Author Topic: Oil fired crucible furnace (Read 161586 times)

awemawson · « **Reply #175 on:** August 15, 2013, 04:41:08 PM »

Well done Steve, it looks as though you've cracked this process and are getting consistent results. It must be very satisfying

tom osselton · « **Reply #176 on:** August 15, 2013, 08:08:22 PM »

I'm glad to see it all coming together, can't wait to try but the basics first (alum / brass).

vtsteam · « **Reply #177 on:** August 15, 2013, 10:17:21 PM »

Thanks Neo, Andrew, Tom!!

Just realized I forgot to black the top of the mold, and that's why the sand cast looks rougher above. Did the bottom though. So much to remember each time.

Tom how close are you to your first melt?

It's really memorable when you do. Pretty amazing when you put the crucible back in the furnace with everything shut down and quiet, the mold filled, and you take off mask and gloves, and realize, "I just poured metal!"

Then the looooooong wait until it cools. One hour seems like ten.

tom osselton · « **Reply #178 on:** August 16, 2013, 03:19:51 AM »

I am day's away I had to pick up some more of the fiber blanket so now just have to give it a zircon coating on the inside then it will be ready. With the blower I am going to shim it 1/8 inch to center it better in the housing I have tryed the blower with a dimmer switch so that controls the blast good lastly I will makeshift a mount to hold it in position till a final frame is made.
Tom

Note to self pick up sand

vtsteam · « **Reply #179 on:** August 16, 2013, 09:09:07 AM »

Tom, would you consider documenting your build in a thread with photos? I and I'm sure others would enjoy seeing it.

Mayhem · « **Reply #180 on:** August 16, 2013, 10:40:04 AM »

Steve - well done!

Tom - I'd like to see a write up and pics.

tom osselton · « **Reply #181 on:** August 16, 2013, 12:01:01 PM »

Well I can probably do something like that mind you it is basicaly the same as Ironmans small furnace build http://madmodder.net/index.php/topic,7802.0.html so far only one screwup

I had the lid marked in two place 2" apart and my son cut the wrong one with the plasma not his fault though I should have said that one.

vtsteam · « **Reply #182 on:** August 16, 2013, 07:16:32 PM »

I'd like to see it, too! And I bet Ironman would be happy to see your new furnace to his design as well.

ironman · « **Reply #183 on:** August 16, 2013, 08:18:02 PM »

Yes I would like to see it.

Was your zircon paint expensive? Here in Australia it is.

awemawson · « **Reply #184 on:** August 19, 2013, 05:03:02 PM »

Steve, I came across these two .pdf files while looking for pictures of my induction furnace - I think that they will interest you perhaps:

Ironman - yes the Zircon was pricey but I didn't use much

tom osselton · « **Reply #185 on:** August 19, 2013, 06:51:31 PM »

Ironman
The zircon is itc 100 that I used it is definetly pricy $100.00 for one pint. It looks different than the paint you used it was quite watery and seemed like it left a sandy substance in the bottom of the tin not too much though. I brushed it into the base joint. I was thinking maybe it reached it's saturation point. The fiberwool was $12.00 and change per foot. It is done though just sitting on the floor I have not made a frame yet to lift the lid but that's what sticks are for! I fired it up this afternoon and it ran great even though I had to use a smaller pipe 1" inside dia easy change when I find some so no worries I am a happy camper

So thanks for posting your video (s) I always learn something.

Ps

Coming soon

tom osselton · « **Reply #186 on:** August 21, 2013, 11:27:56 AM »

Here it is if you haven't seen it in the project''s thread.

http://madmodder.net/index.php/topic,8920.0.html

vtsteam · « **Reply #187 on:** August 25, 2013, 03:52:14 PM »

I've been away on holiday with the family, so apologies for late responses. Thanks Andrew -- those look interesting -- looking forward to giving them a read.

Tom great to see your furnace construction -- looking forward to following your thread!

I was thinking of casting today -- first day back -- but decided to do something instead that I've wanted to do for awhile. Basically set up the wood lathe and make some loose pieces for riser pattern, sprue plug, sprue basin pattern, and a runner pattern.

These will save me a lot of time in cutting these in the sand and then cleaning and tamping the loose sand. These are somewhat similar to the permanent pouring system patterns sometimes seen on match plates. The difference is, these will all be loose pieces -- intended for single piece castings without a mounting plate.

The sprue plug is tapered -- I'd previously achieved that by rapping the top of a straight sprue dowel to form the taper before removing the dowel. The bottom of the plug has a brass pin to fit in a hole in the the sprue basin pattern. That will help keep it in position during ramming.

The riser pattern replaces a piece of 1-1/2" OD pipe I had used on the last few castings -- the new pattern has a rounded bottom and is not hollow as the pipe was. The rounded bottom should reduce loose sand after pulling the riser as well as reduce surface area to keep the metal in the riser hot longer.

The sprue basin has a hole to mate with the sprue. I won't have to dig out a basin any more, and again, loose sand will be less of a problem -- I won't have to smooth it down, and the basin will be pre-formed.

