Pressure casting?????

[bangerjim]

I have searched high and low on here and the net and cannot find any real definitive info on pressure casting. I am assuming that means holding the sprue hole right up to the bottom pour pot nozzle. Correct me if I am mistaken.

I remember reading on here and other places that pressure casting is not remcommeded. WHY NOT?????

Doing exactly as I described above gives me some of the most beautiful boolits I have ever dropped....even out of a stone cold mold!

What problems would there be? They size right on. And are perfectly formed

I have a 45 cal 255 gn Lee 6banger that just refuses to drop non-wrinkled boolits regularly. Even pre-heating does not always solve the wrinkles. And yes......I have plenty of tin in there. I have over 80# of tin available. And melt temp is almost to the "frosty slug" temp. Any other of my many molds drop perfect boolits with the same alloy, temp, and standard pour procedure.

This afternoon, I just shoved the sprue hole up on the pour spigot, counted to 5, and moved on to the next hole. The sprue plate was a bit tight because it was not up to temp, but the boolits were absolutely PERFECT.....from a totally cold (88F) mold! No runs, no drips, no errors! Play ball!

Any words of wisdom would be greatly appreciated!

bangerjim :guntootsmiley:

"inquiring minds want to know".....I feel I may have lost mine!!!!!! [smilie=p:

[dbosman]

If it ain't broke...

[madsenshooter]

Sometimes you get a squirt, depends on how the spout and the sprue plate bevel fit together. Supposedly, you could get some weight variation as the pot empties, just keep it at the same level. The less oxygen gets into the alloy, the better. That's why I pressure cast with a ladle. Some molds one can't. For instance I have an Eagan mold that he must have vented for a pour caster. If I try to pressure cast using my ladle, I get a bullet looks like a stickelback minnow.

[rbuck351]

Sounds like you are trying to get someone to say it doesn't work when you have already proved that it does. Some molds this gives you some serious finning and I have had some problems with the tiny sprue sticking in the sprue hole and having to be dug out. Pouring another bunch of lead on top after the boolit has set cures that and once they start finning you can back away from the spout a little. This whole casting thing is about finding a method that works for each mold and using it no matter what others think. That's my opinion and worth just what you paid for it. Now, go cast a bunch before something in the air changes and it quits working for you.

[bangerjim]

I guess it is a lot like fishing.......gotta hold yer mouth right! HA....ha.

banger

[Le Loup Solitaire]

To pressure cast or not is a discussion that will probably never be definitively resolved clearly. Some molds like it and some don't. If you are getting good bullets with the mold up tight against the pour spout then keep doing it. If you find that a stream of varying height is working better then stick with that. If your mold responds well with either method then you are blessed. The old method of using a ladle was to put the nib in the sprue hole and "roll" the two over so that the ladle was on top...that is pressure casting! It worked. I have also poured from a height from a soup-type ladle and that worked too. I have also tried to snug the mold sprue hole up tight against the valve nib and that simply did not work well for me so I went back to pouring from a height and "puddling"; then with 2 and 4 cavs pouring back over what was just cast to give more alloy to allow for shrinkage. I also engaged in dropping the mold an inch or two with still liquid sprue puddles to "jolt" the setup in an effort to get better fillout. There is a wide variety of tricks, rituals and ceremonies to play with depending on the particular mold to get better castings. I do, and suggest that you do too, keep track of what is going on and whatever works best with whatever mold that you are using....and write things down on a 3x5 card so that you don't have to try and remember what worked well. When you have numerous molds it really helps...plus any other info as well. And keep track of where you put the "mold cards". There is nothing like "finally getting your feces together and then forgetting where you put it". LLS

[Mk42gunner]

I do, and suggest that you do too, keep track of what is going on and whatever works best with whatever mold that you are using....and write things down on a 3x5 card so that you don't have to try and remember what worked well. When you have numerous molds it really helps...plus any other info as well. And keep track of where you put the "mold cards". There is nothing like "finally getting your feces together and then forgetting where you put it". LLS

Words to heed, guys.

Records are a wonderful thing, until you can't find them.

Robert

[bangerjim]

That is ONE thing I DID learn in college (other than beer, liquor, weed, & women) - it's not what you remember, it is remembering where to go to get what you need when you need it!

Excellent recommendations.

banger

[runfiverun]

some molds will pour fins or will get whiskers when pressure poured.
that's the only why not I know of...
I have a couple of molds that love being pressure poured and the long skinny ones seem to like the spout aimed right at the sprue holes and squirted straight in quickly.
the short fat boolits seem to like the swirl method and a medium pour rate.
I even have a couple that like a small sprue puddle.

[Aunegl]

This afternoon, I just shoved the sprue hole up on the pour spigot, counted to 5, and moved on to the next hole. The sprue plate was a bit tight because it was not up to temp, but the boolits were absolutely PERFECT.....from a totally cold (88F) mold! No runs, no drips, no errors! Play ball!

Any words of wisdom would be greatly appreciated!

bangerjim :guntootsmiley:

"inquiring minds want to know".....I feel I may have lost mine!!!!!! [smilie=p:

I pressure cast due to the molds (Hoch nose pour) and small the sprue plate holes. I count to one one thousand and move to the next opening.

