Stained glass for beginners: cutting, grinding, foiling, soldering

This guide walks through the four steps between a printed pattern and a finished panel: scoring and breaking the glass, grinding the piece edges, wrapping copper foil, and soldering the seams. It uses First Cut Medallion, the free pattern on this site, as the working example.

Scoring and breaking

Trace each piece from the numbered pattern onto your glass with a permanent marker, score once along each line with a glass cutter at a steady pace and even pressure, then break along the score with running pliers or by hand over the edge of a table. A clean score sounds like a light zipper, not a scratch; a re-scored line usually breaks unevenly.

Grinding

A wet grinder cleans up the break line and rounds the piece to its exact traced shape. This is also where the pattern's minimum piece width matters in practice: a piece under about 3/8 in wide has very little material left once ground, and is the kind of piece that snaps at the grinder rather than under the cutter. Every pattern on this site is checked to stay above that width at the size you order.

Copper foil

Wrap each ground piece in self-adhesive copper foil tape along its edge, centered so an even lip shows on both the front and back faces, then burnish the foil flat with a fid or the back of a spoon.

Soldering

Flux the foiled seams, then run a bead of solder along every seam with a hot iron, keeping the iron moving so the solder domes evenly instead of pooling. Solder the front side first, flip the panel, and repeat on the back.

See Foil vs Came if you are deciding between techniques before you start, or go straight to the free pattern on the Pattern Sizer tool.

Tool settings that matter more than technique

One score only: going over a score line ruins the edge and blunts the wheel
Oil the cutter, and let the wheel do the work rather than pressing hard
Break immediately after scoring: a score left for an hour breaks less cleanly
Grind wet, always, and keep the sponge saturated so the head does not glaze
Flux only what you are about to solder, and clean the panel thoroughly afterwards

The most common beginner failures

Scores that wander because the straightedge slipped, pieces ground undersize because the line was chased from both sides, foil that lifts because the glass was still damp from the grinder, and solder beads that sink because the iron was too cool or moved too fast. None of them is a talent problem: all four are fixed by slowing down one step.

Working safely

Eye protection while scoring and grinding, because glass chips travel. Ventilation while soldering, since flux fumes are the unpleasant part. Wash your hands before eating when working with lead came or lead bearing solder, and keep food out of the workspace entirely. None of this is optional, and all of it becomes habit within a panel or two.

Bench setup, tools, and working dimensions

Set the pattern on a flat board, then tape a clear copy over it as a layout map. Keep a second copy for cutting templates if you use paper pieces. For a small beginner panel, a work surface of about 24 in by 30 in is enough, but the grinder and soldering area should not share the same puddles, grit, or paper scraps.

Use a marker line that is about 1/32 in wide, then cut just inside the outside edge of that line when the piece must fit tightly.
Leave about 1/16 in between glass pieces on the layout before foil. After 7/32 in copper foil is wrapped and burnished, that gap normally closes into a solderable seam.
Keep a small tray for offcuts that are larger than 2 in by 2 in. Smaller chips should go straight into a rigid waste container, not into a plastic bag on the bench.
Use a square or straightedge that is at least 3 in longer than the cut when scoring straight lines, so both hands stay away from the wheel path.
Plan about 2 to 3 hours for a first panel with 15 to 25 pieces, not counting breaks for cleaning and drying.

If you are changing the pattern size before printing, check the smallest parts before you cut glass. A pattern that is easy at 8 in wide may become fragile at 5 in wide. The sizing process is covered in more detail in how to size a pattern.

Detailed order of work for one beginner panel

Number every glass piece on the pattern and write the same number on the glass before cutting. Also mark the grain direction, streak direction, or textured face when it matters. For cathedral glass this may not change the fit, but it changes the finished look, especially when two adjacent pieces came from different areas of the sheet.

Cut the easiest inside shapes first, then the outer border pieces. This gives practice before the most visible edges are made. When a curve is deep, remove it with several shallow relief cuts rather than trying to snap the whole curve at once. A practical relief spacing is about 1/2 in to 3/4 in along a tight curve.

After grinding, rinse each piece and dry it completely. A towel removes surface water, but the edge can stay damp for several minutes. Let the pieces air dry for 10 to 15 minutes before foiling if the room is cool. Lay the pieces back on the pattern after each operation, because a missing 1/16 in error becomes hard to diagnose after ten pieces are foiled.

Before soldering the full panel, tack the corners and several central intersections with small solder spots. Check that the panel still sits flat. If one corner lifts more than about 1/8 in on a small panel, stop and correct the layout before building full beads.

Figures to check while you work

Item to check	Useful figure	What it tells you
Foil lip on each face	About 1/16 in per side with common 7/32 in foil on 1/8 in glass	The tape is centered well enough for an even solder bead.
Gap before soldering	About 1/32 in to 1/16 in between foiled pieces	The seam can fill without starving or making a wide puddle.
Grinding allowance	Usually less than 1/32 in per edge	The grinder is for fitting, not for reshaping a badly cut piece.
Iron contact time	About 1 to 3 seconds over a small seam area	The solder should flow before the adhesive under the foil overheats.
Cleaning delay after flux	Same day, preferably within 30 minutes after soldering	Flux residue is easier to remove before it dries into corners.

These figures are working checks, not product specifications. Glass thickness, foil width, solder alloy, and iron temperature all change the feel of the work. The useful habit is to measure a few seams with a ruler before soldering, instead of judging every gap by eye.

Recovering from mistakes and handling special cases

If a piece is slightly too large, grind only the high spot and return it to the pattern often. Do not grind all sides equally unless the whole piece is oversized. If a piece is too small by about 1/16 in, it may still work in a non structural area if the surrounding gaps are even. If it is too small at a border or point, recut it.

If foil lifts at a corner, peel back only the loose section, dry and clean the edge, then apply a fresh short piece that overlaps the sound foil by about 1/4 in. Do not try to solder loose adhesive into place. It will usually wrinkle, trap flux, and lift again during cleaning.

If solder bridges across a narrow detail and hides the shape, let it cool, add a small amount of flux, then draw the iron tip along the seam to pull extra solder away. Wiping molten solder toward an edge is safer than pushing it into the next joint.

Opalescent glass, rippled glass, and heavily textured glass need slower layout checks. The cutter normally works on the smoother face, while the visible face may be the textured side. Mirror the pattern piece when needed so the finished face points the right way. For very dark glass, use a silver marker or paper template instead of relying on a black marker line.

For panels with long straight borders, square the outside before final soldering. A border that is out by 1/8 in may still look acceptable on the bench, but it becomes obvious when framed or hung. If you are still choosing between copper foil and lead came for a larger design, read foil vs came before cutting the glass.

Hands scoring and breaking a sheet of colored glass along a cut line

Frequently asked questions

What tools do I need to start?

A glass cutter, running pliers, a grinder, copper foil, and a soldering iron with flux. See the materials page for specific products.

Which pattern should I cut first?

First Cut Medallion, the free pattern: sixteen pieces, straight radial cuts and one ground curve, and a wide margin on every cuttability check across its full size range.