Dental x-ray dams

[Jech]

I scored about 85lbs of these a while back. I expected them to be pure or close to pure but much to my surprise, the ingots have the same bright silver appearance as my range lead and other ingots alloyed with sn/sb.

What are these supposed to be made of exactly? :confused:

[zomby woof]

The lead they use is Lead >96%, Tin 1.5% +/- 0.1%, Antimony 1.5% +/- 0.1%.

[Jech]

So it should cast soft and have fairly decent flow characteristics since the tin content is higher than the antimony content right? Maybe a little low on the sn.sb side but the ratio is viable enough to alloy I presume...

[idahoron]

All the dental lead I have tested was 12.5 BHN. I have NEVER seen it lower than that. Ron

[Jech]

Well, I cleaned everything else out of my pot before I melted it down into ingots. 12-14BHN is just about perfect for the 45auto and mid-range .357mag velocities I currently cast for.

[*Paladin*]

Not to hijack this thread, but what does this dental lead look like, pre-melted of course? I am thinking of hitting up a few dentists and want to know what I'm asking for. Anybody have a pic?
Thanks!

[Jech]

If you've ever had x-rays taken of your teeth, many will remember the small object the dentist puts in your mouth and tell you to bite down on. Inside that object is a very small piece of lead foil. After being in your mouth, it's biohazardous material and is disposed of. Naturally however, the lead foil has to be removed from the insert by hand by the dental assistant or xray tech. These foils collect over a period of time and are eventually recycled or disposed of in some form. To put the size into perspective, 85lbs of them filled one of those classic blue recycling bins to the brim before melting them down. Sadly, as is the case with most lead sources, the majority of dental practices have switched to digital imaging systems quickly eliminating the demand for these foils.

Here's a picture (http://upload.wikimedia.org/wikipedia/commons/8/89/Dental_x-ray_film_05.JPG) of the foil along with the paper insert and sheathing that you actually bite down on.

[zomby woof]

Here's a picture (http://upload.wikimedia.org/wikipedia/commons/8/89/Dental_x-ray_film_05.JPG) of the foil along with the paper insert and sheathing that you actually bite down on.

I have literally made millions of those.

[*Paladin*]

Thanks Jech! That's what I figured they were, but I honestly didn't know. It's been YEARS since I had x-rays done with film like that. The military has used the new digital technology for a long time now...

[sargenv]

my dentist still uses the old school stuff, he likely will until he retires.. and until then will get about a pound or so every 6 months

[montana_charlie]

So it should cast soft and have fairly decent flow characteristics since the tin content is higher than the antimony content right?

The lead they use is Lead >96%,
1.5% +/- 0.1% - tin
1.5% +/- 0.1% - antimony
I'd say the tin and antimony content are very close to being equal.



All the dental lead I have tested was 12.5 BHN. I have NEVER seen it lower than that. Ron
My x-ray foil always tests at 7.8 BHN, so I just call it 20-1.
But if it really is 97/1.5/1.5 it should test at 8.2 when cast, and 9.8 BHN after 18 hours.

CM

[idahoron]

I have tested it many times with my Cabine Tree tester, and it is always the same. It is never softer than 12.5. Ron

[vincewarde]

my dentist still uses the old school stuff, he likely will until he retires.. and until then will get about a pound or so every 6 months

If the insurance companies let him. They would love to have the government mandate electronic billing - which nearly everyone does now anyway - because it is a pain for them to deal with electronic claims. Of course this includes sending .jpg's of the x-rays.

In addition, in both medicine and dentistry, digital x-rays - which use 1/3rd as much radiation - have basically become the standard of care. Eventually everyone will have to go digital.

Did I mention that it saves a ton of money?

Sadly, x-ray film is going away faster than wheel weights.