[fredj338]

When I cast by hand, it's almost always pressure casting, especially HP molds. When I run my Magma, obviously I am not pressure casting, but I get more rejects.

[detox]

I usually stop reading once the word Lee Mould is brought up. If you have to pressure cast, something is wrong with mould or your method. I bet a good caster can make that mould work...too many variables to list. Here is one thing a would do...turn up pot temp. You may have to go to 800 degrees...especially with soft alloys with less tin. Do not pressure cast with bottom pour pot. OK with ladle

The next trick is making that boolit shoot without leading barrel:-)

[Aunegl]

Do not pressure cast with bottom pour pot. OK with ladle

The next trick is making that boolit shoot without leading barrel:-)

BS, I've been pressure casting with a bottom pour pot for decades, which is OK by me.

[bangerjim]

I usually stop reading once the word Lee Mould is brought up. If you have to pressure cast, something is wrong with mould or your method. I bet a good caster can make that mould work...too many variables to list. Here is one thing a would do...turn up pot temp. You may have to go to 800 degrees...especially with soft alloys with less tin. Do not pressure cast with bottom pour pot. OK with ladle

The next trick is making that boolit shoot without leading barrel:-)

Thanks for the comments, but you still did NOT provide the group & I with the reasons NOT to pressure cast with a bottom pour. It seems to work VERY well for me ( and others above) with this specific mold, but I was trying to get other ideas and reasons on the subject......not just "do not do it".

I electrostatic gun powder coat all my boolits, so I have absolutely no problems with leading with any of my cals and guns. If anyone out there is having battles with leading, please consider switching from old fashioned greasy lubes to modern PC technology.

I usually quit reading when I see Miheck molds mentioned, so it looks like we average things out!

From much experience, I have learned to play around with temp when/if something weird pops up. I normally have plenty of tin in my mixes since I have lots of it to play with. Mold fill-outs are a rarity to my casting processes.....just this one example.

And I have cast many thousands of slugs in my sessions over the years, so I am NOT a beginner and consider myself a "good caster"....sorry to disagree with your unfounded comment and I take personal offense to your insinuation of my casting prowess.

bangerjim

[500MAG]

Jim, your confusing me. In this thread: http://castboolits.gunloads.com/showthread.php?211678-Lee-production-pot-4-got-one-in-today-but-I-have-questions
You said, and I quote:
I set my Lee 4-20 or proMelter at between 6 and 7 and pour perfect boolits EVERY SINGLE time. I have never seen the need for any type of control/monitoring other than the on-off bimetalic control in the Lee products.
:kidding:

[detox]

And I have cast many thousands of slugs in my sessions over the years, so I am NOT a beginner and consider myself a "good caster"....sorry to disagree with your unfounded comment and I take personal offense to your insinuation of my casting prowess.

bangerjim

I have tried it (lots of whiskers), but I have never needed to pressure cast for good fillout. I use Lyman and RCBS moulds. Maybe my day is coming

[bangerjim]

Jim, your confusing me. In this thread: http://castboolits.gunloads.com/showthread.php?211678-Lee-production-pot-4-got-one-in-today-but-I-have-questions
You said, and I quote:
I set my Lee 4-20 or proMelter at between 6 and 7 and pour perfect boolits EVERY SINGLE time. I have never seen the need for any type of control/monitoring other than the on-off bimetalic control in the Lee products.
:kidding:

The mold in question was acquired shortly after that post. And yes, it has been giving me fits since I got it. I have been casting standard with it, messing with the temp and alloys, and remelting over 70% of the drops. Not good. After reading the yes's and no's on pressure casting, I decided to give it try. Perfect boolits from the word go!

All my other molds DO give me perfect slugs......with pre-heating as usual.

I was asking the question to get input from others that may have had previous experience with such situations. "2 heads are better than 1." And this forum is a perfect sounding board for asking such questions and receiving bunches of answers.

Thanks for your interest.

banger

[bangerjim]

I have tried it (lots of whiskers), but I have never needed to pressure cast for good fillout. I use Lyman and RCBS moulds. Maybe my day is coming

Fortunately, I did not get any whiskers (flash, I assume you mean) at the part line. I do have a couple molds that have the slightest sliver of light that can be seen between the halves. Those will probably have a bit of flash if I pressure them. I need to work on them to eliminate the "ding" I probably gave them somewhere along the way that is preventing them from closing perfectly.

Thanks!

banger

[500MAG]

The mold in question was acquired shortly after that post. And yes, it has been giving me fits since I got it. I have been casting standard with it, messing with the temp and alloys, and remelting over 70% of the drops. Not good. After reading the yes's and no's on pressure casting, I decided to give it try. Perfect boolits from the word go!

All my other molds DO give me perfect slugs......with pre-heating as usual.

I was asking the question to get input from others that may have had previous experience with such situations. "2 heads are better than 1." And this forum is a perfect sounding board for asking such questions and receiving bunches of answers.

