Why aluminum paint?

My previous arena included criticality safety for weapons-grade materials at various facilities. Even there, one needs must start the mitigation process by realization of what is physically possible with the materials (and particularly important in criticality, the geometry) at hand.

The elements in the can may have the possibility in other forms, but not in the combinations they're in in the paint can with only vibration as an energy input...

So what really happened at the UNC facility at Nuclear Lake in Pawling NY?

'An explosion in the plutonium room' is a bit vague...

...

...

Don't recall ever having read an incident report on it, sorry, so can't say, specifically.

What little I find indicates it wasn't actually a criticality accident but a conventional explosion. That it also apparently wasn't a DOE facility would have kept it off the mostly-beaten track of the arena for which had resposibility. I read and reread about every one of those incident reports plus many non-US ones about yearly looking for the clues of what was overlooked or otherwise went wrong that might be pertinent in any given new situation at hand.

This is a listing of accidents as of 1971.

On 12/16/2013 10:19 AM, dpb wrote: ...

And, just to make it clear--that doesn't mean weren't looking for ways to prevent such accidents; only that those types of initiating events were in others' purview, not mine so my research concentrated on those events that were criticality events foremost.

If we did happen to come across some scenario in our areas would give the ideas to the others for evaluation, of course, but each group concentrated primarily upon their own field for initiating events and the facility operation plan was a then an amalgam for all.

Thanks for all the replies. Especially the knot stain blocking one.

One reply was about painting flashing: when I paint flashing, I use the ordinary latex paint that I use on trim. I want it to look like the trim, not different.

Bob

And it far predates the time period for which NRC has LERs and other documents online. A research expedition in the library hard copy archives thereof would find the details, I'm sure.

Not saying anything about the mechanism, but it *does* happen. Here is a report (from some not very specific time in the past):

====================================================================== ======================================================================

Enjoy, DoN.

That's a good project for someone with faster Internet. jsw

I've got some new old (Co-op brand, even :) ) Al paint still around -- so I went and looked at one. There's nothing on the cans about not shaking. I've not used a lot but did a little touchup with one a few years ago. AFAICT they're still as good as new despite the age as far as appearance in can and behavior in use goes. I didn't drive to town to put one on the paint-store shaker but I did put it on the homebrew vibrator I've cobbled together here out of an old combine pittman sickle drive. It's not as fast and has a longer stroke compared to real shaker but does get the stuff off the bottom...I don't remember noticing any pressure after that when opening it (but then again I wasn't looking for any as had never heard the stories/warnings).

I don't know if there is more than one type of Al paint where there's a significant difference in the makeup or not. I'd guess these go back to around the late '70s/early '80s -- from the stuff in the old wellhouse it looks like Dad bought out a bunch of the stock from the Co-op when it closed the retail store in town but I'm not sure just when that was altho it's been quite a long time ago now...I looked but didn't see anything on the can that indicated a date -- even a tm or c on the label printing. There's a manufacturer's mark which likely has a date in it but it's coded to where can't decipher which letter/number(s) might be a year.

I'd like to see a real explanation--a quick search on manufacturers' sites didn't bring anything to light.

And one that can reach out and turn hardcopy pages as well... :)

First hand accounts - the gold standard. One guy said it popped when he shook it _by hand_ (out in the back yard, about to paint a fence)!

It seems highly implausible & skepticism is good, but ...

Bob

Bob Engelhardt fired this volley in news: snipped-for-privacy@news1.newsguy.com:

...Out in the back yard, about to paint a fence, sitting in the sun for an hour while he ate lunch... and so on...

Look... it takes little heating to raise the vapor pressure of some of the higher-fraction solvents in there to the point of flashing when the can opens. It doesn't necessarily require a violent chemical reaction, nor long sitting in the sun to raise the temperature to the point where that could happen.

Still, it's a long stretch from a 'poof' of vapors from the can to an 'explosion' of aluminum paint boiling out of the can.

Lloyd

You are very generous with other peoples' time and gasoline.

I wasn't the one who asked about the specific event...the definitive licensee response to and NRC evaluation of the incident documents will be on file in the NRC archives -- I can't help it that they've not gone back and put stuff from 40 yr ago online. If sufficiently interested the poser of the question could request them long distance and I believe they still have to respond despite the time of relevance having long since passed. I'm sure they'll have a fee that way, too...

Oh, hell. If you got it from the handyman club, it MUST be true.

There is a description and warning about something called "Black Jack Aluminum" Paint exploding spontaneously.

That stuff is roof coating, not just paint. And it didn't chemically explode - it pressurized and burst the container. No ignition.

Well ... the experience my friend had would have been in the early 1960s, I think. (I never asked him, but he had a summer job in the hardware store at the time, and I knew him first a few years later at work.

And I've never seen a label on the paint warning about shaking it, but I *have* seen such a warning label about aluminum paint on a paint shaker bolted to a vertical floor-to-ceiling I-beam at work (a later job) This was one of the kind which cranks two flat plates down on each end of the can and shakes it around a horizontal axis through the middle of the can half way between the two ends.

While his experience was (as mentioned above) likely in the early 1960s.

I would too. But the one about the "tung oil" makes a certain amount of sense.

Enjoy, DoN.