Fire clay: Getting pissed

There's a foundry down the road from me, but the foundry manager I
talked to seemed to not know what "fire clay" was. He pointed me to his
supplier's website (mainly to get me off the phone, I think) but there's
no refractory information of any kind there, all they have is equipment
I don't need. Some here mentioned "perlite". I've googled for
"perlite" and everyone that's used it also used fire clay, so that's no
help. Even Budget Casting Supply
formatting link
doesn't have it, though
they have "castable refractory"--for $85. I'm starting to doubt this
stuff even exists.
Can anyone who has actually used fire clay provide a brand name from the
bag? Searching for a specific item rather than the protean "fire clay"
(everybody seems to call this stuff by a different generic name and/or
have different things in mind for any given name) would be a lot easier.
No need to tell me to check my "local
fireplace/potter/construction/masonry supplier"--that's been done to
death.
Reply to
PhysicsGenius
Loading thread data ...
It's a natural clay with a high alumina (aluminum oxide) content. The higher the alumina, the higher the temperature it can tolerate. Potters use it to line their kilns. I'd try a big potters' supply.
Reply to
Ed Huntress
Try some ceramic supply or look under refractoriness, it's out there. Try the link below for a start, good luck, Ben
formatting link

Reply to
Mac
I walked into the local potters supply shop (same building as the blacksmith shop I was taking lessons from) and asked if they sold it, they said "we can get it, but we don't normally stock it. here is a catalog, I'll highlight the fire clay for you, it takes about a week to come in, how much do you need?" It is called "Hawthorn Fire Clay" comes in 5 kilo mini-bags (about 11lbs) or 50lb bags (skids of 80 bags available, though why you would want that much...), and it was pretty cheap, about $10 Canadian/ per single bag and the price went down if you ordered more. I nope that helps. Ken
Reply to
Ken Vale
[Let me guess, you've been reading the Gingery books.... If you're wanting to line a furnace, use the castable refractory. These mixtures of fire clay and perlite, etc. are a very poor substitute for the real thing. On the Hobbicast group, I've heard from people who have tried this stuff, and usually they end up having to chip it out and replace it.]
[Try "Lincoln 60" .]
Searching for a specific item rather than the protean "fire clay"
[There's nothing magic about fire clay. It's just a dry stoneware clay. It's often sold as "mortar clay" in masonry supply outlets; it's used to give concrete mortars some plasticity.]
Andrew Werby
formatting link

