Re: Topic: backyard foundry

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Posted by James on January 10, 1998 at 19:22:13:

In Reply to: Topic: backyard foundry posted by roberto on August 23, 1997 at 19:41:49:

: I just ran across some very interesting reading at a site called, "Backyard

: Foundry",

: http://reality.sgi.com/employees/kurts_engr/foundry.page.html

: Very interesting page on an inexpensive way to do some casting.

: Sorry if this is old news to some of those here, it's the first time I've

: read it.

: David

: Graphic Design/Illustration; http://www.flash.net/~dwwilson/

:

: I have also heard that you could simply line a metal trash can with kiln

: wool. I am wondering if the burner has to be forced air or if a venturi

: would work. Anyone ever done that?

: Cynthia

: TX

: Cynthia,

: I don't know about the use of a trash can (I would think that it might heat

: up a lot) but I use 1/2" welded wire screen as a frame, over the wool, and

: it lasts for 30-40++ firings before burning to a point that it needs

: replacing. Actually the top around the exhasut hole and the top edges of

: the body ring are the places that tend to burn the fastest. I fashion

: horseshoe wires with an inch long piece of "ceramic kiln heating element

: wire holder ceramic tubes" (about 1/3" diamater 6"long rods with a hole

: through the center that I score and break into 3/4 - 1" long pieces and

: slip a 6-8" piece of nichrome wire through the hole and form a

: horseshoe/staple deal). These wire/tube staples are pushed through the

: wool to the outside and bent over the wire. I used high temp wool on the

: inside and lower temp on the outside (2 thicknesses of wool).

: I used a forced air (squirrel cage with an air control flap over the air

: inlet) into a 2" black pipe burner (about 3" long) with a 1/2" closed off

: pipe with a 3/32" hole for a gas nozzel stuck into the side of the pipe.

: Currently the fan blows directly into the end of the pipe, but the next

: time I have to rebuild the burner, I will have the fan going into the side

: of the pipe or use a 90 deg elbow on the inlet side (this to get better

: mixing). The venturi would probably work for the shell kiln, but I really

: do not think it would be very good for the melting furnace.

: This is my 2 cents worth. Good luck

: John

: I don't know anything about making a forced air burner. Any books that

: describe how to make one (though I'd rather make something else)? Who

: is a good supplier for one that would work on a small crucible furnace?

: This is something else for my list of rare and hard to find items.

: Cynthia

: TX

: I made a burner something like this for a melting furnace and had a

: problem with it. The flame doesn't have a well defined position. The

: first time I fired it up, the pipe leading to the furnace got hot and

: started glowing. I had to watch it like a hawk and regulate the air to

: keep the flame inside the furnace (not climbing back up the mixing

: pipe!).

: There is an excellent way to avoid this problem called a flame holder.

: You make it by putting a "target" like shape in the end of your burner

: tube. For instance, if you have 2" diameter 1/8" wall pipe for your

: burner, make the target by welding in rings of smaller and smaller

: pipe concentric with the original tube. Pipe, air gap, pipe, air gap,

: etc. so that you have a 1/8" ring of metal, 1/8"ring of air, 1/8"

: ring of metal, etc. Finish it off with a solid 1/2" plug. Use 1/8" rod

: as spacers for the rings and weld them in place.

: The idea behind a flame holder is to introduce turbulence in the

: air/fuel flow at a specific place. That is where the flame stays. A

: flame holder has the fringe benefits of making your burner light

: easily and stay lit. It also makes the flame a lot quieter.

: --

: Steven O. Smith

: steve@cc.com

: >

: >I have the Graingers catalog and see the blower you mentioned. I am

: >wondering how to connect the gas to it. Is that the 90 elbow you

: >mentioned? Is there any safty shutoff equiptment that I might also

: >install on it?

: >

: >Cynthia

: >TX

There is a out of print book on backyard casting. I would like to get it. Also the writer has an newsletter for people that cast at home. can't rem. name will look for it and post.

: Ah yes.... the gas. we took a piece (8") of black steel pipe, welded the

: end shut (cut sections out and bent the remaining sections into a sort of

: bullet nose shape and welded it up tight). Drilled a 1/8th" hole in the

: side of teh pipe neat the end. On the other end we threaded a compressed

: air fitting to the pipe. I have all of my propane lines with compressed

: air fittings, my burnout tourch, melting furnace, shell firing furnace etc.

