Lionel Furnace Build

Some may recognize the furnace kit I will be working on, for those that don't. It came from Lionel from alloyavenue years ago ( I don't think they are available any longer ) .









What I am working with-
: Lionel's Furnace Kit
: Kast-O-Lite 30 LI Plus refractory ( while properly stored it is past shelf life, so it may not work very well. )
: Stainless refractory needles if I can find them in the shed ( are they even necessary? )
: 10" concrete form tube for the center opening of the furnace
: Propane burner, tank, regulator hoses ect.

I also have a old hot water tank in the scrap pile I have considered using for a furnace. It would offer a slightly larger furnace. However I may save it for a future project.



I am planning to melt aluminum cast in green sand. I still need to grab a crucible ( any recommendations for this size furnace? ) lifting , pouring and other related tools will be made in house once I grab a crucible to work off of.

I will be updating this with more progress as I get the shed better organized to make room. I just wanted to drop in and get a thread going to post progress, updates and get welcomed feedback.

 

I had, used, and sold one Of Lionels Furnaces. Might want to make the vent hole a little bigger then recommended, I always had to prop the lid open a 1/2 inch or the reil burner would not work well. I found it too small for my use, and built a larger furnace on an only slightly changed design, I ran the drain out the rear rather then out the bottom .

if I remember an A16 was really pushing it in the Hobby melter , made it really tight to get a lifting tool in, one of the reason, if you watch any of my videos, my lifting tongs look really insugnifigant... same ones

I believe lionel recommended a 6 inch diameter pipe crucible , probably ok for aluminum, I killed several on brass, even with linings of ITC... really try and stay away from pipe crucibles, if you intend to stick with it, they will just slow down your progression in casting


V/r HT1

 

I see the original instructions recommend a 3.5" vent hole, would a 4.5" be more appropriate size? I like the idea of running the drain out the rear and think it could be incorporated. I definitely plan on running a proper crucible right out of the gate, I want to minimize as many headaches as possible. I will have enough other things to be learning lol

 

4 inch should be OK, that is what the Mifco Furnaces run

 

I'm using a Lionel. Don't bother with a drain hole. As designed, any melt down the drain hole tends to freeze between the bottom plate and the refractory making it hard to dislodge; just throw a little sand on the bottom. If you have a fully melted crucible failure just keep pulling aluminum out as it freezes. Additionally, the drain hole cause massive thermal shock to the plynth so they don't last very long.

I've been using propane at 2.5 psi to the burner. I can't crank it any higher or the furnace starts pulsating. I think a larger vent is a good idea.

Several spot welds let loose while "curing" the refractory, I heated it too much too quick.

I don't think you'll gain anything by adding needles. I had a BIG problem with refractory oozing inside the 10" tube and needles would have made it so much worse.

I've been using crucibles made from 5" schedule 40 steel pipe. The weight of the crucibles haven't changed (+/- 2 grams) since I've used them but one has developed a very slight bow.

 

I used Bondo fiberglass resin to coat the exterior of a 10" form tube (9.5" actual) for use w/ Kastolite 30 for my keg furnace. Cardboard discs glued inside the form to hold it round and centered. There was no water or refractory intrusion. IIRC a 9.5" bore will have 1.4" clearance around a Salamander A10.

Good luck with your build.

 

Thank you for the advice everyone, I am learning a lot as I soak in your tips. Reading as much as I can before diving in.

You are correct, I did not realize that concrete forms are nominal. Looks like I will be getting roughly a 9.5" ID Furnace and not a true 10". ( trying to use as much as I have on hand from gathering over the years.) I think this size will be okay for getting started.



I found a E-bay seller listed here on the forums in another post that seems to have decent prices for crucibles that I will most likely be placing my order with here soon. Seller "LINK"

I was just discussing coating the form to prevent it sticking to the refractory in the hopes of being able to pull it out easier (Though I suspect I can burn it out if need be). I also really like the idea of filling the center form with sand to hold its shape.

On the lid front, I have designed a 3d printed plug to give me the 4in vent opening. The plug would also include a slight dome to the underside of the lid. In the screenshot you can see the sheet metal lid with rebar that is included in the kit around the 3d printed plug.

