What's the deal on lead media?

[Mumbles]

I think you're reading that wrong. SS doesn't expire it's the instrumentation, tables, beds, whatever else that gets constantly replaced. When you have the budget of the healthcare industry, you can afford to constantly replace it, and as such anything over 18 months old is obsolete by supplier or purchaser standards.

[tentacles]

Mumbles: Nope, the company that sells it to us as scrap is the manufacturer - all they make is metal. It's terribly ridiculous. We get pallets of sheet steel, stainless, aluminum from the place. Sometimes channel or rod, tubing.

[jacob]

I didn't want to start a new thread for this so I'll put it here.

 

Why not just take a bunch of random scrap Brass, and melt it down to cast milling media out of? sort of the same way as lead. I assume Brass is hard to melt, but it can be done at a hobbyist level.

 

And does anyone have experience useing Stainless steel bearing parts? I've got a friend that works at a Kenworth truck dealership and he thinks he can get me some old bearings.

[FrankRizzo]

Don't know about you, but I'd rather process 30lb of lead @ 650F rather than 25lb @ 1700F.

 

Stainless bearings would work wonderfully. If you have access to more than you need, PM me.

[jacob]

Heh, yeah the amount you would need to melt would be the biggest problem. might work for smaller mills though.

 

I'll definitely see what I can do on the bearings, I should see him Sunday to ask about it.

[justanotherpyro]

I've used some stainless steel ball bearings to grind down Al before. They are very nice to use. The steel slingshot ammo works alright as well but it is just a bit too small for my liking. I agree with Frankrizzo ; If you can get a supplier of them you might have yet another item to sell.

[Apollofrost]

Really now? Because I can get steel bearings(non stainless) in any size for $3 a pound.

[FrankRizzo]

The *stainless* detail is key here, Apollo. Steel media is good for grinding materials like magnalium and charcoal, but is useless for oxidizers and BP compositions.

 

I'm a bit tanked on Patrón Añejo tequila and Lucid absinthe

[Apollofrost]

Cheers, it's my birthday Friday and I'll be enjoying much liquor then as well. Yeah... april 25th, division 2 exams for the first responder course and a unit on child birth and SIDS. The following week I'm moving. I think I'll need that drink.

 

Honestly I'm not entirely sure what they're made of. They had some rust on them when I bought them but I used them to mill some sugar and all the rust was gone.

 

They don't seem to react with kno3 at all and I've got .5"dia lead for my BP. Maybe they are stainless.

[pudidotdk]

Use a magnet to check. Ideal stainless is non-magnetic.

[tentacles]

Stainless bearings would probably be 4 series which is magnetic. Even 3 series is slightly magnetic, to varying degrees.

 

"Chrome Steel" ball bearings (ie standard) are 1.3-1.6% chrome, whereas stainless steel must be at least 12% chrome.

[jacob]

Wow tentacles, you're like an endless font of metal-related information

 

I talked to my friend about the truck bearings and he said they don't get much in way of balls, but they do replace old wheel bearings all the time, which he says are usually Stainless tapered roller bearings, which I bet would work.

 

But he also told me he happens to have about five, 5gal buckets full of what he's pretty sure are odd sized Stainless nuts and bolts he got for free, would these work if they're the right size?

[Swede]

I talked to my friend about the truck bearings and he said they don't get much in way of balls, but they do replace old wheel bearings all the time, which he says are usually Stainless tapered roller bearings, which I bet would work.

If you can get these (the roller bearings themselves, not the races) in any appreciable quantity, and they are in fact stainless (usually they are very hard carbon steel) then they would make a very good media, IMO.

[Mumbles]

To any degree, I'd be slightly concerned about milling live materials with media I was not 100% sure of it's composition. Might be suitable for a bunker test.

 

My main complaint with nuts specifically is that the threaded hole in the center would be hard to clean, and may perhaps gather sticky chemicals. If an appreciable enough quantity is available though, having a single set for each chemical wouldn't be too hard.

[tentacles]

Wow tentacles, you're like an endless font of metal-related information

 

.....

 

But he also told me he happens to have about five, 5gal buckets full of what he's pretty sure are odd sized Stainless nuts and bolts he got for free, would these work if they're the right size?

