Lost wax

Home enthusiasts discuss their Foundry & Casting work.

Moderator: Harold_V

Post Reply
hoppercar
Posts: 616
Joined: Sun Jul 22, 2018 4:09 pm

Lost wax

Post by hoppercar »

In my shop work over the years, I occasionally come across foundry work.....I'm quite familiar with simple wood patternmaking, and cope and drag type molding. But now I have a project I wanna do that requires nice detail, lost wax work... My first question, is, how do they get the very small lettering and number details on a lost wax mold ??....was wondering if there's any good books or reference material out there, that I could study.
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Lost wax

Post by Harold_V »

I would propose to you that such detail is generally accomplished by using CNC equipment. Alternately, a manual pantograph would serve as well, although they are not as commonly found as they once were and you're held captive by the need of fonts, sets of alphabet and numbers that are usually made of brass.

Not all pantographs are capable of full 3D, so if you make that your choice, make sure the one you choose is capable. It can then be used not only for engraving nomenclature, but even for creating the die (mold for the wax). A pattern would be required, needless to say, and it need NOT be the same size as the casting you hope to pour. The pantograph allows for scaling.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
User avatar
NP317
Posts: 4557
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon, USA

Re: Lost wax

Post by NP317 »

One of Chaski's premier modelers is Jack Boderman.
Ask him for good resources for making small part wax patterns, molds, and waxes.
I am sure there are others here who can help, as you have asked for.
RussN
RONALD
Posts: 754
Joined: Sun Oct 26, 2003 7:27 am

Re: Lost wax

Post by RONALD »

Ye Olde Hand Work! That is what you do if you don't have any modern machines.

The Rerailer was carved by hand tools, the lettering was printed on paper, then cut away.

The Rail Braces are made by ACME, the same company that makes Wiley Coyotes Fireworks; actually it is the simplest word to carve!
DSCN1343.JPG
DSCN1343.JPG (966.36 KiB) Viewed 5192 times
DSCN1342.JPG
DSCN1342.JPG (976.32 KiB) Viewed 5192 times
DSCN1341.JPG
DSCN1341.JPG (928.26 KiB) Viewed 5192 times
DSCN2634.JPG
DSCN2634.JPG (356.02 KiB) Viewed 5192 times
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Lost wax

Post by jscarmozza »

Ronald, how hot do you have to get the plaster mold for pouring? I’ve been experimenting with lost wax on the cheap just to get an idea of what’s involved. Today I heated the plaster mold to bright orange and the plaster cracked, I think that was too hot. Any advice?
John
jcfx
Posts: 713
Joined: Sun Aug 09, 2009 1:24 pm
Location: NY

Re: Lost wax

Post by jcfx »

I work with plaster a lot as a mold maker for my work not for metal casting, it's probably from the moisture still in the plaster,
their hydrophillic ( water seeking ) when dry so your mold may have picked up moisture sitting around
or your mold was too fresh, the water turns to steam when heated to high temps and probably is what led
to your mold cracking.

Being that I like looking for new materials to work with, I fell down a rabbit hole that led me to this technical paper
from US Gypsum, might be a good paper to read for you guys doing investment casting -

USG Metal casting plaster
https://www.usg.com/content/usgcom/en/p ... aster.html

The tech paper -
https://www.usg.com/content/dam/USG_Mar ... -IG538.pdf
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Lost wax

Post by jscarmozza »

I think you’re correct about the plaster, I’m going to look for HydroPerm, thanks for the info.
John
RONALD
Posts: 754
Joined: Sun Oct 26, 2003 7:27 am

Re: Lost wax

Post by RONALD »

Having the right equipment and materials helps.

Waaaaay back in the early 80's I bought some Kerr flasks, a wax injector, an oven, a vacuum pourer and a melting furnace from Frank Eliss.

From a Dental Supply I bought a vacuum mixer, and from a Jewelry Supplier a Steamer.

The Steamer was needed because my wife complained about the burning wax from the oven, the steamer melted away 99% of the wax.

I use materials from Kerr, https://www.google.com/search?q=kerr+lo ... nt=gws-wiz

Plaster of Paris, or wall plaster will not do well, you should use an investment compound for Lost Wax, like https://www.waymil.com/INVESTMENT-POWDE ... 68-100.htm. I bought several 100 pound containers a few years ago.

Below are photos of some of my stuff, that vacuum pump, up on the wall, comes out of an old blueprint machine.


DSCN0031.JPG
DSCN0031.JPG (938.4 KiB) Viewed 4652 times
DSCN0032.JPG
DSCN0032.JPG (990.62 KiB) Viewed 4652 times
DSCN2642.JPG
DSCN2642.JPG (371.84 KiB) Viewed 4652 times
DSCN2633.JPG
DSCN2633.JPG (1.45 MiB) Viewed 4652 times


What helped me, was that at the same time I was starting Lost Wax, Mike, the Foundry teacher, was transitioning from big castings into Lost Wax also.

He is also retired now, as are all those other shop teachers.

Replaced by STEM or STEAM, what ever that is supposed to be!
jscarmozza
Posts: 599
Joined: Mon Mar 03, 2014 5:09 pm

Re: Lost wax

Post by jscarmozza »

Thanks for the sources Ronald, I’ll post how I make out with the proper materials
User avatar
Dick_Morris
Posts: 2841
Joined: Sat Jan 04, 2003 2:09 pm
Location: Anchorage, AK

Re: Lost wax

Post by Dick_Morris »

I use a 3D printer and print the "wax" in castable resin. This one in the photo ts waiting for my next casting session.

This is a good technique when only a few items are needed. For higher quantities the master can be 3D printed and used to make a traditional flexible mold for wax injection.

The equipment to do the waxes isn't too expensive. Major items are a consumer level 3D printer (about $250 for a small one) and 3D CAD software (Freecad is free and very capable). Initial consumables will cost about another $125. I have found use Siraya Tech "Cast" castable resin ($75 for 1 KG) to be competitively priced and it prints and casts well. Of course, there are learning curves with both the software and 3D printing, but Youtube is your friend.

For using a 3D printer to print print waxes and cast them I like Youtube videos by VogMan (formerly VOG). The ones he did about three years ago while he was still on the learning curve were particularly useful to me.

For Freecad instruction I like Mango Jelly on Youtube.
Attachments
20230531_225557[1].jpg
20230531_225557[1].jpg (68.03 KiB) Viewed 4183 times
Last edited by Dick_Morris on Sat Aug 12, 2023 7:32 pm, edited 1 time in total.
User avatar
Dick_Morris
Posts: 2841
Joined: Sat Jan 04, 2003 2:09 pm
Location: Anchorage, AK

Re: Lost wax

Post by Dick_Morris »

I finally got around to casting it. .625" X 2" X .065" thick. I'm quite happy with the results.
Attachments
superheater plate 2.jpg
superheater plate 2.jpg (60.18 KiB) Viewed 3212 times
User avatar
NP317
Posts: 4557
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon, USA

Re: Lost wax

Post by NP317 »

Beautiful!!
RussN
Post Reply