Author Topic: My new foundry  (Read 25023 times)

Offline NormanV

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My new foundry
« on: September 24, 2013, 03:48:36 PM »
I had to leave my old foundry behind when I returned to the UK from abroad and now need one for my next project. I was living in the Falkland Islands and sourcing materials was a bit of a problem but I managed to find everything that I needed for next to no cost. For fuel I used peat that was free. I successfully produced a number of castings.
I thought that being in the UK it would be easier, not true, nothing is available locally and I have had to search Ebay or travel long distances to get materials.
At long last I was ready to start building today I obtained an old vacuum cleaner from a scrap yard that was the right size and is on a wheeled trolley, plus the motor will do for the air supply.
The drum is stainless steel which should solve the rusting problem that I had with my old one.

Offline NormanV

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Re: My new foundry
« Reply #1 on: September 24, 2013, 03:57:53 PM »
I found a supplier of refractory materials that were very helpful, good prices and no minimum order.
http://stores.ebay.co.uk/PotteryProUK . I can thoroughly recommend them ( I have no connection with them)
I lined the bottom of the drum with 3" thick fire bricks which cut reasonably easily with a club hammer and a bolster. I knocked the corners of the bricks off with the bolster to enable me to fit seven bricks around the sides.

Offline doubleboost

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Re: My new foundry
« Reply #2 on: September 24, 2013, 03:59:16 PM »
Looking very nice
Are you going to use propane to heat it
John

Offline NormanV

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Re: My new foundry
« Reply #3 on: September 24, 2013, 04:03:42 PM »
I then packed the gaps with ceramic fibre
(I rather foolishly bought 15kg of offcuts which consists of strips approx. 30" x 3" x 1", I used about     1/2 KG and have a lot left over, anybody want some for the cost of the postage and bag from the post office?)

Offline NormanV

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Re: My new foundry
« Reply #4 on: September 24, 2013, 04:15:11 PM »
It is now completely lined, tomorrow I will be making the lid.
For the lid I will be using 50mm thick ceramic fibre board which I intend to plaster over with refractory cement.
John, I am hoping to be able to use it initially with charcoal and eventually with propane, unfortunately there is no free peat in Lincolnshire!
I plan on having the crucible standing on two pieces of fire brick that will enable the propane flame to surround the crucible as there was already a tuyere hole that leads straight into the drum and not at an angle to prevent the flame from burning directly on the crucible.

Offline vtsteam

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Re: My new foundry
« Reply #5 on: September 24, 2013, 07:32:28 PM »
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline NormanV

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Re: My new foundry
« Reply #6 on: September 25, 2013, 10:59:01 AM »
Today I worked on the lid, I cut the ceramic fibre board to shape on the bandsaw and wrapped it in wire mesh from a recycled bird cage and have started to plaster it with refractory cement.
I had intended my furnace to be mobile as it is on wheels, but it is so heavy that I can barely move it!

Offline awemawson

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Re: My new foundry
« Reply #7 on: September 25, 2013, 11:14:43 AM »
Looks very familiar!  :thumbup:  :beer:

http://madmodder.net/index.php/topic,8574.0.html

Hey Steve, I hope that you are claiming Royalties on that 'furnace on wheels'  :lol:
Andrew Mawson
East Sussex

Offline NormanV

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Re: My new foundry
« Reply #8 on: September 25, 2013, 11:32:12 AM »
I've got all the patterns made for my next project, a milling machine. The largest will require approx. 11kg of aluminium, I need to start collecting scrap.

Andrew, The wheels will be mostly for show, it is just too heavy to move. I had planned on moving it in and out of the workshop.

Offline awemawson

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Re: My new foundry
« Reply #9 on: September 25, 2013, 11:35:54 AM »
Norman,

If you look back in Steve's thread he lost his in the snow last year  :bugeye:

Andrew
Andrew Mawson
East Sussex

Offline tom osselton

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Re: My new foundry
« Reply #10 on: September 25, 2013, 12:22:48 PM »
Snow will be here soon maybe a month to go or so usually by haloween. :bugeye:

Offline NormanV

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Re: My new foundry
« Reply #11 on: September 25, 2013, 12:59:02 PM »
Andrew, we had hardly any snow last year here in Lincolnshire, we didn't have a particularly hot summer this year either!
Norman

Offline Pete.