: and they have worked very well. I set up a smallish needle valve and a

: 1/2" ball valve on the end of the gas line before the coupling fitting. So

: from the nozel back towards the gas supply it would look like: 1/2" gas

: nozzel, male gas fitting (this is a complete unit) then the next item in

: line is the female gas fitting, at least 6 feet of hose (to enable gas

: adjustment while not next to the furnace), needle valve, ball valve and a

: male fitting on the end ((this is a complete unit)) (to go into the female

: fittings on the supply line). Got it so far????

: Drill a hole in the side of the 2" burner pipe about 8-10" down from the

: elbow and insert the 1/2" gas nozzel into this hole. The blower is on the

: very end of the 2" pipe on the 90 deg. elbow. I run these at about 20 psi

: gas pressure (I got a variable regulator from my gas supplier, looks like a

: compressed air pressure regulator).

: The needle valve is for fine adjustment of the burner so you can actually

: turn the burner on and off with the ball valve, leaving the finely set

: needle valve where it works best. This makes it very easy to turn the

: burner on and off, as it is relitively "permanently" adjusted.

: I do not use any flame sensers (optical/electrical switch that turns off

: the gas if for some reason the flame goes out or you loose power) so

: someone is always present when we are firing and/or melting. These burners

: are a bit difficult to lite, so either use a piece of lit, crumpled paper

: tossed into the furnace then turn on the gas then the air or a ***very***

: long match. I have been told that if you make a couple of circles of wire

: that fit inside one another and weld them on a cross frame and insert this

: into the outlet end of the burner, it will be easier to lite, but I just

: use the paper (or the burnout tourch, which is about 4 feet long and

: reaches into the furnace easily).

: If you have other questions, please feel free to ask.

: Best,

: John

: first time I fired it up, the pipe leading to the furnace got hot and

: >started glowing. I had to watch it like a hawk and regulate the air to

: >keep the flame inside the furnace (not climbing back up the mixing

: >pipe!).

: Had this problem too until I put on a bigger fan. Also adjusted the gas

: pressure (higher up to around 20 psi). Also, don't insert the nozzel so

: far into the furnace, just to the outside edge (make sure the gas/air mix

: is **all** going into the furnace, use bricks and k-wool to make a sealed

: entry. I a problem, can use a wool hardner/stiffner to make a more non air

: permable seal throught the furnace wall.

: >

: >There is an excellent way to avoid this problem called a flame holder.

: >You make it by putting a "target" like shape in the end of your burner

: >tube. For instance, if you have 2" diameter 1/8" wall pipe for your

: >burner, make the target by welding in rings of smaller and smaller

: >pipe concentric with the original tube. Pipe, air gap, pipe, air gap,

: >etc. so that you have a 1/8" ring of metal, 1/8"ring of air, 1/8"

: >ring of metal, etc. Finish it off with a solid 1/2" plug. Use 1/8" rod

: >as spacers for the rings and weld them in place.

: >

: >The idea behind a flame holder is to introduce turbulence in the

: >air/fuel flow at a specific place. That is where the flame stays. A

: >flame holder has the fringe benefits of making your burner light

: >easily and stay lit. It also makes the flame a lot quieter.

: >

: >--

: >Steven O. Smith

: >steve@cc.com

: I guess I had better make a couple of these and give them a try. Keep

: hearing of their advantages..... Thanks!

: Cynthia, this is what I was trying to explain in my post to you, but Steve

: did a better job of explaining it.

: Thanks again to everyone on this list. I am so very glad we are all here!

:

: I have found light with paper to be very dangerous and set up my forge

: blowers so they can be slide in and out of the burner port. I pull the

: burner out so only the very end of it is inside the burner port and light

: it with a propane torch. When the flame is adjusted and the inside of the

: forge has picked up some heat, I slide the burner head in. This is not only

: safer, but it also extends the life of the burner heads because you can

: withdraw them when you shut down. The slide need be no more complicated

: that a flat bar welded to the side of the furnace and a hanger on the

: burner.

: Another way to light the forge if you have a fixed burner configuration is

: to drill a hole 3/8ths or larger at the port and light it with a propane

: torch through the hole. This small hole is also useful as you adjust the

: fire.

: All of these devices put out volumes of carbon monoxide gases and if they

: are used inside they must have a hood over them to vent. The hood should be

: a foot over the top of the unit and exend beyond it. It should also have a

: straight pipe to the outside with no elbows.

: Don Fogg

: dfogg@concentric.net

:

: Hello friends,

: You've given me lots of great info on this subject. Thanks to John,

: Cynthia, Steven. I produced a web site for this type of forge/foundry using

: a "target" type burner. It's in pdf format. So you need Acrobat to view the

: file. The question I have is, isn't this what your talking about? I'm a

: total novice here. If anyone would please take a look at the plans and let

: me know. The Plan 1 illustration has a "target" type drawing.

