annealing
- Thread starter Walt
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The Hornady system is cheap and has its advantages. The Tempilaq temp-sensitive lacquer supplied with the kit will melt below optimal annealing temperature, but this is because Hornady intends it to be applied on the case 3/8" Below the shoulder. As such it is an "early warning" to prevent body overheating. It doesn't necessarily tell you that your neck temp is hot enough.
From our Annealing article:
Brass is an excellent conductor of heat. A flame applied at any point on a case for a short time will cause the rest of the case to heat very quickly. There are several temperatures at which brass is affected. Also, the time the brass remains at a given temperature will have an effect. Brass which has been "work hardened",sometimes referred to as "cold worked") is unaffected by temperatures,Fahrenheit) up to 482 degrees,F) regardless of the time it is left at this temperature. At about 495 degrees,F) some changes in grain structure begins to occur, although the brass remains about as hard as before--it would take a laboratory analysis to see the changes that take place at this temperature.
The trick is to heat the neck just to the point where the grain structure becomes sufficiently large enough to give the case a springy property, leaving the body changed but little, and the head of the case virtually unchanged.
If cases are heated to about 600 degrees,F) for one hour, they will be thoroughly annealed--head and body included. That is, they will be ruined.,For a temperature comparison, pure lead melts at 621.3 degrees F).
The critical time and temperature at which the grain structure reforms into something suitable for case necks is 662 degrees,F) for some 15 minutes. A higher temperature, say from 750 to 800 degrees, will do the same job in a few seconds.If brass is allowed to reach temperatures higher than this,regardless of the time), it will be made irretrievably and irrevocably too soft.
From our Annealing article:
Brass is an excellent conductor of heat. A flame applied at any point on a case for a short time will cause the rest of the case to heat very quickly. There are several temperatures at which brass is affected. Also, the time the brass remains at a given temperature will have an effect. Brass which has been "work hardened",sometimes referred to as "cold worked") is unaffected by temperatures,Fahrenheit) up to 482 degrees,F) regardless of the time it is left at this temperature. At about 495 degrees,F) some changes in grain structure begins to occur, although the brass remains about as hard as before--it would take a laboratory analysis to see the changes that take place at this temperature.
The trick is to heat the neck just to the point where the grain structure becomes sufficiently large enough to give the case a springy property, leaving the body changed but little, and the head of the case virtually unchanged.
If cases are heated to about 600 degrees,F) for one hour, they will be thoroughly annealed--head and body included. That is, they will be ruined.,For a temperature comparison, pure lead melts at 621.3 degrees F).
The critical time and temperature at which the grain structure reforms into something suitable for case necks is 662 degrees,F) for some 15 minutes. A higher temperature, say from 750 to 800 degrees, will do the same job in a few seconds.If brass is allowed to reach temperatures higher than this,regardless of the time), it will be made irretrievably and irrevocably too soft.
Forum Boss
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With due deference to CatShooter who has lots of experience, novice annealers do need to worry about getting the neck area too hot. If you overheat the neck it gets too soft. You don't want those necks to get orange-red. Catshooter is experienced enough to avoid that mistake, but I don't want novices to ruin brass by overheating the body OR the neck. This from the Ken Howell annealing guide:
"Quick, uniform, consistent application of high heat is the key to good annealing. When the brass around the mouth reaches a temperature of about 660 to 665 degrees Fahrenheit, its surface becomes light blue. This is as hot as you want to let it get. If you let the color run too far toward the other end of the case, you can ruin the head by making it too soft. If you let the color on the neck go beyond light blue, and the shine disappears, you’re on the edge of ruining the case, and you may already have gone too far. If you let the case get red, it’s a goner.
But depending on getting the color just right is too loose and iffy to suit me. I prefer and recommend relying on something more dependable than personal color perception. The most reliable case thermometer I know is a 650 or 660 degree temperature-sensitive crayon called a temp stick. I’ll describe how to use it in a moment.
The hot, small flame of a torch is the only heat source you can rely on to give you the quick, local heat you need for selectively annealing the neck without heat-softening the base. High heat brings the neck and shoulder up to annealing temperature quickly, while the base end is still safely cooler; lower heat lets the base end get too hot while the neck and shoulder are getting just hot enough. Therefore, safe neck annealing takes high heat and a surprisingly short time.
Temperature-sensing crayons allow close temperature control. Any well stocked welding supplier has them or knows where to get them. McMaster-Carr stocks two kinds, and I hope a few handloader suppliers like Huntington’s will stock them if there’s enough demand for them. The mark made by one kind of crayon melts at the rated temperature, plus or minus one degree. The other kind leaves a yellow mark that changes to red-brown at the rated temperature and tolerance.
