Who is annealing in sand?

[Greasegun]

I tested today with medium grit sand using very thick Norma brass. I didn't get a good temperature change on them until I had them in at 750 degF for 45 secs. I picked the cases up with pliers and quenched them. I made a stand in the sand with copper wire to keep the case from tipping. That wire turned black and when it cooled it shed a coating of oxide and returned to copper color.

At that rate I would be worried about the body and head area being softened.

 

[FatOldMIHunter]

At that rate I would be worried about the body and head area being softened.

I don't think the head had enough time + heat to anneal. The color change didn't go more than a half inch down the body. This is old Norma 6.5X55 and that stuff is thick and was very hard. I would definitely reduce the time to no more than 35 seconds for thinner brass.

 

[Mikecr]

There is nothing wrong with melted salt, so you have a safety net to fall back on.
And I applaud your efforts to continue process development, but much of this can be eliminated with logic.
Thermal conductance of dry sand is pretty low. You're heating that in contact with the bottom and sides, and there is heat rising in the voids, but it's going to transfer poorly across the body. Right?
So it would take a long time for sand in the middle to match sand along hot edges.
Then as each granule of sand gives up heat to brass in contact, that granule will not quickly replenish lost heat from adjacent granules, so the brass will serve to quench the contact sand, dropping it's temperature.
Then,, the sand contact with dipped brass is also less than 100%, whereas a liquid like melted salt or lead is in full contact.

Liquids are usually higher in thermal conductance, and wet sand is more thermally conductive than dry sand.
What liquid rests at ~850degF?

 

[birdiemc]

Gallium....its only $350/kg

 

[Flatbow]

Just spent the past hour searching the web for a possible medium and came across HBN, hexagonal boron nitride. I know some folks are using this for coating bullets, but what I read it's close to copper on thermal conductivity and has high heat capacity, keep it under 1000deg C and should be ok.
More expensive than the copper powder, bit added perk that if you air dry your case necks come out already lubed up.
Gonna look more at graphite powder tomorrow and see how it stacks up.
Anybody out there with actual knowledge on these above what I found on google????

 

[Flatbow]

Just curious if any of you have done any more testing with sand and what kind of results you have had.
Thanks

 

[thwatson2]

I was an original advocate for it. I actually did 100 of my 45-110 couple days ago. Once I got the sand to heat in my lee melt pot, it was just too easy. Mine was on 9 setting, it gets sand up around 750 on top so assume bottom is 800 degrees or upward. The brass clearly gets a case color after 20 seconds or so. you will find a groove but very quick and easy and no open flame

 

[whirlwindjml]

I was an original advocate for it. I actually did 100 of my 45-110 couple days ago. Once I got the sand to heat in my lee melt pot, it was just too easy. Mine was on 9 setting, it gets sand up around 750 on top so assume bottom is 800 degrees or upward. The brass clearly gets a case color after 20 seconds or so. you will find a groove but very quick and easy and no open flame

How are you monitering temp?

 

[Flatbow]

That is great info. Thanks
What kind of sand are you using?
About what size are the granules ( consistency of table salt)?
Thanks again

 

[thwatson2]

I use infrared gun to check temp and the lee pot on 9 seems to hold temp pretty good. im using play- sand from Walmart. The stuff you put in a sandbox. First time you use it let the sand heat till it stops smoking, get the impurities burned off. I usually put 4 shells in at once, slightly deeper than what I want annealed then wait 20 seconds or so and remove. I base the time on getting that nice case color change but make sure the brass isn't getting too hot above the sand, I always use a glove as you will hit side of pot every once in a while

 

[eschafer]

Not that I'll deviate from my salt bath technique (as it works well for me), but as an alternative medium for those interested, perhaps a stainless steel medium similar to our tumbler mediums might work? I do believe such mediums come in all shapes and sizes (smaller and less cylindrical might be best).... food for thought...

I do my salt bath annealing on top of our glass top stove with whole floor area surrounding stove with thick beach towels, all before the wife even rolls over in the morning... My water quench is on the floor and all other liquids are miles away from the stove.. If she wanders down for whatever reason, she's summarily ordered "BACK TO BED".. . Works well... I'd be concerned about sand and powdered metal sticking inside the case shoulder (where a bore brush wouldn't be able to remove it)... Would have to be careful with stainless sticking too....

Yesterday:

 

[Wachsmann]

I know we are always looking for a cheaper alternative but t think the Annealeez is a pretty good made machine that offer a good way to anneal the brass. Just have to be careful with the flame.The higher cost induction annealers are very good and I must say the ANNEALING MADE PERFECT machine is probably the best with all the R&D behind it. But with the current conditions of the US and the job market this sand method is showing some good promise and a cheap alternative that just about anyone could afford. I wish I never would have thrown away all the 6.5X284 Norma brass I has shot of the years. I was getting 10 shots on the cases by shoulder bumping without annealing. After 10 the brass was really starting to shows signs of work harden and ES was getting up over 25 to 30 fps. Not good for holding MOA at long ranges. We need some info on how the neck tension is effected, velocity, ES, and SD, in comparison to other annealing methods. Hope someone can get out and do some shooting. We are somewhat on lock down in Idaho with the virus.

 

[fguffey]

I do not get involved in annealing threads. Years ago I thought about building an annealer. My second thought was about the rules; no help but I did decide on rules that cold be necessary. And then I built a machine/tool that was based on the rules. I thought the rule based annealer was worth consideration. That was years ago, today it seems the old problem still exist, no one wants to know, they just want to talk about it.

And I thought the end was near when coils and transducers became the rage.

F. Guffey

 

[Flatbow]

Thanks guys , all good info and food for thought.
The stainless steel medium is a really good idea since I am sure the steel will hold the heat better.
Sorry guffy, not sure what you are talking about.