: David

: Graphic Design/Illustration; http://www.flash.net/~dwwilson/

: Environmental Links; http://www.flash.net/~dwwilson/environ.html

: Forge Plans; http://www.flash.net/~dwwilson/forge/fgpl.html

: David Wilson wrote:

: >

: > It may be "off the wall", but would it be possible to install a barbeque

: > grill spark ignitor? I've seen these for sale at hardware stores as

: > replacement parts.

: >

: > David

: It's not off the wall at all, as a matter of fact it's been done many

: times. You would install it between the flame holder and the 90 degree

: bend.

: Bill

: Another good way to ignite is a spark plug and a flourescent tube ballast(at least

: 10,000 v). Set it up so it shorts to the opposite side of the burner, right after

: the mixing chamber.

: Also, better than chucking paper in, just wrap some cloth around a piece of metal

: rod, wrap wire around it and soak with a little paint thinner or kerosene (not

: gasoline). A very nice little torch that will fit the space between the crucible

: and furnace wall very nicely. You can even put it in and back away as you ignite

: then pull it out after ignition. I keep a length of pipe next to the furnace to

: stick it into after the furnace is lit-it smothers itself and keeps the solvent

: fresh if you need it again. Pyro's unite!!!!

: MP

: I examined the monster burners on my kiln the other day (I don't know

: why I didn't think of this before...duh). On the burning end of a 3"

: black pipe is a 4" section about 4" long. One half inch inside from the

: end is welded a 1/2" ring which chokes the opening down to the 3" pipe

: size. I am assuming this inner ring does the same thing that Steve is

: talking about, if so it would be simpler to make. At 500,000 BTU

: maximum ea. these burners are real quiet. They stay lit *but* there is

: a pilot burner under each one with a thermocouple safety shutoff. So, I

: wonder if this single ring would keep the burner going without the pilot

: burner.

: Cynthia

: TX

: There is a very useful small paperback called The Backyard Foundry,

: written by B. Terry Aspin, ISBN 0 85242 603 8. It was originally

: published in the UK by Argus Publications, since taken over by

: Nexus Specialist Interests. Their latest catalogue does not list

: this book, but does have Foundry Work for the Amateur, by the

: same author. May in fact be the same book, updated. I have no

: ISBN for this title though. It is also available from

: Camden Miniature Steam Services, Rode, Bath BA3 6UB,

: priced at GBP 6-65

: Roughly half the book deals with patternmaking, slanted mainly

: towards model engineering projects, and the sandcasting process.

: The remainder deals with the how-to side of melting metals, using

: solid fuel (coke) fired furnaces, with air blowers. Small designs

: for non-ferrous, and a separate chapter on ferrous.

: In 91 and 92 the author had a long running series in Model Engineer

: which considerably expanded on the book. The parts dealing

: with ferrous foundry work started with Part 10, 6th March 1992,

: Vol 168 No.3916. Model Engineer is published by Nexus

: Special Interest, Nexus House, Boundary Way,

: Hemel Hempstead, HP2 7ST, England. They operate

: a search and photocopy service on back issues.

: Kevin Eva, Northern England, UK

: k.eva@msmail.trctho.simis.com

: Marrin T. Fleet wrote:

: >

: > > This was posted on another list that has a parallel discussion on

: > > foundry stuff going on.

: > >

: > What list? Where? Please explain!

: >

: > Thanks ...

: >

: >

: On theforge@wugate.wustl.edu which is a maillist for blacksmiths

: to subscribe send an email to:

:

: listproc@wugate.wustl.edu

: with

: subscribe theforge

: in the body of the message

: --

: http://www.well.com/user/jbin/MyPage.html

: James Binnion Metal Arts

: Kevin,

: I did a search on that book at http://www.amazon.com which is a

: online book seller and did not have any luck on finding it. Since they

: have about a million books in their data base, I doubt that it is in print

: in the US. I did however find 39 books with the word "Foundry" in the

: title. If you have not looked at this site check it out there are literally

: hundreds of books of intrest to metalsmiths.

: Jim

: >

: >OK, here's a web site for you, good as of 8:39 AM on Monday 11/25/96.

: >

: >http://www.rockisland.com/~marshall/foundry.html

: >

: >It has a link to a page on small cupola furnaces. Here's the relevant

: >text:

: >

: >--------------------------------------------------------------------

: >

: >We have three cupola furnaces of various sizes, the largest being

: >10 inch bore. Cupolas are continous melters, with the charges of

: >metal melted in layers alternating with layers of replacement

: >fuel, usually coke. There are no expensive crucibles to worry with.

