Best exterior wood stain

longwalks1

Any recommendations for a dark brown wood stain (not paint)?  Something like the old creosote, minus the smell or toxicity as it’ll be staining a walkway over a pond.

I’ve looked at the Ronseal one coat fence life and fence life plus.  I know one is a paint, the other a thinner, more watery stain - does anyone know which is which?

any other brands/stains to consider? 

Petriix

Sadolin Classic is probably 'best' but not cheap. 

ThisIsWeird

Hi LW.
As I understand it, there are two essential approaches to this. One is 'stain' in the true sense of the word, and the other is a 'coating'. But note that many outdoor timber products currently described as a 'stain' or 'woodstain' are actually coatings.
The differences between my interpretation of the meanings are, 'stains' are (should be...) thin and watery and soak into the timber, giving the grain an enhanced colour contrast, and ideally - for protective reasons - should also contain a timber preservative to prevent the timber from rotting. Some will also have water repellents, so it also provides timber 'protection'. Your mention of 'Creosote' is the classic example of what I mean as a 'stain'; it literally stains the timber, and also preserves it and has water repellent qualities. It's probably still the best overall timber preservative, but is only available to licensed companies as it's so harmful to wildlife, inc humans. The current 'creosote substitute' Creocote is a very poor cousin as it doesn't 'preserve' the timber, only stain and add water repellent. It doesn't kill you as much, tho'.
'Coatings' like paint, on the other hand, do not 'stain' the wood, but add a colour on top - 'coat'. They do not contain preservatives. They simply make the timber look 'good' - different - and attempt to keep water out of it so it lasts.
You can combine paint with preservative, applying the latter first.
Then there are the products which are often referred to as 'woodstains', and these are like coloured varnish. Ie, they are translucent, so still allow (part of) the grain to show through, but are still 'coatings', so 'protect' the wood but do not 'preserve' it.
Then there are 'oils', clear or coloured, such as what you'd apply to decking boards. Again, oils won't 'preserve' the timber, preventing it from rotting, but are designed to prevent water from soaking in in the first place.

Your two suggestions - fence life and plus - are simply 'coatings', and opaque ones at that. Ie, they will obliterate the timber grain. They appear to enhance the grain on rough wood fences, but that's only because the physical timber grain shows through as a texture - the actual colour will be even, just as with a paint. And the fact that you can still see and feel the grain shows that the coating is very thin when it dries. In addition, all it does is try and keep water out from the timber; it does not 'preserve' the wood. Having said that, it's good stuff for its intended purpose, which is making rough timber look nice, and helping to make it last, whilst being a generally very easy stuff to apply and reapply.
But, it ain't no good on smooth timber - it just won't work stick, and will look pants.
So, I suggest you work out what finish you want on your bridge. What shade of wood, and whether you want the timber to look "natural' with its obvious grain showing through, or do you want it 'coated' and coloured.
The other essential difference between the two types of coating is that soak-in products are easy to apply - can be slapped on - and will tend to get into gaps and joints to help seal and waterproof them. When they 'weather' and bleach and look pale, just wash off any mould or algae and slap on some more. That's why oils are popular for deckings. 'Coatings' such as paints, on the other hand, will often peel and blister, so will need a lot of prep before being recoated.
So, phew, what's best for your bridge? No idea. But I guess anything with a preservative is out since it could be harmful. Bear in mind that even after the coating dries, some chemicals could still be leached out by rain. Coatings - exterior paints and 'Garden Shades' type products - are out if you wish to still see the grain, but if that ain't an issue, then perhaps consider Bedec Barn paint or Zinsser AllCoat with are water-based, easy to apply, and have long life expectancies. Or 'Garden Shades' type coatings if they are designed for smooth planed timber. Make sure the timber is clean and bone dry first, tho'.
Or, perhaps protective oils might be your best bet, such as decking oil or linseed - these comes in lots of colours, soak in and enhance the grain, protect the timber by waterproofing it, get into the joints, and are very easy to apply - no brush marks, just slap on! But you'd need to check they don't have additives harmful to pond life. Then there are Exterior 'Woodstains' such as made by Dulux. These are like coloured varnish, oil-based, allows the grain to show through (tho' the darker the colour and the more coats, the more it's hidden), and are durable. The same ultimate issue as 'paint' and other coatings, tho' - they will almost certainly ultimately blister in areas such as joints. 

What timber is your bridge made from? Will this finish also need to go on the deck part that's walked on? Any chance the bridge can be lifted away to do this work? 

Albermarle

This is definitely new wood with no coatings on it already? as that can make a difference.