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Re: My new foundry
« Reply #12 on: September 25, 2013, 01:24:50 PM »
Our summer down in Kent has been one of the finest I can recall.

Offline vtsteam

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Re: My new foundry
« Reply #13 on: September 25, 2013, 01:35:02 PM »
Norman, I had the same problem you do. It was very heavy for the existing vacuum cleaner wheels. The main problem was the location of the wheels. There wasn't enough clearance under the barrel for rolling well on grass, and the handle was located too far aft -- when leaned over enough to clear the wheels, a large proportion of the weight was on the hands. Also the handle was low, so you basically ended up stooped pulling a lot of weight and snagging on things.

Now, I think wheels can be a good idea, but it just has to be proportioned differently than it was as a vacuum cleaner. 3 or 4 wheels would work, for instance. Or even a moving truck would work with a furnace with no wheels, because the proportions are correct on the truck.

On mine, I finally opted for skids, and that has worked well for infrequent moves on grass.

Looking forward to reading about your progress!!  :thumbup: :clap:
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline awemawson

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Re: My new foundry
« Reply #14 on: September 25, 2013, 01:48:05 PM »
Our summer down in Kent has been one of the finest I can recall.

Pete, I didn't want to 'rub it in', but same here as we are next to you in East Sussex

Andrew
Andrew Mawson
East Sussex

Offline vtsteam

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Re: My new foundry
« Reply #15 on: September 25, 2013, 03:28:37 PM »
btw, Norman, the wheels and attached handle eventually became this:

I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline tom osselton

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Re: My new foundry
« Reply #16 on: September 26, 2013, 02:46:35 AM »
well you could always try something like this, it could slip in to the pin that is connected to the base so when the handle is lowered it suspends the furnace to be wheeled

Offline chipenter

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Re: My new foundry
« Reply #17 on: September 26, 2013, 03:17:32 AM »
Our summer down in Kent has been one of the finest I can recall.

The autumn is turning out nice as well in the south of Kent .

Jeff
Jeff

Offline NormanV

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Re: My new foundry
« Reply #18 on: September 27, 2013, 08:43:41 AM »
Further work on the lid, I made a band of steel to clamp around the lid that had lugs attached that gives a place to attach the lifting handle yet to be designed. I then plastered over the whole of the lid with refractory cement.
I ran a small fire in it last night and noticed that the smoke escaped around the edges of the lid more than through the hole. This morning I applied a layer of cement, covered it in cling film and then pressed a flat board onto it which has given me a nice flat surface. I have done the same with the lid, this should give me a good seal. When it is dry I will try another fire and I hope to see no leakage.

Offline vtsteam

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Re: My new foundry
« Reply #19 on: September 27, 2013, 09:10:17 AM »
Looking good! Norman, what is the bore of your furnace?
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline sparky961

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Re: My new foundry
« Reply #20 on: September 27, 2013, 09:16:39 AM »
I have to applaud your resourcefulness.  Good re-use of items!

Offline NormanV

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Re: My new foundry
« Reply #21 on: September 27, 2013, 11:22:20 AM »
The internal dimensions are 9 1/2" dia x 21" high.
I tried moving it today, I was concerned that the handle might not be strong enough but it seems it will be ok if I am careful.
Now I've got to buy steel tube for the crucible and get it welded.

Surely there is somebody who would like the ceramic fibre blanket that I have left over. I have approx. 60 strips 24 x 3 x 1" ? It's yours for the cost of the postage or collect if you are near Skegness

Offline DavidA

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Re: My new foundry
« Reply #22 on: September 27, 2013, 03:00:31 PM »
Norman,

Thanks for your kind offer. It is about time I started on my furnace,  so I will take half of it off your hands.  No point in me taking it all if I can't use it.

I'm over in Keighley so I can have a run out to the coast and collect.  It will be next weekend though.  This weekend is used up.

PM me with your address and a suitable time.

Dave.

