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Thread: Novice Casting Questions

  1. #51
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    Quote Originally Posted by corky View Post
    oldironfarmer, everybody lost interest in my post, my personality I guess, so thought I better see what your doing, excellent job your doing.
    We're waiting for you!

    I have an SB9 I bought a couple years ago, it's my first lathe and I absolutely love the world it's opened up for me. I've turned wood a couple of times on it but generally stick to the bandsaw and sander for round patterns. The need for precision in the pattern depends on the project, and factors like surface finish, shrinkage, contraction, etc (covered in the Navy Foundry Manual) can negate efforts at precision size in the pattern. So often times I make the pattern on the large side of what I need to end up with and then machine the casting to its final size.

    Pete

  2. #52
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    The South Bend was my first lathe. It was a little small and a little underpowered for "large" work. I wound up getting a Grizzley 13x40 gunsmith lathe. I'm very happy with it. The SB was from a friend's estate and I did not want to sell it, so I gave (loaned) it to a young friend who was volunteering at a steam locomotive facility where they had no tools. He was repairing all sorts of things for the locomotives but the church that owned the facility shut it down due to economic reasons and about the time I need a metal lathe for patterns it is available. Worked out well. The old style rocker toolpost will be better for woodworking than my quick change tool post as well.

  3. #53
    Thanks Petee, I just gave myself a selfy high five,
    If You Cant Be Handsome Ya Gotta Be Handy

  4. #54
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    I tried casting a small shelf bracket pattern I made as I was starting this effort. My dowels were too tight and the drag pattern came out with the cope.

    IMG_1112.jpg

    I cleaned it out best I could. Really should have started over. The book I was given has some solid advice on runner and gate sizing so I'm going to follow that. The risers did not work as well as I'd liked, the bases were too small, and the gates too small. but it is usable.

    IMG_1116.jpg

    At least I'm starting to understand why I'm doing each step.

    IMG_1118.jpg

    Thanks in advance for any comments you may have.

    Andy

  5. #55
    Hi Andy, are ya still casting?

    Had a power surge or something here at my shop last week and burnt out the SSR in my kiln, it was heating at the time so really pulled some amps I guess.
    It was a 25amp SSR but ordered a 40amp, just in case I convert to 220v.

    I was digging in my pole barn, and way in the corner I found 2 alum wheels, thought I got rid of them, about 6" of the rim broke off, they were of my 65 malibu SS Convertible, Nice car for a poor kid.

    Had a hell of a time making the $52 payment every month.

    I remember how I broke those wheels, a long story...but didnt take long to break them.. Showing Off Again for The Girls..

    Anyway, hope things are going well.

    c
    If You Cant Be Handsome Ya Gotta Be Handy

  6. #56
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    Oh yeah! I've been casting asunder. Followed the gating and risering book. Quite different sizes than I had been doing. The gates are only 1/4" thick.

    IMG_1158.jpg

    I used the loose pieces pretty much like in the picture. And yes, I should have had a riser on each gate. I'm thinking use the narrow gate at the runner and then increase the size from a riser into the mold cavity. Here's the flask split open.

    IMG_1191.jpg

    I need a router bit with 2 degree taper, at least I think I do, so I can put draft in a hole or a flange on a plate. Could not find one anywhere so I made one out of a piece of sucker rod (well pump rod)

    IMG_1156.jpg

    IMG_1163.jpg

    IMG_1164.jpg

    IMG_1167.jpg

    IMG_1180.jpg

    IMG_1182.jpg

    IMG_1196.jpg

    It works pretty good. Quenched and tempered. There is no relief behind the cutting edge but it is only for finishing up and seems to be OK on the walnut I'm using.

    Picked up a used oven to use to preheat crucibles and cure refractory and other shop use. $100 and it looks new inside.

    IMG_1139.jpg

    I'm going to build me a furnace at long last. In the spirit of the forum I'm going to post that on the furnace forum.

  7. #57
    Gee's Andy, your good at everything, I can tell your a perfectionist, nothing wrong with that, I was until a head injury, now I don't even know how to organize nut and bolts,lol.

    Thats a nice bit you made, looks good and does the job.

    I just looked some of my router bits and found one for a dove tail of some sort, looks like a short reamer, I remember buying it but dont remember for what.

    Anyway your is just as good if it works.

    I'm still trying to get the hang of gates and runners, there is so much to read it can get confusing, for me anyway, but seems like your doing great.

