ceramic chip forge

[Kiwi Pete]

Has anyone used one of Angele gas forges that use ceramic chips?,Iam interested to find out how good they are before I build one.

Cheers Pete.

[monstermetal]

I'd like learn about them, Ive seen pictures and am quite intrigued. Never seen one in operation though.

Keep us posted

[Kiwi Pete]

I saw one about 15 years ago at Forge in but never got time to use it,By chance I was looking for DVDs and saw Angele make them. I like the idea because like a coal forge you can heat a small section and odd shape that wont fit in the gas furnace.
I would just like to know how they perform.

[SoCal Dave]

I saw a ceramic chip forge at the spring conference in Petaluma, Ca. a year ago. I talked to two people that used them on a daily basis and they said they liked them very much. The chips last about 4 years but I can't say how they were used for that time period. There definitely was no smoke and you could get a localized heat on a small area, but one person indicated that it was more difficult to get a large area to heat up properly. The chips were more difficult to get than coal or coke. Rumor has it that they are more prevalent in England and Europe.

[NeatGuy]

I saw a ceramic chip forge at the spring conference in Petaluma, Ca. a year ago. I talked to two people that used them on a daily basis and they said they liked them very much. The chips last about 4 years but I can't say how they were used for that time period. There definitely was no smoke and you could get a localized heat on a small area, but one person indicated that it was more difficult to get a large area to heat up properly. The chips were more difficult to get than coal or coke. Rumor has it that they are more prevalent in England and Europe.

try using old ceramic ferrules from stud welding machines. Any structural steel place will have an infinite amount for you to experiment with.

brad

[Kiwi Pete]

[i work in a place that makes ceramics, the one use for forges is AO aluminium oxide, the thing I am most inerested in is the burners, they have a ring type that has forced air, my challenge is to design this type.

[ironwolfforgeca]

COOL topic theres a few smiths out there that can't handle coal or coke smoke any more and have to use propane they miss the heat a coal has one friend was looking it to chip forge info I will tell him of this thread he mite have some more info on this :<)

[Kiwi Pete]

I have built a prototype to see how things would go,I havnt added forced air yet but got a reasonable heat with an old propane nozzel but it tended to blow the chips about.

the other problem was the AO2 chips shattered when cold hit them,they dont like thermal shock.
I was in Belgem last week and had a look at the real one,it has forced air but ring type burners that seem to give a softer heat and much hotter so back to the shed for Mk 2.

[pkrankow]

I was in the grocery buying cat litter, and saw this litterbox that uses ceramic pellets. I thought of this thread with a laugh. I don't know what type of ceramic they are however.
Phil

[Ian Wille]

This is something I've been working on for about one year now. I have actually had some success and have been able to build my own chip bed forge that works reasonably well. In use, the chip bed itself will reach lemon-yellow, and will heat a short section of 1" square to working temperature from cold in a little less than 5 minutes.

Some specifics:

I made my own ribbon style burner ( Google pine Ridge Burners; these sound similar to what you are talking about). My burner is 5" square tubing with 3" of steel plate built up for the burner face. In that face, I've drilled 25 0.2188" diameter holes for the gas/air mix to exit through. the burner body, or plenum, is 5" x 5" square tubing, 7" long. The gas/air inlet pipe is 2" diameter, and is bottom center on one of the sides of the plenum. Note that when I say bottom, I am referring to the end of the burner opposite of the face.

I am using a blower (This one). I use a gate valve between it and the burner to control airflow, as well as the damper on the burner itself.

The gas(propane) is admitted just after the the gate valve via a 0.0625" diameter orifice.

The hearth is one I made out of 0.750" plate. it is approximately 2" deep, and 12" long by 12" wide. It used to be my coal firepot, until I made one for coke.

My ceramic chips are broken up crucible material, which looks to be some sort of graphite. I break it up myself with a hammer and chisel. they do stay put while the burner is running.

The burner is mounted as in Angele's, with it shooting straight up into the chip bed.

What I've learned:

The burner, as it is works quite well for its purpose. The port size I'm using (0.2188") seems to be ideal from what experimenting I've done with the above setup. The steel face of the burner was done for temporary purposes and to allow me to easily experiment with various port sizes. Soon I will either make my own cast refractory head burner or buy one from Pine Ridge. I have found that it needs that 3" thickness. In my early models, I only had 1" plate for the face. In use that plate would get to about 1600 degrees F, at which point the incoming gas and air would ignite and flashback through the system. I added 2" of plate, and have not had that problem since. When I make my own burner, i shall make sure I have at least 3" of refractory between the burner face and the plenum.

The graphite crucible material I am using works okay, but could be better. At the temperature the forge runs, the graphite chips do soften and stick together pretty badly, so I end up stirring/breaking up the chip bed every other time I go and take another heat. Of course, the chips scatter around the table top in use, so they have to be raked back into the hearth. The chips do absorb some scale/iron into them, but not too badly. I would like to find some sort of refractory chips that have a softening temperature around 3000 degrees F, maybe 3200 degrees, with some abrasion resistance and ability to withstand thermal shock as well. Mullite seems to fit this bill better than your Aluminum Oxide, though I have only been able to source suppliers of mullite powder here in the U.S. I'm still searching for a company that makes or could economically make mullite chips. I really don't want to start making my own refractories, as I am busy enough making tools, projects, and experimenting, along with school, work, etc... but I digress... Oh, i've also found that around 2" of chips above and below the work piece really cuts down on the heating time.

Overall, my model works, but can be improved. It is very home-grown. I've taken care of as many safety issues as I am capable of. In use, it works much like a coal fire, with about the same amount of maintainance and radiant heat. The principles for fire depth/structure are also similar to that of coal, in that there's an oxidizing layer and a neutral layer, and the whole heats much better if there's a thick covering of chips above the work-piece. I get very little scale on the work when heating, which is nice. The fire is also quite clean, with no soot or smoke, which I like. I can also adjust the atmosphere of the chip bed as well to get the neutralizing fire I want. I have found it works for both short and large heats, though heating up large pieces does take quite a bit longer.

I present this for learning purposes, both for everyone's and my own. I'm just 21, and have a great deal to learn yet, so anything that anyone sees that I have gotten wrong or understand improperly, by all means, let me know. What I've learned here has been through trial and error and some reading and using good old mental reasoning. I know that what I've made works, and now I'm going to improve upon it.

I will be going home this weekend (where I have my forge) and will take picture and get more information while there, maybe even some video too.

Ian Wille