Backyard Foundry – oil burning furnace – moulding and casting a spider

[LukerParticipant @luker]

Posted by the artfull-codger on 03/01/2022 18:52:35:

Interesting posts about different fuels,I built my first furnace nearly 50 yrs ago with my late father,[& burnt a few out since!!] the only information for an amateur [like me] was B.Terry Aspins "bible" foundrywork for the amateur, no internet then, with folk casting alloy wearing flip flops & shorts & pouring it into tart tins & getting loads of praise on their apparent skills, as Luker says [& I really enjoyed his articles & also learned a few things from him!!] there's various ways to build a furnace, when I started I built mine to run on coke with a blower, as per B.T.A. 50 yrs on I'm still on coke poss because we always have a couple of tons in for our rayburn cooker but as said above it's getting more difficult to get coke now with demise of the steelworks,I did build a small propane furnace powered by my flamefast torch & it's really good but having inherited a large amount of central heating oil along with the central heating burner I might try that, propane is really expensive, of course you can get re-fillable bottles & it's much more cheaper at the forecourts.

Graham.

Thanks Graham. There's a few more I've submitted to ME about casting, from methoding to furnace linings, and alternative-simpler alloys from base metal scrap for the model engineering. I hope you guys find them interesting!

[LukerParticipant @luker]

Posted by the artfull-codger on 03/01/2022 19:12:59:

Hi Luker I must look at your oil fired burner seeing as how i inherited gallons of oil from my late father in laws central heating tank, next door. luckily I live in a village & we have a large back yard so noise isn't an issue & we're not in a smokeless zone , the good thing about coke furnaces is they're quiet, I use a bouncy castle blower with a home made restricter disk on the inlet, no electronic gizmo to go wrong, in fact when I'm fully glowing the inlets almost closed so the motors doing hardly any work in fact it's using less electric!! btw I've mixed up some of your additive for melting fine turnings, I'll be trying it this week. as I have some nameplates to cast for his loco .

Graham.

If you're melting brass fines rather pour them into ingots, you might end up with too much super-heat. Gunmetal and the bronzes work a little better when pouring directly into moulds from fines.

Yep please give it a go and let us know how the burner works for you.

[LukerParticipant @luker]

Posted by MikeK on 03/01/2022 19:15:27:

Posted by Luker on 03/01/2022 18:59:44:

The running joke in our house is that anyone who looks over the wall and complains about someone casting metal should rethink their strategy. At least the person casting has a hobby and doesn’t get up to mischief. Seriously though, I live in a city suburb and have asked all my neighbours if the furnace makes a noise and they all said it does not. I have a large box covering the blower (this makes most of the noise) with inverted egg boxes glued to the inside which dampens most of the noise. The furnace itself isn’t too noisy.

Thanks, Luker. Unfortunately, I live in the city proper. Small city lot and exposed to neighbors on all sides, no fences. If I lived in the suburbs I would have much less concern. My next door neighbor has complained about a lot of things, including me parking my car in the *public* street in front on her house. I suspect she would think I *was* up to mischief with a casting furnace. Some people take the hint when being ignored, others unfortunately don't. From the videos I've seen, the burner has a pretty big roar even without the blower. No?

Yep it does… I would guess its similar to a vacuum cleaner.

[the artfull-codgerParticipant @theartfull-codger]

Thanks for the info Luker I'll let you know how I get on.

Graham.

[PatJParticipant @patj87806]

There is a fellow in the Pacific Northwest who build an iron furnace, and his neighbor complained about the noise.

He added a six foot sheet metal chimney that is lined with ceramic blanket, and installed that over his lid opening, and build a box for his combustion air blower.

He verified a very low dB with an inexpensive measuring unit.

My neighbors have not complained (yet) about my furnace, but I do live next to an expressway, and the dB level from cars and trucks passing is absurd already in my back yard.

One trick I have used is to place small sections of rubber floor mat under each wheel of my furnace, and this takes out a lot of the low frequency rumble that many hear.

An oil burner and furnace is basically acting like a V1 pulsajet, and thus the noise created, plus the blower noise.

At some point soon I will move my blower indoors, and stretch a hose out to the furnace, to eliminate that noise.

I have excess combustion air, and so the pressure drop across a long hose is not a problem.

If an oil burner is tuned correctly, and especially if it is operating on diesel, it should start cleanly, and operate with no smoke at all. It should not produce any smoke upon shutdown either. In some of my videos, you can see what looks like a lot of smoke, but it is actually steam from water that has crept into my ceramic blanket.

I keep my furnace outdoors at all time.

A muffler stack is an option, but uncoated ceramic blanket in the exhaust stream will produce fibers that you do not want to inhale.

Here is the fellow with the muffler stack.

Be sure you have some outriggers on your furnace if you crane out your crucible like this, because it is easy to flip over your entire rig with a crucible full of iron.

https://www.youtube.com/watch?v=LSQ-NbMpaMg

 

Also I don't use rubber or plastic anything near a furnace, since it is only a matter of time until you will melt and ignite that material.

