Beginners Guide to Painting with Water-based Paint. How to avoid using a primer!

A common complaint we see from homeowners and beginner DIY decorators, is how water-based paint doesn't last like the old oil based paint does. Although this is true in some respects, there are a few things which people don't realise are required when they switch to water-based paint which greatly improve the finish and durability of the paint. If you start seeing chipped or, peeling paint, then you know something has been missed during the paint process. Keep reading and we'll go through the things you need to consider when using water-based paint for the first time to ensure the perfect finish.

We'll start at the beginning. Up until around 10 years ago all paint used on woodwork was oil based paint. This is the paint which people see go yellow over years and it's the thing which people want to avoid when then come to re-paint their skirting boards and doors. Then all of a sudden water-based paints were introduced. The problem is the manufacturers didn't really explain or make apparent what water-based paints were and how you had to use them differently. To this day, the majority of homeowners don't use water based paint correctly and end up with a poor finish which flakes and chips away after a few years. The big problem with this is once you use a water-based paint incorrectly, it's very difficult to get back to a good long lasting finish.

So why so many problems with water-based paint?

The manufacturers really haven't helped themselves here. If you look on a can of water-based paint you will see no mention of this. This is why so many people end up with the wrong process and poor results. The key thing when using water-based paint over oil based paint is that you need to prime the surface first. It goes one step further than this though. Not all primers will even adhere to old oil based paint. Only the more premier trade primers are more effective to creating a good surface to which the water-based paints can adhere. This one factor alone can transform the finish you will achieve when then applying your topcoats.

How do you know if you need to use a primer?

There are a few ways of checking if you need to use a primer. One is to use Acetone to see if this wipes off any paint. We're not going to recommend this however, as most home DIY people won't have this lying around.

There are a couple of ways we can tell if a primer is required from just looking at the paint. If the paint is yellowing and if it is over 10 years old then you care guaranteed to need a primer. This is will definitely be oil based paint you will be painting over and need a primer.

Also if the existing finish is a gloss finish, then the chances are you will need a primer.

If the paint is newer and is a satin finish then the chances are this is a water-based paint already. Therefore there is no need for a primer and you can go straight on with your topcoats.

If you're unsure or would like to check if you need a primer then there is a simple test. Take your water-based coat. Paint a small area (around 25mm long) and leave it for around 6 hours. If you can easily scrape this off with you nail, then you need a primer. If not then you know you're good to carry on without.

So which primer to use?

For this there are quite a few. As mentioned above, we would recommend a good trade primer. Our preferred primer is Johnstones Trade Joncryl Primer Undercoat. This is a stain-blocking primer which can go over most materials, will stop knots and stains from bleeding through your finished paint, and can be used in nearly all applications. It's also very cost effective and can be bought online. You will only need 1L of this and it will last you a long long time.

There are also other primer out there which will do a similar or even better job (although not as cost effective). Zinsser BIN Aqua, Dulux Trade One Primer, to name a few.

Not just the primer!

Now we've covered the primer, we will also say that not all the top coats are created equally. First of all, if you are looking for a wood paint then choose a trade paint. They are far superior than what you can buy from a DIY centre. They will apply easier and last longer and just make the experience easier for you and your decorating. You can see paints from Dulux Trade, Johnstones Trade, Crown Trade along with other manufacturers like WRX and Benjamin Moore.

Our current favorite is Johnstones Trade Aqua Guard in Satin Finish. This paint leaves a great finish. It's extra white and VERY durable. It will last longer than most paints, which is why we use it ourselves. Just don't forget the primer first!

There is another option!

After everything we've just covered about needing a primer, there are 2 paint which have recently come along which don't need a primer when going over oil-based paint.

The first is Benjamin Moore Scuff-X. This is a great paint. You could say the market leader, however there is one big drawback. The price. It's around £95 for 4L which is around double the price of most other paints. For this we just can't recommend this paint.

There is luckily one other lesser known paint which is an option. WRX Satinwood. This is only available online and is very new to the market. As long as you lightly key the surface, you can use this over oil based paint. It's easy to apply and is ideal for the DIY decorator. It is a little thing which means you sometimes need a third coat if going over a poor surface. It's also not as durable as the Aqua Guard paint we mentioned, however if you'd like a good quality paint which doesn't require a primer, then this is the paint for you. 1L is all you will need for 3 or 4 rooms so it really won't break the bank. Happy Decorating!