Offline vtsteam

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Re: My new foundry
« Reply #23 on: September 27, 2013, 04:40:32 PM »
The internal dimensions are 9 1/2" dia x 21" high.

That's a nice size. I wish mine was at least an inch larger bore.

I sometimes wonder if I could make a boring tool with a carbide insert, an external  frame of some sort to guide it and enlarge the bore a little using a half inch electric drill.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline NormanV

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Re: My new foundry
« Reply #24 on: September 27, 2013, 06:42:55 PM »
I'm sure that it would be possible  to bore it out, but not on mine as I don't have solid fire cement between the bricks.

All of the ceramic blanket has been claimed.
« Last Edit: September 28, 2013, 04:44:11 AM by NormanV »

Offline NormanV

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Re: My new foundry
« Reply #25 on: October 03, 2013, 09:31:05 AM »
The lid is complete, there is a good seal around the edges. I know that it won't affect the performance of the furnace but it will prevent surprises when I am standing next to it.
I obtained 60kg of scrap aluminium castings today, the crucibles are being welded today also.
I will be doing my first melt this weekend. I will be using charcoal as a fuel as I have spent enough already over the last few weeks and a gas cylinder will have to wait.
I'll just be making ingots at first as I still have to get the sand and also make some flasks.

Offline vtsteam

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Re: My new foundry
« Reply #26 on: October 03, 2013, 09:37:06 AM »
Norman I know you've cast already so pretty sure you already know this, but if not, take a thin sliver off of those wheels and other castings and try to light those individually with a torch to see if they burn white -- a check for magnesium. Apologies for the presumption if you already have done this, or know about it.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline NormanV

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Re: My new foundry
« Reply #27 on: October 03, 2013, 02:10:27 PM »
 I will check them but I am pretty sure that they are not magnesium. I've only ever used wheels in the past and never had a problem but there is always a first time.
thanks, Norman

Offline NormanV

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Re: My new foundry
« Reply #28 on: October 04, 2013, 04:25:07 PM »
My next task is to obtain some sand for making my moulds. The two suppliers that I have located charge £15 for 25kg. That is not much sand for the money! Can anyone suggest a supplier in UK that are cheaper and won't charge an arm and a leg for delivery? I am not even sure how much I will need, my biggest moulding box will be 30" x 12" x 8", what weight of sand will I need to fill that? As I understand it I need sharp sand, the grains of sand from the beach will be too rounded, is that correct?
When I was casting before I used sand from the local sand dunes and bentonite cat litter, it worked fine.
Norman

Offline awemawson

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Re: My new foundry
« Reply #29 on: October 04, 2013, 04:45:27 PM »
Conventionally Mansfield sand is used in the UK being a self bonding sand with good porosity and refractory properties. Have you tried John Winter in Halifax?
Andrew Mawson
East Sussex

Offline vtsteam

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Re: My new foundry
« Reply #30 on: October 04, 2013, 05:34:47 PM »
I am not even sure how much I will need, my biggest moulding box will be 30" x 12" x 8", what weight of sand will I need to fill that?

About 170 lbs dry if you'll be mixing in clay. If using pre-mixed greensand and with moisture, figure on 200 lbs. But you'd be well advised to have more on hand than will fill the flask.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline NormanV

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Re: My new foundry
« Reply #31 on: October 05, 2013, 11:38:05 AM »
Andrew, I had seen the John Winter website but unfortunately he does not list prices, come to that nor do Mansfield sand. I will give them both a ring on Monday. thank you for the info.
Steve, thanks for the figures, 4 bags of 25kg will do it then.
I live right next to a sandy beach, it is so tempting!
Norman

Offline awemawson

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Re: My new foundry
« Reply #32 on: October 05, 2013, 11:42:43 AM »
When I used to travel around the country muchly for my job I called into John Winters several times to collect stuff - very friendly and helpful. But this meant that the carriage cost was zero (unless you count the wear and tear to the company car with several sack of sand in the boot  :ddb: ) I seem to remember that the approach to their place is up a very steep hill - but then most of outlying Halifax is up a steep hill come to think about it !)

