Another noob question- delicate/thin part removal from mold

Awesome input. I’m on it.
Question: would this design also be better for the wax pour?

 

Get the aluminum version, and then try Everdur?

 

And now for the latest update on a simple project gone mad...
I reworked the sprue configuration as suggested and buried it in a plaster/ceramic mud mold. What could possibly go wrong?

 

Only one sure (?) way to find out - run it.

(I've had my share of trouble with lost-wax...)

 

Yet another learning event.

 

Here's my home grown foundry built from an old water heater. I have NO idea how how she runs so am wanting to add an inexpensive thermocouple. From what I'm reading, I need a K type to range me correctly. Any other words of wisdom? I see a variety of probe types. Thinking the ceramic bead type?

 

Awesome stuff. I used to set up my molds that way as well. But David is correct in pointing out there is a better way. Wax love to float and even when you think it's where you want in the mold it will try to move. IE: float towards the side while the top looks good. therefore much to close to the sides. Or just the movement alone trying to keep it still while setting up can cause small defects and just some other ugly stuff. David suggestion is to turn the piece upside down and place on to a puddle of melted wax and let harden. You can do this on a piece of 4inch tile/glass or whatever. Once it is set make sure it is secure so it will not brake loose and float. I use stainless exhaust pipe for flasks. 2.25" buy 4 5 or 6 inches tall. Regular steel will also work but will not hold up for many burnout cycles. Place pipe/flask over/around piece and seal it to the base. Hot glue works but if it is bumped while pouring, the seal will break. Use clay or (i use duck seal putty) to seal to the base. Now when pour the plaster everything stays in place. Let it set up and harden. Take the flask off the base turn over and there you go. Note flasks without some support to hold them together have a tendency to crack. That's why i use the pipe. I cracked many of flasks before this simple idea came to me. I kind of started all of this like the ancient casters. No google, you tube, or any other type of help. That really is a Lie I constantly do research but only if I'm stumped about something. Now I am here because learning the hard way cost me to much money.

Harbor Fright K-type for about $55. I dont remember where i bought the thermocouple's but the ones I bought were cheap. NOT $8 a piece maybe (https://www.ebay.com/itm/152475235258?ViewItem=&item=152475235258)

I use ceramic fiber in my furnace so I drilled a small hole in the side of the furnace and worked the coupler (careful these are fragile) into and through the fiber to just poke out of the hot face. Position where you think best. Mine is about two thirds around the interior away from the burner. This will give you a good idea of the temp. Just a thought but you can also learn the color of the different temperature ranges and judge from that.

Even though I am retired I have to get ready for work so I can buy more foundry stuff. LOL

bill

 

The jewelry shop I worked at positioned the trees in the flasks by using an intermediate step of mounting the trees to coffee filters.

The details:
Waxes injected in toughy green. Sprues made in a high rosin, low melt, red-brown wax. (Designed to melt clear before the patterns heat up.) Trees pressed onto two stacked pleated coffee filters on a hot plate. (We used the top of a wax pot for a hot plate.) The squeeze out of wax from mashing on was faired out with a wax pen. The base of the flask was warmed on the hot plate. (Without the warming, the wax weld was prone to failure.)Flask set over tree onto the filters on a formica surface and wax pen welded in place with bendy pink sprue wax. Flask twisted free from the formica before the wax is fully hard. The extending excess of filter outside the flask was rubber banded up to the flask.

Flasks prepared this way can bear careful handling filled with fluid investment, if needed. (Our platinum investment called for drying on stacked paper towels, water wicking through the filters to the paper towels, after being vacuum debubbled on a tray.) After the investment sets, the coffee filters can be peeled off.

 

Latest attempt... I'm not sure if I'm getting closer or further away..
The new sprue design worked better, but still got an incomplete pour in a couple areas. So, seeming that it was "close" , I decided to clean it up a little for practice. This is when I noticed that it is physically smaller than the parent...
Summary-
- Flow did not fully fill the mold
- Surface finish not great
- overall piece is not a "crisp" reproduction.
- Part is physically smaller
So, all in all, I suck at this....lol

 

Yes, shrinkage. You'll most likely need to make a (wax) "cast" of the original, section it in a number of places with a jeweler's saw, then fill those places in with more wax. Scale of shrinkage on aluminum is roughly 3/16 inch to the foot, or 1/64 inch per inch.

 

Oh sure....NOW you tell me...lol

 

- How am I doing my burn out? Well...I’m faking it like everything else so far. I am working with a primitive set up at best. I get it really hot, wait a while, and see what happens.
I’m using a home mix investment, scrap aluminum, questionable methods, and little to no experience. With each effort I do learn how truly primitive my methods and materials are. As a hobby, I really couldn’t justify blindly buying all the “proper” gear, only to figure out it wasn’t really my thing. The good news is, I enjoy it, and over time I’ll improve my equipment and processes. Doing crap totally wrong is the best teacher on how to do it totally right.

 

Lol... like I know? When I fly under the Noob banner, I really mean NOOB.
I just received my first thermocouple which may require a total rebuild of my foundry.
I inherited bits and pieces of a diy foundry and faked it into completion. It’s an old shorty water heater which had already been cut open (which appears to be too tall). I cut up the inherited fire brick to form a chamber and back filled it with...you ready for this....dirt. I welded up a hinge, handle and inserted the free burner jets (from a bbq grill attached to 3/4” pipe). My crucible is made from a free fire extinguisher.
All in all, what could possibly go wrong?

Nope. I'll keep an eye out for one in the local thrift shop.

 

At least the local Goodswill is open again!

 

Even if you don't spend 5cents on this stuff, buy real investment materials. The free time you'll save is worth it and you'll pull out less hair!
https://www.riogrande.com/product/ransom-and-randolph-ultra-vest-investment-44-lbs/702314

With your homemade brew, its kinda hard to help you with burnout times/temps. Some materials and investments require pretty specific burnout schedules.
I watched someone that was hell bent on replicating ransom&randolphs suspendaslurry for 2 years because he didn't want to spend 300bucks. He quit the hobby.
It's wise to pick your battles. 2 things I wont screw with is investment and alloying my everdur. I've got better stuff to do.