Casting a Bearing Cap in Iron

Discussion in 'Sand Casting' started by PatJ, Dec 5, 2018.

  1. PatJ

    PatJ Silver

    The weather is good today/tonight, so I will try to finish sanding out the bearing cap and get it ready for molding.

    I think this casting will go much better than the windmill gear.
    This casting is pretty simple compared to what I have cast previously.

    Its time to wrap this one up and get it sent.

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  2. PatJ

    PatJ Silver

    I got a little more work done of the flask for the bearing cap, and another project I am working on at the same time.

    The thermometer was at 93F in the shed today, and unfortunately I have moved my molding stuff out there where there is no AC.
    I could put AC in the shed, but don't have time for it.

    I am close to making a mold.
    I will do a little more sanding on the pattern tonight, and I should be ready to mold sand at that point.

    The heat sort of sucks the life out of you, even with a fan going, but makes one appreciate having AC when you go back inside the house.

    The snap-flask thing seems to be working well, and I am starting to think more in terms of post mold making work on the bound sand to make the sprue, runners, gates, etc., which would greatly speed up the mold making process.

    Here is a good video showing what can be done with a bound sand mold after it sets, using ordinary woodworking tools.




    The flask is glued on two opposing sides, and can hinge open on the other two sides, in snap-flask fashion.

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  3. PatJ

    PatJ Silver

    I am back out in the hot box for round two.

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  4. Jason

    Jason Gold

    105 here today.:( I spent the day inside. I decided I'm going to install a 2ton mini-split in my garage. I'm sick of this shit. I can get a bryant for about 1300. The best part is I'll only have to make two holes in my brick for the condensor sitting outside. Prices have really come down on these things. If you want to roll the dice, you can get a cheap one for under a grand with free shipping.
    These are so easy to hook up it's not funny. https://www.alpinehomeair.com/viewproduct.cfm?productID=453077957 Keep in mind, most are heatpump units so it might not be the best for those of you where it gets really cold. I've got gas heat for the winter so I'll probably just run the fan in the winter to move some air.
     
  5. Jason

    Jason Gold

    Hey! How in the hell did her little glass stones not blow apart from the temp of the cast iron?
     
  6. PatJ

    PatJ Silver

    That is a very good question, but not one that I know the answer to.
    Zircon must be some good stuff.

    I am having good luck with LG window units at the moment for the house.
    The AC folks were very proud of their new units, and the reviews on all the AC units manufactured now are "DO NOT BUY FOR ANY REASON !!!!", every brand.
    So I can replace the window units every two years if required, and still come out thousands ahead.

    I think an LG will run longer than 2 years, but the game plan right now is window units.
    My central heat works fine, and I can repair that myself if required (it has been quite reliable).
    And I have have a window unit replace in a few hours or less, without having to call anyone.

    I sanded out the bearing cap pattern, but it still had a few low spots in it, so I added some filler.
    I will sand it again tomorrow, and then whatever it looks like is what is going to get cast.
    Its time to git-er-done.

    The cope and drag sand are measured out, and ready for mixing.
    All the sand has to be weighed in order to get the correct mix ratio.

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  7. Jason

    Jason Gold

    I kinda doubt she used CZ's for that.

    I don't have a window in my garage so I'm kinda stuck with a mini split. My only complaint with them is they are highly computerized for what they are. The Mitsubishi's are extremely complicated and not cheap. I would not recommend touching anything using R22 if you can even find them anymore. Jan 1 2020 and it's 410a stuff only. Window units usually are R134a, like your fridge.
    Every brand out there has bad reviews. Gotta pick the best of the worst.:rolleyes: Built to a price mentality really sucks.:mad:
     
  8. Jason

    Jason Gold

    Hey Pat, Gypsy girl told me they WERE cz's.... Pretty wild. She said it doesn't always work.
     
  9. PatJ

    PatJ Silver

    That's what she said in her video.
    You would think the expansion would explode them for sure.

    It is hotter than hades here today.
    I had to do some outdoor surveying in the sun today, and I about heat-stroked out.
    Dang humidity is redlining.
    Its like walking around in a sauna gone wild.

    Suppose to be cooler later this week, so the wife says (LOL, I just checked the forecast, and it is dropping all the way down to 91 this week; well that puts my mind to rest........NOT !).

    Anything below 96 F and 87% humidity (todays temp and humidity) would seem cool at this point.

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  10. PatJ

    PatJ Silver

    I am going to try and fire up the furnace today, and cast the bearing cap.

    Hope it all goes well.

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  11. Jason

    Jason Gold

    Get to work! Film it will ya?
     
  12. PatJ

    PatJ Silver

    I got the camera ready.
    Need to check the battery.

    My overlapping lid design did not work out, and it kept jamming as the refractory shifted around a bit.
    For the last iron pour at the Metal Museum, I built the insulating fire bricks up to the same level as the hot face, and let the lid sit on top the IFB's.
    That worked ok, but there was a bit of the lid metal lip exposed to the heat was was tending to overheat.

    My solution was to mix up some Plastic A a little on the wet side (manufacturer recommends not to do this, but it seems to work well and help with the adhesion to the existing refractory), and filled in around the lip on my lid.