The 650-degree crayon, which melts at about 10 to 15 degrees below annealing temperature, is Number 3261K449 in my old McMaster-Carr catalog, at a nominal price of $7.80. Be sure to specify crayon when you order. McMaster-Carr also sells 650-degree temperature-sensing pellets under the same catalog number. These pellets are for other applications and aren’t adaptable to case annealing. The 660-degree crayon changes color at approximately the correct annealing temperature,within 2 degrees or so). Its catalog number is 5960K71 and sells for $6.20. Both come with aluminum pocket holders."
NOTE: Howell refers to a temp "around the mouth" of 660 but he's ascertaining this by reference to a temp crayon mark below the shoulder. The actual spot temp on the neck would be higher. 730-750 deg F seems to be the consensus for ideal neck temp during annealing of cartridge brass.
---
I've just contacted Hornady. They recommend annealing necks at 700 to a max of 750 deg F,400 Celcius).
Catshooter is correct. Hornady intends the 475 deg Tempilaq to be brushed on the case 1/4"-3/8" below the shoulder junction. In Hornady's experience, when the neck reaches 700+ the Tempilaq on the case body will melt. Hornady does not sell the higher temp laquer or crayon because when the lacquer was applied higher up on the case they found it melted too quickly when exposed to a direct flame.
The last line in Catshooter's post is also a very important tip:
"One interesting note on case annealing. Most folks I know don't lube the case necks when neck sizing - but if you anneal case necks, you MUST put a bit of lube on the neck for the first sizing, or brass will stick to the die or bushing."
This is because: 1)All residual oils are burned off the neck; 2) Annealing,at the right temp) actually changes the grain structure of the metal.
"Quick, uniform, consistent application of high heat is the key to good annealing. When the brass around the mouth reaches a temperature of about 660 to 665 degrees Fahrenheit, its surface becomes light blue. This is as hot as you want to let it get. If you let the color run too far toward the other end of the case, you can ruin the head by making it too soft. If you let the color on the neck go beyond light blue, and the shine disappears, you’re on the edge of ruining the case, and you may already have gone too far. If you let the case get red, it’s a goner.
But depending on getting the color just right is too loose and iffy to suit me. I prefer and recommend relying on something more dependable than personal color perception. The most reliable case thermometer I know is a 650 or 660 degree temperature-sensitive crayon called a temp stick. I’ll describe how to use it in a moment.
The hot, small flame of a torch is the only heat source you can rely on to give you the quick, local heat you need for selectively annealing the neck without heat-softening the base. High heat brings the neck and shoulder up to annealing temperature quickly, while the base end is still safely cooler; lower heat lets the base end get too hot while the neck and shoulder are getting just hot enough. Therefore, safe neck annealing takes high heat and a surprisingly short time.
Temperature-sensing crayons allow close temperature control. Any well stocked welding supplier has them or knows where to get them. McMaster-Carr stocks two kinds, and I hope a few handloader suppliers like Huntington’s will stock them if there’s enough demand for them. The mark made by one kind of crayon melts at the rated temperature, plus or minus one degree. The other kind leaves a yellow mark that changes to red-brown at the rated temperature and tolerance.
The 650-degree crayon, which melts at about 10 to 15 degrees below annealing temperature, is Number 3261K449 in my old McMaster-Carr catalog, at a nominal price of $7.80. Be sure to specify crayon when you order. McMaster-Carr also sells 650-degree temperature-sensing pellets under the same catalog number. These pellets are for other applications and aren’t adaptable to case annealing. The 660-degree crayon changes color at approximately the correct annealing temperature,within 2 degrees or so). Its catalog number is 5960K71 and sells for $6.20. Both come with aluminum pocket holders."
NOTE: Howell refers to a temp "around the mouth" of 660 but he's ascertaining this by reference to a temp crayon mark below the shoulder. The actual spot temp on the neck would be higher. 730-750 deg F seems to be the consensus for ideal neck temp during annealing of cartridge brass.
---
I've just contacted Hornady. They recommend annealing necks at 700 to a max of 750 deg F,400 Celcius).
Catshooter is correct. Hornady intends the 475 deg Tempilaq to be brushed on the case 1/4"-3/8" below the shoulder junction. In Hornady's experience, when the neck reaches 700+ the Tempilaq on the case body will melt. Hornady does not sell the higher temp laquer or crayon because when the lacquer was applied higher up on the case they found it melted too quickly when exposed to a direct flame.
The last line in Catshooter's post is also a very important tip:
"One interesting note on case annealing. Most folks I know don't lube the case necks when neck sizing - but if you anneal case necks, you MUST put a bit of lube on the neck for the first sizing, or brass will stick to the die or bushing."
This is because: 1)All residual oils are burned off the neck; 2) Annealing,at the right temp) actually changes the grain structure of the metal.
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