Thread: light machine oil for timber decks?

The reason is plain mineral oil will provide very little protection to the timber, and it will not last very long at all.

The oil will eventually either wash off ( it don't go in far), evaporate or simply be absorbed by the bulk of the timber and thus be no protection on the surface.

To provide any significant water repellant properties,you will have to drench the timber in oil...this has the effect of making the timber very good to burn...and you will use heaps of oil

Oil does not exclude water, not on metal, not on timber, oil and water can coexist in most materials quite happily.

These fungusides...they are there for very good reasons.......fungas is what rots timber.

As for the colour of the decking products, a major issue is UV stability....in general.....the clearer the finish, the less resistant to UV it is.

We live in a time where many people have a fantasy about natural looking clear finished timber in the outdoors.......its a fantasy.

Clear finished timber outdoors is hard work, it may look great for a short time, but ya cant change the laws of nature.

OH...BTW have you ever tried to walk on wet, oily timber...slippery as.

sorry

cheers

ok, thanks soundman - feedback is what i was looking for

your point about slipperiness taken - seeing that mineral oil is non-hardening

i see that one product contains oil, resin and wax - so as you say, just oil is not enough ...

a clear finish is not what i'm after - my decks have long greyed off - just protection from the timber becoming too deeply wet ...

Sound man is right about wood absorbing heaps of mineral oil. Years go I oiled the low Jarrah sleeper retaining walls of a BBQ pit/pergola area - I must have put on 10 coats which turned out to be a big mistake since one of the ideas was once the oil on teh surface had dried out one would be able to sit on the edge of the pit.
What happened was the oil attracted dirt and eventually the surface turned black and sort of friable and would easily mark clothing for years afterwards. Every summer some oil would wick back out and continue the process. In the end we gave up and ripped it all out. What was interesting was how rotted the back of the sleepers were indicating that the oil had not provided much protection after all.

when I say a clear finish I mean anything that is not opaque.

If you paint something white and do it well you will get 10 to 20 years out of it outdoors, use even the best clear finish outdoors and you will get 2 to 5 out of it tops befor its starts to look ratty.

The fact is clear finishes let light and UV into the film and onto the timber.

good paints degrade on the surface, even the best clear finishes degrade thru the whole depth of the film.

cheers

thanks, bob very interesting - a great experience (tho not for you at the time) for us to learn from ...

If you paint something white and do it well you will get 10 to 20 years out of it outdoors, use even the best clear finish outdoors and you will get 2 to 5 out of it tops befor its starts to look ratty.

mm good point especially here in NZ where the UV is supposed to be xtra bad

so in the end it becomes something of a compromise - some pigment in the product (against UV) and some nasticide (against organic beasties)

find the least disturbing colour (they do fade of course) and accept that you will probably absorb yet some more toxins through the skin

at this point i am willing to compromise because i am still getting over having to rebuild a deck which had no treatment ...

the decking was japanese cedar which is OK for cladding but not ok for decking, especially on the south side ...

I would not get too twisted about the toxins.

most of the anti mold agent will either be bound into the finish or the finish/timber margin, the remainder will be washed off by the weather.

besides many of the antifungals are pretty basic chemicals unlike pesticides and herbacides.

cheers

you're probably right

in any case i live in a fruit growing area where general spraying is widespread - i will be getting far more toxic input from that through the air, than from my deck!