Green marks in pine

[sueonmull]

We have just had a pine staircase fitted. The wood was given one coat of waterbased acrylic varnish prior to delivery.
There is some green staining under the varnish on one part of the staircase which we understand from asking around could be mould. We have managed to reduce the intensity of some of the worst marks by light sanding but the wood is still left with a grubby appearance and further sanding will reduce the profile of the wood.
We are chasing the supplier for help but so far with little success.
Does anyone have any experience of bleaching wood, or any other suggestions which might help.
Thanks

 

[ratman123]

Try wood cleaners like net-rol or oxalic acid itself.

 

[sueonmull]

Thanks, I'll get hold of some and let you know how I get on
Sue

 

[sueonmull]

Have spoken to Owatrol who manufacture net-trol. They say that Net-trol is only suitable for outdoor use as it needs to be washed down after treatment, also it is unlikely to remove mould stains.
They have suggested that I try a solution of 50:50 bleach in water so I'm going to do a spot test with that.