Aussie Clear on Merbau decking

decking oil | timber finishes

One of the most common mistakes when people apply Aussie Clear as a decking oil onto new Merbau timber, is that people don’t properly read the application instructions. The instructions read: “allow new Merbau timber to weather for 6 to 8 weeks prior to applying Aussie Clear” and “… any excess oil remaining on the surface after 2 hours should be wiped off.”

Aussie Clear on Merbau Decking

Over oiled Merbau deck. Note the sheen which should not occur if Aussie Clear is correctly applied.

The reason for this is two fold:

1. Merbau is a very resinous timber.

If the timber is new then when you apply any decking oil product, those resins will mean you won’t get as much of the oil into the timber. It is preferable to allow it to weather for 6-8 weeks, or wash it regularly with fresh water if under cover for about the same period. It’s the water that bleeds the resins out of the timber. In other words, timber finishes work best when you allow the timber to weather. When you do this, your first application of Aussie Clear will be a proper “dose” and should last between 9-12 months (depending on exposure).

However, there is one exception to this where Preschem would recommend oiling the timber straight away, and that’s if the deck has been completed in the middle of a heat wave. In this instance, put one very light coating of Aussie Clear down immediately, as this will prevent the timber rapidly drying which can cause dimensional instability resulting in cupping, splitting and checking. However, this light application will not last all that long for the reasons explained above, so you will need to reapply sooner than what would normally be expected.

Over oiled Merbau Deck

Over oiled Merbau decking. Note the film is wearing off quickly.


2. Aussie Clear that hasn’t soaked in after 2 hours will form a semi-gloss film.

When applied correctly to a timber deck using a lambswool applicator, Aussie Clear decking oil will not form a film. If there is an excess on the timber, then that oil forms a film on the timber if it’s not removed with a clean dry rag. This film actually looks quite pleasing, so the common mistake is to keep re-applying the oil until its a “nice” looking finish. This film can occur with any timber, but is more likely to occur with new Merbau due to it’s high resin content.

The problem with this is that the film is not durable. It’s very easy to scratch and scuff the surface, which is a common complaint when this occurs. This is especially true on a hot day, as the coating softens significantly with heat.

Aussie Clear is designed to be a true penetrative matte wood finish. It will protect and enhance the timber through it’s proven formulation by:

  • protect against UV weathering
  • improve dimensional stability by controlling moisture content
  • prevent unsightly sapstain/bluestain moulds
  • enhance the natural beauty of timber season after season with regular maintenance