The purpose of this ‘blog’ is to try and help walk you through the minefield that is primers. This is from the view point of a trade customer rather a retail one as from past experiences, the trade products are far more superior than their retail ‘cousins’. Choosing the right primer may save you plenty of time and as such plenty of money.
If you have just had some new works carried out, more than likely the works will need priming before you start to apply the finishing coat. This helps seal the new work to increase the adhesion of the paint and hopefully reduce the re-paint cycle.
– New Plaster
When it comes to new plaster, it is recommended by the manufacturers to ‘thin’ the first coat down which is often known as a mist coat. Generally, this is usually 1 part water to 10 parts of paint but some might be different so it is worth looking at the tin/tub first.
– New wood
For new wood that is getting painted, it is best to apply acrylic primer undercoat prior to any undercoating. This is a water based product that can be put on with ease and is reasonably cheap compared to some other primers. Only rub down the wood once you have put a coat on. This can be done with wire wool, sand paper and/or wet and dry paper. If the required finish is to be stain/vanish, it is advisable to ‘thin’ the paint similar to when painting new plaster. However, you may need to do this with white spirits as the product may be oil based (solvent).
– New/Rusty metal
If you have any rusty metal, you can scrape off all the rust and apply a zinc phosphate primer. Alternatively, if it is all new metal works, you can coat it all up in this and use it as an undercoat or leave it in that finish with an extra coat. It can come in certain colours and either quick drying or oil based for ease of use. There are products on the market that each of the major supplier has that is a metal primer/undercoat and top coat in one which could be a possible alternative.
– Alkali resisting primer
This is a product that we have used a lot in the past particularly in old buildings. It is used to ‘kill’ off the salt that may be coming in through the stone or brick work. The best thing to do is to wire brush the salt off and apply the alkali resisting primer. This should stop the wall from being chalky and enables you start painting.
– Grip primer
Arguably the most important but under used product is the Grip primer. The idea of this product is to use it on areas that shouldn’t be painted ie glass/tiles/pre-finished cupboards. If you paint these items in normal paint first they are likely to just scratch off with ease as the paint won’t adhere. By applying a grip primer, you can treat it like a blank canvas. You must first sand down the item to help provide a key.
– Stain sealer
The majority of grip primers I have seen also act as a stain sealer. Be aware that you can stain seal something 100 times but if the leak isn’t dry you are wasting your time. The one and only product plug I will make for a product is Zinessar Bin 123 (Red tin). It is expensive but as a product I feel it is head and shoulders above the rest due to it being a shellac based product and not water based. An interesting fact for you is that shellac is a resin secreted by the female lac bug, on trees in the forests of India and Thailand. It is processed and sold as dry flakes and dissolved in ethanol to make liquid shellac, which is used as a brush-on colorant, food glaze and wood finish. So don’t try making it at home.
I hope that this information helps but for more detail, the major paint suppliers have some really good literature should you want to continue your research.
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