We get a great many questions regarding filling cracks in all materials, of all shapes and sizes. Fortunately there is a filler for just about every occasion so here is a list of them.
For fine, internal, surface cracks, mostly in plaster, fine surface filler is usually the answer. Fine filler can be applied with a sponge to force it into small cracks and then sanded very lightly with a fine grit sandpaper.
For larger holes use One Strike lightweight filler. One Strike Filler is a great new filler that is made with lightweight polymer bubbles. It fills even deep holes and cracks with just a single application, which avoids levelling off and secondary filling. It doesn't shrink, crack or sag, but gives a smooth finish, without a lot of sanding. It's quick too; within 30 minutes it will be ready to be painted or wallpapered. You can use One Strike Filler for repairs to wood, brick, plaster, stone and rendering.
There are many types of wood filler and most depend on the colour of the wood. They are available in all timber colours or simply just light and dark. The multi purpose wood filler below (In the top tools box) is applied easily with an applicator gun and can be sanded down and stained.
External timber has a special two-part filler which is rock hard in about 30 minutes, can be sanded, screwed, nailed and planed.
For ceiling or other cracks which, up until now, have opened up time and time again, its probably best to use a flexible filler coming in the shape of this decorators caulk. (See Top Tools below) An applicator gun is required to apply this filler which can be used internally or externally. Decorators caulk is like flexible pollyfiller in a tube, can be squeezed into corners and tidied up by wetting your finger and running it over the bead of filler.
Chemical Metal fills, seal, joins and replaces metal, wood, stone, concrete etc. It sets in minutes. and can be sanded, machined, drilled, tapped and polished. It is also resistant to water, salt water, oil, petrol , heat and cold and can be used to bond together different materials and seals leaks in Steel, Copper. Lead, Asbestos and Glass Fibre. This product can be bought from most DIY sheds.