(M)

suitability of refractories

Recommended Posts

Hey gang, 

I got a hold of all these refractories for my single burner (3/4" T-burner) propane tank forge that I plan to build.  

I plan to put the 2600*f kaowool in the inner layer, and the 2300*f stuff on the outer layer.  why both types? 2300*f was almost half price.  

2sqft of 2600*F kaowool, 2sqft of 2300*F kaowool, one 500ml jar of ready mixed colloidal silica rigidizer,  one 55# bag of MIZZOU CASTABLE PLUS,  One gallon of premixed zirconium infrared coating (only $20, specifically called "ZK-W WASH") 

all this totalled to 145$ somehow! (5$ more than i was going to spend on one pint of itc100:lol:)

I have a few questions.  

1.) the zirconium wash's composition is as follows 97.5% ZrSiO4, 0.4% SiO2, 0.1% Al2O3.  Is this normal/is any of this toxic cold or when heated/special precautions?

2.) I was told to pour (not trowel) the Mizzou in as thick a layer as possible ("it works better thicker"), up to 4 inches, and that a layer as thin as 1/2" would never work.  is this correct? 

3.) Should I mix this type of mizzou with Styrofoam to make it more insulating? 

4.) is the 500ml jar of rigidizer enough for the propane tank forge? 

5.) is there a good way to reduce the forge's internal diameter to the required 350 cu/in? I did the maths and I need to take off 1/2" from the radius.  

That's alot of questions, I know:rolleyes:

Thanks in advance

Share this post


Link to post
Share on other sites

1/ There doesn't seem to be anything nasty in there. The big question is really "what is the other 2%?" There doesn't seem to be anything that would fuse the Zirconia together and it might tend to come off easier than you'd like. I gather other products can be prone to this too.

2/ We tend to use refractories in ways that do not correspond to the manufacturers intended scenarios. In particular, we cycle the temperature at rates and frequencies that are simply not seen in their usual industrial applications. Applied over rigidized Kaowool, or its equivalent, many smiths have found 1/2" of Mizzou to work well. The number of variables in forge building and use is vast, so it is unlikely that anyone will be able to say definitively that you'll have no problems. 

3/ No. If you need insulating, use Kastolite 30.

4/ Probably not. However, within reason, you can usually dilute it with water and make it go further. You need some depth to the rigidized layer and it is probably better to soak deeply with a diluted mix than to only get shallow penetration at full strength/comcentration.

5/ Not worth the effort for such a small reduction in forge volume. It would be better to reduce the opening(s) with a narrow strip of Kaowool, rigidized and coated, wrapped around the inside. It might be thought of as a way to reduce the chamber length to get the volume down. More importantly, it reduces the open area and therefore reduces the heat loss. The volume-per-burner guidelines are just guidelines, based on "normal" practice. If you build a 3" diameter forge 50" long or a 9.4" diameter forge 5" long, you are unlikely to find they work well, despite meeting the 350 cu in guidelines. 

Share this post


Link to post
Share on other sites

OH I think a 9.4" Dia. x 5" chamber would work a treat if you oriented the burner tangential to the wall to induce a vortex. I think you're mistaken on that one Tim. :rolleyes:

M: 

Don't eat or drink the kiln wash, otherwise it's non-toxic. Do you know how to search out the MSDS for a product? Check the manufacturer's web site and maybe ask them questions?

Who told you to "pour the Mizzou as thickly as possible?" It was certainly NOT someone who's used it. The guy at the counter where you bought it, right? Trowel it on 1/2" thick, it's been getting used that way for decades. If you want to know for sure, ask the manufacturer. 

Mix styrofoam beads in the refractory? Where'd you get that idea? NO, don't be silly. <GOOD GRIEF!>

The product label or web site will tell you how many sq/ft a can will cover, divide by 2 for a little margin. Wet the Kaowool before applying the rigidizer and feel free to dilute it a bit.

Do you read labels at all? All the above products are sold to do a job and the makers WANT them to perform well so more people will buy them. They answer questions gladly unless you ask something really wonky silly. See the styrofoam in Mizzou question for a good example.

Tim suggested shortening the chamber a bit and reducing the size of the openings. I like both myself but can YOU think of another way to reduce the volume without reducing the overall diameter? . . . Think . . . Think . . .  Put a flat floor in it?!:o Oh MY, shred the edges of a piece of Kaowool a couple inches wide the same length as the chamber to it meet the curve of the wall smoothly, lay it down rigidize it and cover it with Mizzou when you do the rest? 

Naaaa, too simple.

Sorry for messing with you but you have to admit those were some questions just a LITTLE reading would've answered with solid data but NO, you played the lazy card and asked the world expecting US to spend the time answering questions that 5 minutes of reading would have. If you're going to do that, expect an old curmudgeon to mess with you. 

