If you’re thinking about making some home improvements any time soon, it is a wise idea to do a bit of research into what exactly is involved. After all, a simple paint job involves a lot more than just buying a tin of paint and applying it to the walls. You’ll no doubt have heard people mention primer and undercoat before – but if you’re even a little bit unsure about them, you’ll want to ask some questions. So here is a guide to primer and undercoat, and when and where you will need to use them.
What is primer?
You generally use primer when preparing wood or metal for painting and varnishing. It helps to give an even finish and prevents rust from developing at a later date.
What is undercoat?
Undercoat is an extra layer of paint, usually applied after the primer and before the topcoat of paint or varnish.
Are the two interchangeable?
The short answer is no. it is advisable to use a primer to treat new surfaces and undercoat when repainting a surface. With that in mind, undercoat can always be used as a primer, while primer cannot always be used in place of an undercoat. The main point of an undercoat is to ensure that the surface is even and smooth before you apply a topcoat of paint – this ensures a better finish afterwards, while primers are definitely the base coat, the very first coat you apply to a brand new surface. Some primers even help to seal the surface which in turn gives a better finish once the topcoat has been applied. This helps to minimise the impact of rust and corrosion.
How to apply them
If you apply primers and undercoats incorrectly, you will risk problems developing further down the line. You should apply primer to a clean surface, making sure that the surface temperature is not too hot, otherwise the solvent will evaporate and the film will not form properly. Similarly, if the air temperature and surface is too cold, the film will not form properly.
Should you thin primer?
There are some who advocate and some who are against the thinning of primer. What everyone does agree on, however, is that it is important to follow the manufacturer guidance on the label, as far as thinning is concerned. This will tell you whether or not the specific primer you have chosen should be thinned, what you should use to thin it, and how thin you should make it. If you do decide to go along the thinning route, make sure that you do not over-thin the product you’re using, and always ensure each coat has fully dried before recoating, otherwise you risk the topcoat lifting and wrinkling.
Which surfaces should be primed?
Undercoat is a little easier to understand than primer, so let’s focus on the latter. You should use primer on glossy, hard surfaces, especially ones which are porous or prone to rusting, in order to seal them. It’s important to be aware that primers can be used for a variety of surfaces so always check the label or ask a professional if you are unsure.
Do you have any further tips about using primer and undercoat?
This has been supplied by http://www.leyland-paints.co.uk/