: >The molten metal is accumulated in the base of the furnace and

: >tapped into homemade ladles as needed. The 10 inch Marshall furnace

: >is capable of approx. 20 to 25 lbs. of grey iron every 5 minutes or

: >about 40 to 45 lbs. of bronze every 6 minutes. Heats of upwards of

: >two hours are possible, so it is obvious that these furnaces are

: >capable of producing vast amounts of metal for their size and cost.

: >The 10 inch furnace costs less than $200. US to build and the blast

: >can be provided by a large shop vac. One man can easily operate it

: >alone. If you are interested in building one, there is more

: >information on our foundry page for ordering our book, BUILDING

: >SMALL CUPOLA FURNACES.

: >

: >And, from the foundry page:

: >

: >CUPOLA FURNACE BOOK

: >

: >Our small Cupola Furnaces are our own design and have proved so successful

: >that we have produced a 100 page book with over 50 drawings and sketches

: >showing how anyone can build their own home hobby foundry for casting iron

: >and bronze with this type melter. The book is available direct from us for

: >$25. plus $3. postage and handling at the following address:

: >

: > Marshall Machine & Engineering Works Ltd.

: > P. O. Box 279

: > Lopez Island, WA 98261 USA

: >

: >-------------------------------------------------------------------

: >

: >Intriguing!

: >

: >Morgan

: http://www.mokume-gane.com

: James Binnion Metal Arts

: 2916 Chapman St

: Oakland, CA 94601

: 510-436-3552

:

: > What list? Where? Please explain!

: Try rec.crafts.metalworking

: They tend to be more oriented toward machining and Tim Allen, but some

: really good stuff comes out of the group. We have just been through a

: MAJOR (for us) flame, but I think that the embers are dead now.

: Lee Marshall

: Bonny Doon Engineering http://www.bonnydoonengineering.com

: I know the Nexus Special Interest books are available in North America,

: maybe you have to go to a model engineering supplier rather than a

: *normal* bookseller. I'll bet a query to the rec.crafts metalworking

: newsgroup would throw up a source.

: But if anyone, anywhere, is having problems finding locally a book

: published here in the UK, I'll be happy to try to get hold of it for you

: and post it on.

: Kevin Eva, Northern England, UK

: Does anyone have

: a source for a continuous mixer for ceramic shell?? Maybe 15 to 20 lb

: capacity??

: Cynthia,

: I saw a real nice rig at a guys shop. He had barrels on turntables with a

: single fixed flat bar sticking down into the barrel on the back side which

: continueously scraped accumulation from the surface and threw it back into

: suspension. (I assume the bar was el shaped so that there was a scraper on

: the bottom too.) It looked real simple to build.

: For the capacity you are talking about, a 5 gal plastic pail ought to work

: fine. Since these pails nest so nicely, I would start with two, cut off the

: top of one and bolt it to the turntable (centered obviously) then set your

: pail of glop into it. (this will make dumping glop or replacing the mixture

: easier too.

: Good luck,

: Gene

: http://www.artmetal.com/gene-olson

: mailto:GeneOlson@artmetal.com

: ynthia asked if anyone had an idea of a source for a continuous ceramic

: shell mixer. Where I was doing ceramic shell, we used a stainless steel

: barrel that was set on the table of a drill press. We had about 150 Lb. in

: it...the table was set as far down as it would go. With stainless steel, we

: made a shaft and then propellers at the bottom. The drill press was set on a

: timer- a rather expensive one that could be set in 15 minutes increments.

: When the slurry was first mixed, we would have it going continously for the

: first evening. We would check on it every hour or so and poke at the edges

: to help to get the material in full suspension. After a day or two of being

: sure that the material was fully in suspension, the timer would be set to 15

: minutes on for each hour...I believe. It might have been 15 minutes on/15

: minutes off cycle. The reason for the cycle rather than continous was that

: if you had it continously stirred, there would be heat build up from the

: mechanical action and this in itself could cause the slurry to begin to set up.

: The reason for the stainless steel container rather than plastic was that

: the sides of the container would not flex as in plastic. If the sides flex,

: the dried splatters of slurry would fall into the mix. Unlike thick,

: settting up slurry - this dried flake would not remix or reliquify into the

: slurry.

: One very important thing when using the timer is to be sure to turn it off

: before you dip into the container. There were several times when someone

: forgot to turn off the timer...and the thing turned on when their piece was

: being dipped into the slurry..yikes!

