't been spelled out but I guess that it is referring to single sheet plain glass - and not laminated, toughened or other specialised or sophisticated glass/es.

                    How are these glasses cut? Can it be done by your average HSM or must it be done by a specialist glazier - or can it be done at all?

                    How are rough edges ground and/or beveled?

                    One other methods I have seen Glaziers use is to first score the glass as previously and then put some methylated (de-natured) spirit (alcohol?) on the scored area and light it. The score goes straight through and the separate pieces just fall away. Worked beautifully for cutting non-straight lines (which had to be scored as well) - and particularly for cutting circles etc.

                    The Glazier always used "Red Devil" cutters - but he had several of them. He used to (re)sharpen them on a piece of slate (stone) - wet with water or spittle/saliva.

                    It was a pleasure to see him remove a full or broken pane of glass from a window etc. as it was to see him fit a pane as well. He only used (Linseed) Oil putty, a putty knife and a Plaster's "small tool".

                    He was "from the Old School" where Painters were also Glaziers and Decorators (wall-papering etc.). He made his own paint up from "Special Recipes" - which included a lot red or white lead. He only used oil paints as he did not like "plastic" paints. I asked his Apprentice one day why his boss didn't like or use "Acrylic" paint. To which the reply was "He couldn't even spell it, didn't want to and wasn't going to". End of conversation.


                    • #11
                      Score one for the good guys

                      I agree with all that has been said on this thread. What I would do is re-enforce the concept of a single stroke...edge to edge. After the scoring, support the glass from the underside and simply grasp the portion to be removed and give it a simple "flex" similar to what it would take to break a soda cracker.
                      If removing a thin strip adjacent to the edge, you may fine it useful to grasp the edge with a pair of pliars, but in no case should it require much pressure or force.
                      Forget about trying to cut tempered or laminated glass. Specialty glass such as these are designed so as not to be "cutable". Any attempt to cut it will probably result in completely shattering the entire piece such as when a car's windshield is hit with something heavy.
                      Mirrors which are not tempered are no different than ordinary window glass and can be cut easily.
                      Use caution when handling the freshly cut glass since the edges will be extremely sharp.
                      Again, a single stroke going from edge to edge and a crisp "snap" should give good results.
                      There is no shortage of experts, the trick is knowing which one to listen to!


                      • #12
                        Good points all. BTW, there are different edge-angles available for carbide wheel cutters. A stained-glass shop will have both. One is for red glass, which is harder than the other colors, and the other angle is for everything else. I have a "red" one (I don't remember the angle, and while I know it's in the shop, I haven't seen it in a while), and it will cut regular glass too.

                        The ease of cutting is entirely in the hands of the operator. I've watched professionals do it and it amazed me - one little swipe with the cutter, a light "pop" on the table, and there it was. One guy said to me "you just have to have confidence".

                        Then I got some practise: I had to cut close to a thousand small glass panels (about 2" x 3"). Since I was working with stock sheets of glass, that meant a lot of cutting. I had cut glass only very rarely before that. When I started, I botched about every other panel. After a couple of days, they all started coming out OK, and just for fun, I started trying to cut squiggly curves in some of the leftover sheets - that worked too.

                        As to putting a liquid on the score-line - There was a longstanding debate among chemists about whether applying a dab of spit or water to a notched piece of glass tubing made it any easier to break. The hypothesis was that the liquid wicks down into the little fissures the cutter starts, and keeps them from fusing together. (Remember, glass is a viscous liquid, not a crystalline material.)

                        Back in the 60's (I think) someone did a detailed study on this - built a jig to uniformly score the glass, and another fixture (they may even have used an Instron) to apply pressure to the opposite side from the score. They tried distilled water, spit, meths, and acetone, as well as dry-breaking it. I believe they concluded that distilled water and spit were best, then meths, then acetone, which made very little difference, possibly because it evaporates so fast.

                        I don't think they tried oil or kerosene, probably because they were chemists, and didn't want to muck up the glass with something that might be hard to remove. But just about every glazier I've ever met keeps the cutter standing in a can of kero, and makes the score "wet". Must be something to it.

                        Incidentally, I once saw a pro cut some wired glass. He scored both sides and then tapped the glass with his pliers until it cracked; then bent it back and forth to break the wires. Messy.

                        Oh... if you're going to cut mirror glass, do it from the unsilvered side.

                        Pete in NJ
                        Pete in NJ


                        • #13
                          Thanks everyone for the suggestions and advice!

                          I stopped by a hobby shop and they had a Toyo on sale for $12.00. Got it and it works great. The oil on the wheel sure makes a difference. I cut 30 panes out of a large sheet of glass and didn't break anything!


                          • #14
                            I have cut a fair bit of glass,both old and new.Clean old glass before cutting
                            I use a piece of smooth rug on the table.The cutter I use is the type with a reservoir ,which I fill with a kerosine/oil mixture.I stand the cutter in a can,which has a piece of cotton cloth in the bottom,also soaked in the mixture.
                            As every else has said,one cut only!.Then I use a lenght of piano wire under,and just beside the cut.Even pressure on both sides will give a nice clean break.
                            Edges are rubbed with a stone,or even fine emery cloth.Don't forget the corners,these are the most dangerous.
                            I've cut up to 1/4" using this method,and most of the time it works.Really old glass seems to become brittle,so can be troublesome.
                            my $0.02.