 

Edit:

You can notice the dB level drop dramatically when he closes the lid at 0:36.

His blower is in the box behind him, and so no high pitched whine from that is evident either.

.

Edited By PatJ on 03/01/2022 20:11:18

Edited By PatJ on 03/01/2022 20:12:17

Edited By PatJ on 03/01/2022 20:13:28

Edited By PatJ on 03/01/2022 20:14:18

[noel shelleyParticipant @noelshelley55608]

For a simple gas furnace see, dubious engineering – melting brass in a spindrier, You will see me and my mobile foundry in operation ! Enjoy. Noel

[the artfull-codgerParticipant @theartfull-codger]

Hi Luker, lit the furnace today, [coke fired] & cast 2 nameplates & 2 number plates in brass for a friends little boy [6 yr 0ld] for his 5" battery loco he built for him, patterns made from mdf cut out on a fretsaw, I had small turnings chrome plated brass bath taps few plumbing fittings & few old steam rally plaques,,Put a tablespoon of your additive in the crucible & the brass cast really well, no porosity lovely castings, cleaned up well, very little if any zinc loss I always keep a lid on my crucibles & coat tools,skimmers pyrometer probe etc in contact with the metal with zircon based refractory wash also ingot moulds & tart tins as well as you will know molten alloys corrode steel as well as poss contaminating the melt, did you put details of your oil burner in model engineer? I'm interested in building one & like the sound of it ,thanks.

Graham.

[LukerParticipant @luker]

Hi Graham, that's great news! Thanks for the feedback. I'm always glad when someone can take something I've written about and reproduce the results, then I know I'm sharing knowledge and not just boasting .

Yep my furnace design, including the burner, is in ME4626. I gave the ratios of what will work based on my calculations, but my actual sizes are also given.

Please let me know how you get along!

PS have you got some pics of the name plates?

[the artfull-codgerParticipant @theartfull-codger]

Hi Luker, thank you for that info, [embarrassed now as I have the back numbers of ME, & should have looked,!!] I've taken some photo's of the melt & the furnace in action & have just been fettling the castings up today I'm etch priming then paint with traditional red background I've polished the letters but I'll have to get my son to print them in here as I don't know how to, he should be up this week sometime once again thanks for your help, photo's to follow.

Graham.

[noel shelleyParticipant @noelshelley55608]

Hi Graham Ladle wash will help to reduce cross contamination from one metal to another, though the level of contamination will be so small as to make little difference. Whilst the heat will accelerate corrosion The real matter is that of molten metals dissolving one into another, even when the solid metals melting point is way above that of the molten metal. Noel.

[the artfull-codgerParticipant @theartfull-codger]

Hi Noel, thanks for that info, when I started work at the local high school one of the first things I did was get the unused flamefast crucible furnace up & running I had no ingot moulds so I poured surplus alloy into large jam tin till it was semi-hard then tipped it out into crucible sized lumps all ok for a few melts till one day the bottom fell out!!! after that I made moulds & got refractory wash. hehe .I'll look at your " melting brass in a spin drier"

Graham.

[Dave Wilson 4Participant @davewilson4]

Posted by MikeK on 03/01/2022 18:40:50:

I'm curious…How quiet can these furnaces be made to run? I would love to try casting, but live in the city with close neighbors who may complain.

Your neighbours will complain if you are in close proximity. If you are experimenting it may produce a lot of smoke and noise. Try propane fuel but i have had success with solid fuel ie. blacksmiths nuggets and anthrocite with a small blower, very quiet, when running right no annoyance.

[MikeKParticipant @mikek40713]

Posted by Dave Wilson 4 on 11/01/2022 20:17:48:

Posted by MikeK on 03/01/2022 18:40:50:

I'm curious…How quiet can these furnaces be made to run? I would love to try casting, but live in the city with close neighbors who may complain.

Your neighbours will complain if you are in close proximity. If you are experimenting it may produce a lot of smoke and noise. Try propane fuel but i have had success with solid fuel ie. blacksmiths nuggets and anthrocite with a small blower, very quiet, when running right no annoyance.

Thanks Dave.

[the artfull-codgerParticipant @theartfull-codger]

Posted by Luker on 10/01/2022 17:13:25:

Hi Graham, that's great news! Thanks for the feedback. I'm always glad when someone can take something I've written about and reproduce the results, then I know I'm sharing knowledge and not just boasting .

Yep my furnace design, including the burner, is in ME4626. I gave the ratios of what will work based on my calculations, but my actual sizes are also given.

Please let me know how you get along!

PS have you got some pics of the name plates?

Hi
Luker, [son came up & loaded up for me!! thanks Philip] a few pictures of my set up 1st one showing the drag with the patterns removed,2nd one the "pot fodder" bath taps rally plaques plumbing fittings etc,3rd one moulding boxes ready to pour 4th one shakeout & lastly the finished castings for the little lads loco fettled polished acid etch primed & 2 coats of 2k suzuki red.