    I formed it a bit more from the photo below, and got it more into shape.
    I put a heavy coat of graphite on the top of the IFB's, and then closed the lit, and rocked it a little bit.

    I have the propane on low now and will get it dried out in a few hours.
    I have the IFB's temporarily removed from the lid, since I had it turned upside down.

    I have one mold ready to go, and will make another mold today for the bearing cap.

    I have the bearing cap pattern finished, or as finished as I have time to make it, and while it is not a perfect pattern, I think it will be usable for one-time use.
    I used sheet rock filler, which is easy to sand, but fragile.
    I shellaced over the filler, and that give it a bit more ridigity.
    The filler will be easy to clean off, if Ron ever wants to salvage the existing bearing cap.

    I am hoping to get ready for a pour today/tonight.
    The weather is much cooler this morning, and the shop is about 76 degrees, which is basically a new ice age for around here.

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  13. PatJ

    PatJ Silver

    I guess I will try about 2.5 oz of ferrosilicon for 25 lbs of iron.

    I have been trying to keep up with melter's ferro ratios, but he changes his mix so much that it is hard to keep up.

    2.5 oz seems like a good compromise between too much (with shrinkage) and not enough (with iron that is too hard to machine).

    I am going to spray on some mold wash in a minute, and see if that helps with the surface finish.

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  14. PatJ

    PatJ Silver

    I have not used the slurry sprayer yet for mold coat, so we will see how it works.
    It is suppose to spray heavy material easily.

    The mold coat is alcohol-based.

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  15. PatJ

    PatJ Silver

    I sprayed on the mold coat for the first time tonight.
    I had to adjust the vertical tip on the sprayer.
    It will not work where shown in the photo above; the vertical tip has to be raised so that its top is at about the centerline of the horizontal tip.

    I got the first half of the bearing cap mold made (the drag), and am getting ready to make the second half (cope).

    I am totally out of time, and so I used painter's tape to cover some rough spots in the filler.
    I think the tape will work for a one-time use pattern.

    I went ahead and taped the entire bottom of the pattern to reinforce the edges and help with release from the sand, and taped part of the top.
    The pattern has a coat of shellac on it, but the filler is rather fragile and was trying to break off on the ends.

    The sprue I show in one photo will actually go 180 degrees from what is shown in the photo.

    The wood on the bottom of the pattern is very thin plywood, which gives some machining allowance.
    There will also be machining allowance on the ends of the cap.

    I tried to get the letters/numbers as clean as possible with a dremel and a fine bit.

    The snap flasks are working well, but I need to glue a small strip around the interior so that the flask grips the sand after the sand hardens.

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  16. PatJ

    PatJ Silver

    I got the cope mold made, to go with the drag mold shown above.
    I forgot to use the Adolf's inserts on the drag, so I drilled two 1/4" holes in adjacent corners, and will insert dowl rods for alignment, since you otherwise lose alignment once the snap flasks are removed.

    I used a temporary filler in the center when ramming the drag, and then removed that when ramming the cope.

    I am hoping the pattern will pop out somewhat easily.
    I don't have a pull hole so I can't use the slide hammer that I normally use.

    I need to spray on the mold coat in about 30 minutes, and then everything will be ready to be cemented together.

    If all goes well, I think I will be ready to pour today, or worst case tomorrow.

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  17. PatJ

    PatJ Silver

    The bearing cap mold is complete.

    I had to pry out the pattern, and so that left a little divot at one of the feet, but it can be ground off as flash.

    I drilled six vent holes in the cope.
    I know ironsides is big on not drilling vent holes, but he does not use bound sand molds either, and I ruined a complex casting by getting two large trapped air bubbles, due to lack of vents, so I am not going to chance that again.

    I machined in a runner with the wood rasp, and then cut two gates with a wood chisel.

    I coated the pattern with mold coat, and burned it off.
    I was a bit wary of burning off the mold coat in the shop, and was afraid it may go WHOOOSH !, but it was a mild mannered flame, and did not damage the flask or blow up.

    Now I need some new furnace cement.
    The stuff I had has dried out, so I will run down to the hardware store in a minute.

    Its a little overcast today, but the molds will be ready, and they will keep for 30 days, so I will not try to pour in wet weather.

    I think we are getting close to finding out if this wild goose chase is going to fly.

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    Tobho Mott likes this.
  18. PatJ

    PatJ Silver

    Maybe its just me, but the mold cavity in the last photo looks convex, but is actually concave, I guess because of the way the shadows are falling, or perhaps the way the mold coat dried; or maybe its just me.

    Edit:
    I think melterskelter recommended the gating, and so if this does not work, we have a scapegoat to blame.

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    Last edited: Sep 10, 2019
  19. Tobho Mott

    Tobho Mott Gold Banner Member

    As long as we know who to blame, lol. :D

    Good luck with the pour, got my fingers crossed for you. Mold looks great, can't see any reason why it wouldn't fill.

    Jeff
     
  20. Jason

    Jason Gold

    You gorilla tape that Pat?

     

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