    Just got the SSR for kiln today so will get that going again.

    Are you building an electric or gas powered furnace?

    Cant wait till you start your build.
    Good Work As Always,
    Later,
    c
    If You Cant Be Handsome Ya Gotta Be Handy

  8. #58
    Dang that sucker rod looks big!! Or is it for an oil well? Nice bit of machining, I guess I have never tried to create a router bit.

    So, how did that shelf bracket come out with the different risers and gates? Temp is starting to warm up a little up here. I may start getting forms together to cast my hot face. I have not been in a real big hurry as I don't want to have the temps dropping before it is all dried out. But I am probably at a point that leaving a light bulb in would keep me above freezing.

  9. #59
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    Quote Originally Posted by corky View Post
    Gee's Andy, your good at everything, I can tell your a perfectionist, nothing wrong with that, I was until a head injury, now I don't even know how to organize nut and bolts,lol.

    Thats a nice bit you made, looks good and does the job.

    I just looked some of my router bits and found one for a dove tail of some sort, looks like a short reamer, I remember buying it but dont remember for what.

    Anyway your is just as good if it works.

    I'm still trying to get the hang of gates and runners, there is so much to read it can get confusing, for me anyway, but seems like your doing great.

    Just got the SSR for kiln today so will get that going again.

    Are you building an electric or gas powered furnace?

    Cant wait till you start your build.
    Good Work As Always,
    Later,
    c
    I'm sure not good at everything. People tell me I'm a perfectionist but I think I'm pretty sloppy. Just trying to do better. But thanks!

    I could not find a bit less than 30 degrees, and really don't want that much draft. We'll see how well mine actually works.

    Making the patterns for gates is really simplifying things for me.

    I plan to build a gas/used oil furnace. I have two kilns for pottery but don't want to open them hot. I do plan to use one of them for curing refractory, but it needs to stay shut until cool. I have bought a temperature controller for them. Is that an SSR?

    Thanks for your kind comments,
    Andy

  10. #60
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    Quote Originally Posted by Mister ED View Post
    Dang that sucker rod looks big!! Or is it for an oil well? Nice bit of machining, I guess I have never tried to create a router bit.

    So, how did that shelf bracket come out with the different risers and gates? Temp is starting to warm up a little up here. I may start getting forms together to cast my hot face. I have not been in a real big hurry as I don't want to have the temps dropping before it is all dried out. But I am probably at a point that leaving a light bulb in would keep me above freezing.
    Yes, we have lots of oil field sucker rod in Oklahoma, that was a 1". I have some new mill reject sucker rod up to 1-1/8" that I use for machining and a lot of tooling. Usually I use sucker rod to forge tooling in my blacksmith shop because it heat treats so easily. There are several grades but they all seem to do good with a water quench. Thanks for the kind words.

    I screwed up with the new runners and gates. forgot to put any risers in. And I got a shrink hole all the way through at the corner. I also had a gate close to the corner, so it was the last to freeze. The next one I want to put the gates away from that thickest corner, and also put a riser close to the mold with a larger gate from riser to mold and use the small gate size between the runner and riser. I'm still learning. but at least I can see what I did wrong even if I don't know how to correct it. The gates are really small by the book.

    A lot depends on the refractory you use. I find the Indiscriminate Scrounger's thread interesting. He could not use Greencast 94, which is what I have had given to me. From his description, I don't think he knew the full dryout procedure. 24 hour cure after placement, then 60F per hour to 250F and hold for an hour per inch of thickness, then 60F per hour to 500F and hold for an hour per inch of thickness, then 60F per hour to 1,000F and hold for an hour per inch of thickness, then 60F per hour to 1,500F and hold for an hour per inch of thickness. That works out to a minimum of almost 30 hours to properly cure. The fact that he had surface spalling indicates he had steam generation at higher temperatures. Refractories will lose all the free water by the end of the 250F stage. However, steam is still generated by chemically generated water release at higher temperatures, thus the slow rise and hold points for the dryout process. I've only cast a little Greencast 94 at home and only did the dryout to 500F. However my plinth has been in direct flame impingement and shows no deterioration after a few heats (about ten) other than fine surface cracks.

    You should find the proper dryout schedule for the refractory you choose and attempt to follow it. You might succeed if you don't but it is easy to google it and use it.

    Looking forward to seeing your progress!

    Andy

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