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Osmo UV Protection oil - chair restoration

I mentioned grit type in another post and referred to some bench restoration. I have just restored three garden chairs, so I decided to share it. Work is going to dry up again with these new restrictions so I can see myself performing a lot of work at home.

The chairs were from Next and about sixteen years old. One had suffered from weather exposure, and two painted with a strange substance. I am not sure what it was, but it felt like creosote!

The unpainted one was sanded first with an 80 grit to break the surface. I finished with a 120 and wiped it off with a wet multifibre cloth to remove dust and particles. I let it dry naturally while it moved onto the painted chairs. I used 80 grit followed by 120, but I then had to use a 180. The grain lifted when I applied my Osmo oil, and the finish resembled sandpaper! I would not usually use 180, but the wood is of low quality, and thankfully, this worked. I used Abranet Ace on my trusty Festool RTS400 sander connected to their dust extraction unit.

The chosen OSMO oil is a cedar colour; my wife loves it. It is expensive for some, but the result is worth it. I use a quality brush, one I reserve for this type of oil. Afterwards, you must clean the brushes thoroughly using white spirit or similar. I have tried using cheap throwaway brushes, but they do not give the desired finish. I also found myself picking bristles off the surface. The oil is best painted with the grain where possible. It is not a forgiving substance, and when you do have to apply it across the grain, you must take your time. Okay, so this is garden furniture, but I am a perfectionist and cannot slap it on like some of the family suggested! I find two coats provide a decent finish and it will last for years.

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Osmo do some good products for sure. Thats a transformation. :+1:


That looks great. I keep looking at my teak 6’ bench and chair and thinking that I’ll have another go at them. Over the years I’ve done these with tung oil and whilst it looks brilliant to start with it eventually gets black marks in it which is annoying. For the homemade iroko table I sanded off the tung oil and degreased it before applying this which is said to prevent the black spots from forming. It does seem to do what is says on the plastic bottle but I’m not sure that it is as protective as the tung oil. The search goes on. Have you tried the Tonkinois varnish?

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Thanks, guys, I appreciate the kind words.

I have also completed a bench made from a similar wood to the chairs. I haven’t tried the varnish you mention, I have used the Osmo for years, and it has never let me down. What kind of black spots are you getting @Tykebike? You can get the Osmo oil in teak and a clear version.

For keeping teak in shape on a boat deck, the marine product of choice is washing down with a soft mop and salt water. The sun bleaches it that telltale grey and the mop is non abrasive so it doesn’t wear down the thickness / integrity of the decking that happens with repeated sanding and oiling which boat owners are prone to do. Garden furniture isn’t so mission critical though, unless there is flooding. The products mentioned in this thread so far seem very suitable options.

This thread covers a bunch of high grade marine varnishes. After looking around a few boats and spec sheets,I flipped a coin between Epiphanes and Tonkinoise.

Although this is not the tung oil finish, the black marks, which I presume is mould, looks the same.

From @fxdecor

Hi john, these are water marks in the grain, check out my case study ‘Oak door renovation’ on my website, it has all the info you’ll

@andycrichton has beaten me to it. The moisture stayed in the surface when you prepared it, and the coating gave it nowhere to go. The water slowly releases and causes black marks. I had it on an old church bench, and the spot had to be slap bang in the centre for all to see! The dark grain could also have a moisture content which causes later issues. If possible, I try to achieve a clean surface, including the grain. It is not always achievable, but you soon get to know what is acceptable with the grain.

Thanks guys, it will be easy to take the table in the photograph indoors and follow your recommendations. As for the bench and chair I may have to wait until next year when the weather is more conducive unless of course a miracle happens and we get a week of dry mild weather with no overnight dew.

Hi you can remove watermarks, some people swear by mayonase,others bar keepers friend,or oxalic acid.