If the sand on your beach is nice and fine why don't you consider the sodium silicate process. Dry sand, add up to 4% by weight of sodium silicate, mix well then pass CO2 through it. Sets nice and hard but permeable. It's total loss as far as the sand is concerned but then you have the beach ! JW stock sodium silicate. When I was last casting I mainly used silver sand and sodium silicate as it saves faffing about with collapsing moulds! Mind you the garden was starting to fill up with the detritus of knocked out moulds!
Andrew Mawson
East Sussex

Offline NormanV

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Re: My new foundry
« Reply #33 on: October 05, 2013, 12:35:13 PM »
I suppose I won't know if it is any good unless I try it. There are dunes at the top of the beach where the sea doesn't reach so it shouldn't be so salty. I'll gat some sodium silicate and give it a try.
Norman

Offline DavidA

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Re: My new foundry
« Reply #34 on: October 05, 2013, 01:15:40 PM »
Norman,

This may be of interest to you.

http://mistralni.co.uk/products/sodium-silicate-solution-q70

Dave.

By the way,  how did the first firing go ?

Now the flue is abating I will be over to collect the bits next Saturday.

Offline vtsteam

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Re: My new foundry
« Reply #35 on: October 05, 2013, 02:12:55 PM »
Well, if it was me, and the sand looked good and fine I'd go get some, mix it with some bentonite and cast someting small to see how it worked. Why not?
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline NormanV

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Re: My new foundry
« Reply #36 on: October 05, 2013, 03:19:39 PM »
There's probably some bylaw about taking sand from the beach, I will have to be discrete.
I haven't done a firing, can't find any charcoal!!!!!
Glad you're feeling better Dave, see you next weekend.
Norman

Offline awemawson

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Re: My new foundry
« Reply #37 on: October 05, 2013, 04:08:12 PM »
Usually from high tide mark down to the sea is common land, and from high tide mark up to first property boundary, field etc belongs to the Crown. You could always reverse the WWii  POW trick where they lost sand from bags down their trousers - just don't release the knot :)
Andrew Mawson
East Sussex

Offline vtsteam

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Re: My new foundry
« Reply #38 on: October 05, 2013, 04:40:44 PM »
There's probably some bylaw about taking sand from the beach, I will have to be discrete.

Well, for just a test of the usefulness, maybe even just a quart container or two would do, or a small child's bucket. Can't imagine anyone would have a hard time with that. Now if you brought a wheelbarrow and started carting loads to a pickup truck, I imagine there might be some nitpickers aroused.

Who was it -- someone here, I think, was bringing out sand from a beach in their shoes. Must have taken a lot of trips to the car.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline awemawson

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Re: My new foundry
« Reply #39 on: October 05, 2013, 05:01:41 PM »
Safest way is a tipper truck with rotating yellow flashing beacon, and wear high viz jacket with 'EU Beach Sampling Team' on the back. Take as much as you want and I'm willing to bet NOBODY would challenge you !   :clap:
Andrew Mawson
East Sussex

Offline vtsteam

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Re: My new foundry
« Reply #40 on: October 05, 2013, 05:25:52 PM »
How about "Decontamination Unit" if there are too many bathers about?
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline SwarfnStuff

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Re: My new foundry
« Reply #41 on: October 06, 2013, 01:58:27 AM »
Sand from the beach? Here in OZ they probably have a law requiring a permit for the sand in your shoes when you leave the beach. Understandable really  :lol: considering we only have 35,887km of coastline on the mainland and another 23,895km round our islands = 59,736km altogether. (depending on how you measure the coastline.) That's 37,119miles in the old (more familiar to many of us) measurements. Wonder how many sackfulls that would be?  :smart: Ah well, what were we discussing again? Oh yes Awemawson's new foundry. :coffee:
Converting good metal into swarf sometimes ending up with something useful. ;-)

Offline awemawson

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Re: My new foundry
« Reply #42 on: October 06, 2013, 02:29:56 AM »
No not MY new foundry - it's NormanV's new foundry.

