Quick and dirty brass pour questions.

[opensourcefan]

I saw it mentioned in another post so I thought I'd ask here. What would be the best type (material) of pipe to pour brass into to make a 3" round maybe 5" long round stock for the lathe?

This is really a one off project so just a quick and dirty method to re-use a few kilos of brass shavings I've saved. I was thinking of buying one of those inexpensive 3kg electric melting furnace.

The brass is a mix of red to yellow. All different shades I was hoping to mix into one.

 

[trevj]

If I were going there, I'd likely bury a suitable size tin can in some damp sand and fill the can with the molten metal.

Be aware that you will se a LOT of the Zinc burn off, it will form snotty white clouds in the area. If you breathe in too much, you get Zinc Fume Fever, which is unpleasant but not life threatening. Drink milk to offset if you suffer from!
Also, as chips, you have a LOT of surface area, so it is not going to melt very cleanly, lots of dross to skim!

Couple firebricks, and a Tiger Torch, should serve as a melting furnace, can use pipe as a crucible, though not ideal.

 

[opensourcefan]

I've been watching as many videos as I can find about melting brass since I made this post. I'm starting to think melting brass shavings and chips might be a dumb idea.

As mentioned above the amount of dross will be insane. I simply want to melt some material for nostalgia reasons and create something from where it originally came. Just not sure if this will be feasible in a smaller furnace.

This video in particular shows most of the "dust" going in as dust and coming back out as dross! Don't know what to think really.

 

[jcdammeyer]

What I've seen but not tried is that the shavings/dust need to be compressed. So a 20T press and the material is compressed into an ingot with as little air as possible. A 1" ID piece of steel pipe and a 1" OD piece of steel. Fill with particles and press. Add more particles and press. And so on until the pipe is full. Rinse and repeat.
I believe there will still be dross but far less.

 

[trevj]

I think I would try something along the lines as suggested by John, above.

Perhaps some looking in to what acts as a flux for brass or bronze, as well.

edit to add: Without having tried this, I would 'think' (dangerous!) that you could offset some of the problems by saturating the melt with an inert gas, and adding a layer of dry sand over the top of the crucible of chips to seal out the oxygen. In theory...

 

[Tom O]

I think I’d pack it down fairly tight and cover the top with Borax with a removable top cover, or maybe crushed bbq bricks to use up the oxygen with a top cover.

 

[opensourcefan]

I think I’d pack it down fairly tight and cover the top with Borax with a removable top cover, or maybe crushed bbq bricks to use up the oxygen with a top cover.

I was planning on buying this for the job?

https://www.amazon.ca/TOAUTO-Upgraded-TGF3000-V1-1-Electric-Smelting/dp/B0B9BJ25GL?th=1&psc=1

 

[jcdammeyer]

It's a lot of money for a tiny bit of brass and even less aluminum. Even just with firebrick, a blower of some sort and charcoal you can melt metal.

 

[opensourcefan]

It's a lot of money for a tiny bit of brass and even less aluminum. Even just with firebrick, a blower of some sort and charcoal you can melt metal.

I just don't have the location to do open flames and blowers etc. I would definitely go that route if I could.

I don't suppose I'd be able to melt with a mapp torch huh.

 

[Tom Kitta]

I did it few times. Without some additives brass is porous. i.e. it has small inclusions and not 100% smooth. For a lot of work its totally fine.

 

[Janger]

I was planning on buying this for the job?

https://www.amazon.ca/TOAUTO-Upgraded-TGF3000-V1-1-Electric-Smelting/dp/B0B9BJ25GL?th=1&psc=1

That is an interesting device. I want something more comprehensive. Something for heat treating with temperature control, and the ability to melt aluminium etc. for casting, and if that was not enough what about forging? I used to have a big kiln but it was big & awkward to use, temperature control was fairly basic, and kiln's are slow. You can't use them for forging. You could stick a crucible in the kiln and melt for casting but again it's big and awkward. Anybody know of some sort of combination heat treat, crucible heating machine. And I'll forget the forging as that seems like quite a different problem.

