Lucifer furnace firebrick repair

[rabtrfld]

Old Lucy here has some serious leaks around the door. There are so many firebrick repair products out there, I don't know where to start. It is so crumbly, it would be easy to make it worse.
Any experience? This is a 2000F heat treat furnace, so no fireplace goop allowed. Even ceramic kiln stuff is suspect. I would consider just packing the gap with asbestos cloth. I would rather consider a multi-step process if it is really better than one step. Seen a video using runny gray cement, followed by trowel-on white stuff, then sanded & glazed with a third substance. The only thing I don't want to do is replace whole slabs, the entire kaboodle would disintegrate.

Also (breaking forum rules), any advice about case hardening in here? I've only done various alloys with Tool Wrap. We have Kasenit or Cherry Red or something that we use with a torch. Just submerge the 1018 in an open pan? Can case compound be re-used? Ever bother tempering Kasenit after quench? Ever get banned for asking too many questions in one post?

 

[crossthread]

Just making an observation but you said no furnace goop and then suggested putting on layers of goop?

 

[Scottl]

Check McMaster for refractory cement. They should have products with different densities and temperature ratings. You might want to chisel out suitable cavities and use the cement to mortar-in firebrick.

I've done all my case hardening with a torch. Heat, dunk in compound, heat to red heat. Repeat three times and then quench. I use peanut oil and then temper in a toaster oven never used for food.

You can reuse the compound left in the can or tray, but not the stuff in direct contact with the part or torch flame. If it becomes less effective you'll know right after quench (the file test).

PS: Can you get banned for answering too many questions in one post?

I doubt it, as long as intent matched spirit of useful technical question and answer for which PM is intended.

 

[Mark Rand]

Ceramic kiln stuff goes up to 2300°F, so any of that would be applicable. 20 or 23 grade insulating fire bricks would also do the job. Higher grades of calcium silicate wool wlould also work. Plenty of refractory cements are available. Ceramic maker's suppliers may be the best bet for less than sack full amounts.

Heat the part to a dull red. Dunk in kasenit or sprinkle it on to get a good layer, it should melt onto the part rather than falling straight off. Heat more, for longer, then quench. The hardened layer is so thin that tempering serves no purpose. Reuse the powder that didn't get hot and it'll be ok.

 

[johansen]

if you have anyone local who does ceramics i would ask them for advice.

2000F is not all that hot. my cone 8 rated kiln goes to 2300F and cone 10 is 2600F.

2000F looks mighty hot until you open a kiln at 2600F and it instantly lights your cloths on fire.

 

[rabtrfld]

2000F looks mighty hot until you open a kiln at 2600F and it instantly lights your cloths on fire.

I understand one doesn't open a ceramic kiln until it has cooled?
Our stuff heat treats under 1800F, so it's no big deal to open the door and rake it out.
But a friend from high school became a glassblower, in apprenticeship he was exposed to fused quartz
over 2500F and said it was something to reckon with.
By your advice I will trust it to the local ceramic shops, which are easy to find around here.
And no fireplace goop from the hardware store, that's for the masonry in Grandma's parlor.

 

[dgfoster]

Satanite is a high temperature masonry cement I use in my 3 kilns and in my oil-fired cast iron foundry furnace. It is the best masonry cement available so far as I know. I have used it to repair broken insulating fire brick like you have in your oven. IFB does deteriorate with age. But it should last a long time. IFB come in different temp ratings commonly up to 2600F. They are very easily cut with common tools.

You can buy Satanite from High Temperature Tools.
High Temperature Tools & Refractory | Refractory Coatings

You can also get tech info from them. A good-sized local ceramic shop should also be a good source of information and likely supplies.

I commonly open my kilns hot. Not recommending it, but it is a necessary part of my heat treat or casting process.

Denis

 

[Overland]

dgfoster,
Maybe not totally OT, but could you tell us about your oil-fired cast iron foundry please ?
Maybe a new post ?
Thanks,
Bob

 

[J Henricksen]

I get refractory cement, castable , from Rockford Steam Boiler. They are about 4 miles south of the state line out of Beloit. I've repaired a few kilns with it. They can get about any temp styff you need. It needs to dry then be fired to the operating temp to make it durable

 

[dgfoster]

Bob,

Where to start? If you saw the video, you have some general concept that I run a highly modified 50-gal drum lined with refractory and fired with an atomized stream of diesel fuel to melt small (70 pound max) batches of cast iron. It is a one-man operation based in a barn. The setup allows me to cast iron straight edges of my own design that are unique in the industry.

Casting them myself came about as I had designed patterns and was having them cast in a commercial foundry. Though the foundry was competent and reasonably conscientious, I was experiencing some damage to my rather delicate paaterns as the foundy was more geared toward 600 or 6000 pound castings rather than 30 or 50 pounders. I decided that setting up a foundry "could not be that hard." (Hilarious in retrospect) So, about 4 years down the line now and countless hours designing and fabricating furnaces, materials handling equipment for both hot and cold stuff, innumerable trials and lots of failures, I have a pretty well tuned tiny operation that is the source of continued challenges as improvements are constantly made and I add new patterns and methods. This is the most complex puzzle I have ever worked on outside of my profession prior to retirement in 2012.

Here is a vid of a 40 pound pour that is representative of a 40 pound pour

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And here is a 36" camelback like the one poured that time.




Here is a 48 and a detail from a 48



Obviously, I have thousands of photos and many many videos of various aspects of foundry operation. But maybe the above will give some indication of what it is all about. If anyone is more interested, just PM me and I will provide some more links to another forum I frequent that is dedicated to small foundry operation and to which I have contributed a couple thousand posts along with a lot of other entusiasts regarding all aspects of small foundry construction and operation.

Incidentally, everything you see in the video was fabricated in my shop and the lifting tongs and trolley are original designs.

Denis

 

[dian]

some refractories are hydraulic so you have to let them cure, some are not and cure by heat.

 

[garyreach]

Old Lucy here has some serious leaks around the door. There are so many firebrick repair products out there, I don't know where to start. It is so crumbly, it would be easy to make it worse.
Any experience? This is a 2000F heat treat furnace, so no fireplace goop allowed. Even ceramic kiln stuff is suspect. I would consider just packing the gap with asbestos cloth. I would rather consider a multi-step process if it is really better than one step. Seen a video using runny gray cement, followed by trowel-on white stuff, then sanded & glazed with a third substance. The only thing I don't want to do is replace whole slabs, the entire kaboodle would disintegrate.
View attachment 335306
Also (breaking forum rules), any advice about case hardening in here? I've only done various alloys with Tool Wrap. We have Kasenit or Cherry Red or something that we use with a torch. Just submerge the 1018 in an open pan? Can case compound be re-used? Ever bother tempering Kasenit after quench? Ever get banned for asking too many questions in one post?

Hopefully this isn't against a forum rule, but I just joined and was searching for my company. I realize your post is 3 years old, but if you would like to discuss your furnace, please give us a call at Lucifer Furnaces. We can reference the product information and design drawings and share any information you may need. Any parts are available too if you haven't already found a source. It can't be too old. We have files and routinely sell parts for 50+ year old furnaces and ovens.

Call 215-343-0411 and ask for me, Gary.

 

[gbent]

Welcome to the forum. While blatant advertising is frowned upon, people who are willing to support their product and use their expertise to help forum users are welcomed with open arms.