My foundry is still all packed away after a move six year ago, now where are those 'roundtuits'  :scratch:
Andrew Mawson
East Sussex

Offline vtsteam

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Re: My new foundry
« Reply #43 on: October 06, 2013, 10:16:10 AM »
Norman, sorry, back to the subject, how will you roll your largest flask of about 100 kilos? Or will that particular pattern not require a roll?
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline NormanV

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Re: My new foundry
« Reply #44 on: October 06, 2013, 01:52:12 PM »
I haven't thought about that yet! I might get some help or make some sort of crane.
Norman

Offline vtsteam

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Re: My new foundry
« Reply #45 on: October 06, 2013, 02:54:48 PM »
Norman, maybe some kind of rolling frame? Like two plywood disks with a rectangular cutout in the center?

Maybe it is split, and latches together to do the roll, then latches are released to lift the cope?
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline awemawson

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Re: My new foundry
« Reply #46 on: October 06, 2013, 03:28:47 PM »
I ran a 10x6 rsj across the roof of my last foundry and had a trolley running on it with a chain block.Not only useful for lifting large crucibles, and pouring them, it was handy for lifting the furnace, which I had in a pit in the floor. You could easily jury rig something similar over your furnace. A horizontal scaffold pole and runner would probably be enough with an 'A' frame either side.
Andrew Mawson
East Sussex

Offline NormanV

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Re: My new foundry
« Reply #47 on: October 06, 2013, 04:29:56 PM »
Up to now the biggest casting I have made is the bed for the Gingery lathe, most of the castings for my milling machine will be around that size so I know that I will be able to handle them. It is only the main table that is so big that it will be a problem. It will need to be rolled twice, I was thinking of fitting a pivot each end of the flask and support it with a frame similar to what Andrew is suggesting.
I am intrigued by Steve's idea but it sounds as though it would need a lot of space to roll it over, which I don't have. I am going to build a moulding bench that will have to live outdoors. First I have to find some old pallets that I can dismantle for the timber.
Norman

Offline vtsteam

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Re: My new foundry
« Reply #48 on: October 06, 2013, 05:06:36 PM »
Norman, another possibility is to make your bed in a couple of pieces rather than one, with flanges that bolt together. The flanges will actually help stiffness and act as webs. If it's anything like the Gingery, it will scraped (or milled) after, and then be covered with a full length slab of cold rolled steel anyway. It will easily be as strong and stiff as a full length bed, and the molding, melting and casting will all be easier.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline SwarfnStuff

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Re: My new foundry
« Reply #49 on: October 07, 2013, 02:27:28 AM »
OOPS My error. Didn't look far enough into the posting.  :hammer: Apologies to both Awemawson  NormanV. Better get me glasses checked - Again.  :doh:

John B
Converting good metal into swarf sometimes ending up with something useful. ;-)

Offline NormanV

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Re: My new foundry
« Reply #50 on: October 07, 2013, 07:37:33 AM »
It is certainly worth bearing in mind the idea of casting it in two halves if I can't manage it in one piece.

Offline NormanV

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Re: My new foundry
« Reply #51 on: October 13, 2013, 08:51:38 AM »
I did my first firing yesterday using charcoal and was pleased to find that I had molten aluminium within 20 minutes and cast 2 ingots weighing a total of 1.75kg 30 minutes after lighting the fire.
I did find that it was very smoky for the first few minutes, I need to hurry up with a propane burner.
My next task it to cut up all my aluminium and cast ingots in order to produce some clean aluminium ready for casting parts for my milling machine.
Norman

Offline NormanV

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Re: My new foundry
« Reply #52 on: October 14, 2013, 10:34:57 AM »
I did another firing today. I must get a propane burner made as soon as possible, when I switched on the air blast I had smoke pouring out of the furnace. God knows what they put on B & Q charcoal, it is supposed to make it easy to light! It's appalling! I lived in Kenya for 10 years and used charcoal a lot, the locally made stuff was easy enough to light and clean burning. In fact it was smoke free and the Masai people used it inside their houses (never mind the carbon monoxide).
The smoke died down after about 10 minutes and then a huge flame burnt from the hole in the lid for another 10 minutes, after that it was fine, except that I had to recharge it twice and had to go through the whole business again.
Anyway, I produced 2 large ingots that weigh a total of 7.5kg. Two loaf tins full, now I can't make any bread until I buy some new tins!
Cutting up the big lumps of scrap is not too bad with an angle grinder, I read somewhere that I should use a stone cutting disc. I tried both stone and metal cutting, the metal cutting disc clogged immediately but the stone cutting disc worked well until it was worn down. 
Norman
The smoke is leaking from under the lid as it is jammed up by aluminium in the crucible, it stopped once the aluminium melted a bit.