The runner has a taper at the end to serve as a slag trap. Again -- a nice pre-formed channel with less cleanup required.

I can see making a few more of these kinds of mold parts to put them together like "TinkerToys" to fit various situations.

vtsteam · « **Reply #188 on:** August 25, 2013, 03:54:03 PM »

This is more or less how they might look assembled with a pattern for a pour:

vtsteam · « **Reply #189 on:** August 26, 2013, 08:03:04 AM »

Finished.

ironman · « **Reply #190 on:** September 17, 2013, 09:20:23 PM »

Photos of crucibles

dsquire · « **Reply #191 on:** September 17, 2013, 10:01:20 PM »

ironman

I have edited your post to remove the duplicate photo's for you.

Cheers

Don

ironman · « **Reply #192 on:** September 19, 2013, 12:20:50 AM »

Thank you for that.

stvy · « **Reply #193 on:** September 26, 2013, 01:58:26 PM »

Steve,

Just wanted to thank you for this thread. I have been following it since it started and because you shared your failures on the way to your final well earned success I feel inspired to one day try some casting at home. Its a while off for me, too much DIY at home yet. But one day.....

Thanks,
Steve

vtsteam · « **Reply #194 on:** September 26, 2013, 04:24:20 PM »

Well thank you Steve in return!

I hope you will share your progress with a furnace of your own when the time comes, too. It's great to see people master this stuff. I think it is always going to be a little different for everybody, because materials, burners, fuels, shapes, and sizes are always going to be different. Each will present a unique set of problems and requirements, and it will probably take a while to figure out how to get the best out of each one.

I hope to cast at least one more iron part I need before the snows hit, and I'll put that here.

I'm not sure of my ability to cast during the winter in Vermont. Maybe I can create an outside snow free space nearby, along with re-organizing my workshop. I also do wonder what the cold will do to my ability to reach iron melting temps. It will probably require pre-heating of the blast. I have done aluminum before in winter with a simple charcoal furnace, so I'm sure that at least is possible.

An interesting point -- heated blast opens possibility to experiment with the furnace as a cupola one more time using anthracite coal as a fuel. From what I've read about historical blast furnace practice, anthracite would require a heated blast to be successful. I have some anthracite coal, and it is readily available here, so very tempting to try.

Anyway, this thread may not be at an end yet.

Thanks again for your thanks!

mattinker · « **Reply #195 on:** September 26, 2013, 04:30:21 PM »

Quote from: vtsteam on September 26, 2013, 04:24:20 PM

I'm not sure of my ability to cast during the winter in Vermont. Maybe I can create an outside snow free space nearby, along with re-organizing my workshop. I also do wonder what the cold will do to my ability to reach iron melting temps. It will probably require pre-heating of the blast. I have done aluminum before in winter with a simple charcoal furnace, so I'm sure that at least is possible.

I doubt that the 40°C difference in temperature is going to make a lot of difference in comparison with the temperature needed to melt and pour cast iron!

Good luck! Regards, Matthew

unc1esteve · « **Reply #196 on:** November 02, 2013, 11:45:37 PM »

Vtsteam,
I have read your casting posts several times.
Any more progress?
I use to carve profiles of my grandchildren in wood
and have them cast in brass, 9" x 9" x 3/4".
I want to do several more of these but the foundry
I dealt with has long closed.
I would like to cast my own carvings.
Just getting started.

vtsteam · « **Reply #197 on:** November 03, 2013, 05:41:13 PM »

Hi unclesteve. I haven't cast since I last wrote here -- I started on a major moving and cleanup of my "shop". It's now in fairly good shape. I have moved my furnace down the hill to be near the shop, and have kinda been entertaining the idea of trapping heat from it to heat the shop. Not too attached to that idea, but still holding it as a possibility.

Meanwhile have been cutting trees and splitting wood to prepare for winter. Also been building a small foam RC airplane in the evenings.

I'm sure you can build a furnace to melt brass, and would be happy to help if I can. Brass melts at a lower temperature than iron, so a furnace and fuel requirements are easier. I've melted brass with store bought charcoal briquets in a regular Gingery charcoal furnace. Of course you can use any other fuel as well.

Brass does present its own problems -- overheating burns the zinc in it -- and there are some casting differences -- but these are all pretty well covered in the available info. Temperature control is important.

But I think it is very do-able, if you are interested.

unc1esteve · « **Reply #198 on:** November 04, 2013, 04:34:03 PM »

Vtsteam,
Have you seen this burner?
Comments.

unc1esteve · « **Reply #199 on:** November 04, 2013, 07:00:34 PM »

I just made this burner.
I used 2" outer tube.
I used 1/4" pipe for the oil feed with a
cap drilled similar to a shower head.
Tested it with water, works great but
I have no experience with oil burners.
I will continue on tomorrow, right now it is
time for a beer. Anyone else like
Budweiser & Clamato?

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Author Topic: Oil fired crucible furnace (Read 161586 times)