On Tuesday, 20 October 2015 12:02:49 UTC+1, rick wrote:
Any chemists here ?

Need to re-stain my fence panels ... these are 4x1 pails staggered either
side of 4x2 horizontals, in 6' x 5' panels .. set into concrete H posts,
atop of concrete gravel boards (painted to match stain colour)
Around 300' of it to do.

Some of the panels in shady areas have the dreaded green algae finish.
Intending to wash down with pressure washer ( fan setting not to raise
grain) ........... many US videos advise pre-treat with a cleaning solution.
3:1:1 water:bleach:TSP

When I cleaned my patio ... I used a cleaning solution of
Sodium Hypochlorite (14%)
Lauryl Dimethylamine Oxide
at 3:1 hypo mix with water and around 2% of amine as a surfactant.


As I have plenty of these left, anybody know if this would be suitable
for washing down the panels ? .... or do I need to get some TSP.

It makes little difference what you use,
There will be algae back in a few months anyway.