Offline awemawson

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Re: My new foundry
« Reply #53 on: October 14, 2013, 11:37:07 AM »
All very good  :thumbup:

But have you tried the beach sand yet!
Andrew Mawson
East Sussex

Offline NormanV

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Re: My new foundry
« Reply #54 on: October 14, 2013, 12:07:57 PM »
Thanks Andrew, I haven't tried the sand yet. I can only do one thing at a time, money!!!!
Norman

Offline vtsteam

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Re: My new foundry
« Reply #55 on: October 14, 2013, 04:47:13 PM »
The reason for the smoke is most likely that the upper coals weren't hot, while the lower ones were. This usually occurs when someone adds a large amount of fresh charcoal on top of burning coals and turns up the blast. Smoke issues until the upper coals reach ignition temperature. Once the upper coals are glowing, the smoke (unburned fuel gasses) will burn cleanly, with as you mention, a large flame issuing from the port in the lid.

True charcoal, made from wood, burns very differently than compressed briquet type charcoal, which may contain wood waste, low grade coal, and petroleum waste products. I've used both.

The briquets will work well for aluminum melting but must be started properly, starting with a low layer, making sure that is glowing, and gradually addling layers bringing them to ignition with no blast and the lid off until all briquets are well lit. They do produce a lot of ash, and in a big melt will require replenshing during the melt. The frequency of replenishing will be proportional to the amount of fuel you can fit in the furnace compared to the crucible size. Obviously, a big melt volume requires more fuel, but reduces the fuel capacity of the furnace barrel at the same time, so has a doubly negative effect.

A furnace can also smoke if the volume of fuel is disproportionately large compared to the air supply. As the fuel is used up, the proportion of fuel reduces, and a smoky burn can clear up that way, as well.

I love it when a Plan B comes together!
Steve
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Offline NormanV

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Re: My new foundry
« Reply #56 on: October 30, 2013, 09:19:19 AM »
Well, I've made a propane burner and tested it on a small melt. It works ok but seems a bit slow compared to charcoal but the convenience it offers far outweighs the time factor. Anyway, I'm retired, my time is my own and I can always find something to do whilst the metal if melting.
I did a few calculations, it took 4.5kg of charcoal to melt a load of aluminium. Charcoal produces 29,600 Kilojoules/kg, which means 29600x4.5=133,200kj were used. Propane produces 49,500kj/kg therefore 133,200 divided by 49,500 equals 2.69kg of propane to deliver the same energy. The charcoal cost me 89pence per kilo, total cost £4. 2.69kg of propane at 1.42 pence per kilo equals£3.82. I am amazed that propane works out cheaper and is cleaner and easier to use. Have I got it wrong?
Anyway here is my burner, I made it from a 10" length of 1" galvanised water pipe, I drilled 3 10mm holes each side a short distance from one end. I then turned a steel plug, with an eight mil threaded hole through the centre. One end of the plug I turned down for a 1/2" compression fitting and attached a ball valve. The jet screws into the 8mm hole and has a 1mm through hole.

Offline NormanV

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Re: My new foundry
« Reply #57 on: October 31, 2013, 03:49:53 PM »
I need some advice from someone who is familiar with using propane as a fuel.
Today I melted 5.5kg of aluminium scrap to make ingots. It took two and a half hours! That is far too long. As I said in my previous post, I used a 1mm drill for the burner jet. If I increased the size to 1.2mm or 1.5mm would that give me a more powerful flame or would it reduce the velocity of the gas so that it would not draw enough air? Can anybody help who has experience messing around with gas jets?
Thanks, Norman