Roble Garden furniture using Surfix Outdoor OS?

[bobbyp]

I've got a garden table and chairs that urgently need a bit of attention, the wood has greyed and there is slight black fungal growth in some of the grain.

First of all, would the Surfix oil be suitable for use on roble wood? I've found some information that says not to use teak oil on roble due to the high sap content of the wood and that I should use aftercare wax. Any wood finishing experts on here that could help me out? I can find very little information on the oil other than that its suitable for outdoor use on all woods.

Also, I'm assuming the whole thing should be sanded down first to get rid of the black fungus. Any nicer ways to do it? Or is this my excuse to get an RO90?

 

[leakyroof]

Since I don't live where you do, or understand exactly what wood you're working with, let me confine my remarks to what I've found in my neck of the woods.  I also don't know what oil is in the Surfix system. [huh]
 Bleach mixed with water may remove most, if not all,of the black marks if they're not too deep into the wood.  Anything else left afterwards may require sanding if it bothers you.  Oxalic Acid is another wood bleach that is often used.
For an oiled outdoor product, on multiple types of wood from Mahogany to Cedar and Purpleheart, I've have very good luck with Polymerized Tung Oil. This will dry much faster than regular tung oil, and while no oil does much to stop UV/Sun damage to the Cellulose Fibers in the wood, it will repel water and general crud fairly well once you've built-up a few coats.  Sand with a fine 3M type Scotchbrite Pad/ Festool equivalent in between coats, not steel wool so that you don't leave tiny pieces of steel/iron down in the wood that might rust and mar your work.   Just expect to not stop the graying of the wood that much from the Sun since there are no UV inhibitors in the oil like a High UV rated Varnish would, or a pigment stain also.
 It does seem to make the wood look nicer than when you started, and water sheds well too, but trying to beat the Sun is hard to do.  [Just ask people who work on Boats.. [embarassed]]
Lee Valley sells the Tung Oil, I think it's actually from someone here in the States and is rebadged for them.
Not sure what's available for you locally.  Be VERY wary of Linseed Oil or other "oils" sold as Teak or Tung Oil.
The Linseed oil will easily turn black or mildew on an outdoor project, and since it's often included in an oil mixture since it's cheaper than other oils, you end up using it without knowing.
 Hope this helps you out.  [wink]