After several attempts, got the mast step out. Three of the four bolts responded to a 6-point 9/16" socket and breaker bar. Last bolt was too far gone so had to Dremel off the remainder of the head. After the step was out was able to vice-grip onto the stub of the bolt and twist it out.
Step is steel with a fair layer of rust but not enough to compromise strength. Have decided to de-rust it myself with white vinegar. Have got 30% vinegar on order so we'll see how that works. After de-rusting, will multi-coat with cold galvanize paint. After reinstalling the step will give it a coating of Fluid Film. In another post I was talking about having the step hot galvanized but the 300 dollar charge put me off that plan.
I would HIGHLY recommend that you glass in some plywood to lift the step out of the bilge water. A small chunk of 3/4 Marine grade coated with epoxy and a layer of glass would do it. I stacked 3 ea 3/4 and cut 2.5 inches from the bottom of the mast. Never had any issues after that.
Recommended cleaning/treating:
Bead blast or sand blast the rust (I used a pin needler)
Treat with Ospho to set the metal neutral
Good ferric primer
Overcoat paint
LPS3 or equivalent on mast install.
Good for another 40 years.
Thanks Journey! Will proceed in that direction.
One my complaints about the mast step situation is that sea water dribbles past, over & around the step. Source is the chain locker draining water & mud all the way through the bilge to the deep bilge. To me, unless you have a hull leak somewhere, the bilge should be DRY. My plan to achieve that is to build a watertight platform above the waterline in the chain locker and install small clamshell drains through the hull port & starboard at the after end of the platform. Any water & mud brought aboard by the chain would drain directly overboard. The bilge area makes for considerable stowage space and I'd use it if it were dry. Right now it is a water & mud gutter.
After 2 hrs. in 15% white vinegar a fair amount of rust has been dissolved. Another hour or so should finish the job.
Step de-rusted well in the 15% white vinegar. Wire bruhed under hot water and sprayed 6 coats zinc chromate primer. Final 2 coats will be white Brightside. Now on to rebuilding the raw water pump.
Primed, painted and ready to be installed. Small amount of pitting but still in good shape.
Instead of raising the step out of the bilge water using plywood I would recommend Coosa Board. See Boat Outfitters as a source down your way...
Dale
Coosa is awesome for rot resistance. Ideal for the bilge. However I would be careful as its compressive strength is MUCH less than plywood. The mast is pushing straight down, but the weight is spread over the base sooo.... I dunno.
http://www.coosacomposites.com/images/Test_Data_0412.pdf
http://www.matweb.com/search/datasheet_print.aspx?matguid=bd6620450973496ea2578c283e9fb807
I think G10 would be ideal for this application. It's strong stuff.
Was thinking of G-10 myself. 1/4" thick should be enough to keep the step out of trouble.