Old bronze screw recycle?

[sdowney717]

Can the bronze in bronze screws be reused, melted down?
Has anyone melted down old screws and cast something new?

[seayou77]

The foundry is picky about the content for Hdw. Working from known ingots. Since the screw has lost an unknowable amount of its alloy, may make good artwork. Propellers are an avail. source too.

[scepticus]

I took the bronze casting class at WB last year. We were cautioned against using any metal of unknown origin or alloy and that once a crucible was used for a particular alloy, it should only be used for that alloy. However, we also learned that bronze can be melted and cast repeatedly without damaging its properties so it seems to me the old stuff can be melted down and used for something, but you won't really know what you've got and whoever does it would have to consider the crucible used for this "contaminated" so it could only be used for like stuff in the future.

[Thad Van Gilder]

I haven't done it yet, but I am planning this spring on lost wax casting some fittings for my dinghy, and melting the bronze screws with mapp gas in a crucible.

-Thad

[Clyderigged]

I have also wondered about melting down old bronze screws. Just finished refastening my boat and have quite a few 2 ½ inch #12 bronze screws. Thought about casting up some chart weights for myself and the previous owner.

Jamie white

[Dean4140]

I am not a metals expert, but I have done some bronze sculpture. I also would like to see bronze fastners be recycled, but you need to be careful. Marine bronze fittings can have other metals in them that are different from bronze bars used for sculpture that may contaminate a crucible.

It is important that the foundry foreman inspect all bronze before putting into the crucible for melt down. Even bronze bars purchased from a metals company are usually sand blasted before melt down, so the metal is as clean as possible.

Foundry work falls under OSHA standards. If OSHA should make an unannounced inspection of a foundry and find contaminated metals are being used, OSHA will shut the foundry down. Residences of a major California University complained of odors from the campus foundry. OSHA inspected the foundry, found contamination, shut it down and the foundry has never reopened.

I would think the best foundry to use would be a foundry that specializes in marine work rather than a pure sculpture foundry. A nice touch of bronze was done on the Silva Bay School 15' Gartside project by Rick Corless. See www.rickcorless.com/page26.html. (http://www.rickcorless.com/page26.html.) That's my input. Dean

[Dean4140]

Try www.rickcorless.com (http://www.rickcorless.com)

[George Roberts]

You can sell the material at a scrape yard.

You can recast it.

Good commercial foundries can recycle it.

[Bruce Hooke]

Regarding OSHA, it is worth remembering that OSHA does not regulate situations where there is not an employee involved, so they have no say over what you do in a "hobby" foundry (the city you live in may have something to say but that is another matter!). I cannot imagine a commercial foundry bothering with reclaimed metal of unknown origin...the material is such a small part of the overall cost of a casting that it is not worth the trouble of messing around with questionable materials. Whether it makes sense for a home foundry may at least be debatable, although if it were me I think I'd stick with known material.

[Bob Cleek]

Common practice in boatyards of long ago was to keep a bucket on hand with some sort of acid or oxidizing agent, which I can't recall, into which all the old shot bronze and copper fasteners were thrown. They would break down into a green copper oxide ooze. This would then be added to the paint mix as cuprous oxide, for use as bottom paint. Maybe somebody can remember what they threw the copper scrap into to get it to break down.