How to oil a deck with black stains?

Samnet

Hi,

I am new to applying paint/oil on decking. Not sure if I need to sand beforehand. There are black stains on my decking (photos attached). I bought Acquadeck from Bunnings which says no sand required but not sure if it works on stains. Really need help to know what exactly I need to do step by step. It's my project in Xmas

thanks

JacobZ

Hi @Samnet,

Looking at the timber, I don't think it is necessarily at the point where it needs to be sanded back.

I would suggest you pick up some Cabot's Deck Clean, which contains oxalic acid, which is an effective timber stain remover. Mix it to a 1:4 ratio, following the instructions on the packaging, then scrub your deck with it using an Oates Long Handle Deck Scrub Brush. After scrubbing, allow the solution to sit on the deck for 10-20 minutes before cleaning it off with a pressure cleaner or garden hose with high water pressure.

After cleaning, reassess the deck. If the dark stains have been removed and things are more uniform, you should be fine to coat your deck with the Aquadeck. If the stains have not been removed, then you may need to sand it back.

Based on what I see, I'd be surprised if a good cleaning didn't remove them, but it is hard to say. I'd give this a try and let us know how you go. We can certainly assist further if required.

Jacob

Samnet

Hi @JacobZ

I used Cabot's deck clean and brushed it but still dark stains.

What sort of sand should I use?

Thanks

Sam

EricL

Hello @Samnet

I'm afraid standard cleaning will no longer work in this situation. It will be necessary to sand the deck surface thoroughly. I suggest starting with 60grit followed by 180girt and finally finished off with 240grit sandpaper. I recommend hiring the rotary floor sander to make the sanding of the decking frame much easier.

Here are some handy step-by-step guides:

If you need further assistance, please let me know.

Eric