Exterior wood - stain or varnish, but not both?

[Glastoun]

I'm refurbishing a cast iron bench with some new wood slats, and someone told me I should use either stain or varnish, but not both. Any reason why? Surely the stain would be for colour while the varnish would be for protection, or does it not work like that?

The wood is mahogany so once I see it I may not want to stain it in any case, depends how naturally dark it is.

 

[Gerrydelasel]

You're correct. I'm guessing they meant preservative, not stain.

 

[JohnD]

"Stain" is commonly used to mean a tinted, somewhat flexible, often porous, low-gloss finish. It is preferable to varnish outdoors because it is not so prone to crack and craze with the natural expansion and contraction of the wood, and is easier to sand and recoat.

Are you thinking of wood dye such as Colron? This is a colour not a protective coating, and can be very good for bringing out the natural beauty, and blending together pieces of wood that may look dissimilar. The spirit based dyes are much better than the water ones, and can be used over Cuprinol and other preservers, and after drying can be treated with stain, oil or varnish.

IMO you get a better and more even appearance by tinting the wood with dye and protecting it with a clear finish, than by trying to achieve both with a coloured stain.

 

[Glastoun]

Just checked the cupboard and we have access to Rustins yacht oil, and Ronseal Hardwood Garden Furniture stain, which does look like it has protective properties so probably doesn't need the varnish on top. The wood guy recommended just teak oil, to let the wood breathe and be less prone to cracking and flaking than with a varnish.

What would you do? Am happy to buy another product if necessary, it'll only be a small tin.

 

[darkan9el]

I refurbished a cast iron garden seat and used Osmo

 

[Brigade77]

Where do I claim my £10 for mentioning 'OSMO' on social media ?