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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Painting, Decorating & Tiling Questions >> black stains on windows https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1194789921 Message started by gulpy10 on Nov 11^th, 2007, 2:05pm

Title: black stains on windows
Post by gulpy10 on Nov 11^th, 2007, 2:05pm

On some recently installed windows black stains are appearing on the woodwork. The windows are idigbo and coated with sikkens cetol hls, which contains a fungcide.

images avialable at: http://privatewww.essex.ac.uk/~colbi/windows.htm

How can the staining be prevented

Title: Re: black stains on windows
Post by CWatters on Nov 12^th, 2007, 12:00am

Was it allowed to get damp before painting?

Google suggests this is a characteristic of idigbo...

http://www.woodconservatory.co.uk/whyoak.htm
"...most idigbo conservatories are painted due to the wood staining that can occur".

http://www.eoburton.com/Timbers/Idigbo.htm

"The wood contains a dye which may stain other materials when wet; it also contains tannin which causes staining when in contact with iron under moist conditions."

You anywhere near a dusty iron works?

Title: Re: black stains on windows
Post by CWatters on Nov 12^th, 2007, 12:08am

Google also found that some sikkens (eg Cetol marine) contains iron oxide. Perhaps worth calling Sikkens to see whay they say.