to the average homeowner, all metal which is not obviously brass or copper is known as "iron." Of course he is not quite right on that score, because today there are many different kinds of metals and metal alloys used in the make-up of our houses and our equipment. The art of metallurgy has advanced beyond the wildest dreams of past generations, until we have arrived at a point where the entire body of an automobile can be stamped out of one sheet of metal at one punch, and castings can be made which are so intricate, that a few years ago it would have taken ten castings and a lot of machining to produce the same unit. Research and development on the part of the large manufacturers can be thanked for it. As a net result, we find that almost all the sheet metal used in the modern house is particularly adapted for the job it is intended to do, and all the sheet-metal used in our numerous household appurtenances has been specially made for a purpose.

The most important pieces of sheet-metal in your house are the flashings around the chimneys and above the door and windows. These are usually made of copper and should never give you any trouble, but if they are of sheet-iron or any other corroding metal, they will have to be watched carefully. Full instructions for the proper treatment of flashings has already been given in the chapter devoted to exterior household repairs.

The next sheet-metal work, in line of importance, is the smoke-pipe from the heating plant. Usually this is of plain black sheet-iron. If you have a particularly good installation job, it may be of heavy-gauge galvanized sheet-iron. Whichever it may be, it will not last too long, because the intense heat from the boiler or furnace will burn it out. We have seen smoke-pipes that looked perfectly good, but upon pressing the surface with our finger, it went right through. The best way to test a smoke-pipe, is to jab it lightly with a heavy nail. We do not mean to stab at it violently; just poke it lightly. If the nail goes into the pipe, you have a completely burned-out section and it will have to be replaced. New sections of standard diameters are available in any hardware store at a cost of about fifty cents each. If the point of the nail alone enters the pipe, you had best test further along, as the metal is about on its last legs. You may get another season out of it, and you might not.

Another important item of sheet-metal work is in the vent from the gas range. This should be tested in the same manner as the boiler or furnace pipe. Both range-vent and boiler pipes should be painted or enameled. The best method for this is to use the special "smoke-pipe enamel" made for this purpose. Ordinary paint is useless and dangerous on hot surfaces.

Much of the cabinet work used in kitchens, and some of the bathroom cabinets are made of sheet-metal. Practically all oven doors in modern ranges are made of sheet metal. Usually this metal is not spring-steel but simply sheet-steel, and so, it can be very easily bent out of its proper shape. Once this has been done, it is a job for a sheet-metal worker to take care of it, and it is questionable if even he can ever get the door back in true shape. There are lots of housewives who are very careful of the things in the house, but who have a bad habit of opening the oven door, sliding out a roasting-pan with a heavy piece of meat on it, and letting it slam down on the open door. After a year or so of this performance, they will start to notice that the oven "smokes" and the kitchen is filled with fumes from the roasting food. The oven is not smoking one bit more than it used to; but the door is not closing as tightly as it used to, because it has been gradually bent out of shape. You must remember that sheet-metal is quite thin, usually not springy, and can easily be bent.

Pots and pans, coffee-pots and percolators, trays and metal dishes can all be straightened out and dents removed, if you know the trick. The basic rule for removing dents, is first that the article you are working on must be backed up. In other words, if you have a nice brass tray with a bad dent in it, you should lay the tray on a flat hard surface, such as an upturned flat-iron (an anvil is the right thing, but you won't have an anvil around the house), and lay it so that the bump or dent is up, and not on the iron. The next rule is that you take a medium heavy hammer, and tap the protruding dent with slow-light raps. If you give it heavy hammer blows, you will mark the whole surface around the dent. After a dozen or so light raps you will see the dent melting away, and before you know it you will have an even surface again. The reason for this is that the metal is malleable, and the repeated light blows gradually move it flat against the backing.

All sheet metal is subject to denting

All sheet metal is subject to denting. Most of the damage can be repaired by beating out the dent while the undamaged surface is backed against a hard and solid base.

If you have badly dented pots, they can be worked back into a smooth surface again by setting them on the side over a hard backing, and tapping out the dents with a light hammer.

Your first attempts at sheet-metal work may be rather bad as far as professional results go; but if you fool around with it long enough, and learn the temper of the metal you are working on, you will be surprised at what you can accomplish.