Whine and I won't answer your questions at all.'

Frosty The Lucky.

Share this post


Link to post
Share on other sites

Lol i did read some of the labels, however home forge applications are typically quite unique require experiential knowledge of which i have none (and all y'all do).  I didnt want to go hunting around for obscure info-the place where i got this stuff doesnt even have a website.  didnt think much about the MSDS, but the MSDS for kaowool doesnt say anything about it's fibres being distributed in air when fired in a forge.  I learned that from you guys, and im thankful for that so i didnt kill myself.   

 In this thread, https://www.iforgeiron.com/topic/6614-high-alumina-refractorycement/

you discuss putting sawdust (others reccomend styrofoam) in clay to make a makeshift refractory.  I had heard of doing that in other places too. Thats where i got that idea. Can u explain a tad more whats wrong with it in this application?  

With the rigidizer, i knew what the label said, just asking for personal experience/any tidbits of advice

The guy i talked (through my dad, i did not go personally) to is a professional refractory worker, he builds crucibles, furnaces etc, not just an over the counter guy (he made the crucibles for the gold supplier of the Canadian mint).   Thats what shocked me, it went against everything i learned here.  

And making a flat floor is a great idea, didnt even think about that one.  That is perfect.  I was thinking all kinds of wierd ideas.  

I DO have a method to my madness, i DO appeciate all your help, even if it is a bit curmugeomly :lol:

And yeah i admit i was a bit lazy with the first question, but again, heat applications are unique

Share this post


Link to post
Share on other sites

Thanks irondragon, i just had a look and i think i learned most of those things the hard way by asking stupid questions.  I hope i have gotten better.  

Share this post


Link to post
Share on other sites

The MSDS for ceramic blanket lists the breathing hazard only occurring with heavy and repeated exposure. It's not intended as a flame contact refractory so vitrified little spears don't happen when used as designed. WE don't use things as intended, our forges typically get hot enough to vitrify the high temp blankets so the breathing hazard is higher in a propane forge. The breathing hazard from off the roll ceramic blanket may not be something to freak out about but it's EASY to take precautions even if nor really necessary. 

Your main concern was for the kiln wash.

Again, we aren't using these things the same way a factory would. If you're patching or rebuilding a furnace that gets charged with rail road gondola cars, 4" thick is pretty minimal. A guy who maintains an industrial furnace works in a different world, it'd be like asking the A&P specialist who works on F 18s how to tune a Cooper Mini. They may both burn fuel and get hot in places but they live and operate in different worlds.

Using fire clay and saw dust to make light insulating fire brick is okay IF you don't have professional fire brick available. I know I've thought about using styrofoam bean bag chair beads and probably mentioned the thought many times. I've never done it though, the days of trying to make my own refractory liners are long past. I can buy far superior products by the bag about 55 miles from here and I have to go to Anchorage occasionally anyway.

You can buy small quantities  of forge building supplies from Wayne Coe so you don't end up with 40 lbs. left over from a 50 lb. bag.  He also has proven forge plans posted on his site.

It's good to see you have a sense of humor, too many guys take curmdgeonly responses personally. You're going to fit right in here. Like puns, know any good jokes? :)

Frosty The Lucky.

Share this post


Link to post
Share on other sites
3 hours ago, Frosty said:

 

The MSDS for ceramic blanket lists the breathing hazard only occurring with heavy and repeated exposure. It's not intended as a flame contact refractory so vitrified little spears don't happen when used as designed. WE don't use things as intended, our forges typically get hot enough to vitrify the high temp blankets so the breathing hazard is higher in a propane forge. The breathing hazard from off the roll ceramic blanket may not be something to freak out about but it's EASY to take precautions even if nor really necessary. 

Your main concern was for the kiln wash.

Again, we aren't using these things the same way a factory would. If you're patching or rebuilding a furnace that gets charged with rail road gondola cars, 4" thick is pretty minimal. A guy who maintains an industrial furnace works in a different world, it'd be like asking the A&P specialist who works on F 18s how to tune a Cooper Mini. They may both burn fuel and get hot in places but they live and operate in different worlds.

 

Thanks this explains alot.  

 

3 hours ago, Frosty said:

You can buy small quantities  of forge building supplies from Wayne Coe so you don't end up with 40 lbs. left over from a 50 lb. bag.  He also has proven forge plans posted on his site.

I dont mind the extra, i can make crucibles and share it with my local smiths.  

As for puns and jokes, my best one is:

What do you get when you cross a rhetorical question with a joke?

Think about it....:lol:

Share this post


Link to post
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now