How to seal Merbau decking timber?

[saxon12]

I have used a bunch of Merbau timber for the deck railings as pickets, the Merbau was pre-oiled however when we get rain, stain drips down the side of the house/deck floor.. what should i be sealing the timber in?

[Dave-1]

Good morning @saxon12 

Ahhh fun isnt it, When I was looking at merbau before I bought some I do remember it warned me that there may be some oil runoff after rain. I noticed my bacony posts that I used merbau on did leach colour for a while but that stoopped after about a month. I did not seal them or oil them. I was going to scrub the area with warm soapy water to remove the staining but the rain washed most of it away

I did 2 oil coats of my timber privacy screen after about 4 weeks after install and didnt see any of the drips afterwards in the rain.

How long has the colour been dripping after rain?

Id also like to add a warm welcome to the Bunnings workshop community page Its a great place to hang out and troll through all the projects and questions. 

Dave

[EricL]

Hello @saxon12 

Allow me to welcome you as well to the Bunnings Workshop community. It's marvellous to have you join us and thanks for sharing your question about Merbau decking timber.

Unfortunately, the oil and tannins leaking out of the Merbau decking panel is a natural consequence of the product. The Merbau panel must be given time to season, and it could take anywhere from 8 to 12 weeks. One way to accelerate the process is to wash it with Feast Watson 1L Woodclean. It is a powerful, oxalic acid-based preparation treatment that aids the removal of oils, mould, stains and tannins from new and weathered timber. Ideal for rejuvenating grey, weathered timber, Woodclean is suitable for restoring decking, outdoor furniture, fences, pergolas and other exterior woodwork.

But even after washing the surface there may be some residual tannins and oils left on the decking panels surface, make sure to give it time to dry off. Once the oil and tannins have stopped leaking out of the Merbau panel, that is the time that you can oil or seal the Merbau panels. 

I suggest going to the paint department of your local store and having a look at the stain and sealing sample board. There you'll see what the different types of oil and sealers are. For example, if you are after something that will not radically change the finish of your merbau panel, I suggest looking at Cabot's 4L Aquadeck Natural Exterior Decking Oil.

Here are some handy step-by-step guides:

• How To Clean A Deck (the techniques used are applicable to your project)
      
• How To Oil Your Deck

If you have any other questions we can help with, please let us know.

Eric