[the artfull-codgerParticipant @theartfull-codger]

Oops, added more pictures & got details mixed up!!1 & 2 ok 3 first lighting up with wood4 moulding boxes ready to pour 5 pre warming brass on top of crucible with more on the top of the lid 6 ready for lift out 7shake out & finished castings!

[LukerParticipant @luker]

Hi Graham, the name plates look great! Surface looks spotless and they polished and painted beautifully. Thanks for the pictures.

[LukerParticipant @luker]

Hi Fellow foundrymen… I took some time off my day job to get some casting done this week and am putting together a few videos. Dave’s original post was inspiring! I thought I would start with a short video on melting fines for bar stock…

[the artfull-codgerParticipant @theartfull-codger]

Hi Luker,I need to cast bronze barstock but the last time I tried it [a few yrs ago] vertically it was great on the outside but after turning it it was full of porosity,inside so I cast some horizontally with sprue & feeder & they came out ok but a mess on molding them, this of course was before & knew about your inoculant which I've just used[big thanks] perhaps I'll try again vertically.,saves time .

[LukerParticipant @luker]

Posted by the artfull-codger on 05/02/2022 14:25:18:

Hi Luker,I need to cast bronze barstock but the last time I tried it [a few yrs ago] vertically it was great on the outside but after turning it it was full of porosity,inside so I cast some horizontally with sprue & feeder & they came out ok but a mess on molding them, this of course was before & knew about your inoculant which I've just used[big thanks] perhaps I'll try again vertically.,saves time .

Hi Graham, the trick to stop that is the dusting with coal dust. The inoculant won't prevent porosity or piping from happening. If the top freezes first you likely to get porosity or piping in the bar. The idea is the coal keeps the top surface hotter for longer and the draw is from the top surface not the middle. I cast all my bars vertically.

[the artfull-codgerParticipant @theartfull-codger]

Hi Luker thank you for that info [priceless!] it's a faff on 2 part molding from bar I'll get the furnace fired up this week.& see how I go,.

[LukerParticipant @luker]

Hi Graham, my pleasure. Please let us know how it goes (pictures are always nice!). Here’s another video I took the day before of me moulding, with the sprue on the parting line to improve the quality of the outer surface, and increase the head in the mould. My neighbour was interested to see me moulding and casting and asked if he could watch me mould a pattern. I explained what I was doing and we had a good old chat. The video is long (20min) and is probably only of interest to guys that have moulded cored-split patterns in green sand. The casting is copper chimney caps for my current build.

[Roger QuaintanceParticipant @rogerquaintance14196]

Any foundry men in north Devon I wonder, time I got into it

[noel shelleyParticipant @noelshelley55608]

Hi Luke, in the first your pouring brass ? there seem to be plenty of fumes ! It was good to see another tradesman at work ! To cut the gates may I suggest you take bit of tin plate cut from a 5L metal can about 3"W X 4"L and bend it into an S so the top part is 1/2" dia and the other end is 3/4" dia, this will cut the sand as clean as a whistle up to the pattern and then use a 4" hat pin or sharpened hard wire to clear the sand right to the pattern side. Always cut down so that you do not brake away the edge as you exit the sand, so down 120* round and then from the opposite side 120* round. The same when using the pasterers tool to cut the runner, cut down from both side so the sand is in compression, it's much quicker and reduces the chance of broken edges. An easy way to make good heavy mold boxes is to visit the local scrapman and but a yard/metre of LARGE box section and cut it into suitable matching lengths, add handles of 10mm round and locating pins. Have you tried using an insulated sleeve to help control shrinkage ? Best wishes Noel.

Edited By noel shelley on 24/02/2022 16:42:28

[LukerParticipant @luker]

Hi Noel, thanks but technically I'm not a tradesman, just a guy who plays engineering in his back yard . Those were fines so they do get cast at a slightly higher temperature. I have found the loss of Zink is negligible for all the castings I've tested so I don’t worry too much about it. I've set my furnace up in such a way that the exhaust acts as an extractor for the immediate area which clears up very quickly.

I’ll give your ingate maker a bash, thanks for the tip!

Unfortunately buying from the scrap industry is very difficult with all our legislation. Lucky my boxes were made some time back. I do like your idea for a box though…

I have experimented with home-made insulating risers and even hot capping (that can be a little dangerous if you get the calcs wrong), but to be honest I don’t bother. Most of my casting issues can be solved with proper risering or mould orientation. BTW here’re some pictures of the one piece in the video. It’s been machined and gone over with a little emery, just needs to be polished…

[the artfull-codgerParticipant @theartfull-codger]

Another excellent casting video Luker, I modified a couple of my flasks a good few years ago as I had a number of

"claw feet" to cast for a large alter cross for our local church that had "lost" them,[traditional

brass casters flasks] they all came out well,cast like this, brass is a "dirty metal" to cast, bronze being much nicer,as an aside I have a great supply of zinc, the garage in our village get's the odd machining done by me & as well as getting alloy from him he saves me all the wheel balance weights as they don't use lead now but steel or zinc,& they usually have zn cast in them so I sort them & make nice clean ingots.

Graham.

[Author]

Posts