Hello Guest it is March 28, 2024, 10:37:04 AM

Author Topic: Fun project, hopefully a moneymaker!  (Read 17913 times)

0 Members and 1 Guest are viewing this topic.

Fun project, hopefully a moneymaker!
« on: September 09, 2012, 07:53:17 PM »
This is adapted from a post I saw on a hotrod site. He had used a router to route out hisname by hand and poured Pewter in it and busted it out. I routed my son's name in reverse using F-engrave and used the rails on the back half to hold the letters together. Just for this test, I cast the letters with hard type lead. Next time I'll route the letters a little deeper and cast it with Pewter. I have to be a little careful with that, the pewter is $16 to $20 per pound. The Lead is less that $1/pound, I don't have near that much in it. I've several hundred pounds of old letterpress type. The name pattern is still fine and can be used again. The back piece with the rails broke when I tried to get the piece out.
The black on the pattern is graphite to keep it from sticking.




Offline ThomasCB21

*
  •  19 19
  • If it ain't fun, don't do it!
    • View Profile
Re: Fun project, hopefully a moneymaker!
« Reply #1 on: September 10, 2012, 10:46:59 PM »
Very, very cool!  Hope you make lot's of money!

Offline Tweakie.CNC

*
  • *
  •  9,196 9,196
  • Super Kitty
    • View Profile
Re: Fun project, hopefully a moneymaker!
« Reply #2 on: September 11, 2012, 11:51:35 AM »
Hi Jammer,

Another brilliant idea.  ;)

I do admire your casting work.

Tweakie.
PEACE

Offline budman68

*
  • *
  •  2,352 2,352
    • View Profile
Re: Fun project, hopefully a moneymaker!
« Reply #3 on: September 11, 2012, 12:22:21 PM »
Hi Jammer,

Another brilliant idea.  ;)

I do admire your casting work.

Tweakie.

Ditto! Great job-  :)

Dave
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)
Re: Fun project, hopefully a moneymaker!
« Reply #4 on: September 11, 2012, 05:11:52 PM »
Thanks, by the way my son has a '56 Buick Century. He doesn't have his license yet, but he' got a car.
I'm going to try one more like a plaque and cast it in Aluminum or Zamak a Zinc/Aluminum alloy. Then on to Bronze. :)
I won't be able to use the MDF with Bronze, too hot. May try plaster or make a wood positive and cast it in sand.
Re: Fun project, hopefully a moneymaker!
« Reply #5 on: September 13, 2013, 02:23:36 AM »
I won't be able to use the MDF with Bronze, too hot. May try plaster or make a wood positive and cast it in sand.
All of my aluminum casting attempts have been done in sand. Although, the very first time I tried pouring some molten- I had a couple of pieces of plywood that were left over scraps from cutting some wooden gears out on the CNC Router table. I will never forget that experience! I knew that the molten would probably burn the plywood, but I THOUGHT that it would at least solidify before too much burning occurred. WRONG! That plywood did not even slow the molten's descent down, on it's way to the ground! (It literally VAPORIZED the plywood on contact!).
Since learning from that experience, I have been making sand molds. And being retired, (and unable to afford Petrobond casting sand), I learned how to make my own foundry sand. After trying many different recipes, the one that finally worked with good results was: 80% sand, mixed with 15% Bentonite clay (CLUMPING type Kitty Litter), and 5% Charcoal ashes. I had to construct a special machine to use for grinding the kitty litter into powder, which consisted of a steel turn-table, with two grind stones (like those on a bench grinder) which ROLL against the surface of the steel turn-table. A variable-speed DC motor was used to drive the turn-table, at the slowest possible speed, while friction drives the grind stones.

The slow speed is needed to prevent centrifugal force from simply slinging the kitty litter to the outer rim of the turn-table, (and thereby OUT of the path of the grind stones). Only small amounts can be ground at a time, as it is after all, Bentonite clay, and will begin to clump onto the grind stones. A knife-edge was later added to the stones, to keep the clay scraped off during the grinding process. It is also helpful, to first DRY the kitty litter, by placing it in a pot, and into the foundry furnace, stirring constantly until it is completely dry. Once the kitty litter clay has been ground into the finest possible powder consistency, then pour it into the sand, add the charcoal ashes, and begin mixing by hand, until all three elements are evenly mixed.