Reply to
Andrew Werby
Any brick, ready mix, contracctor's supply or fireplace company will have it. Lowes and the Despot will not. It is just a high alumina clay that is mixed with morter for laying fireplace liner brick.
PhysicsGenius wrote:
Reply to
Glenn Ashmore
Yes, I have been. I found "castable refractory" at my local hardware store (but not at Home Depot) and a heating supply place. But it's around $10-$15 for something like a quart. I haven't measured, but I'd surely need at least 5 or 6 of those to line bucket....wouldn't I? Dave's instructions talk a lot about fire clay but only mention castable refractory in passing. Very frustrating.
Reply to
PhysicsGenius
Here's a link to laguna clay, the top of this page lists 10 different ones for around 15 cents a pound dry in 50 lb quantities. Their homepage has a list of distributors all over the US.
formatting link
Reply to
Bob Robinson
Hi,
While there is definitely value in buying the commercial castable refractory, I use a recipe by John Wasser. The recipe is here:
formatting link
if the link breaks google for John Wasser and castable refractory. It is pearlite and fireplace 'cement' (note: contains no portland).
I tried the sand/bentonite/fireclay recipe. I was not impressed: the completed furnace was tremendously heavy and underinsulated. While firing the lining, the paper label on the side of furnace would have caught fire had I not removed it in time. It was interesting to watch as the paint chalked and the label turned pre-combustion brown.
With the new recipe in place, it is both significantly lighter and much better insulated.
The only change I would recommend is to add a thin interior glazing of refractory, sans pearlite.
StaticsJason
Reply to
Statics
Ah, this has some promise. They have "Hawthorn Fireclay", as mentioned by someone else, for $.189/lb for 50 lb. Of course, their New Hampshire distributors are in Maine and Mass...But I have a brother-in-law who might be able to pick up some for me. It says "35 mesh"--I guess it doesn't matter what particle size I use for the furnace lining, within reason.
Thanks.
Reply to
PhysicsGenius
Thats because old Dave is really in the business of selling books and tons of his ideas and items he refers to is out of date or no longer available. He only mentions castable in a passing sense due to the fact he would not not have as interesting concept if he merely stated check with your foundry supply place for a good grade of castable. Its more intrigueing to "make your own just like Dave" and it takes more pages you have to pay for to spell out the way of doing it.
Daves homebrew and most of the others I have seen can't hold a candle to commercially available castable stuff. There just is no comparison in any aspect. In a lot of cases it will cost you almost as much to homebrew it and not have anything as it will to buy commercial stuff.
Refractory and the burner is the 2 key parts, and its really the heart and sole of a furnace so why use inferior stuff.
My way of thinking is the foundry did not have a clue as to fire clay as most today use a commercially made bentonite or Petrobond to make greensand, and I know of no commercial foundries out there homebrewing their refractory. A 50 or 55# bag should run you between $25 and 35 at most places, unless you buy from BCS in which case it will be close to double or more. If you can't find castable look for ramable. It will work just as well as castable and is sometimes even cheaper.
-- Visit my website: Remove nospam for correct address http:// snipped-for-privacy@hotmail.com Contents: foundry and general metal working and lots of related projects. Regards Roy aka Chipmaker // Foxeye Opinions are strictly those of my wife....I have had no input whatsoever. Remove nospam from email address
Reply to
Roy
I don;t understand why folks use Bentonite in refractory mixes. Its intended in foundry use to be used in making greensand, not refractory. Furnace cement is usually a lot higher $$ than castable or ramable refractory is.
-- Visit my website: Remove nospam for correct address http:// snipped-for-privacy@hotmail.com Contents: foundry and general metal working and lots of related projects. Regards Roy aka Chipmaker // Foxeye Opinions are strictly those of my wife....I have had no input whatsoever. Remove nospam from email address
Reply to
Roy
You have a point. OTOH, I'm not doing this project because I seriously think I'm going to end up with a metal shop at the end. I'm doing it because it's fun. If I buy commercial refractory, I might as well just buy commercial cast parts or even the whole lathe and what's the fun in that?
It's like people who add water to cake mix and call it "cooking". Sure, you ended up with a "standard" cake--but where's the love?
Reply to
PhysicsGenius
No kidding? That is cheaper than making the recipe i referred to elsewhere in this thread...even if labor is not figured into the cost.
Good to know, thanks!
StaticsJason
Reply to
Statics
Hello again,
If you build a Ron Reil style burner, the orifice assembly can be simplified using Tweco contactor tips (the short style) with the threads cut off. The ones I have use a metric thread, but the body diameter is 0.250 in. and fits perfectly in a 1/4" compression fitting.
Some pictures of mine are posted here:
formatting link
Yes it is clunky looking but it was built to be quick and dirty, as well as adjustable for testing. The air intake bell has been removed in the photo and will not function correctly without it.
There is also a photo of the furnace running at night, with some really rough lining in it.
With the on/off toggle valve I can easily shut it down to remove the crucible and the furnace walls automatically relight it when the gas is turned back on.
StaticsJason
Reply to
Statics
Well I sure don'[t have a metal or foundry business, but I would rather spend my time melting and casting odds and ends and enjoying my home made lathe etc than piddling with an inferior furnace refractory, and spending larger sums of money on fuel due to heat loss. Sometimes you can get by on cheap or home brew other times and for the most part with refractory, commercial is the only way to fly. Buying commercial refractory is certainly not in the same ball game as casting your own lathe, and it certainly will not distract one little bit in the lathes parts castings or its use when completed. I love to tinker, but I love to produce something and not have to keep tinkering to produce something. Have fun and be safe no matter what route you take. Regards
-- Visit my website: Remove nospam for correct address http:// snipped-for-privacy@hotmail.com Contents: foundry and general metal working and lots of related projects. Regards Roy aka Chipmaker // Foxeye Opinions are strictly those of my wife....I have had no input whatsoever. Remove nospam from email address
Reply to
Roy
I'm not sure what you're planning on using the clay for, but you might check out Kaowool. It seems pretty inexpensive and is used to line furnaces, forges, et. al. Check it out here:
formatting link

Also, look at this link:
formatting link
for ceramic coatings for the kaowool. Together, I believe they will fit your needs.
I hope this helps,
rvb
Reply to
rvb
After all this discussion about the relative merits of home-brew vs commercial refractories, all I have to say is that my Gingery style furnace (made using Dave's recipe) is holding up very well (even the lid) after 4 years, many many uses, and being stored in an unheated garage in an area of the world that experiences a wide temperature variation (30 C in summer to -40 C in winter). Perhaps the castable refractories are better, but I've no motivation to try as the furnace works fine.
Dave
comparison
Reply to
Dave Keith
"fun"? The subject says "Getting pissed" and your original post talked of all the frustration you're experiencing. That doesn't sound like fun to me. _Casting_ is fun, much more so than building the furnace.
Forget all the home-brew stuff, it's not worth it. If castable refractory is too expensive, just use some fire brick. They're about $1 apiece around here (4" x 8"). I used "splits" (1/2 -thickness, i.e., 1"), stood them on end and bound them together. It was quick & dirty and allowed me to get on with it.
Bob
Reply to
Bob Engelhardt
Perlite is best bought at garden supply and home centers. A good place to try is a fireplace supply or service. If there is a fireplace store or wood stove store near - talk to them - ask to their local supplier.
I found one only 3 miles from my house. It supports foundries, and many pottery furnaces in the local area.
budgetcasting is a good company. buy investment and other items there.
I have and will again. In fact need to.
Martin
Reply to
Eastburn

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.