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chevyiron420
08-18-2009, 05:49 AM
well, sunday i got out a 44 mold a buddy loaned me. i cleaned it up good and after about 20, i started casting some nice boolits, but with a single cav. and ladle pouring it was slow as moses. the plan for today was to get my bottom pour pot out and make up a big bag of boolits. i cleaned up the pot good and filled it with ingots of WW's and a smidge of tin. i fluxed it good with a stick first, then after a bit i fluxed again with my flake stuff i got from NEI or LBT. my aloy was clean and the mold was hot so i got down to it. soon i had the temp and the rithum down and had just a hint of frost, like i like it, and was water dropping. after about 5 pounds of aloy i stopped for a break and also to measure the boolits. man, was i dissapointed! its the same trouble i have always had when i bottom pour. its little bubbles in the surface of the boolits! there nothin in them, no trash, and they are random locations. i dont know why i cant get good results with this thing, it realy ticks me off. i would love to watch somebody make good boolits with a lee bottom pour so i can see what im doing wrong!! i can drain the same aloy into my little lee dipping pot, with the same mold and go to ladleing beautiful boolits. my biggest problem with just ladleing is my pot is so small and i have to keep stopping to refill it and starting over.:confused:

Bret4207
08-18-2009, 08:00 AM
Simple answer- get a bigger ladle pot. Mine holds over 20 pounds and works great. Still not sold on the BP idea.

Calamity Jake
08-18-2009, 08:21 AM
Next time you try that BP let the lead stream slide off the countersink area around the fill hole, this causes a swirl in the cavity and helps remove any trapped air.

Hardcast416taylor
08-18-2009, 10:53 AM
The only dipper molding was when I started casting back in the `60`s. I have used Lyman, saeco, RCBS and of course LEE drip-a-matic bottom pour pots. I don`t have this air pocket problem you are talking about, for that matter I never have had this problem. I let the lead stream hit the side of the sprue hole and it swirls around the cavity forcing out any air. I would almost say you have clogged vent lines in the mold not allowing air to escape when casting. An x-acto blade lightly run thru these vents once in a while insures air escape.Robert

WILCO
08-18-2009, 10:59 AM
First time I've ever heard of this problem, as I use a ladle when casting.
Just one more reason why I love this place.

AZ-Stew
08-18-2009, 11:46 AM
I'm guessing you put the mould up against the pour spout. I've seen the same effect when doing so.

Hold the mould an inch or so below the pour spout and let the stream run into the mould. Stop when you have a small puddle of alloy on the sprue plate. Allow the sprue puddle to cool until a couple of seconds after you see the alloy sink in the location of the sprue plate hole. This indicates that the cooling boolit has sucked alloy from the sprue plate puddle into the base of the cooling and shrinking boolit to prevent base voids. You may have to adjust the flow rate so you fill the mould quickly, but don't "fire hose" it. See if that works for you.

Regards,

Stew

SierraWhiskeyMC
08-18-2009, 12:23 PM
Are you certain that the mold is completely clean?

Any traces of oil or carbon in the mold will cause bubbles in your boolits until it's burned out.

Try cleaning the mold with brake cleaner in a well-ventilated area, and don't breathe the fumes. DON'T use a wire brush on ANY part of the mold.

Denatured alcohol also works well.

Like Robert suggested, make sure the vent lines are clear. Inspect the mold faces carefully to see if there might be small solder splashes clogging some vents.

I've had a couple of recent casting sessions with a Lee production pot 4 (bottom pour 10# pot) and a Lyman 429421 dual-cavity mold (245g for .44 Mag) and have not experienced any "bubbling" in the boolits, aside from the typical "wrinkling" before the mold is up to temp.

Nora
08-18-2009, 04:49 PM
Would you be able to post a picture? I've got a good idea of what I feel you are trying to describe, but am still curious as to see it.

Nora

Cherokee
08-18-2009, 04:54 PM
I do what AZ-Stew said and have been for 30+ years - I do not get bubbles. I quit using the ladle when the Lee BP pots came out & have never looked back.

TAWILDCATT
08-18-2009, 05:15 PM
never had them.sound like your hot enuf.I started with mold againts the spout
many yrs ago,I used a Gilbert caster as I did not know of the potter pot.there were no lyman pots then.I now pour from a small distance.simply because it works for me.your mold has to have oil on it somewhere some how.:coffeecom

leftiye
08-18-2009, 07:41 PM
Too cold mold. Lead freezes too fast for air to escape. Hotter mold will accomplish same thang as hotter lead. Some alloys (a lot of 'em) don't make shiny boolits sucessfully and have to be cast hot enough to frost a little to get rid of issues like this. Bottom pour pots let impurities in the lead into the mold that dipping doesn't reach. These show up as bubbles sometimes, as inclusions other times (heat helps here). Ladle pouring has its own problems - just different from bottom pour. Some oils show up as tiny bubbles too (look at a new Lee mold).

chevyiron420
08-19-2009, 01:46 AM
I'm guessing you put the mould up against the pour spout. I've seen the same effect when doing so.

Hold the mould an inch or so below the pour spout and let the stream run into the mould. Stop when you have a small puddle of alloy on the sprue plate. Allow the sprue puddle to cool until a couple of seconds after you see the alloy sink in the location of the sprue plate hole. This indicates that the cooling boolit has sucked alloy from the sprue plate puddle into the base of the cooling and shrinking boolit to prevent base voids. You may have to adjust the flow rate so you fill the mould quickly, but don't "fire hose" it. See if that works for you.

Regards,

Stew

thanks stew, no i dont put the mould up against the nozzle. i have heard of people doing that but i never had any luck with it. i have been holding it about 3\4 down. its funny i didnt realy expect many replys to this thread cause i have been down this road many times before and was mostly blowing off steem. i think part of the problem is in the pot nozzle cause even though the stream isnt large it does have alot of preasure. if i hold off center a little so the stream kinda skids off the countersink it tends to blow aloy all over. anything more than just barely cracking the valve and the flow just goes over kill. the flow rate is hard to controll. it goes from too little to too much quicky. i aint sure if thats the problem or not, but about half the boolits are good that i pour with it. this happens with all the moulds i have. again, i can use any mould i have and drain the alloy out of the pot, into the dippin pot and go straight to making beautifull boolits.

1Shirt
08-19-2009, 11:37 AM
Yep, Like Az Stew says. Have run thousands this way without a problem. That is the reason for mold guides on BP pots.
1Shirt!:coffee:

runfiverun
08-19-2009, 05:30 PM
i put a piece of thick fence wire under the pot where the little guide thing is at it stops the flow, or you can bend the thing that connects to the little wooden handle to act as a stop on the bottom.