Any metal exposed to the weather should be painted as often as is necessary to prevent it from rusting. Remove the old paint and rust from the surface with steel wool and emery cloth. When the metal is clean, wipe it off with petrol to remove any grease that is present. If this is not done, the grease and oil will prevent the paint from sticking, and it will chip off easily and quickly once it is dry.
After the metal is clean, apply a coat of metal primer. Ordinary exterior paint is not suitable for priming. Red lead is one of the best metal primers, and the entire metal surface should be given a full coat of it. Do not use a good paintbrush for metal work, but have a special brush for this purpose alone. After the priming coat is dry, put on the finishing coat. This can be any good exterior paint.
Check painted metal work often, and when it begins to crack and chip off, scrape or sand and repaint.
Painting galvanized iron
When a piece of metal is galvanized, it is given a thin coat of zinc to prevent the metal from rusting. As long as the zinc coating remains undamaged the metal will not rust, but the first scratch in the zinc surface will allow moisture to reach the metal. When galvanized iron is new, the zinc will prevent paint from adhering to it properly, but after the metal has been exposed to the weather for a few months, the zinc surface will be rough enough to receive paint successfully. The only preparation required is to remove any grease from the metal with petrol.
Before new galvanized iron can be painted, the surface must be chemically treated in order that the paint will hold. Do not use strong acid solution for this purpose, as it will completely remove the zinc coating. A solution that will roughen the zinc surface enough so that paint will adhere, without destroying the coating completely, can be made by mixing 2 oz. of copper chloride, 2 oz. of copper nitrate, 2 oz. sal ammoniac, 2 oz. of crude hydrochloric acid, and 1 gallon of soft water. Brush this solution on the metal surface and allow it to dry; then rinse with fresh water.
Painting metal toys
Good quality toys are expensive items and when a bicycle or coaster wagon begins to show signs of wear it should be taken in hand at once. A few hours spent in fixing a toy will make it as good as new in most instances.
Metal coaster wagons and other toys of this type when dented can usually be straightened by the home mechanic with the aid of a ball peen hammer and some blocks of wood. An alternative measure is to take the dented part down to a local garage. Here, a mechanic possessing the proper tools and skill can knock out the dents in a matter of minutes and give the cart its original shape.
The charge is usually slight. Broken metal parts should be welded back together-solder will not hold on a joint subject to stress.
Before you attempt to paint any complicated
toy it is a wise plan to strip it down as far as possible. Remove all
the parts and while doing this look to see if any nuts or bolts are worn
or badly rusted. If they are, use new ones of the same size when you reassemble
the parts. Once you have the cart or bicycle disassembled, give all the
parts a good cleaning in gasoline or petrol. Do this job outdoors so as
to avoid any fire hazard. With the grease and dirt out of the way, inspect
each part to see what sort of condition the finish is in. If the paint
is chipped in a few spots, it will not be necessary to scrape all the
rest of the paint off. To fix up the chipped spots, take some steel wool,
emery cloth, or sandpaper, and remove any sign of rust. Sand the edges
of the paint around the exposed metal until you get a tapered edge. Rub
a piece of sandpaper over the entire painted surface to cut the finish
enough so that the new paint will adhere properly. Now go back to the
chipped spots, wipe them off with gasoline, and apply one coat of metal
primer. When this is dry, apply a coat of finish paint over the primer.
After this is dry, brush on another coat or coats until the surface has
been built up level with the rest of the painted metal. After this, give
the spot a light sanding, wipe all the painted surface clean, and apply
enamel for a finish coat.
Aluminium must be treated differently from other metals as there is a chemical reaction between it and the lead in base paints. First scrub the surface with a non-alkaline cleanser. Then apply a prime coat of zinc chromate. When that is dry, any good exterior paint can be applied.