Hot blast rebuild materials

[Stevejo]

Looks like I should really disassemble and refurbish the old Florence hot blast. Not necessarily a full restoration, just for functionality and longevity.
Few questions.
General materials.
So far I’ve come up with stove bolts (are there a specific kind?) gasket tape and rope for joining the sections back together and the doors (think I’m opting to use ceramic fiber gaskets) and refractory cement to line the pot after cleaning. Either direct to the pot or non bound. But either way either sectioned and overlapped or at least “scored” with relief cuts for expansion/cracking.
Anything else?
And, once the pot and inner surfaces are cleaned (sandblasted or whatever) is there any kind of protective coating that can be applied to protect it? Hard chrome ? A thin ceramic coat?
The gas ring prospect is looking like a dead end, so I’m just going to make one using refractory cement (the play doe kind). Maybe fashion some wax “rope” for the gas path to be melted out after it sets. Same for the holes. (Still have the rear section that connects them to the under pot duct)

Thoughts?

[grumpy]

First what stove do you have? I have a 77.

I use Rutland stove cement to seal the parts together. It will last about five years. You can get it in a caulking tube.

[grumpy]

https://images.homedepot-static.com/productImages ... 4_1000.jpg

[Stevejo]

No idea what model. Best guess is made in late 40’s.

[Stevejo]

Doesn’t the rope seal last longer?
The stuff in it looks like it’s lasted 7 decades. The ceramic fiber looks like an even more durable option.

[grumpy]

I thought you had a Florence Hot Blast like mine, forget what I said, I know nothing about that stove...

[Stevejo]

Actually, the inside of mine is probably very similar in shape and construction to that one. Without the ornamentation, obviously. Take the sheet metal box off mine and it’s almost the same thing.
Any info you have would probably apply.

[fig]

Does that have a round pot or an oval pot? On the round one like the other stove the gas ring goes around the entire pot. As far as stove bolts I have just used grade 8 socket head cap screws. A lower grade would probably be more acceptable, a hard screw isn't necessary but it's what I had on hand. The thing is not to tighten them too tight or when the stove expands during a hot fire the heads will be ricocheting all over the place.

I just wire wheeled the stoves I worked on. One I painted and one I just used stove polish on. I wouldn't bother with coatings. Plating is for ornamental stoves, mostly decorative parts.

I used stove cement to seal everything up. I think gaskets are mostly for doors.

[Stevejo]

Does that have a round pot or an oval pot? On the round one like the other stove the gas ring goes around the entire pot. As far as stove bolts I have just used grade 8 socket head cap screws. A lower grade would probably be more acceptable, a hard screw isn't necessary but it's what I had on hand. The thing is not to tighten them too tight or when the stove expands during a hot fire the heads will be ricocheting all over the place.

I just wire wheeled the stoves I worked on. One I painted and one I just used stove polish on. I wouldn't bother with coatings. Plating is for ornamental stoves, mostly decorative parts.

I used stove cement to seal everything up. I think gaskets are mostly for doors.

It’s round. The reason I was questioning the fiber seal/gasket application is because it looks like that’s what is between the sections of this thing now. Actually seems to space the parts a tiny bit. Maybe 1/8 or less.
Would stainless bolts have any advantages? May be softer than high grade, but that doesn’t seem to be critical. Maybe stainless would be less inclined to corrode?
And yes, seems like the gas ring went all the way around the top of the pot, except where they met in the rear at the “connector” piece. I guess it couldn’t hurt to try and fabricate a gas ring out of refractory cement ? Call it an “experiment” wth. It could probably last as long as the “stove brick” liner I’m going to put in it anyway. As long as I’m careful about loading it. Maybe even put a threshold/sill guard over it at the door opening. Maybe wedge and braze a small steel plate over that spot.

[warminmn]

If you want to try making a air ring, try black pipe, 3/4", short sections of angled pieces, possibly mixed with straight pieces to fit around it. Drill holes around it spread out well. i think its 1/8" holes you'd want. Its going to leak at the joints so may have to seal them too. Anyway that might be easier and cheaper than trying to use refractory. Not as good as new but would work at least some.

Take a look at how some antique Hotblast models were made with the big pipe going right thru the top of the stoves too. Unsure if thats an option. The air rings may have helped more with soft coal than anthracite. Im unsure I'd even worry about it.

I would have guessed stove cement was used also, except for doors. But you can see what we cant.

[Stevejo]

If you want to try making a air ring, try black pipe, 3/4", short sections of angled pieces, possibly mixed with straight pieces to fit around it. Drill holes around it spread out well. i think its 1/8" holes you'd want. Its going to leak at the joints so may have to seal them too. Anyway that might be easier and cheaper than trying to use refractory. Not as good as new but would work at least some.

Take a look at how some antique Hotblast models were made with the big pipe going right thru the top of the stoves too. Unsure if thats an option. The air rings may have helped more with soft coal than anthracite. Im unsure I'd even worry about it.

I would have guessed stove cement was used also, except for doors. But you can see what we cant.

Hey, that’s actually a very good idea. I could even braze a section 1/4 cast iron or steel to the bottom so it catches in that track that it sits on.
Maybe I could even just get 2 long sections and heat and bend em to fit the curvature?
(Would cover most of the original gas ring area anyway)
Not a lot of experience with cast iron so not sure about that. Steel pipe I would have filled with sand and got it hot and bent to fit.
Still on the edge about the gap seals, but I imagine either would work so not gonna sweat it. Maybe use both? Coat the fiber gasket with that sealant and mash it in?
Definitely got me thinking of different options.
Thanks!!

[waytomany?s]

I believe braze would melt. Seems as though I read that somewhere.

[Stevejo]

I believe braze would melt. Seems as though I read that somewhere.

Not sure if “braze” is the right word. I know that cast iron can be “rejoined”, but it’s not called welding. I’d definitely find someone that could do it competently though.

[fig]

I wouldn't worry about what material you use for bolts as long as it isn't brass or aluminum. Stainless is expensive and the next time you take this thing apart you may find that half of the bolts will break when disassembling. Black pipe makes a good gas ring. If you search the thread about a stove "Tom" you will see that the builder used black pipe to make a gas ring. The tricky part might be incorporating it into the existing air intake on your stove. You might be able to find hot blast gas ring parts. They are elusive but I've seen members offer them up occasionally when someone needs them.