racer3j Posted June 3, 2008 Share Posted June 3, 2008 Though yet a child in the smithing world, I am intrigued by tools of most all crafts. In the woodworking world I have no interest in building fine furniture. I enjoy restoring and making and trying to improve handtools. I took delivery of a nice propane forge and I haven't fired it yet- I want to paint the liner with ITC-100 first. The forge is a nice little unit but I can rarely leave these things alone. So I have two coal and one coke forge to build- material gathering as we speak. Plans on a "bar napkin." The real news is that a very well respected refractory products and process company is only 3 miles from my house. A phone call got me to the owner/founder( five other locations in the US). So, I have an invite to come out- with plans- I get the grand tour and a sit down with him and other engineers to work up a super-forge. Cast in foundry grade liner, cooked- then coated with a product like ITC-100 and cooked again. He said that my needs would provide something to make with their linings "sweepings." Once trained, I will be authorized to make my shells, soft set the liner material and take to the plant to piggyback on a commercial bake and coating. Now, what may be a downside- the liner ends up being near 4" thick, but it is developed for high production foundry use so it is tough as nails and extremely efficient. He indicates I should look at a clamshell style forge. The floor will be ceramic and coated too and replaceable so post-flux renewal will be simple. I know it sounds like "Forgezilla" but it is an experience I cannot pass up. I would be glad to ask questions on behalf of any of you. I will likely go there next week. So, think about it. Hybrid burners will be providing the fire.jet Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 4, 2008 Share Posted June 4, 2008 Sounds like an opportunity for sure. Why does the liner have to be 4" thick? If it's castable you can make it whatever you like within reason of course. I'm no fan of clamshell forges. They sound like a good idea and to a point they are. Unfortunately the IR radiation the smith takes when it's open is horrendous. A vertical lifting lid keeps the yellow hot refractory aimed away from you so you don't end up a crispy critter. Who's the refractory manufacturer? Frosty Quote Link to comment Share on other sites More sharing options...
racer3j Posted June 4, 2008 Author Share Posted June 4, 2008 "Refractory and Insulation Supply, Inc." One of the things I was planning on learning is why the 4". It might be that the fellow was enthusiastically offering me the "ultimate" in insulation. I wasn't going to start complaining about materials and thickness- the offer is so generous. Once I get the knowledge of what they are doing, my thought was then talking about thickness and other things that come up. It would have been pretty ungrateful to starting questioning his generosity. But, Frosty, your point is appropriate- just not for the first introduction.jet Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 4, 2008 Share Posted June 4, 2008 (edited) What I've discovered talking to refractory, furnace and fuel gas guys is if you just ask the questions cold you get inappropriate answers and ideas. The propane guys invariably hand you a jet plumbed for 1/2" pipe as if that's all there is. The refractory guys are always thinking in terms of commercial size units, even a small ceramics kiln is unusably enormous for a forge. Unless of course you're a spring shop or something similar. They're ALL thinking on this scale and bigger which is like the parts store guy handing you semi air bags instead of struts for your Miata. It's good stuff, it just doesn't really apply. If you can present a basic knowledge of what you need and want, at least sizes and temp ranges they'll listen to what you need and THEN start supplying ideas. What you'll discover about castable refractories is thermal efficiency, it's generally about 60-70% of a ceramic wool blanket. There are some insulating refractories that are high alumina with hollow glass sphere insulation that are close to 90%. It's REALLY expensive though. They're all vulnerable to fluxes at welding temps. If they have a high phosphate refractory, either rammable or castable then a thin inner liner of that will protect everything from fluxes. Then an outer liner of insulating refractory for efficiency. It gives you the assets of both systems but like all compromises falls somewhat short. Next time you talk to them let them know you're building something with (probably) between 350-800 cu/in volume that will hit temps of close to 3,000f on occasion. That there's likely to be caustic fluxes involved at temps around 2,600f or higher. If the liner is 4" thick the openings you'll need to get anything that isn't straight in and out will have to be so big you'll negate the extra insulation. It never hurts to have some background knowledge when you talk to professionals. It usually kicks the discussion to the next level where the really juicy stuff is. I REALLY try to keep to that level, the next one up involves a lot of math and I don't have enough fingers and toes to go there. On the other hand, if they're like EJ Bartells in Anchorage they're really INTO fire and get enthused about really HOT fire. The guys at Bartells have always gotten right into the spirit of forge linings, given me superior price breaks and often loaded me up with chipped or broken fire brick and Kaowool trimmings from the fab section gratis. Bringing drawings is always helpful. Lastly, if possible talk to the guys on the floor, they have the hands on knowledge, the engineers tend to lean to the theoretical, you don't want to become a pet experiment. At least till after you get a good working forge that is, then becoming an experimental test facility could be not only interesting but profitable. Frosty Edited June 4, 2008 by Frosty Quote Link to comment Share on other sites More sharing options...
Dodge Posted June 4, 2008 Share Posted June 4, 2008 Where abouts in Iowa, Racer? I live in Omaha and we have a fine refractory supply here that sells Inswool ceramic blanket, as well as castables and brick. Convenient, but if your source is close enough, I might save by cutting out the middle man Probably not, given today's gas prices unless it is in Council Bluffs BTW, I used castable on my gasser at 3" thick and I believe this became more of a heat sink rather than an insulation factor. I wish I would have made it much thinner with a ceramic wool blanket. (Kinda like my next forge LOL) Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.