 I use one of those plastic tubs, with a snap-on lid to store the foundry sand in, to prevent (at least as much as possible) the sand mix from becoming too dry, or too wet. When using the sand to make the sand molds, I use a spray bottle of water, and lightly moisten the sand, stirring constantly by hand, until it becomes wet enough to form cakes when squeezed in my hand. At that point, it is ready to pour into the flasks to make the sand mold. The sand mix is re-usable, however (because of the kitty litter) has to be re-ground to break up the clumps back into powder form. I have learned, that this step is only necessary for a small amount. (The sand that actually contacts against the pattern being molded). The rest of the sand acts as just a "filler" of the flask. And when rammed up (packed into the flask) properly, it will ALL become very similar to concrete. Especially after a pour, and must again be broken up, and ground. A five gallon plastic bucket, with a few rocks thrown in, and turned tumbler-style (again, S-L-O-W-L-Y) will speed up the process.

Sorry to ramble, but I know that others are reading this with interest, and I just wanted to warn folks that metal casting is VERY DANGEROUS. I am actually amazed at the results you were able to achieve with the MDF, that it did not Vaporize on contact with the molten metal! I would hate to hear that someone tried this, and lost a foot or something, as the molten metal poured right through the MDF or other non-fire proof mold material. Metal Casting is very dangerous, and must be done with respect, paying attention at all times to what you are doing. Serious injury can occur!

Offline Tweakie.CNC

*
  • *
  •  9,196 9,196
  • Super Kitty
    • View Profile
Re: Fun project, hopefully a moneymaker!
« Reply #6 on: September 13, 2013, 03:35:46 AM »
Hi Adprinter,

Excellent information indeed - thanks for sharing your knowledge and experience.

Tweakie.
PEACE
Re: Fun project, hopefully a moneymaker!
« Reply #7 on: September 13, 2013, 02:47:07 PM »
My greensand is made with Kitty Litter also, I ground mine in an old blender. I heard of guys just soaking the litter in water until it breaks down to mud, then dry it out some and add sand. I haven't tried that yet. I think my mix is about 10% clay to 90% fine sand. I've been going to add coal dust because it gives a better finish.
Everything stopped last year when I was downsized at work and then went on disability due to some health issues. Then we moved twice and I've ended up in Southern Tennessee. I didn't have a garage or any storage space so I put all my toys in a storage locker.
Well now my garage is finished and I just got out of the hospital...Again! Now, as soon as I'm allowed by the warden (aka wife) :), I'll get my CNC and all my casting stuff out of limbo and start doing something again.
I've cast Lead, Aluminum, Brass, and some Cast Iron. Hope to smelt some Iron this year, from ore I've collected. Casting is my primary hobby, I built the CNC to make some patterns for casting signs and gears and such. Can't wait to get back at it.

Offline RICH

*
  • *
  •  7,427 7,427
    • View Profile
Re: Fun project, hopefully a moneymaker!
« Reply #8 on: September 14, 2013, 07:27:50 AM »
Jammerm,
Neat idea and hopefully you'll get back to norm and enjoy what you like doing.
Long time ago we used pewter for forearm end caps on kentucky rifles we made.  
At that time we just went to the flea market and bought all the pewter spoons we could find!
Just used paper wrapped around the forearm as a big spru and filed it to finished shape.

Have fun,
RICH
Re: Fun project, hopefully a moneymaker!
« Reply #9 on: September 14, 2013, 01:35:43 PM »
Rich, that sounds like a good approach to a casting like that. I really like Pewter and have collected a few pounds of it at auctions and flea markets. Problem is, I don't always know what I have. I'm pretty sure it all Lead free from looking up manufacturers online and sticking with newer castings. I also bout a bar of pewter from a metal supplier. I got some Nickel too, I hope to make some Monel sometime but would have to build a tougher furnace.