Pewter is a soft, malleable metal alloy traditionally composed of tin and lead. However, due to the poisonous effects of lead, modern pewter is now 92 percent tin. Small amounts of copper, bismuth or antimony, which make up the remaining 8 percent, are added to the tin to give it extra strength. Repairing antique or valuable pewter should be left to an expert, however modern, inexpensive pieces can be repaired with some skill and patience at home.
Clean and polish the pewter item and any pieces that have been broken from it. If it is a hollow piece, fill it with water to inspect for any leaks along the seams, then dry the item.
In a well-ventilated room, turn on the electric iron and put on work gloves. Test the heat of the iron by touching it to the plumbing solder. If the solder liquefies, the iron is hot enough to be used.
Test the fitting of any broken pieces by placing them on the pewter item. Look for any gaps in the fit where you can apply additional solder during the repair.
Heat the solder with the electric iron, holding it no more than a half inch above the spot on the pewter item that needs to be repaired. Let the liquid solder drip onto the piece. Use more solder in any areas you detected gaps in the fitting.
Place the broken piece onto the pewter item, pressing it against the liquid solder you just applied. Hold it in position for at least thirty seconds to allow the solder to cool.
Hold the end of the plumbing solder against any seams or gaps that need to be repaired. Then gently heat the solder with the tip of the electric iron. As the solder melts, drag it across the faulty seam or joint.
Wipe away any excess solder from the seam or joint with a cloth rag before the solder cools.
Sand down any lumps of solder on the pewter item with a fine grade sandpaper after the solder has cooled.
If you are unaccustomed to soldering, practice several times before attempting to repair your pewter item.
Never heat lead or items containing lead, including antique pewter. The fumes are poisonous.