It's hard to keep the natural colour of wood outdoors. A polyurethane varnish would retain the colour best, but varnishes tend to crack and peel under long term weather exposure. A finish that soaks into the wood such as decking oil, rather than one that forms a film on the surface, would be easier to maintain but is likely to darken the wood. We suggest you try decking oil on an offcut, or perhaps on the underside of the table, to test the effect. More detailed information is contained in our Technical Design Guide no. 13 titled Finishing Timber Externally. A copy can be downloaded free of charge from our website here: https://www.woodsolutions.com.au/publications.Outdoor finishes
Answered on 15-01-2021
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