Jacob: I suppose you could use the nuts and bolts, but you'll end up with a lot of comp residing (permanently, pretty much) in the crevices and whatnot. The bolts could be made more useful by cutting off the heads (you can mill with those pieces too) and the threads (maybe not so useful). The unthreaded shafts would work fine, and the heads too.

 

A hell of a lot of work to make up your media though, unless you have a bandsaw and a bi-metal blade. I'd sort them with a magnet before cutting anything, too.

 

Alternatively, take em to a scrapyard and see if they have any stainless rod in their SS scrap that they would trade, pound for pound, or sweeten the deal, say 3lb of bolts for 2lb of rod.

[jacob]

I actually probably wouldn't use the nuts due to them collecting too much material like you guys mentioned, unless maybe I thread them onto the bolts, but from the way he talked it didn't sound like there're alot of nuts anyway.

 

But I'm worried about the bolts tearing up the jar, so I thought I might tumble them alone in a Steel tube at a faster then optimal RPM to beat the sharp edges off, or perhaps add an abrasive?

What do you think?

[jacob]

Woot, double post.

 

Turns out the bolts aren't SS, just coated, and I don't want to wait a while to get bearings that may or may not be SS.

 

So would 303 Stainless work well? I'm sure it's not as good as 316 but I have a source for it in 5/8'' round rods and for 21lbs it comes out to about $2.90 per lb shipped. as long as it's corrosion resistant enough for milling oxidizers I'm good with it.

[FrankRizzo]

Yes, 303 will work fine.

[Swede]

I wrote to a company in India that sells SS "eclipse" style balls... the problem with stainless balls is that most companies seem to assume they're for bearings, and they're ground to some insane tolerance, like +/- 0.00005" or so. Big money.

 

We'll see if the Indians write back, and what sort of price they will quote. Would anyone be interested in a group buy?

 

The other problem is that metal prices worldwide have just gone insane, and even plain SS in any form, like ingot, is going to cost. But it sure would be nice to not have to saw a 1/2" bar into a zillion little segments. That's almost impossible without a powered saw of some type.

 

Question: What would be a better media shape, cut-off round bar, or cut-off hex bar?

[Bonny]

That's a tough one, but in this case I'm sure either would be fine. I'd go with whatever is cheaper.

[Swede]

I did a bit of prowling, and probably the cheapest EASY source of stainless round bar is https://www.onlinemetals.com/index.cfm

 

I've dealt with them before. If you get your order over $100 (easy to do) they cut 10% off the total. They have good prices on 303 stainless, and they have plastics too like nylon if you are looking to make rocket tamps.

[lostfido]

Sorry about reviving an old post, but I thought it would be better than starting a new post.

I have used the search feature and did not see anything on this application.

 

I am in the automotive/truck repair industry and have acces to old lead wheel weights.

I am wondering about the quality of the lead used in these weights as far as melting them down and using a sinker mold to make some 1/2 or 3/4 inch balls.

 

I am a Newbie to this and I am trying together some product and equipment for making some BP.

 

I have the double jar Harbor Freight mill and already have 3 pounds of ceramic media off E-Bay but I thought if there was a use for all of the old wheel weights, I could keep media seperate for fuels and oxidizers etc.

 

Thanks, Fido

[Richtee]

if there was a use for all of the old wheel weights, I could keep media seperate for fuels and oxidizers etc.

 

If you have the casting equipment, I would think the wheel weights would be fine. Dunno if they have antimony content for hardness is the only thing I can think of.

[Senz]

ive heard about poring molten lead into a pipe of some sort, but wouldnt it stick?

[Mumbles]

It depends. The pipe in question was copper. He says it works, most of mine stuck, though did move. I found applying a thinned solution of vaseline in toluene to the inside of the tube allowed them to come out every single time. It did put a series of tiny dimples in the side of the media though, presumably from the toluene boiling. They were very very small though, so I would assume they'd mill themselves out pretty quick. I never went full scale, I wanted to make sure the lead would come out, which I did have doubts about.

 

Another popular method is to drill a series of holes in a 2x4 or other scrap wood, and fill these in. Yes it does char the wood. I don't remember if you could pop these out or not. The wood might of had to have been split. I'd imagine this would produce similar dimples, but maybe not if the roughness was burnt off.