You try some oxalic acid (decking cleaner) from the popular auction site. Give the wood a good wipe over with meths first then apply the mixture to the dark bits. Rinse with plenty of water afterwards.
You try some oxalic acid (decking cleaner) from the popular auction site. Give the wood a good wipe over with meths first then apply the mixture to the dark bits. Rinse with plenty of water afterwards.
Rust never sleeps !