De-rusting a spiral sraircase

Needle scaler, if you have a good compressor.

If he's going to put it in his house, he should take it to a sandblaster and have it blasted and then primed, and then he should paint it. Or he can take it and have it hot-dip galvanized. Either way will cost a few hundred dollars but the fix will be right. This isn't a temporary lashup to hold firewood, this is something he's going to look at for many years, and one of the first things a buyer will look at.

Something that big is way too big to do a metal prep type solution on, or to do anything remotely like electrolytic derusting. It's like a small piece of a ship, and ships get sandblasted, period.

GWE

Depending on size you could make a temporary tank out of a large tarp and fill it with water and some washing soda and use electrolytic rust removal on it. I've done that on full sized car frames and even a 20 foot trailer frame. Or rent a large compressor and blaster unit and have at it.

Need I?

You could spray or brush on hydrochloric acid and wash off/dry and paint it quickly.

Need I say wear eye and breathing protection and even maybe a disposable painters suit.

I set up one of my neighbours to do his staircase electrolytically. It was a cast iron spiral bought S/H as salvage and already dismantled into segment treads. Tread-by-tread, this was easy. Four treads would just fit into a plastic wheelie bin, bolted together on lengths of threaded studding. Two days for a set of four.

For power we used the old Vax PSU I'd previously used to do a canal boat hull (polythene sheet and _lots_ of duct tape).

Pity that the waterways people would get pissed off if you dropped some scrap iron anodes in the canal :-)

Mark Rand RTFM

DO you own a swimming pool and a big battery charger?

Gunner

"Deep in her heart, every moslem woman yearns to show us her t*ts" John Griffin