The Black Spot

[MarAzul]

Any thoughts on how to rid your teak of the black spot. You know that deep ingrained marking that blights your teak when the varnish has gone past its' best. I have been told that bleach will do it but I'm reluctant to have diluted bleach flow over the gel coat for fear of damage. I tried a light sand then varnished over it but it soon reappeared when the varnish hardened.

 

[VicS]

Not sure I'd want to treat my woodwork with a domestic hypochlorite based bleach if that's what you mean. Would not worry about it on the grp though, at least not briefly.

Are you sure its not oxalic acid that you should be using.

 

[boatmike]

Are you sure its not oxalic acid that you should be using.

Er yes! In fact although we use it to clean GRP it's traditional use in woodworking is for just this purpose and it wont hurt your GRP. (although if you get it on one bit you will probably need to do the rest as it will be clean)