Has anyone melted down their old bronze?

[Nick F]

I need some oddball pipe fittings in bronze and they are not available off the shelf (1-1/4" by 1/2" reducing street tee, for example).

I priced out some bronze bar stock and it costs a fortune. At the same time I have maybe 100lb of disused quality bronze pieces.

I am thinking of melting down my old bronze into ingots and machining the parts out of this.

So far I have failed to find a local foundry who will do this for me, but I see that I can buy a small melting furnace for $199.

Has anyone done this? Suggestions? Tips?

 

[PierreR]

Pretty tough to pour ingot without a lot of defects. Better to make some wood patterns and pour rough cast fittings and then machine. Bronze is not tough to melt but can be off spec. Brass is much tougher.
I would have no issues doing this but I am a superb foundryman. Someone probably makes these somewhere but then a combination of standard T and a reducer can to the same thing as a full fledged reducing T

 

[RT Firefly]

Greetings,
Mr. NF. Wow. Interesting approach to a problem. I like it! Only question I might ask is what is the capacity of the $199 furnace? Is it big enough to allow you to cast adequately sized machinable ingots?

 

[Nick F]

Here is one example of a furnace. Available in both propane and electric.

https://www.vevor.ca/melting-furnac..._XDDrhryKyS6rD0tkscZdWIbckzfWwsxoCVFoQAvD_BwE

 

[RT Firefly]

Greetings,
Mr. NF. You've only got $152.99 to lose. Good off season project. I notice they also offer a 12kg model.

 

[Nick F]

Yes, but I want to go into this with my eyes open. I need some mentoring from Monsieur Pierre.

 

[koliver]

Nick
Have you noticed my boarding ladder, hanging from the side of my boat on bronze hooks?
I replaced the bronze supports when I expanded my swimgrid many years ago. One of the old bronze supports was then melted and now has a second life as hooks holding up my boarding ladder.
Call me and I will be happy to discuss teh methodology. Your project sounds interesting.

 

[klee wyck]

I am guessing that Pete at the Port Townsend Foundry in Port Townsend Washington could take care of you. All he does is marine fittings, and he is an artist for sure. Seems like he can make anything.
Just a ferry ride away from Vancouver.

 

[PierreR]

Yes, but I want to go into this with my eyes open. I need some mentoring from Monsieur Pierre.

Sounds like the suggestion of a foundry locally is a good idea but if you decide that you are really serious i can send you the non toxic binders to do the job and give you some guidance.

 

[Nick F]

Thanks Pierre. Offer much appreciated.

Port Townsend is not actually that close - across the border and most of a day to get there. I am still looking for a small foundry closer to home.

 

[KnotYet]

I'll make the obvious comment that using a 1-1/4" street tee
with a 1/2" bushing is the easy way.

 

[PierreR]

Thanks Pierre. Offer much appreciated.

Port Townsend is not actually that close - across the border and most of a day to get there. I am still looking for a small foundry closer to home.

Still might be worth you time. Pete might be able to tell you where to buy them off the shelf.
I almost get the impression that you are looking for an excuse to play. I am guessing that pouring an ingot to machine out of bronze and have anything really useable is probably pretty slim. Making a pattern and a sand mold is the likely path to success.

 

[Delta Riverat]

Bronze is really cool stuff. Almost as strong as steel. A close fit brazed joint is as strong as a welded joint and a loose fit not much weaker.

And brazing is easier to learn then welding.

 

[Tomas]

Have you checked with this company?

https://getpipe.com/125-bronze-threaded-reducing-tee/

 

[Nick F]

Still might be worth you time. Pete might be able to tell you where to buy them off the shelf.
I almost get the impression that you are looking for an excuse to play. I am guessing that pouring an ingot to machine out of bronze and have anything really useable is probably pretty slim. Making a pattern and a sand mold is the likely path to success.

I regret listing the tee as an example! There are other parts I want that are definitely not available. For instance, I want to make some bronze substitute caps for my Groco sea strainers. These caps will have a connection for fresh water flushing.
(A bronze version of the image attached, which is available on Amazon.)

Pierre - I am curious as to the difference between casting an "ingot" and casting in sand. You suggest that the latter would be more likely to yield better quality. I am guessing that an ingot would be cast in a metal (iron?) receptacle. Is this the difference? BTW, although I said ingot, I was thinking of trying to sand cast a short bar shape. If the crucible dimensions were suitable maybe I could just let it solidify in the crucible. I am thinking of a short piece of approx 3" diameter.