: A friend of mine obtained a chocolate mixer for small batches at her home.

: It seemed to work fine...but again...be sure to turn off that timer before

: getting your hand in. She stopped using it after getting a rather nasty

: wrist twist - almost breaking it - when her timer turned on during dipping.

: I thought that a commercial bakery mixer would be a good idea for keeping

: the slurry in suspension. The trick is to either have the mixer mechanically

: scraping the bottom of the container....or having propellers that force

: material upwards. When we were mixing new batches, we used a more

: "uplifting" propeller than when just maintaining suspension. Good luck!

: ~~~~~~~~~Valerie Weihman~~~~~~*

: The rig I saw turned continusously, it the slurry rotated slowly in the

: moving barrel and the single fixed 'spatula' kept it mixed. He had two 55

: gal barrels on turntables with a single fixed flat bar sticking down into

: the barrel on the back side which continueously scraped accumulation from

: the surface and threw it back into suspension. (I assume the bar was el

: shaped so that there was a scraper on the bottom too.) It looked real

: simple to build. He never shuts his off. If fact, he has a honda generator

: with automatic electric start hooked up to kick in in case the power fails.

: If it stops it will set up.

: Since there are no moving parts in the mixture you just dip your part into

: the rotating slurry. His has been literally running for years.

:

: For the capacity you are talking about, a 5 gal plastic pail ought to work

: fine. Since these pails nest so nicely, I would start with two, cut off the

: top of one and bolt it to the turntable (centered obviously) then set your

: pail of glop into it. (this will make dumping glop or replacing the mixture

: easier too.

: http://www.artmetal.com/gene-olson

: mailto:GeneOlson@artmetal.com


Follow Ups:


