Thread: Marbau decking

Originally Posted by Vern

That almost looks like it has had some sort of varnish on them

That's right, that is what water based decking oil is. A "coating" that encapsulates the timber rather than soaking into it Its probably way better than oil, but don't ever let it deteriate like this, or it must be sanded off.

Originally Posted by DoubleChevron

That's right, that is what water based decking oil is. A "coating" that encapsulates the timber rather than soaking into it Its probably way better than oil, but don't ever let it deteriate like this, or it must be sanded off.

Hmmmm all my decks are water based and not like that.
My last house which had a lot of big cypress posts and rough sawn silvertop ash was water based oil aswell and still nothing like yours.

This is our decks Back around 20 years old ,recoated with water base about April this year DSCN4682.jpg & front deck was coated with same water base stain same time , this deck is only about a year old ,DSCN4683.jpg It needs a wash I've been working in front garden pulling dead tree stumps so lots of dirty foot prints.

Originally Posted by 1950landy

This is our decks Back around 20 years old ,recoated with water base about April this year DSCN4682.jpg & front deck was coated with same water base stain same time , this deck is only about a year old ,DSCN4683.jpg It needs a wash I've been working in front garden pulling dead tree stumps so lots of dirty foot prints.

That's pretty amazing if that deck has been in the full weather for 20years! The one that has been undercover here isn't anywhere that nice. probably due to me using oils with stains in them at different times. I'm guessing raw oil with no colour is best

I have no idea what the 'coating' is on the deck here. I'm just assuming water based, as its a "coating". There is no way anyone would have varnished it ... Unless you can buy "pre-varnished" decking boards

The back deck has had a shade sail over it for a least 15 years may be longer but dose get full sun for most of the morning . Things I like about the water based stain you can recoat in a couple of hours where with oil based you need to wait 24hrs or longer before recoat , so I can wash the deck & get 3 coats on in a day . The deck can be wet when painting & as long as it has a couple hours to dry if it rains it won't hurt the finish. & clean up is much easer just washing with water rather than turps.

Originally Posted by DoubleChevron

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Attachment 174745

Hi Shane,

The black marks in this pic are caused by the fasteners (containing iron) corroding.

I'm actually replacing a merbau deck (5.4 x 6m) for someone in the next few weeks coz the builder 20 / 30 years ago used gun nails, maybe galvanised, in a coastal environment and they've corroded and the wood is rotting around the nails.

Rusting metal containing iron promotes the growth of the organics that cause rot, even in merbau. The new deck will be screwed down with stainless.

cheers, DL

Originally Posted by 350RRC

Hi Shane,

The black marks in this pic are caused by the fasteners (containing iron) corroding.

I'm actually replacing a merbau deck (5.4 x 6m) for someone in the next few weeks coz the builder 20 / 30 years ago used gun nails, maybe galvanised, in a coastal environment and they've corroded and the wood is rotting around the nails.

Rusting metal containing iron promotes the growth of the organics that cause rot, even in merbau. The new deck will be screwed down with stainless.

cheers, DL

In those piccies, it isn't corrosion. The wood is just still wet as the screws are countersunk ... so there is still water pooling there . I'll take the same photo tomorrow if I get out there before it rains again . they will be galavised decking screws. the boards are the same dark colour anywhere they are wet if you look around the edges of the puddle of water there.

seeya
shane L.

Hi Shane,
In Post #19, the third picture, looks very much like the weathered deck I have which was originally treated with Intergrain DWD. A water-based acrylic. I unknowingly got VERY bad advice re. its suitability to an exterior deck---it's NOT. It's weathered and sanding takes forever to remove it. There's an Intergrain product, a sort of paint stripper which is very expensive also...in terms of $$ per sq. metre it was almost worth ripping up the boards and replacing them! The DWD is an acrylic coating which hardens, water gets trapped under it and the hardwood (Merbau) rots as a result. I've had experience of this. I have a firm coming next week. They have a special machine which doesn't sand the surface as such but essentially grinds the surface coating without removing timber, nor disturbing the stainless steel screw heads. Cheaper than replacing timber, and /or using Intergrain "Liquid8".
After they've cleaned up the deck, I'll probably oil it with a decking oil product containing a pigment tint which helps reduce the UV deterioration...I'm uncertain about water-based 'oil' formulations. I'll know more next week...