Heat treating question

[Neverhome]

I'm a low volume caster and shooter. I shoot maybe 80 rounds a week and rarely cast much more than I need for a couple weeks of shooting.
I just this week started playing with heat treating.
First attempt was to see if I could heat treat 50/50 Lyman#2/lead. 95/2.5/2.5
460 degrees for 1 hour in convection oven. Within 3 days they were over 22 bhn using the pencil test. Got a result!

Now here is where my question comes in. I tried a different alloy 2 days ago. This one is roughly 91.75/4.75 tin/3.25 ant/0.25 As. 420 degrees for 1 hour.
I've gotten MAYBE 1 point of hardening so far. I understand that it takes time but figured I'd ask to see if that was normal. I don't want to go much higher in temp because I'm only shooting for around 18-19 bhn. Started around 13 and might be 14 right now. Hoping to be at 18 by Friday when I test my good loads with the harder alloy.
Normal?

[Dusty Bannister]

From the LASC site:
The higher the tin content of the alloy the less the alloy will respond to heat treating and the faster it will age soften. (2-3% is fine unless your goal is 30+ BHN which is very rarely needed)

[Neverhome]

I've heard that too but also HEARD of people heat treating Lyman #2 which is 90/5/5. I've never tried it so can't say. The 50/50 Lyman/lead heat treated nicely and as you said has a lower tin content but equal to the Ant content.
At what point does tin by itself become too high to support heat treating. Is it the absolute level of tin that fights heat treating or just the level relative to antimony that fights the heat treat? How does arsenic play into the balance of tin to antimony with regard to the effectiveness of heat treating. Yes I'm aware that just a trace amount of arsenic makes heat treating more effective. Does that increased effectiveness offset the lesser effectiveness of alloys heavy in tin?
I've read the LASC article and I don't believe it gives hard and fast rules. For instance it clearly says that 2% antimony isn't adequate for effective heat treating but that clearly isn't so since so many folks heat treat 50/50 ww/lead +2% tin. That actually works out to 96/2/2 or 96.5/1.5 Sb/2 Sn. Both with a trace of As.
So where's the line drawn?

[Dusty Bannister]

Choose a path and follow it. If you follow the path as suggested on the LASC site, you will find success.
"There you have it. It's that simple to achieve the BHN that is proper for your load. Sufficient antimony (4%) and only enough tin to aid in mould fill-out, the proper convection oven temp and... exercise constraint."

If you prefer to play in other fields, please do so, and let us know how you get on. Do oven heat treat and quench Lyman #2 and post the results. Do oven heat treat and quench your trial alloys. It will only add to the knowledge pool. But let the alloys age a sufficient time to show what they are really going to do. Perhaps at 7 days and again at 14 days, test the hardness and add to this thread.

Please keep in mind that present clip on WW are not a clean product. They are usually in a range of content and only adjust the mold to produce the weight desired. Having likely been recycled a few times, the "line" will be very indistinct. So expect that the make up of your alloy is likely a guess and not a sure thing. Unless you are fortunate enough to have access to an xrf scanner.

[popper]

Pb doeswn't heat treat. So adding the Sb (which does) gains you hardness. 1% Sb (~ COWW 50/50) will heat treat but you don't gain much. 2.5% (WW or 50/50) does very well. As seems to accelerate the hardening.

[Neverhome]

Still looking for an answer, if one is available, to this series of questions I buried in my second post on this thread...

"At what point does tin by itself become too high to support heat treating? Is it the absolute level of tin that fights heat treating or just the level relative to antimony that fights the heat treat? How does arsenic play into the balance of tin to antimony with regard to the effectiveness of heat treating. Yes I'm aware that just a trace amount of arsenic makes heat treating more effective. Does that increased effectiveness offset the lesser effectiveness of alloys heavy in tin?"

[Neverhome]

To be clear, I accept that heat treating of the alloy I mentioned may be ineffective. Now I'm trying to figure out where the line in the sand is because there are some conflicting reports from articles and anecdotal posts. Can't take everything you read as gospel.

[Neverhome]

Just ran a method of speed aging I found.
Alloy was 93/3.65 Sn/2.95 Sb/0.4 As

Heat treated at 460 earlier today. Sat for 2 hours then heated again at 185 for an hour.
Before heat treat bhn 12-13. 4 hours later 22-26

Works for me short term. No idea how fast they'll age soften but for me it doesn't matter because I typically don't pour much more than I can shoot. If I was going to stock up I could simply wait to do the heat treat and acceleration

Anyone one have any experience with this? The accelerated aging I mean