Technique questions Accurate Molds brass

[Grandpas50AE]

I managed to get some time today to fire up my Pro Melt 20# pot and initiate my new brass Accurate mold 35-140S. I expected to have a fair amount of rejects learning the difference in technique when using a brass mold, and my expections were unfortunately met. Not complaining, just looking for feedback. First pot full was mostly wrinkles and a few not quite filling out completely, melt temp was 700 F. I figured I was also not pusing the cadence fast enough. I did get some keepers that looked pretty nice, but 2/3 went back in the pot for the second pot run. Also turned up the hot plate a little which seemed to keep the molds closer to casting temp. Second pot was running 720 F. and I sped up the cadence a bit more than the first pot. Got just over half being keepers. I know I need to speed it up just a little more, but I will say that there isn't much time to run alternate molds this way, since my final cadence was very close to 4 pours per minute. This is the first time I have had a mold where I could use a gloved hand to cut the sprues, and I will say these molds are a real pleasure to use. I have some tin on the way, but it won't arrive until later this week, so I was just using WW plus 5% extra PB that I have been casting with for a long time. I'm sure it will fill more consistently when I get the tin to add back in.

I will say this, when the boolit melt is up to temp, and the molds are up to temp, it is apparent why Tom is well spoken of on this website - beautiful molds that make beautiful boolits. So, do I need to up the melt temp another 10 to 20 degrees, or just let the molds break in a little more?

[geargnasher]

Quit trying to cast with two moulds when using brass. Brass has three to ten times the specific heat of iron, you can't keep it hot enough that way. Put a minimum of four pours a minute through ONE mould with a cavity that small to keep it hot. Brass moulds with larger cavities can do with three pours per minute.

Alloy at 700 degrees is plenty.

Gear

[runfiverun]

i can't keep two steel molds going at once,
i can't imagine someone using two brass ones.

[Jailer]

One other thing to keep in mind is try keeping the sprue puddle a little smaller than usual. The thick sprue plates on Toms molds will hold quite a bit of heat. You'll end up dropping your mold temp below optimum waiting for the sprue to solidify if you leave a large sprue puddle. You have to concentrate on heating the mold from the inside out.

Smaller sprue puddle and cast faster and that should help keep your mold happy.

At least that's been my experience.

[Grandpas50AE]

Thanks for the input guys. I was only using the one mold since this was my first try with brass, and was was obvious that with brass you only have time to run one mold at a time. While I was observing that, it also dawned on me that with the faster cadence a single brass mold will turn out about the same number of boolits per hour as two steel molds anyway, or at least pretty close to it. Weekend before last I had run two steel molds in alternating pours, and cast a lot of nice boolits for the amount of time I had the pot going. Towards the end of today's session I had noticed what Jailer said - keeping the sprue puddles a little smaller helped keep the cadence up.

One other thing I have seldom ever had happen with the steel molds that I got really tickled about with the brass mold today: the boolits just fell out of the cavities when I opened the mold.

Gear, thanks for the confirmation on the melt temp. I had to turn it up a little since the garage was a bit cool today (mid 50's), and at 700 the drop spout would run a little slow if I kept the pours fast, but with those small cavities it just seemed to want 720 to run right. I had the spout set at the drop rate of my .44's, so I had to adjust the flow rate of the drop back a little too. It's a little bit of a learning curve, but I made progress and you guys are helping with good info I can apply on my next session.

[Mal Paso]

With Miha's 503 in brass small sprue puddles got me incomplete fillout of the base. Full puddles and a sprue plate cooling fan for 5 seconds to cool that steel plate fixed the problem.

[geargnasher]

An ambient temp of 50 degrees does make it a bit difficult, especially if you're in the wind or drafts. You might find that after about three or four sessions that mould really starts to shine, I think once the brass gets heat-oxidized in the cavities is when it really starts to make good boolits.

