Do you anneal your cases?

[Gene]

Midway sells it: MidwayUSA - Advanced Search

They have temps from 400-1500 degrees. 2 oz bottle.





When I rotate my Lapua cases under the flame, I count 1, 2, 3, 4, 5, 6, and usually in that time, the neck is just beginning to turn red, so I drop it in a pan. Keep the neck about an inch away from the flame. Try to be consistent with each case.

 

[Loner]

Now you can heat just about anything hot enough to make it burn (even water). The temps vary per element, and somethings added here and there increase the burn temp of course. It's common knowledge that a bronze bushing used as a bearing will start to go south at a little over 300 degrees, and often will completely weld itself to a shaft at 400 degrees. Brass will not handle the temps that a pice of bronze will before the surface metal starts to let go. This is why they will often silver plate bronze when the temps exceed 250f. degrees. Whats this got todo with a case neck? It gives you a hint as what heat will do to brass or a brass alloy. There are brass welding rods that are made to melt at temps under 400 degrees (there is one that melts at under 250 degrees). These are used in special apps where you donot want to disturb the metal you are brazing (usually abrasive resistent steels). I would suspect that if you could look at the surface of a .015" thick piece of brass subjected to 750 degrees it would appear to be moving, or starting to go molecular. This is not melting, but when the metal is starting to let go. Yet I'd say the same piece of brass a quarter inch thick would be OK. I need to hunt up my heat treat hand book to see what they have to say on the subject as right now I'm on the verge of guessing
gary

Metals - Melting Temperatures
Answers.com - What is the melting point and boiling point of bronze
http://www.mysculpturesgallery.com/melting-point-of-bronze-23632.html

the ASTM spec code for cartridge brass is B19.
MatWeb - The Online Materials Information Resource

 

[Pdvdh]

When I rotate my Lapua cases under the flame, I count 1, 2, 3, 4, 5, 6, and usually in that time, the neck is just beginning to turn red, so I drop it in a pan.

Based on use of the welder's crayons, I've identified a residence time of about 5 1/2 seconds of rotation in my 3/4" long propane torch flame. I'll have to check out your MidwayUSA link and see how expensive their 2 oz bottles are. That liquid painted on the casings has always seemed to be the better way of identifying when the case neck/shoulder has reached the proper annealing temperature - from everything I've read and heard.

I'm in the ball park with my 5 1/2 seconds, based on what I've read from others. However the length of time is, of course, dependent on the temperature of the flame. Ken Markle, founder and former owner of K & M Services reloader's tools and products told me he had determined a residence time in the flame of 5 to 5 1/2 seconds to be about right, with the case held at the tip of a 3/4" hot blue flame from a standard propane torch. Which matched my own findings.

 

[Trickymissfit]

Based on use of the welder's crayons, I've identified a residence time of about 5 1/2 seconds of rotation in my 3/4" long propane torch flame. I'll have to check out your MidwayUSA link and see how expensive their 2 oz bottles are. That liquid painted on the casings has always seemed to be the better way of identifying when the case neck/shoulder has reached the proper annealing temperature - from everything I've read and heard.

I'm in the ball park with my 5 1/2 seconds, based on what I've read from others. However the length of time is, of course, dependent on the temperature of the flame. Ken Markle, founder and former owner of K & M Services reloader's tools and products told me he had determined a residence time in the flame of 5 to 5 1/2 seconds to be about right, with the case held at the tip of a 3/4" hot blue flame from a standard propane torch. Which matched my own findings.

I've seen the liquid stuff, but have never used it. There is also a product that you actually paint on an object to resist heat transfer. Looks like plain old white out, and never had much luck with it. Your timing is pretty much spot on.
gary

 

[Pdvdh]

Midway sells it: MidwayUSA - Advanced Search

They have temps from 400-1500 degrees. 2 oz bottle.

$15.00 per bottle. Not as expensive as I remember. Maybe Midway's price is less than Brownell's. Thanks for that link. Think I'll order some.

 

[trailrider121]

Great topic on case annealing. I'm in the process to anneal some brass. If you plan to use tempilaq paint 650 degrees, where is the best place to paint the strip?

 

[Pdvdh]

If my case necks are large enough for access, I plan to paint a line on the interior of the case neck. At least initially, I will also run a 2nd paint strip from the case body/shoulder joint down the body toward the case head.

This way my propane flame won't be in direct contact with the tempilaq.

 

[Trickymissfit]

If my case necks are large enough for access, I plan to paint a line on the interior of the case neck. At least initially, I will also run a 2nd paint strip from the case body/shoulder joint down the body toward the case head.

This way my propane flame won't be in direct contact with the tempilaq.

there you go, now that's a great idea if you can do it. It will show complete heat saturation without over heating the O.D. metal.
gary