DIY

How to Cut Glass and Cut Costs

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Cutting your own glass is a great way to save money on those home projects.
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These pictures, referenced in the article, display how to cut your glass.

One skill which can come in mighty handy to just about
anyone — whether you live on OR off the farm — is knowing how to cut glass.

Now, many homesteaders and suburbanites have taken the time
to become competent carpenters but for some reason,
very few people have ever learned how to 1.) find free or
inexpensive glass, and 2.) cut it once it’s found.

Fact is, of course, a lot of folks are intimidated by glass
because they assume it’s too difficult to work with, or too
dang costly in the first place — neither of which is
true. Glass cutting is merely a skill that can be learned
(like tanning, canning, or composting) and the techniques
involved are not at all complicated. And anyway, it’s just
a matter of time before you’ll need to use glass
for your home, cold frame, greenhouse, solar collectors — or whatever.

Sure, you can substitute polyethylene. In a short time,
though, the plastic will become yellowish and brittle and
have to be replaced. Glass is all-around superior because
it’s durable, it’s not that costly, it’s forever
transparent and — best of all — it’s not made from
energy-intensive, non-recyclable materials.

Types of Glass

Let’s briefly look at some of the different kinds of glass
you’ll run across:

WINDOW GLASS is the most common variety
you’re likely to work with. It’s available in single- and
double-weight thicknesses.

PLATE GLASS is both stronger and thicker
than double-strength window glass, while usually not more
than 3/8″ thick.

LAMINATED SAFETY GLASS: Two sheets of
glass bonded together by an extremely tough, clear plastic.

MIRRORS need no introduction, but I might
point out that you can scrape the reflective backing off
most any mirror with a single-edge razor blade,
and–presto!–you’ll have another see-through
pane.

Where to Find New and Used Glass

HARDWARE STORES usually sell window glass
only, cut to order. (Here, you might as well let them cut
the glass for you. That way, if anything gets broken, the
fault lies with them not you.) While these outlets
are convenient, they are also the most expensive everyday
source of glass.

GLASS STORES specialize in window glass,
plate glass, auto glass, stained glass, or any combination
thereof. You can pick up new glass at such outlets for less
than you’d pay at a hardware store. These specialists also
are often willing to cut your purchase into some pretty
weird shapes, if you want them to.

Aside from dealing in brand-new wares, specialty stores are
also frequently a good source of inexpensive and
(sometimes) free glass. Ask if there are any seconds
available. A second could be a pane that’s pitted,
scratched, or perhaps a bit distorted — none of which,
for all practical purposes, affects the piece’s utility. If
you don’t mind such imperfections, seconds offer the
purchaser a good way to save a substantial amount of
bread.

Also inquire about cracked laminated satety glass. The
store’s manager might think you’re cracked, but actually,
damaged safety glass can be put to good use in cold frames,
greenhouses, and whatnot. (The “sandwich” material leaves
even cracked sheets of glass with enough strength so that
they’ll work OK in most applications.) If your shop carries
cracked safety glass, you should be able to get it for free, or nearly so, in any case. Busy shops constantly
remove such damaged panes and sheets from cars or trucks
that are having new windows installed. If your local
outlet doesn’t carry any cracked auto
glass — and they may not — it’s probably because
more and more cars today are equipped with tempered windows
which, instead of cracking when damaged, just disintegrate
into thousands of jewel-like bits and pieces.

Unfortunately, dealers simply don’t use as much laminated
glass as they once did. Nevertheless, inquire anyway and
ask if they’ll save you any odd pieces they come across
which might otherwise go in the trash.

AUTO WRECKERS are, of course, a good
potential source of laminated safety glass–cracked or
intact–should your local glass shop not have any.

BUILDING WRECKERS, SALVAGE YARDS, SECOND HAND
STORES, AND COUNTRY AUCTIONS,
all are good places
to look for low-cost used glass. If you dig awhile, you’re
likely to find old storm windows, sliding glass doors,
framed picture windows — and who knows what else.

One good way to save a bundle on glass is to seek out old
storefront windows. These plate glass wonders are usually
scratched, chipped, painted, and lettered over, but you’d
be surprised how quickly a razor blade and some paint
stripper will tidy things up — and the price is usually
right, if you volunteer to scrape the paint off yourself.

TOWN DUMPS? Why not? Better to be down in
the dumps than to be without glass.

How to Cut Glass

The following basic techniques should get you through most
glass-cutting jobs. Needless to say, you should practice on
unusable bits and pieces first.

1. Dust off the top of your cutting surface, preferably a
smooth table.

2. Lay out all tools: oil, pliers, tape measure,
straightedge, and glass cutter. (I always use either a
Flatter or Red Devil cutter, which in my estimation are the
most reliable brands. Whatever you do, don’t go in for a
combination cutting tool, screwdriver, knife sharpener, and
Lord knows what else. Just a glass cutter, please.)

3. Place the pane or sheet you want to trim or divide on
the table and be sure the area which you intend to cut is
scrupulously clean . . . no paint, dirt, putty, etc.

4. Next, hold a straightedge against the glass and run a
thin stream of lightweight oil down the cutting line (Photo
2). 

5. Now, “make your mark”. Bear down firmly-but not
stiffly!–with the cutter and score the glass in one
even, sweeping motion (Photo 3). If you score the glass
properly, you’ll hear a very pleasant clicking sound.
Remember, the cutter only scratches the surface . . . it
doesn’t cut through. If you see little flakes of glass
flying into the air during this part of the operation, it
means that either you forgot the oil or your cutter is too
sharp or you’re bearing down with the weight of
Gibraltar. 

6. After you’ve scored–as we say in this business-go
right ahead and-snap the piece in two. (Don’t wait around,
or it may not snap as cleanly.) Photos 4 through 7 show
several ways of making the break.

The whole idea of scoring is to weaken the glass by
focusing internal stresses along a single path. These
stresses are then relieved as you break the glass in two.

7. Finally, if necessary, you should smooth the edges of
the two new panes or window lights with wet emery cloth (or
with a grinder, if one is available).

(Click on the “Image Gallery” to see all photos mentioned in the above steps.)

How to Cut Safety Glass

First score the glass on one side, and press your thumbs
firmly on the unscored side until you hear the etched side
snap. Then score and snap the other side. Finally, apply a
thin stream of lighter fluid to either cut, ignite, and
step back.

When the fire has gone out, the heat will have weakened the
plastic between the layers of glass and you can cut the two
pieces apart with a razor blade.

Some Suggestions

You’ll find that new (that is, sharp) cutters work best on
window glass, while cutters that have been around
awhile-and no longer have their original keen edge-do best
on plate and safety glass.

A final tip: Instead of tossing away all those seemingly
unusable shards of glass which begin to accumulate, why not
read Mary Lou Stribling’s Art From FoundMaterials? With her ideas for glass mobiles and
mosaics, she takes the concept of recycling a
delightful–and welcome–step further.