Gear

[Grandpas50AE]

Thanks gear. I always have the windows and garage door open to draft to keep the smoke out, so I'm sure that was part of it too. I'm going to keep the melt temp at 720 for now anyway, and adjust the cadence a little more. I am also going to adjust the pour rate to get a good stream without over-straming, which is what is started out doing since it is adjusted for those big .44's I often cast.

[cajun shooter]

First I will say that I use the Accurate Brass moulds that are three cavity two at a time every time I cast my 44-40's.
I just finished casting 2000 for a closer friend with no rejects. I designed the Accurate mould 43-210B with Tom when he first got started. My moulds are his older models with no set screw holding tension on the sprue plate bolts.
It's very easy and fast if you do it correctly.
You need a good single burner hot plate with at least 800 watts of power. You set it to wide open and put both moulds on it to preheat them the same time you turn on the lead pot. I use a RCBS Pro-Melt with a Wagge pot melting lead for my next pot when it runs out.
(1) Turn on lead pot and hot plate at full power to heat moulds
(2) Set lead pot at 750 degrees
(3) When all is ready turn the hot plate back to about a little less than half.
(4) Remove first mould and fill the three cavities, then place back on hot plate
(5) Remove second mould and fill it and return to hot plate
(6) Pick up Mould one and empty into box or container of choice.
(7) Refill mould one and return to hot plate
(8) Repeat all steps with mould two.
(9) After using each mould it is refilled and returned to the hotplate before using the second mould.
(10) You develop a cadence and every mould fill will produce perfect bullets
Now this method was used by me with my equipment and your choice of tools and alloy may result in different results.
RCBS PRO MELT
20-1 alloy
Accurate 3 cavity brass mould
GE 800 watt single burner HOT PLATE purchased from Walley World
lead kept at 750 degrees
moulds used in order that is posted

I will have to disagree with GEAR on This One. I do read and respect his opinons but I've been at this game a long time and not all rules always apply to every person or method used. Take Care David

[stubshaft]

On some of my molds I don't wait for the sprue to fully solidify. I pour and count to 5 and knock it off. If I wait them the mold gets too cold.

Just sayin.

[geargnasher]

True, David, there's more than one way to skin a cat, but you also are very familiar with what you're doing and have developed a process with extra equipment that enables you to cast with two moulds alternating. Possible to do, yes, but a good way to learn the ropes with a new brass mould? I hardly think so.

I'll also wager that you didn't start out doing it that way, but after you got familiar with the moulds and what they like first.

Gear

[Grandpas50AE]

On some of my molds I don't wait for the sprue to fully solidify. I pour and count to 5 and knock it off. If I wait them the mold gets too cold.

Just sayin.

Once I got the cadence going where the boolits would just drop out, it was a five-count from the sprue just beginning to solidify. At that five count, no more than five, I could push the sprue plate open with my thumb (had an insulated glove on) and then open the molds and the boolits just fall out. If I wait much longer the sprue and boolits cool a little too much and the wooden persuader has to be employed to open the sprue plate (gently, mind you).

[Grandpas50AE]

Cajun Shooter, when I get used to using brass molds and find out what this one likes, then I will probably be able to adjust hot plate temp and casting cadence to allow for using alternating molds for the pours, but for now I'm just learning the differences of brass over steel.

[cajun shooter]