 

Ive built 3 monolythic furnaces , I dont know who had a Sonobouy form colapse, but you did something wrong. too much water, or Ramming way too hard

you do need support at the top and bottom ends, cut a circle in 1/2 or 3/4 Ply to fill the top and bottom of your form, staple or nail the tube to the exterior or the Plywood circles, if i remember right I put a couple(probably3) of 1X1's running top to botttom to hold the circles in the correct location, this will give the concrete form way enough strength

, you can enlarge or shrink the form , My third furnace, I cut a section out of the tube , to take a 14 down to 12, the Plywood ends dictate your Diameter, you an also add a section if you need to go bigger .

the top Plywood ends need openings for air, because you will have to burn the form out, this is your first sintering of the furnace , I remember specifically cutting 2 Half moons out leaving a handle in the center with a jig saw

do you not have Lionels instructions? I thought this was all in there step by step


V/r HT1


P.S. I would definately use needles if you have them, it's just insurance

 

I cut cardboard discs w/ an Allpax circle gasket cutter. Punched center holes w/ sharpened 1" pipe on shop press. Glue gunned discs inside tube about every two inches, double discs top and bottom. 1" PVC pipe centered in cast in drain in floor of furnace, previously poured and set. Coated entire exterior of form tube and discs w/ two coats of fiberglass resin.

Was going to weight the form w/ brake rotors or drums but decided on holding it down w/ square tubing and all thread. Form tube didn't move when ramming and held center well. N,S and E were dead nuts equal tube outer to keg wall. W was + 3/32", not too shabby.




Let dry 3 days. Tube removal was easy. Pulled 1" pipe. Pulled out discs one at a time, kinda like opening a cardboard shipping box. Remove tuyere form pipe. Could then collapse the form tube in on itself and remove. No buckling in, no water or refractory intrusion. I would do this again.

 

Today I got everything setup and ready in the shed to mix the refractory and pour the furnace on my next free day. Waiting for a full free day as to not rush myself. Getting excited to have my own furnace on site. In the past I have always relied on others to fill any cast part need I had. I am very much looking forward to learning to cast my own.

No, no printed instructions came with the kit that I recall ( however having been in storage i may have just lost them ) . Lionel's Hobby Melter kit page has reported as "End of Internet" since I purchased the unit. Luckily there has been a ton of info available from old threads on the internet and folks like we have here on the forums willing to answer my questions.

Okay cool, That was my thought as well. Good insurance and a no harm no, foul kind of deal.

 

OK When I sold my furnace, I gae the instructions to the fellow I sold it 2 Let me see if he might be willing to share

V/r HT1

 

A bit of productivity today
I don't have any cardboard tubes or pvc ect. around the place. So for the vent and drain I used what I know and 3d printed a plug for both. Each heavily waxed with paste wax in the hopes I can pull them free, each also has a fair amount of draft. We shall see how that works out when I go to pull everything apart.

In the documentation that came with my refractory, it calls for 4.5L of water per 55lbs bag. It seemed rather dry to me when mixed however I pushed forward with the recommended amount. To each bag of refractory I added seven large hand fulls of stainless steel refractory needles mixed in. For the center concrete tube I followed the advice from Fasted58 and cut a number of cardboard circles that I proceed to hot glue into place. In total I used about 1.25 bags of Kast O'Lite 30 refractory.

The 10" concrete tube was initially planned to be coated in the same heavy wax product I used on the 3d printed vent and drain plugs. In my work flow however I neglected to do this. The cast base is roughly 2" thick and the furnace walls right around 1-5/8" thick.

 

Looking good! Won't be long now. I haven't used kastolite as I run mizzou, but with any refractory, slow curing is the name of the game. Follow the curing instructions from Kastolite and you'll enjoy nice long service from it.

 

Thanks, yeah the drywall paddle worked really well for the min or two my battery drill lasted. I think a corded unit + that paddle would have been perfect for mixing.

Well everything came out of the furnace with ease. The concrete tube left the furnace a little fuzzy and the drain hole plug did not work as well as I was hoping, other wise no problems.



The way the drain plug was held in place prevented the refractory from properly flowing around it leaving a rough finish.



The 3d printed form for the vent worked really well.



Yesterday I spent the day slowly drying out the furnace and heating it up over the course of about 8-10 hrs after letting it sit covered overnight.

 

Nice work!