Kelsey 5”x8” Restoration?

Am I correct in assuming the electrolysis was complete immersion? If so, then heat appears the last resort. Carefully done, the danger of cast cracking is low. I suggest a two-man approach: as one applies the torch flame, the other gently twists the disc back and forth. Also, whilst applying the heat, use a back-off method, ie: heat the cast, back off flame, squirt oil into stem crevice, repeat. Touching an ice cube to the bottom of the disc stem might also prove successful. You’ve come a long way thus far, best of luck in completion.

joshua, we met at the printers fair in san jose. congratulation to your work so far. you are doing well.
forme has some good advices. instead of tapping it out, try to turn the ink disk back and forward. little by little. it may help to clamp a 2x4 on the disk and slightly tap it with a small dead blow hammer. heat will help for sure. you want to heat the ring around the disk and not the disk, so cool it with ice or turn a spray can with air upside down, it sprays than very cold. i removed the bent disk activator with that method go slow, good luck.
ernst

Yes, complete immersion, maybe more would help, but the affected parts are so tightly bound not sure how much.
Hot with cold a good idea, maybe a little dry ice is in order.
For all seized pivot points too. tried tapping with a punch on some of those, not a hair of movement.
Alas, no movement at all so getting to twisting is a ways off-
Ah, clamping a long piece of wood to disk for more leverage!
back at it.

Given that the press sat for so long, the rust formed in the close-fit points has literally ‘welded’ the pieces together. Although electrolysis is a good method of eliminating surface rust, even your lengthy immersion would not be enough to free the frozen parts. I suggest using concentrated cleaning vinegar (10%, available at most hardware or grocery stores) with, again, total immersion, soaking the press a minimum of 24 hours, then attempt movement and if none, repeat until the parts free. If you don’t have a large enough container, double or triple heavy duty garbage bags. And remember, it took years to rust - it will take time to de-rust. :o)

I had the same press in about the same condition a few years ago. I bought a 5 gallon bucket of evaporust and left it in there for many days. Probably similar results with vinegar, as suggested above. The key is to just let it work. I think I may have kept it in the evaporust for nearly a month, taking it out to try and move every few days. Eventually it started to unseize and that’s when I went in with the penetrating lubricant. Good luck!

The price of both high concentration vinegar and evaporust is high- did a little digging and found this promising formula, for chelation of rust- much more economical-I’m going to give this a try:
Per 1L of H2O
1: 100 Grams Citric Acid.
2: 40 Grams - Sodium Carbonate
3: After Co2 reaction (acid neutralization) add a little dish soap as a surfactant.

And less potential metal damage than vinegar.
I also used sodium carbonate (washing soda) in the electrolysis bath.

But first some printing with my working press!

Local redwood community radio celebration

Citric acid (eg: lemons) is a great rust remover. And when heated, works rapidly as well. I limit its use to more delicate objects having fine lines (rulers, compass, as example) as it leaves a bright finish and attacks the rust without affecting the base steel. Acetic (eg; vinegar) leaves a dark finish, unimportant for most cast iron, but can, if left unattended, remove good metal.
However, vinegar is very inexpensive ($4 gal.), which meets most goals, and can be used with little preparation. Each use depends upon desired effect. I would use Citric on an ink disc, Acetic on the main body of the press. A disadvantage of both is longevity; both deteriorate rapidly and are generally seen as a one-use approach. Oh they can be re-used, but their strength is is very much weakened.
Evaporust is also a great product, But, and it is a big But, the expense must be carefully considered. $40 a jug is its range. Advantages are superior to the aforementioned acids though (it is compatible with aluminum, copper, brass, and others), whereas vinegar eats aluminum. And it does remain active a long time.
If all the acids fail to see result, the old standbys of diesel fuel and heat are still there. :o)
So the gist is: whatever best works for your desired result is the one to use. :o)
It will be quite the revelation when little Rusty Kelsey produces those printed cards after all is said and done! :o)

I was looking at higher concentration vinegar which seemed pricey for the gallons needed to submerge. (the press just fit to complete submersion in a 30 gallon plastic tote) then I read that acetic acid can negatively affect cast iron structure unto brittleness, if soaked too long.

The formula above was from YouTube:
https://www.youtube.com/watch?v=fVYZmeReKKY

This gun smith explained some of the chemistry, the sodium carbonate neutralizes the citric acid creating a citrate that does the trick with negligible metal loss. He did side by side tests with evaporust and his formula was faster and lasted longer (used more times and still effective.)
There is also some info that citric acid could enhance the sodium carbonate electrolyte for electrolysis.

pacing myself.