Gear, What you say is true but it also applies to all mould material and not just brass.
I started casting in 1970 and was very lucky to have a mentor who was an accomplished caster of many years.
When I started it was with H&G moulds with some Ideal thrown in. All made from a iron product.
When I purchased my first aluminum mould I was like a brand new caster with my first casting sessions. There were many that were close to being total losses so it was a learning process.
I enjoy the weight of aluminum moulds but don't care for the process of maintaining the correct temperature in them.
I was in several custom mould buys and ended up selling each one that was from aluminum.
I had wrongly thought of brass as being a 19th century skill and not able to pour bullets in this day and time.
I heard about Tom from a source that was not connected to this forum and contacted him about making me a mould. I advised Tom that I was looking for a better design for my 44-40 guns used in SASS competition.
I received my first mould on Friday after ordering on Monday. The first thing was the weight and it only took me about five minutes of pouring to work that out.
I did have my process worked out from many years ago when I started casting bullets to sell to the gun store that I worked for.
We all know that any mould can be over worked and you have warped blocks. I was using 4 Lyman and Saeco pots with about 8-10 moulds.
I ordered two more of the same design from Tom and received the same fast service.
So yes it was a process that was from years ago that was applied and yes it came from a learning process.
That very same thing may be applied to everything we all do on this forum and that is to work out a process and then pass it on to the members.
That is not a odd or different thing that you yourself have done many times over.
So for me to say I disagree with your posting had nothing to do with my respect for you or your knowledge of casting.
It was posted to show that there is a way to produce very nice bullets in a faster manner than may be had with one mould or the belief that brass is not able to do this.
I also said nothing about my method being used as a learning process!!
That is something that you chose to place in my OP that is not there. Again I respect you but you should be open to constructive criticism which my entire post was not posted to teach the OP how to learn but to advise anyone who wanted to know that the use of two "BRASS MOULDS" was possible.
I wish every one a good casting Day, Later David

[geargnasher]

Gear,

......It was posted to show that there is a way to produce very nice bullets in a faster manner than may be had with one mould or the belief that brass is not able to do this. Ahhhhh. :Bright idea:

I also said nothing about my method being used as a learning process!!
That is something that you chose to place in my OP that is not there. True, I assumed that we were all directing our posts to the OP, rather than sharing general information. Nothing wrong with that, I just missed your intent. Again I respect you but you should be open to constructive criticism which my entire post was not posted to teach the OP how to learn but to advise anyone who wanted to know that the use of two "BRASS MOULDS" was possible. GOTCHA! That makes much more sense now.
I wish every one a good casting Day, Later David

This fellow is going through a learning curve with the new mould material, I can certainly identify, as I know you can. I was just trying to help him get it sorted out, and couldn't figure out why it seemed you were throwing the Ph, D. course in speed-casting at him. You weren't, you were sharing your methods of doing more with brass moulds with all of us and pointing out that my above advice to the OP doesn't have to be limiting for him or anyone else. I'll add: doesn't have to be limiting once you get the brass moulds figured out. I get it now, thanks for clearing that up.:drinks:

Gear

[cajun shooter]

You now have it as I knew you would. It was intended just as it was posted by you.
I thank you for your posting and will continue to read all your post as I always have because we all learn till we hit that final Day.
Have a Good One Sir, Later David

[happyret65]

I have to pre heat the mold by putting the sprue cutter to the heat source. Once that is hot the rest of the mold usually is hot enough to start. I start with the heat on the pot at high and lower it as the mold starts giving out good bullets.

[geargnasher]

Happy, I do that too sometimes, especially with brass moulds that have thick steel sprue plates. Once you get the steel hot, the brass is hot, too, but not so much the other way.

Gear

[Grandpas50AE]

Thanks Happy and Gear, I hadn't thought of turning the mold upside down (sprue plate down) on the hot plate to get the sprue plate a bit hotter for starting out. Another wonderful tidbit from you wonderful folks.

[runfiverun]

odd the things you do but don't think to tell others about.
i will even turn a mold over while waiting the 5 count to keep the heat going into the mold if it's one that don't hold it well.
i don't even think about it

[Irascible]

About 2 weeks ago I started heating the mould with the sprue plate down. It helps.
I tried casting with two, iron two cavity moulds for the first time yesterday, what a workout. About 10% culls. I had the hot plate on low and set the mould on it to cool the sprue while I emptied and refilled the other. After reading the above posts I'll give her another go with the hot plate turned up. I really should buy one of those Harbor freight infrared thermometers too see what temp the hot plate and the moulds really are.