How long to wait between paint coats?

[ivk]

Given:

If we are talking about quality (vs fast) type work at home.

Wall, ceiling, doors and door frames (with enamel).

Questions:

How long would you suggest waiting between putting Primer/Undercoat to painting?

The same question if two layers of primer are applied?

Does it make sense to put two layers of undercoat - new gyprock wall vs already painted?

What about decorative paint itself - two layers I assume?

I have read that a layer of decorative paint can be applied 24 hours after priming.

Thank you

[JacobZ]

Hi @ivk,

Thank you for your question about paint products and their drying periods.

Each specific product will have a datasheet that defines the manufacturer's advised recoat time. For example, Dulux 1Step Prep Primer, Sealer & Undercoat's datasheet, which can be found here, recommends a minimum of 2 hours before recoating. If you use two coats of this product, it is best to allow a minimum of two hours between the coats and then a minimum of two hours before painting. You can certainly let it dry for longer, but this is the minimum amount of time their testing has proven is adequate with their product. 

For new gyprock, two layers of undercoat can help seal the surface and ensure even coverage and is certainly worthwhile. For already painted walls, a second coat of undercoat might only be necessary for significant colour changes, stains, or imperfections. Always check the surface after the first coat of undercoat to decide if a second layer is needed.

The number of coats of paint can vary depending on colour and product used. Once again, the datasheet of the specific product will give information about how many coats should be applied, but generally you'd apply a minimum of two and then assess the coverage before adding a third if necessary.

If you can't find information from the manufacturer that is specific to their product, allowing at least 8 hours and up to a day between coats is a good idea.

Let me know if you have any further questions.

Jacob

[ivk]

Thank you, Jacob!

Re: "If you can't find information from the manufacturer that is specific to their product, allowing at least 8 hours and up to a day between coats is a good idea."

From your practical experience - two coats of undercoat and two coats of paint if done once per day will give a total time of 4 days. I know the masking tape promises 30 days bt in most videos it is recommended to remove it while the paint is still not dry. Can this 4-day painting job cause the masking tape to rear the paint when removed and should I target 4 layers in 2-hour increments in one day if making those lines perfect is important?

If lines are not that important - 4 days is fine, if important paint it all in one day. Right?

[JacobZ]

Hi @ivk,

It really is a case of weighing up what you value more, clean lines, or the warranty of the product and the timeframe you can expect the product to last. 

Following the manufacturer's recommended recoat times, that are based on their testing and analysis, will ensure it is installed in line with their warranty and will meet the life expectancy for their product.

Going outside of the recommended recoat times, you run the risk of the products failing prematurely. It's unlikely that they will fall off the wall in a week, but the life expectancy would certainly be reduced.

Ultimately, the choice is yours, but making an educated decision is important and checking the products datasheet is the best way to educate yourself on the recommendations for that specific product. I'd be happy to assist with this if you can advise what products you plan to use.

You can always remove and then reapply the tape between coats if you are looking for a happy medium.

Let me know what you think.

Jacob