Post a Followup

: : >I have the Graingers catalog and see the blower you mentioned. I am : : >wondering how to connect the gas to it. Is that the 90 elbow you : : >mentioned? Is there any safty shutoff equiptment that I might also : : >install on it? : : > : : >Cynthia : : >TX : There is a out of print book on backyard casting. I would like to get it. Also the writer has an newsletter for people that cast at home. can't rem. name will look for it and post. : : Ah yes.... the gas. we took a piece (8") of black steel pipe, welded the : : end shut (cut sections out and bent the remaining sections into a sort of : : bullet nose shape and welded it up tight). Drilled a 1/8th" hole in the : : side of teh pipe neat the end. On the other end we threaded a compressed : : air fitting to the pipe. I have all of my propane lines with compressed : : air fittings, my burnout tourch, melting furnace, shell firing furnace etc. : : and they have worked very well. I set up a smallish needle valve and a : : 1/2" ball valve on the end of the gas line before the coupling fitting. So : : from the nozel back towards the gas supply it would look like: 1/2" gas : : nozzel, male gas fitting (this is a complete unit) then the next item in : : line is the female gas fitting, at least 6 feet of hose (to enable gas : : adjustment while not next to the furnace), needle valve, ball valve and a : : male fitting on the end ((this is a complete unit)) (to go into the female : : fittings on the supply line). Got it so far???? : : Drill a hole in the side of the 2" burner pipe about 8-10" down from the : : elbow and insert the 1/2" gas nozzel into this hole. The blower is on the : : very end of the 2" pipe on the 90 deg. elbow. I run these at about 20 psi : : gas pressure (I got a variable regulator from my gas supplier, looks like a : : compressed air pressure regulator). : : The needle valve is for fine adjustment of the burner so you can actually : : turn the burner on and off with the ball valve, leaving the finely set : : needle valve where it works best. This makes it very easy to turn the : : burner on and off, as it is relitively "permanently" adjusted. : : I do not use any flame sensers (optical/electrical switch that turns off : : the gas if for some reason the flame goes out or you loose power) so : : someone is always present when we are firing and/or melting. These burners : : are a bit difficult to lite, so either use a piece of lit, crumpled paper : : tossed into the furnace then turn on the gas then the air or a ***very*** : : long match. I have been told that if you make a couple of circles of wire : : that fit inside one another and weld them on a cross frame and insert this : : into the outlet end of the burner, it will be easier to lite, but I just : : use the paper (or the burnout tourch, which is about 4 feet long and : : reaches into the furnace easily). : : If you have other questions, please feel free to ask. : : Best, : : John : : first time I fired it up, the pipe leading to the furnace got hot and : : >started glowing. I had to watch it like a hawk and regulate the air to : : >keep the flame inside the furnace (not climbing back up the mixing : : >pipe!). : : Had this problem too until I put on a bigger fan. Also adjusted the gas : : pressure (higher up to around 20 psi). Also, don't insert the nozzel so : : far into the furnace, just to the outside edge (make sure the gas/air mix : : is **all** going into the furnace, use bricks and k-wool to make a sealed : : entry. I a problem, can use a wool hardner/stiffner to make a more non air : : permable seal throught the furnace wall. : : > : : >There is an excellent way to avoid this problem called a flame holder. : : >You make it by putting a "target" like shape in the end of your burner : : >tube. For instance, if you have 2" diameter 1/8" wall pipe for your : : >burner, make the target by welding in rings of smaller and smaller : : >pipe concentric with the original tube. Pipe, air gap, pipe, air gap, : : >etc. so that you have a 1/8" ring of metal, 1/8"ring of air, 1/8" : : >ring of metal, etc. Finish it off with a solid 1/2" plug. Use 1/8" rod : : >as spacers for the rings and weld them in place. : : > : : >The idea behind a flame holder is to introduce turbulence in the : : >air/fuel flow at a specific place. That is where the flame stays. A : : >flame holder has the fringe benefits of making your burner light : : >easily and stay lit. It also makes the flame a lot quieter. : : > : : >-- : : >Steven O. Smith : : >steve@cc.com : : I guess I had better make a couple of these and give them a try. Keep : : hearing of their advantages..... Thanks! : : Cynthia, this is what I was trying to explain in my post to you, but Steve : : did a better job of explaining it. : : Thanks again to everyone on this list. I am so very glad we are all here! : : : : I have found light with paper to be very dangerous and set up my forge : : blowers so they can be slide in and out of the burner port. I pull the : : burner out so only the very end of it is inside the burner port and light : : it with a propane torch. When the flame is adjusted and the inside of the : : forge has picked up some heat, I slide the burner head in. This is not only : : safer, but it also extends the life of the burner heads because you can : : withdraw them when you shut down. The slide need be no more complicated : : that a flat bar welded to the side of the furnace and a hanger on the : : burner. : : Another way to light the forge if you have a fixed burner configuration is : : to drill a hole 3/8ths or larger at the port and light it with a propane : : torch through the hole. This small hole is also useful as you adjust the : : fire. : : All of these devices put out volumes of carbon monoxide gases and if they : : are used inside they must have a hood over them to vent. The hood should be : : a foot over the top of the unit and exend beyond it. It should also have a : : straight pipe to the outside with no elbows. : : Don Fogg : : dfogg@concentric.net : : : : Hello friends, : : You've given me lots of great info on this subject. Thanks to John, : : Cynthia, Steven. I