Bonnet
I had left the bonnet aside after removing the steel support frame from the Birmabright skin.
The frame is like most of the steel parts after their 42 years of exposure to air, cold, heat, and moisture. Not too bad as it happens, but definitely in need of its share of TLC. I've been contemplating how best to go about rust removal on this and the remaining disassembly. I was thinking sand blasting would be effective although it won't get inside the welded together u sections that form a box section. Same with the wire wheel on grinder, not to mention the noise, dirt, and effort involved. I might have to yet, but I decided to first have a go at setting up an electrolysis bath.
My existing bath is nowhere near big enough ...
... so after some head scratching and thinking about what I could utilise, I came up with the following; a temporary bath made up from some left over DPM sheet and timber from an old bed frame I took apart (from my "it might come in useful" stash).
Now, I have to confess, this is a photo of the MK1 version, which after filling with water and loading the frame, I managed to puncture the DPM and then had a catastrophic flood as the whole thing collapsed and half drowned me! I kind of threw my toys out the pram and went and sulked for a week before resuming with the MK2. I added a bit more side support and and extra layer of DPM.
I loaded the frame carefully having removed the sharp edges that had caused the problem before
Next I ran copper wire around the periphery and connected scrap steel pieces to it, placing the steel around the tank so that it surrounded the frame
I then hung the rear support that I'd cut from the frame so that it was above the frame but not touching; the frame was also lifted just off the bottom of the tank.
It was now time to fill the tank and completely submerge the frame pieces. I mixed up some water with washing soda separately in a bucket and mixed this in with the main tank fill.
All looking good, I hooked up the battery charger and connected +ve to the steel anode circuit, and -ve to the frame cathode circuit. It now remains to be seen if I get the results I'm after or not. It will no doubt take a few days stewing in there before I can assess whether or not it's been successful or if I have to go visit the sand blasters.