 

[sean9c]

Why not just machine whatever you want to make out of solid stock? Though to be honest I don't know if you can buy bronze bar. You'd have to also figure out which bronze. It'd sure be easier than melting down old bronze and how do you know what that even is? Could be some cheap chicom something.

 

[Circumnavigator]

McMaster lists a 1 1/4 by 1/2 tee in brass -- no good under saltwater, but OK for anything else.


If it's for saltwater use, you could use galvanized -- all of the engine room piping on Fintry (ex Royal Navy) is galvanized steel and she's just turned 50.


They also sell square bronze bars and rods in a variety of sizes that would fit your needs (up to 4" square and 2.625" diameter) in a variety of alloys. Not cheap.


Jim

 

[Nepidae]

Old Bronze

Unless you want the experience, you might want to try McMaster-Carr (www.mcmaster.com) and see if they might have what you need.

IF they don't you could ask them if they might know where you could find what you are looking for.

Finally, you didn't mention what this reducer was for, but you could go to the company that makes the unit you need the reducer for to see if they have it.

Good luck in either case!

 

[Nepidae]

Bronze fittings

I need to add to my previous post.

You should have mentioned that you wanted a project.

I take my Groco caps off the strainer and use a funnel when we do our winterizations.

What is wrong with the cap you illustrated in plastic? IF you want Bronze, then why not buy at Amazon.

Again, good luck.

 

[PierreR]

Pierre - I am curious as to the difference between casting an "ingot" and casting in sand. You suggest that the latter would be more likely to yield better quality. I am guessing that an ingot would be cast in a metal (iron?) receptacle. Is this the difference? BTW, although I said ingot, I was thinking of trying to sand cast a short bar shape. If the crucible dimensions were suitable maybe I could just let it solidify in the crucible. I am thinking of a short piece of approx 3" diameter.

An ingot can be cast in both sand and metal. An ingot is nothing but a block of metal cast for the purposes of re-melting. Cast metals shrink when they solidify and the last metal to solidify is the center of the ingot an that is where all the shrinkage occurs. The ingot is basically swiss cheese. In addition, slag will form in the metal during melting and end up in the metal causing defects and machining problems.
by my calculation, a 6kg gold equivalent is a little smaller than the size of a 12 once soda can. The crucibles appear to be graphite. Good stuff but graphite is brittle and easily broken when hot and deteriorates with each firing. You have to have a decent ladle handle to pick up a graphite crucible.
Now lets look at the scrap. There are over a hundred bronze alloys and about a dozen of them are suitable for bronze casting. The problem is the chemistries of bronze vary greatly and your mix maybe total junk. Will it look like metal? Yes. In addition alloying elements such as lead and zinc are toxic and volatile so don't get your nose over the top of any fumes.

You might as well cast something very close to the shape of what you want with passage ways already cast because to get a sound casting requires a mold with risers (heavy sections not part of the casting that freeze last) and a gating system ( a series of passage ways and pour holes designed to trap slag and deliver clean metal to the casting. Patterns are not difficult to make and binding sand around the pattern, curing the mold and removing the pattern are not difficult but require knowledge of what you are trying to achieve.

When I was young, I would have tackled this, now I will make a pattern and give it to someone I know and get back a casting. The pattern would be made out of wood as well as a wood core box. A core makes the passageways in the casting.

 

[AUXOPdwp]

1-1/4" by 1/2" reducing street tee

I need some oddball pipe fittings in bronze and they are not available off the shelf (1-1/4" by 1/2" reducing street tee, for example).

I priced out some bronze bar stock and it costs a fortune. At the same time I have maybe 100lb of disused quality bronze pieces.

I am thinking of melting down my old bronze into ingots and machining the parts out of this.

So far I have failed to find a local foundry who will do this for me, but I see that I can buy a small melting furnace for $199.

Has anyone done this? Suggestions? Tips?

I suggest you contact www.fawcettboat.com, a chandlery in Annapolis MD that stocks an excellent assortment of bronze fittings. You will find a form under the 'Contact Us' link. Direct your inquiry to Rick Sadler who is one of the owners of this and prior marine hardware businesses in Annapolis over forty years. Ask Rick for suggested sources if he doesn't have all you want.


Alternatively, Have you searched McMaster Carr, https://www.mcmaster.com/products/street-tees/?s=reducer+street+tees ??



