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Oil fired crucible furnace

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vtsteam:
Thanks greatly Ironman!!

Crucible life:

I will definitely drop using the sodium carbonate. I also put a few charcoal pieces in, but I would guess you wouldn't think that hurt anything this last time.

Risers:

I did watch all of your casting videos last night looking for clues and tips about my shrinkage and bubbles problem, so I definitely noticed the two big risers on that pulley.

But I also noticed lots of castings where you had no risers, and much smaller sprues, and different shapes and sizes for gates than I used -- so I would like to try to get closer to what you do there first, to see what happens, before adding a riser. My sprue was 1.25" diameter. And I couldn't pour fast enough to fill it -- I think my 2 gates were too big in cross section, too.

Actually, I probably can't add a riser because of lack of crucible capacity. Although smaller sprue might help that quantity problem. Everything is interrelated.

Crucible distortion:

That happened in the last melt -- it didn't do that in the earlier ones. But I really cranked the furnace in the last 20 minutes this time -- and there was more flux.

Or maybe as you say, I should try a different make of crucible. Can you recommend a brand to look for? Is there any particular one you like?

I have one more new one, and I will try to see how it lasts without flux, a little gentler temp ramp up, etc. Maybe there will be a difference in lifespan. I will be very cautious about any leathery "feel".

I'm very happy copying what you do in preference to books where they differ, and grateful for your experience.

vtsteam:
One more thing I noticed in the video -- if a video can show such a thing -- I don't think you ram as hard. I'm guessing that would affect blow holes if your sand is more permeable because of lighter ramming.

vtsteam:
Sorry to make multiple posts, but I just also re-read your post and  you mentioned your shallow cope height. I definitely noticed that!

I have been thinking of making some of your style aluminum flasks. My eyeball estimate from the video is something like 1.75" flask height by 9" by 12". Is that right?

And about 3/8" thickness with small triangular corner gussets with tapped holes for screwing frames together, and positioning pins and holes mid frame(1/4" diameter?) Probably offset in position some so they can't be put together the wrong way.....

MetalCaster:
Use one 1/4" and one 5/16" pin so you can't reverse the cope and drag.
The Alloy Avenue guy mentions that carriage bolts with the head sawn off make good pins, and I can vouch for that.

Ironman- You are familiar with my work too.  PatJ from you-know-where.

vtsteam:
Pat, this is what I'm talking about wanting to make:

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