produced a web site for this type of forge/foundry using : : a "target" type burner. It's in pdf format. So you need Acrobat to view the : : file. The question I have is, isn't this what your talking about? I'm a : : total novice here. If anyone would please take a look at the plans and let : : me know. The Plan 1 illustration has a "target" type drawing. : : David : : Graphic Design/Illustration; http://www.flash.net/~dwwilson/ : : Environmental Links; http://www.flash.net/~dwwilson/environ.html : : Forge Plans; http://www.flash.net/~dwwilson/forge/fgpl.html : : David Wilson wrote: : : > : : > It may be "off the wall", but would it be possible to install a barbeque : : > grill spark ignitor? I've seen these for sale at hardware stores as : : > replacement parts. : : > : : > David : : It's not off the wall at all, as a matter of fact it's been done many : : times. You would install it between the flame holder and the 90 degree : : bend. : : Bill : : Another good way to ignite is a spark plug and a flourescent tube ballast(at least : : 10,000 v). Set it up so it shorts to the opposite side of the burner, right after : : the mixing chamber. : : Also, better than chucking paper in, just wrap some cloth around a piece of metal : : rod, wrap wire around it and soak with a little paint thinner or kerosene (not : : gasoline). A very nice little torch that will fit the space between the crucible : : and furnace wall very nicely. You can even put it in and back away as you ignite : : then pull it out after ignition. I keep a length of pipe next to the furnace to : : stick it into after the furnace is lit-it smothers itself and keeps the solvent : : fresh if you need it again. Pyro's unite!!!! : : MP : : I examined the monster burners on my kiln the other day (I don't know : : why I didn't think of this before...duh). On the burning end of a 3" : : black pipe is a 4" section about 4" long. One half inch inside from the : : end is welded a 1/2" ring which chokes the opening down to the 3" pipe : : size. I am assuming this inner ring does the same thing that Steve is : : talking about, if so it would be simpler to make. At 500,000 BTU : : maximum ea. these burners are real quiet. They stay lit *but* there is : : a pilot burner under each one with a thermocouple safety shutoff. So, I : : wonder if this single ring would keep the burner going without the pilot : : burner. : : Cynthia : : TX : : : There is a very useful small paperback called The Backyard Foundry, : : written by B. Terry Aspin, ISBN 0 85242 603 8. It was originally : : published in the UK by Argus Publications, since taken over by : : Nexus Specialist Interests. Their latest catalogue does not list : : this book, but does have Foundry Work for the Amateur, by the : : same author. May in fact be the same book, updated. I have no : : ISBN for this title though. It is also available from : : Camden Miniature Steam Services, Rode, Bath BA3 6UB, : : priced at GBP 6-65 : : Roughly half the book deals with patternmaking, slanted mainly : : towards model engineering projects, and the sandcasting process. : : The remainder deals with the how-to side of melting metals, using : : solid fuel (coke) fired furnaces, with air blowers. Small designs : : for non-ferrous, and a separate chapter on ferrous. : : In 91 and 92 the author had a long running series in Model Engineer : : which considerably expanded on the book. The parts dealing : : with ferrous foundry work started with Part 10, 6th March 1992, : : Vol 168 No.3916. Model Engineer is published by Nexus : : Special Interest, Nexus House, Boundary Way, : : Hemel Hempstead, HP2 7ST, England. They operate : : a search and photocopy service on back issues. : : Kevin Eva, Northern England, UK : : k.eva@msmail.trctho.simis.com : : Marrin T. Fleet wrote: : : > : : > > This was posted on another list that has a parallel discussion on : : > > foundry stuff going on. : : > > : : > What list? Where? Please explain! : : > : : > Thanks ... : : > : : > : : On theforge@wugate.wustl.edu which is a maillist for blacksmiths : : to subscribe send an email to: : : : : listproc@wugate.wustl.edu : : with : : subscribe theforge : : in the body of the message : : -- : : http://www.well.com/user/jbin/MyPage.html : : James Binnion Metal Arts : : Kevin, : : I did a search on that book at http://www.amazon.com which is a : : online book seller and did not have any luck on finding it. Since they : : have about a million books in their data base, I doubt that it is in print : : in the US. I did however find 39 books with the word "Foundry" in the : : title. If you have not looked at this site check it out there are literally : : hundreds of books of intrest to metalsmiths. : : Jim : : > : : >OK, here's a web site for you, good as of 8:39 AM on Monday 11/25/96. : : > : : >http://www.rockisland.com/~marshall/foundry.html : : > : : >It has a link to a page on small cupola furnaces. Here's the relevant : : >text: : : > : : >-------------------------------------------------------------------- : : > : : >We have three cupola furnaces of various sizes, the largest being : : >10 inch bore. Cupolas are continous melters, with the charges of : : >metal melted in layers alternating with layers of replacement : : >fuel, usually coke. There are no expensive crucibles to worry with. : : >The molten metal is accumulated in the base of the furnace and : : >tapped into homemade ladles as needed. The 10 inch Marshall furnace : : >is capable of approx. 