Cast brass

[Andrew Knowles 2Participant @andrewknowles2]

Question about casting brass

[Andrew Knowles 2Participant @andrewknowles2]

As a complete beginner to the world of clockmaking I am working on a lantern clock based on Malcom Wilds ME article

I have made the finials,columns and feet by turning from bar stock but this is very wasteful. I understand that originally these items would have been turned from castings

Are there any clock maker members who cast this type of part?

Is a furnace essential or could I get by with some firebricks and a couple of propane torches? I assume a crucible is essential

Ant help would be much appreciated

[PatJParticipant @patj87806]

This fellow in the States uses a tabletop electric furnace.

He told me that the crucibles do not last very long (perhaps five pours?, check me on that).

You can melt brass with propane if the burner is tuned correctly, and a combustion air blower is used.

Avoid the zinc fumes, they will make you sick.

https://www.youtube.com/watch?v=PYI69NiG2Fs

 

And check out the Union Pacific Big Boy passing on the tracks at 16:00 in the video.

Don't see one of those going by very often.

 

 

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Edited By PatJ on 03/01/2022 17:54:24

Edited By PatJ on 03/01/2022 17:57:54

[pgk pgkParticipant @pgkpgk17461]

Would it be sacrilege to suggest brass powder and resin casting?

pgk

[PatJParticipant @patj87806]

Would it be sacrilege to suggest brass powder and resin casting?

In foundry circles, yes it would be.

In the modeling world, anything goes.

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[noel shelleyParticipant @noelshelley55608]

PGK ! Sir you are a phillistine ! Brass powder Etc tut tut ! And Pat, some of the worlds best precision engineers, are model makers, so I cannot accept that anything goes ! ! !

Andrew, NO a furnace is not essential, but a crucible is ! (I have done it ) As to a crucible lasting only 5 melts I would suggest that something is wrong ! I recon to get 20 or 30 melts at least ! That is with a salamander, not a cheap one- A6. It would be possible to cast the columns, solid or better cored ! If you really want to have a go PM me and I will explain in more detail. Noel.

[BazyleParticipant @bazyle]

The tabletop furnaces are for jewelers and use small (thinner) crucibles.
Bronze is easier if the design – appearance allows as it does not give off fumes,
We have one person in the cub who does aluminium and I have been collecting stuff to start casting when I retire.

On my list which may be relevant to Andrew is spandrels (for your next clock). I'm thinking 3D printing will make the patternmaking easier as fancy designs could be imported to CAD for incorporation into a personalised set.

[PatJParticipant @patj87806]

Posted by noel shelley on 03/01/2022 20:49:55:

And Pat, some of the worlds best precision engineers, are model makers, so I cannot accept that anything goes ! ! !

Yes, we are of the same mindset, but I was trying to be polite to those who do not want or cannot get into casting metal.

My mindset is "Make your own engine castings in gray iron, or go home", but that is just me.

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[noel shelleyParticipant @noelshelley55608]

For fine detail, 3D printing on a DIY unit will require post printing work to give the smooth finish that will be vital to get good molds and castings. For REAlLY fine detail lost wax is the way to go, but it is a more complexed process. See the other thread on foundry work running at the moment here. Noel.

[pgk pgkParticipant @pgkpgk17461]

Posted by noel shelley on 03/01/2022 20:49:55:

PGK ! Sir you are a phillistine ! Brass powder Etc tut tut ! And Pat, some of the worlds best precision engineers, are model makers, so I cannot accept that anything goes ! ! !

Likely I am.. but the cross-over world exists albeit 3d printed metals or bar stock and fake fillets with JB Weld or filler to hide your blemishes or heaven forbid subbing out your work….

[John RutzenParticipant @johnrutzen76569]

Hi, I've done brass casting but for the time and effort involved it's probably not worth it. Could you semi – fabricate them, using different diameter brass bar for the different parts, pegged and soldered together? That way would use much less brass and be cheaper.

Edited By John Rutzen on 04/01/2022 09:54:04

[Neil WyattModerator @neilwyatt]

I've done 'lost PLA casting using a very fine layer height (just one or two thousandths of an inch).

I found that using borax as a flux to cover the melt massively reduces zinc oxide fumes -you don't want to lose zinc content anyway.

Neil

First try – contaminated with aluminium foil:

Next batch of lost PLA castings

1 thou layer height print:

Lost PLA casting straight from the mould abut 1 1/4" tall:

Edited By Neil Wyatt on 05/01/2022 15:19:37

[bernard towersParticipant @bernardtowers37738]

When I did my turret clock I cast my own wheels and added a small amount of lead as in cz120 and it machined beautifully and you have the satisfaction of doing it yourself.

[Andrew Knowles 2Participant @andrewknowles2]

Many thanks for all the suggestions

I think I will get all the wheels,pinions and plates made first

Best wishes to all

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