Good Luck

 

[HopCar]

For your strainer cap I think you could just order a bronze one from Groco. I’m pretty sure the bronze cap from an AARG Groco strainer will also fit the similar sized ones that come with plastic caps. Ask Groco if it will fit. https://www.groco.net/products/raw-water-strainers/basket-strainer/aarg-series-bronze-enclosure

As for the reducing street tee, just make one from a regular tee, reducing bushings, and a close nipple.

 

[joezzz]

getting parts cast

I believe there is a bronze foundry in Washington State. They do excellent work. The wooden boat crowd out there uses them.
On the East Coast, there is the Mystic Foundry, Mystic, CT. who also does excellent work. They can take an old part and cast from it. Over the years they have done a lot of work for the Mystic Seaport. I have used them to make up bronze items like opening ports...... Good Luck.

 

[jflongwell]

Additive manufacturing

I was a metallurgist in brass, bronze and iron foundaries. Jay Leno's solution for parts for his cars was 3d scanning and printing the part (addative manufacturing).
Take a look at that.
At the risk of offending anyone, lets get out of the '60s.

 

[Pcpete]

A couple of thoughts. First, go to YouTube and search for Tally Ho, then to the “floors”. The process is presented in detail, and will explain some of the pitfalls that can show up later. Second, at least for the pipe fittings, why not buy steel and have it ceramic coated? If you want to cast them to learn the process, you may want to look at “lost wax” casting. Rather than casting into a cavity created using wood patterns, a representative part is printed on a 3d printer or, in larger quantity requirements a pattern is made, out of wax. The wax model is set into the sand and vents, drains, for the wax are created, the molten metal melts the wax and the part is created. In any case there will be machining required.
Personally, I’d be very reluctant to use a critical component that I made using a process as surprisingly complex as casting. Machine a part from plate like the strainer cap? No problem. To cast it first? I think not.
One thing for sure, you’ll have a whole new appreciation for guys who get their hands dirty.

 

[PierreR]

Rather than casting into a cavity created using wood patterns, a representative part is printed on a 3d printer or, in larger quantity requirements a pattern is made, out of wax. The wax model is set into the sand and vents, drains, for the wax are created, the molten metal melts the wax and the part is created.

The patterns can certainly be created with 3 d printing. Something I don't know much about.
Lost wax does not work the way you have described. Wax patterns are coated with a ceramic slurry and the wax is then baked out. Cores are made from a water soluble wax and washed out of the wax pattern with water before ceramic coating. Gating and risers must also be lost wax or tree mounted. Bake out is critical on time and temperature. Loose sand is vibrated around the ceramic shell to form the mold. It's much more complex than simple sand casting. Hot metal will not wash out the wax.
You are probably thinking about lost foam where parts are made from Styrofoam, coated with ceramic and bedded in loose sand. The metal burns out the foam upon pouring. Lost foam never really worked as the melted foam often creates defects and a lot of toxic gas.

 

[Pcpete]

I happily stand corrected. Thank you.

 

[PierreR]

I was a metallurgist in brass, bronze and iron foundaries. Jay Leno's solution for parts for his cars was 3d scanning and printing the part (addative manufacturing).
Take a look at that.
At the risk of offending anyone, lets get out of the '60s.

Forget the 60's, try the 40's. His garage is not a modern manufacturing facility and he has stated what he wants to do is melt his old scrap. Easy to make wood/Bondo patterns mounted on a piece of plywood would allow him to simply build a wood flask and ram up a simple sand mold. He can either beg some green sand, find some bentonite and mix his own or beg me for some non toxic organic binder that he can bake out in the oven at 180 deg F to cure a mold.

 

[Nick F]

I was a metallurgist in brass, bronze and iron foundaries. Jay Leno's solution for parts for his cars was 3d scanning and printing the part (addative manufacturing).
Take a look at that.
At the risk of offending anyone, lets get out of the '60s.

Thanks for this, but . . .

I researched this last year and, as far as I can tell, there is currently no 3D printing process available that works for bronze. You can do SS, but not bronze. If you do know of a bronze 3D process I would very much like to know about it.

 

[Nick F]

Forget the 60's, try the 40's. His garage is not a modern manufacturing facility and he has stated what he wants to do is melt his old scrap. . . . .

Thanks Pierre - exactly this !

(also I now know from this post what the "binder" is for)