Painting the exterior walls of your home with a brush or roller can be a fairly time consuming job. But with a properly-used spray gun you can soon finish the job.
Although you don’t need special paint, you do need costly special equipment: you need a spray gun. Fortunately, these are widely available at a modest rental from good local tool hire shops. The important thing is that you choose the right kind of spraying equipment for the paint you wish to use. Choosing the gun can, in fact, be rather complicated – there are so many different kinds available – so you could tell the hire shop what you want to spray and leave the decision to them.
The simplest type of spraying equipment you are likely to be offered is called an airless spray unit. It is a straightforward pump which takes paint from a container (any container will do) and then squirts it out through a spray nozzle. It is very efficient in terms of labor and use of materials and very fast. It is capable of delivering up to 2.25 liters (4 pints) of paint per minute (a practiced operator would normally cover about 240sq m/262sq yd in an hour). This type of gun does however, have a few drawbacks. To begin with the paint must be thinned before ii can be Sprayed, which may mean applying an extra coat in order to achieve the required coverage and color density Also, with the pump at ground level, problems may arise when you are working on buildings higher than about two stories. The machine may not be powerful enough to pump the paint that distance. In addition, this type of unit will not handle paints containing fillers.
An alternative is a machine that works a bit like an old-fashioned scent spray: the air flow is provided by a compressor which may or may not be rented out as a separate item (if you do have to hire the compressor separately, make sure it is sufficiently powerful for the application you have in mind). Reaching heights with a machine of this type should paint spray gun not be a problem. The only limitation is the length of the hose between the compressor and the spray gun, but many hire shops supply 10m (30ft) hoses. A point here: not all compressor-operated units are the same and you should check that you are using a suitable type. At the bottom end of the scale, you’ll find small portable units primarily designed for spraying cars and the like. So long as you use a paint that does not contain fillers, these can be used to spray walls, but since the integral paint container normally has a capacity of less than a liter (1 pint), you will spend a lot of time running up and down to refill. Larger ‘industrial’ versions using more powerful compressors are available and these are faster and have feed cups of around 1 liter (1 pint). They too will only handle ordinary resin- and water-based paints.
If you want to spray on a reinforced paint there are a number of options, with different suppliers calling them by different names. Those able to cope with most ordinary filled exterior paints may have a shoulder-carried, or back-pack style, paint container. Those capable of spraying anything from reinforced paint to very heavy, plaster consistency materials tend to be fed from a gravity feed hopper on top of the spray gun, or from a separate pressurized tank.
Whatever you decide on, do double-check that the gun is suitable for the material you wish to spray; even if the basic equipment is right for the job a different nozzle may be required. Also make sure you get adequate instructions on using and cleaning the equipment before you take it home. If you damage it or return it dirty, you may lose some or all of your deposit. Again, bear in mind that some compressors are electric and some petrol driven, but the smaller units are almost always electrically operated (check that you get a 240V model, not a 110V one).