How to prepare and paint cypress pine picket fence?

OliveM

Hi, I've just had a new cypress pine picket front fence installed. The installer told us to wait at least 6 weeks before painting to allow it to season. In terms of preparation/painting, I'm looking for some guidance. The plan is to do a light sand, particularly where the nail/screw holes are, then to prep/fill the nail holes, and the prime and paint the fence with Dulux Weathershield.

Some things I'm not sure on: with the sanding, what grit is recommended? Do you need to prime the nail holes, then fill it, then prime again? What filler is recommended? Should the primer be oil based or water based? I did see a suggestion somewhere that oil based is better, and can still paint Weathershield over it.

The plan is to paint with a roller and brush for the gap (only 20mm).

There is also a steel frame on the back of the gate. I understand that will need to be painted with metal specific paint.

Any tips/suggestions greatly appreciated!

JacobZ

Hi @OliveM,

Your installer's advice to wait around 6 weeks before painting is sound, as it will give the cypress pine time to season and allows excess moisture to leave the timber. Your proposed process is generally the way I'd tackle it.

For sanding, a light sand with 120-grit sandpaper should be sufficient. The aim isn't to remove material, but rather to smooth any rough areas, remove handling marks and provide a good surface for the primer to bond to.

For the nail and screw holes, I'd recommend using an exterior-grade timber filler such as this https://www.bunnings.com.au/polyfilla-450g-exterior-timber-filler_p1210571 . Once the filler has dried, sand it flush with the surrounding timber. There's generally no need to spot-prime the holes before filling. Instead, fill first, sand smooth, then apply your primer over the entire fence, including the filled areas.

For primer, I'd also lean towards an oil-based primer such as https://www.bunnings.com.au/dulux-4l-white-prepcoat-1step-oil-based-primer-sealer-and-undercoat-4l_p1371224 . Cypress pine will often contain natural resins that may bleed through paint, and an oil-based primer typically does a better job of sealing it inside the timber. Once the primer has cured, Dulux Weathershield can be applied over the top without issue.

Your plan to use a roller and brush is also a good one. A roller will cover the broad faces quickly, while a brush will allow you to work paint into the edges, gaps and joins. Just be sure to coat all exposed faces, edges and end grain where possible, as these areas are often where moisture enters the timber. I'd recommend a 10–12mm nap microfibre roller and a https://www.bunnings.com.au/uni-pro-50mm-you-can-do-it-angled-sash-cutter-brush_p0019773 for the gaps.

For the steel frame on the gate, start by cleaning the steel with a degreaser as the manufacturing process will often leave an oily residue on the steel which can affect adhesion. Once clean, apply a suitable metal primer such as https://www.bunnings.com.au/dulux-500ml-metalshield-all-surface-primer-grey_p1400535 followed by a metal top coat such as https://www.bunnings.com.au/dulux-1l-metalshield-epoxy-enamel-gloss-paint-black_p1400488 .

You might like to check out https://www.bunnings.com.au/diy-advice/diy-skills/painting/how-to-add-some-colour-to-your-timber-picket-fence and https://www.bunnings.com.au/diy-advice/diy-skills/painting/how-to-paint-metal for some further guidance.

Let me know if you have any further questions.

Jacob