today's casting

[DaveH]

DA,
Very smart

DaveH

[dallen]

(11-03-2012, 12:46 PM)EdK Wrote: Looks like a good fit. Is that aluminum you cast it out of?

Ed

Ed
The fit was pretty easy, Aluminum, I try to use car wheels when I can get them, I been throwing in some copper lately and I always remelt the sprues so the mix varies a little from pour to pour. some people use lite salt as a flux but I find that the stuff doesn't melt so I buy and use regular commercial flux/degassing chemicals at 5 to 10 bucks a pound its not like the stuff is so expensive that I can't afford it.

Thanks Dave

DA

[dallen]

sorry almost forgot about posting a picture of the flask that I knocked together that I used to mold the pistol grips.

[sasquatch]

Nice work Dave an interesting post.

[dallen]

here's the part that I did today so I could finish the second flask in the same size as the blue one.



and some alignment handles that I didn't do such a good job on

[DaveH]

DA,
Goodness me you don't hang about.
Smart casting

DaveH

[dallen]

I try to stay busy, helps me stay young in my old age plus I like casting and it won't be long till its too cold to do it all my foundry stuff is outside, so its gotta be calm so the dry grass doesn't catch fire, and warm so I feel like doing it. if my pattern making skills ever get good enough I hope to cast some steam engine parts in Cast Iron and build an engine in the 2 to 3 inch piston size.

[sasquatch]

Those castings look nicely fine grained, very nice!!

[dallen]

(11-09-2012, 08:26 PM)sasquatch Wrote: Those castings look nicely fine grained, very nice!!

Thanks for the compliment!
I have to give the sand credit for the finish, that and metal temp. it gets pretty critical when it comes to finish, those were poured when the furnace temp reached around 1300 degrees, you get it too hot with thin casting and the metal will try to run between the sand grains especially if using water bonded sand.

DA

[dallen]

I'm still playing around with these grips. and since its to wet and not that cold but anyway me and the little dog are hold up in the house so I thought I would post up a couple pictures of some of the problems that something simple like this can cause a person.

This first photo shows a spot on the what is the bottom back of the grip that is really rough, this was caused by the part moving in the flask when I rammed it up. that corner ended up almost touching the flask with only a few grains of sand to seperate the flask from the part.

The spot up at the top that is really rough was caused by the metal going cold, not sure but thats what it looks like cause the part was poured with that side up so I don't think its from loose sand but it may be.



This second picture shows where I had what is termed the gate or where the metal flows into the mold. I had it at what is the bottom of the grip but am thinking that I may need to move it up so that its in the middle of the part, reason for moving it is that I have had parts that were poured closer to the middle that didn't have the rough area what is showed in the first photo.



Oh yea almost forgot these were molded in silica sand and sodium silicate and hardened with CO2 gas I used 5% SS, this gave a very good mold and the part wasn't all that hard to remove, texture of the checkered part on the grip was pretty good, its a little messed up around the two recesses where the bolts go but most of that gets machined out anyway. I filled those two spots with wax so I could have a tapered slope in them so the sand would pull out.

anyone with any idea throw em out, it'll give me another reason to fire up the furnace
DA