"Iain Hibbert" wrote in message
news
On Thu, 12 Jan 2006 15:45:50 +0000, Tony Brooks wrote:
Just a word of caution and something to be checked if using rotary
brushes.

Blakes state that such brushes polish the metal and can cause adhesion
problems for blacking. I know we are probably talking antifouling here
but to be sure I think I would follow the brush up with a grinding disk
to give the keel surface a key. This should be fairly fast and remove
the worst of any surface corrosion that took place after rotary
brushing.

a grinding disk will do exactly the same thing!

its the raw speed at which the disk/brush passes over the metal that
causes the polishing. A grinding disk may leave a scored surface, but
inside the grooves the metal will still be polished (even more so)

You really need to use an etch primer to get a good bond after attacking
metal with a grinder, this eats into the metal a little bit and anchors
itself to any voids.

regards,

--

http://maps.google.com/maps?q=irelan...244,0.0822&t=k

Cutting tools do not polish unless they are dull and rub. Wire brushes can
be kept sharp