20 to 25 lbs. of grey iron every 5 minutes or : : >about 40 to 45 lbs. of bronze every 6 minutes. Heats of upwards of : : >two hours are possible, so it is obvious that these furnaces are : : >capable of producing vast amounts of metal for their size and cost. : : >The 10 inch furnace costs less than $200. US to build and the blast : : >can be provided by a large shop vac. One man can easily operate it : : >alone. If you are interested in building one, there is more : : >information on our foundry page for ordering our book, BUILDING : : >SMALL CUPOLA FURNACES. : : > : : >And, from the foundry page: : : > : : >CUPOLA FURNACE BOOK : : > : : >Our small Cupola Furnaces are our own design and have proved so successful : : >that we have produced a 100 page book with over 50 drawings and sketches : : >showing how anyone can build their own home hobby foundry for casting iron : : >and bronze with this type melter. The book is available direct from us for : : >$25. plus $3. postage and handling at the following address: : : > : : > Marshall Machine & Engineering Works Ltd. : : > P. O. Box 279 : : > Lopez Island, WA 98261 USA : : > : : >------------------------------------------------------------------- : : > : : >Intriguing! : : > : : >Morgan : : http://www.mokume-gane.com : : James Binnion Metal Arts : : 2916 Chapman St : : Oakland, CA 94601 : : 510-436-3552 : : : : > What list? Where? Please explain! : : Try rec.crafts.metalworking : : They tend to be more oriented toward machining and Tim Allen, but some : : really good stuff comes out of the group. We have just been through a : : MAJOR (for us) flame, but I think that the embers are dead now. : : Lee Marshall : : Bonny Doon Engineering http://www.bonnydoonengineering.com : : I know the Nexus Special Interest books are available in North America, : : maybe you have to go to a model engineering supplier rather than a : : *normal* bookseller. I'll bet a query to the rec.crafts metalworking : : newsgroup would throw up a source. : : But if anyone, anywhere, is having problems finding locally a book : : published here in the UK, I'll be happy to try to get hold of it for you : : and post it on. : : Kevin Eva, Northern England, UK : : Does anyone have : : a source for a continuous mixer for ceramic shell?? Maybe 15 to 20 lb : : capacity?? : : Cynthia, : : I saw a real nice rig at a guys shop. He had barrels on turntables with a : : single fixed flat bar sticking down into the barrel on the back side which : : continueously scraped accumulation from the surface and threw it back into : : suspension. (I assume the bar was el shaped so that there was a scraper on : : the bottom too.) It looked real simple to build. : : For the capacity you are talking about, a 5 gal plastic pail ought to work : : fine. Since these pails nest so nicely, I would start with two, cut off the : : top of one and bolt it to the turntable (centered obviously) then set your : : pail of glop into it. (this will make dumping glop or replacing the mixture : : easier too. : : Good luck, : : Gene : : http://www.artmetal.com/gene-olson : : mailto:GeneOlson@artmetal.com : : ynthia asked if anyone had an idea of a source for a continuous ceramic : : shell mixer. Where I was doing ceramic shell, we used a stainless steel : : barrel that was set on the table of a drill press. We had about 150 Lb. in : : it...the table was set as far down as it would go. With stainless steel, we : : made a shaft and then propellers at the bottom. The drill press was set on a : : timer- a rather expensive one that could be set in 15 minutes increments. : : When the slurry was first mixed, we would have it going continously for the : : first evening. We would check on it every hour or so and poke at the edges : : to help to get the material in full suspension. After a day or two of being : : sure that the material was fully in suspension, the timer would be set to 15 : : minutes on for each hour...I believe. It might have been 15 minutes on/15 : : minutes off cycle. The reason for the cycle rather than continous was that : : if you had it continously stirred, there would be heat build up from the : : mechanical action and this in itself could cause the slurry to begin to set up. : : The reason for the stainless steel container rather than plastic was that : : the sides of the container would not flex as in plastic. If the sides flex, : : the dried splatters of slurry would fall into the mix. Unlike thick, : : settting up slurry - this dried flake would not remix or reliquify into the : : slurry. : : One very important thing when using the timer is to be sure to turn it off : : before you dip into the container. There were several times when someone : : forgot to turn off the timer...and the thing turned on when their piece was : : being dipped into the slurry..yikes! : : A friend of mine obtained a chocolate mixer for small batches at her home. : : It seemed to work fine...but again...be sure to turn off that timer before : : getting your hand in. She stopped using it after getting a rather nasty : : wrist twist - almost breaking it - when her timer turned on during dipping. : : I thought that a commercial bakery mixer would be a good idea for keeping : : the slurry in suspension. The trick is to either have the mixer mechanically : : scraping the bottom of the container....or having propellers that force : : material upwards. When we were mixing new batches, we used a more : : "uplifting" propeller than when just maintaining suspension. Good luck! : : ~~~~~~~~~Valerie Weihman~~~~~~* : : The rig I saw turned continusously, it the slurry rotated slowly in the : : moving barrel and the single fixed 'spatula' kept it mixed. He had two 55 : : gal barrels on turntables with a single fixed flat bar sticking down into : : the barrel on the back side which continueously scraped accumulation from : : the surface and threw it back into suspension. (I assume the bar was el : : shaped so that there was a scraper on the bottom too.) It looked real : : simple to build. He never shuts his off. If fact, he has a honda generator : : with automatic electric start hooked up to kick in in case the power fails. : : If it stops it will set up. : : Since there are no moving parts in the mixture you just dip your part into : : the rotating slurry. His has been literally running for years. : : : : For the capacity you are talking about, a 5 gal plastic pail ought to work : : fine. Since these pails nest so nicely, I would start with two, cut off the : : top of one and bolt it to the turntable (centered obviously) then set your : : pail of glop into it. (this will make dumping glop or replacing the mixture : : easier too. : : : http://www.artmetal.com/gene-olson : : mailto:GeneOlson@artmetal.com " />



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