Thanks for your interest.

banger
Just messing with you. :bigsmyl2:
Charles

[rintinglen]

There ain't any "one true way" of casting.
I have a single cavity 311-291 that loves pressure casting. An externally identical 311-465 will give you nothing but rejects if filled the same way. For that one, you need a hot melt, a hot mold and about a quarter inch gap, and then tilt the mold slightly so the lead swirls in. I have a 4 cavity SAECO that wants the lead shot straight down the sprue hole with a huge sprue to give good boolits. I've a 311-467 that seems to change its mind every other time I cast with it. There is science in casting, but a lot of it is art.
However, getting back on track. Pressure casting can have several draw backs. First, poorly vented molds need space for the air to bleed out through the sprue hole. If the pot drain spout is jammed in the sprue hole, the air doesn't bleed out and you get deformities. In well vented molds, you'll get whiskers once the mold heats up. If the sprue plate is loose or warped, you can get severe flashing on the base. Hollow point molds may get flashing around the plug. If I sit for a minute, I can probably come up with one or two more reasons why pressure casting may give problems.
However, sometimes it works wonderfully well. That 311-291 shoots like a house a fire and has given me some of the best groups I've ever achieved with a cast boolit--when pressure cast. You won't know until you try how a mold will respond.

[Janoosh]

I find that when I ladle pressure cast Lee (Ok, stop reading) 405 hb/hp boolits, the boolit weight is more uniform. And I know from this forum that many others cast better, and work out problems easier, than I can. I have pressure cast from a bottom pour pot and had NO difficulties until the mould started to overheat. At which time I simply switched to another mould. The only problems I 've found is when I rushed the pour or overheated the mould.

[fredj338]

I have tried it (lots of whiskers), but I have never needed to pressure cast for good fillout. I use Lyman and RCBS moulds. Maybe my day is coming

Your technique needs refinement. There is no diff using a ladle or BP pot, pressure casting is pressure casting. It's all about proper technique. I can get whiskers if I try, but usually not. What I get are a greater % of well filled out bullets.

[dudel]

I've found it produces good boolits on my smallest (.22 Lee Bator) and largest (Lee 1oz slug) molds. On the smallest, it seems to help get the mold filled because it really cools quickly. Same on the largest, except it's the lead that's cooling quickly. I've not found much benefit in the other sizes .308, 357, 9mm and 45. This is all from a bottom pour pot.

The only problem I have with pressure casting is getting the tiny sprues to release. Many times I have to poke them out with a bamboo skewer which really slows things down and cools the mold faster. When I fill the molds with a gap, and generate a good sprue, the sprues release much easier and the pattern is more consistent.

I guess I would pressure pour if the small sprues would release. It is much less messy, and I get more boolits per fill of the pot from the smaller sprues.

Everyone should try it at least once with each mold. Don't set your expectations too high, and you won't be dissapointed.

[dtknowles]

Mold Cards, who was the genius who said that. I often don't cast from May until November because of the hot weather so when I start casting again in the fall I have to relearn my lessons. If only I wrote that stuff down last winter. I do have at least one mold that prefers pressure casting but I don't remember now which ones. :sad:

When I pressure cast, I double pump the handle to get a bigger sprue so they don't stick, I think someone else mentioned this.

Tim

[Old Caster]

When pressure pouring, there are a couple of things that need to be done differently depending on the mold. First is column height of the lead. Some molds are a bit loose, sloppy, or have big vents so pressure pouring can give fins and consequently need a lower column height or maybe can't be pressure poured at all.

Another thing to watch is setting the pour speed too fast because when lead blasts into the mold, dirt can be forced in so fast that it gets caught by the turmoil. It is better to make it so that a 200 grain bullet will take about 2 seconds to fill and then drop the mold down a half inch or so and move it away from the next hole to get a decent sprue size so the dirt has a chance to float up into the sprue. This has to be done fast and will take some practice.

If you see pits in the back of your bullets like small cavities the pour spout is open too much and the speed in which the lead goes into the cavity is too fast. Anytime lead is pouring slowly through a small spout, dirt starts to stick and affect the speed in which the lead comes out and might need constant cleaning or it might at any time go into the pour. This can be a pain in the neck when using the slow bottom pressure pour method but will give you the best results.

I like to have the shelf at a height that is right for me to drop the mold onto and then all I have to do is move the mold a half an inch or so in the right direction. When the mold is opened I like to have all the sprue from all the holes stick together to make it easier to handle.

If you are using a ladle, it is constantly being cleaned by the movement and consequently doesn't matter if you pour fast or slow because you will rarely get dirt in the back of a bullet.

If you just pour into a mold, you don't get the best fillout but like I said, some can't handle good fillout so you might have to just pour in. It is easy to get dirt in when doing this also and not know it unless you weigh everything and wonder why it is so light when it looks so good. Also if you don't care about just the best bullets that you can mold, do it the easy way. There is a difference but for some circumstances it won't matter. If I shoot steel plate matches I never cull a bullet unless it is ridiculously poor and do not pressure pour. The farthest shot is 25 yards and the smallest is somewhere around 8 inches and usually bigger.