 

[Tom Kitta]

That is an interesting device. I want something more comprehensive. Something for heat treating with temperature control, and the ability to melt aluminium etc. for casting, and if that was not enough what about forging? I used to have a big kiln but it was big & awkward to use, temperature control was fairly basic, and kiln's are slow. You can't use them for forging. You could stick a crucible in the kiln and melt for casting but again it's big and awkward. Anybody know of some sort of combination heat treat, crucible heating machine. And I'll forget the forging as that seems like quite a different problem.

I have one of these https://www.fishersci.ca/shop/products/lindberg-blue-m-lgo-box-furnaces/p-4529147#?keyword=

Just an old model. Worked great for melting aluminum. Also good for melting brass. Note that thermocouples above around 1000C start drifting - i.e. they no longer function well and instead of recording 1000C they show only 950C. I managed to overheat my furnace and now have to change coils.

It takes a while to melt stuff with these - temp rise is good but especially aluminum has high heat capacity and just soaks up all energy thrown at it.

This has temperature control so can be used for heat treating. Actually has two - one in the furnace and one for outside thermometer. Then just look up temperature needed, time per inch of steel and setup alarm clock on your phone.

 

[jcdammeyer]

There are all sorts of small kilns now.

Small Kilns for Pottery, Ceramics, & More | Mini Kilns for Sale

Kiln Frog has a huge selection of small kilns for sale, including ovens for pottery, ceramics, enameling, and more. Explore the collection of mini kilns today!

kilnfrog.com

And with Raspberry Pi and Arduino's etc. ramping and holding and slow cooling are all easy to do. I guess you have to decide how big a crucible you want it to hold and how big the heat treated items are.

My Kiln is two levels with 220VAC for each. I could build up the base with firebricks so only the top windings would be used. I think the #6 will fit at that point. However it's still really large in diameter but then it depends on what is being heat treated too. A larger weldment to remove stresses needs the space.

 

[jcdammeyer]

Remember too, although you might heat up aluminum in a small #4 crucible the size of what you cast may be considerably different in size. If you then decide to anneal it by bringing the casting up to 150C to 200C and holding it there for 24 hours will it still fit?

Heat Treating of Aluminum Castings

The heat treatment of cast aluminium alloys is carried out to increase their strength and hardness and to change their physical, mechanical and metallurgical properties. Let’s learn more.

www.industrialheating.com

Of course a regular oven easily reaches that temperature so just bump SWMBO out of the kitchen for the day...

 

[Susquatch]

It's a lot of money for a tiny bit of brass and even less aluminum. Even just with firebrick, a blower of some sort and charcoal you can melt metal.

Good advice John.

I'm not even remotely considering reusing my own swarf. I collect it, take it to a recycler, get pennies back on the dollar, and then go buy new stock. Done.

I admit I always wanted to recycle my own swarf. Then I think about the cost of doing so vs the cost of buying new stock. Then I hit my thumb with a hammer and go buy new stock. Maybe if I had tons of swarf I might feel differently. But at a few hundred pounds a year of brass and aluminium combined, it doesn't pencil out.

 

[Tom O]

Way back around 1968 we were casting the handles for the school fire poker metalwork project in a cast iron forge with about a 6” x6” door on it.

 

[PeterT]

There are all sorts of small kilns now.

Kiln Frog is a good site! Lots of goodies of interest & found this nice documentation package.

https://www.secowarwick.com/wp-content/uploads/2017/03/HeatTreatingDataEBook.2011.pdf

 

[Mcgyver]

I have one of the cheap electric metlers. I use it indoors and rigged ventilation with an inline fan. Its worked well for the stuff I've done, but imo, its not a suitable set up for brass. Problem is the zinc coming off it, (don't want that in the house where my family is) and the slow heat up. Brass should be melted fast so you don't burn off all the zinc or you can get kind of a crumbly mess

 

[kevin.decelles]

My thoughts:

Expensive for the limited capability. Build the gingery electric furnace for a fraction of that with larger capacity

Melting shavings for me is a non starter , especially for aluminum. I tried many ways including pressing shavings into a beer can with the press . Dross percentage was through the roof, poor quality castings, and required about 50% more burn time

I melted solid brass cupboard door knobs from my old house , this worked great.

 

[kevin.decelles]

Final note, if confined to a small space, low volume requirement etc. i would definitely buy a machine like you posted as any casting is better than no casting