Casting an aluminum hammer

[flht1997]

Little walk through about what I did at school today.

I have a foundry and molders bench in my metals shop, and the first year metals students are required to make a casting, while the second year students make a pattern and a casting.

Today I made a casting of a split pattern hammer. It is made of aluminum, but it is a very useful hammer to have and when it gets damaged too bad, you toss it in the forge and make another one.

Start with the split pattern



Place it in the drag and apply parting compound




Start the forge up. I use mainly old small engines and screen door frames, I tried soda cans but it takes too long and there is too much dross.



Using the fine screed you need to get a good covering of fine grain sand over the pattern, then switch to the course screed for another covering, then scoop in the rest.







Then using the rammer you compact to perimeter first, then the middle






then strike off the extra sand and flip it over





Had a little fall out around the head, but it will work. Now install the top half of the pattern and repeat.



cut in the sprue and riser, some people do this while they are filling the cope, but i like to just cut them in after.




cut in the gates, I like to do two on the hammer cause it is so long



Forge is hot and crucible is ready, I am not the best a judge when exactly to pour, but a little super heat is in it, I'm guessing the Al is around 1500f right here.




pour it in and let it cool



remove and cut of the extra and sand off the flash





then pass it through the blast cabinet



beginning to end is about two hours or so. I do not let the students handle the liquid aluminum and I will pour about forty of these hammers every school year, this is the first one I have made for myself. Hope you enjoyed the show

 

[Movover]

I remember taking metal class in Jr high in 86 and it was done the exact same way.. All the students boys and girls had to do metal class, wood shop, small engine repair, electronics, drafting and home economics.. I think this should still be in place today hands on is how kids really grasp and learn

 

[Steve.S]

I remember taking metal class in Jr high in 86 and it was done the exact same way.. All the students boys and girls had to do metal class, wood shop, small engine repair, electronics, drafting and home economics.. I think this should still be in place today hands on is how kids really grasp and learn

 

[Pardigital]

Very interesting. Thanks for sharing.

 

[Strouty]

That is pretty cool. I have watched lead being cast before, really had not thought about aluminum.

 

[RiverRider]

Very cool. I've cast a ton of lead bullets, it's not difficult but to do it right there are things to know...and it's a lot of work. I've been interested---or maybe "curious" is a better word---in investment casting for many years but it's just one of those things I probably won't live long enough to fiddle with.

 

[SteveH-CO]

Great photos and explanation. Thanks!

 

[whyNick?]

Nice writeup OP. What are your impressions of that forge? I have one exactly like it that I bought 15 years ago when the local school district shut down their industrial arts program. I'd always intended to set it up and play around with it but I never got around to it and it's buried in the back of the garage. To be honest, until I saw your post I'd forgotten all about it. Anyway, any tips for operating it? I may just get it set up one of these days...

 

[bczygan]

1400 degrees of fun!

 

[ADSR]

that's pretty cool!

 

[lilcraigford]

Very cool! My dad got into aluminum casting when he discovered the Dave Gingery book series in our subscription to Lindsay Publications. He ended up with a Gingery lathe, a milling machine attachment for the drill press, numerous accessories and a lot of one-off parts. The throttle bodies he cast and machined for the EFI setup in his '60 Cal-Looker come to mind. I made good use of the lathe/mill but never dabbled in any casting myself. I know he wanted to attempt brass but never got around to it.

 

[Dagny]

thanks for sharing .

 

[flht1997]

Nice writeup OP. What are your impressions of that forge? I have one exactly like it that I bought 15 years ago when the local school district shut down their industrial arts program. I'd always intended to set it up and play around with it but I never got around to it and it's buried in the back of the garage. To be honest, until I saw your post I'd forgotten all about it. Anyway, any tips for operating it? I may just get it set up one of these days...

It is a pretty good forge/foundry. Basically what i do is turn the gas all the way up and adjust the fan to suit. I dont remember where it is exactly set but somewhere near the middle. They are a bit forgiving, if you try and run them too lean they will flame out and shut down. It is good for melting, not the best for blacksmithing cause it is pretty small and you cannot fit much in there

 

[Lippyp]

Cool, takes me back to school. We cast a handle for a junior hacksaw from aluminium. Then we bent up a steel frame and machined the adjuster on the lathe.

 

[DenisG]

What type of sand do you use? Any binder?

 

[Movover]

What type of sand do you use? Any binder?

Our teacher use to use some sort of motor oil with the sand. I am not sure thats what it was and if you could any more with all the epa regs.. The sand would catch fire though

 

[kkroger]

I remember lots of things that I learned in basic Metal in 7th grade and on up through Special Projects in Metal high school, I learned how to use a scroll bender, to gas weld and braze, Gmaw, Gtaw, Smaw, I learned to Mill, to Turn, To forge, to Cast, To do a great many things, I worked with a few younger folks at my previous job who were astonished that I learned such things in Public School, They didn't.... I learned a lot of woodworking in school as well in General Shop Classes until I went the metal route, but my dad was a carpenter so I learned a lot more from him. I also had auto mechanics in Vo-Tech, That got me my first job out of high school.

 

[flht1997]

What type of sand do you use? Any binder?

the sand is called oil-bond or petrobond. Mine is donated to the program from a local foundry.
when it gets too dry, i use ATF as a bonding agent. I dont have a sand muller so I need to work it in by hand.

 

[Duker]

Now that is pretty cool... Just out of curiosity what does that roughly weigh?

 

[wingnut_1]

Flashback to my high school Metals class, thanks!

 

[flht1997]

Now that is pretty cool... Just out of curiosity what does that roughly weigh?

I would say about a pound and a half, I have two in the tool room at school and it has kinda become my go to hammer for alot of stuff.

 

[DenisG]

the sand is called oil-bond or petrobond. Mine is donated to the program from a local foundry.
when it gets too dry, i use ATF as a bonding agent. I dont have a sand muller so I need to work it in by hand.

Thanks, I was curious. When I worked in a foundry in Mass. they sprayed some sort of resin binder in the sand. In the lab, I'd have to test "dog-bones" made with that stuff to check it's strength.

It's been a while, but I remember cope & drag, risers and sprues, etc

Sometime I'll try home-brew casting. For a sand muller, couldn't you use an old cement mixer, or is that too big?

 

[Capt Chrysler]

FLASH BACK!!!!! 1978 Metals class..The teacher told us if we went and picked up and crush beer cans we wouldn't have to buy supplies. The local country club use to dump all the cans in a hole on their property. We hauled pick up loads of cans back. (High school shop class riding in an open pick up full of beer cans!) We had a blast! Also remember tossing saw dust into the top exhaust vent and watch the pretty little fire! For some reason Mr. Dietzs didn't share the same enjoyment of the burning saw dust as I did.......



OK the flash back is over. I was talking to a local guy last week about casting aluminum. He said if you spray the mold with kerosene. The parts will come out a lot smoother. Have you ever heard of that?

Nice work on the hammer. Would you sell any?


Capt. Chrysler