Lee mould not filling out

[Greg in Malad]

The mailman brought me some holiday cheer last weekend, a lee .457-500 gr.
something strange happened while casting. After pre-heating the mould the first 20 or so bullets had poor fill out, so I smoked the mould and the next bullet filled out perfect. Then they stopped filling out, so I smoked the mould again and presto the next one was perfect, then they stopped filling again. I was using my standard 45/70 alloy 90%WW 10%Lino at 750 to 800 deg.
Is this the cutting oil seeping out of the blocks? And has anybody else had this happen.

[madsenshooter]

Sounds like there's still some of the cutting lube they use still in the blocks, as you surmised. Though recommended by some, I would never smoke a mold, you're just changing the diameter. If it needs smoke, in my opinion, something is wrong. I left a Lee mold sitting in the melt overnight, next day, no more lube, burnt out nicely and it makes good bullets now.

[chris in va]

Did you clean it first?

[geargnasher]

Clean the mould surfaces and cavities with a good degreaser like brake cleaner to remove the smoke and residue, then you might consider soaking the blocks in Kroil, mineral spirits, or denatured alcohol overnight to remove the original oil. After having to cast 1-200 boolits from a new Lee mould each time (with a quick degrease up front) I have come to believe that this "break in" is really just a "boil out" of the cutting oils and such used in manufacture. Same thing holds true with steel, brass, or iron moulds as well, gotta get the oil out of the pores, and soaking the virgin blocks is a worthwhile shortcut to quality boolits.

Smoking the cavities of any mould is merely a band-aid for a bigger problem, and often creates more issues than is solves.

Gear

[sagacious]

Having poured only 20+ bullets with your new mold is not enough of a test to come to any conclusions at all. If one takes a shortcut in preparing his mold for pouring, he risks a wasted or frustrating first pouring session. Better to take care of everything before the pouring starts.

You'll need to clean the mold properly using alcohol or another solvent. Mop-out the cavities with a cotton swab to remove any machining chips and cutting oil. Aluminum molds are not porous like iron molds are, and do not absorb cutting oil, so that factor is not present in your situation. Once your LEE mold is properly cleaned of cutting oil, it's clean.

Inspect the mold. Make sure the sprue plate is adjusted properly: snug but not too tight. If it's too tight, some molds will not have adequate venting, and poor fill-out can result. Inadequate venting can be a frustrating situation until identified and remedied.

Once the mold is clean, resmoke the cavities with a butane lighter. Be sure to smoke the underside of the sprue-plate. That will put a coat of soot less than one ten-thousanth of an inch on there-- not enough to effect any dimensional change. However, it will provide a low-friction surface that the lead swirls on easier, which can help with fill-out. It also slightly reduces the conductivity of the cavity surface, slightly delaying the solidification of the lead, which helps prevent wrinkle-lines and keeps the edges sharp on the casting. Smoking the cavities also has the effect of giving the mold a surface that is similar to that of a 'cured' or 'broken-in' mold. Smoking the cavities very often reduces reject rate, or eliminates it entirely. That alone is worth the little time it takes. I politely beg to disagree, strenuously, with those who hold that it is an expedient or improper technique-- it is certainly not. While each will cling to his belief, proper technique and success speaks loudest, and that's what we're after here.

Next, flux the melt before you pour! The importance of this cannot be overstated. It can make all the difference with some alloys and some molds. Again, some may suggest that fluxing is unnecessary and a crutch, but shortcuts are the road travelled most frequently by those who trust in stop-gap measures. Let the results be the judge for you.

Now, beyond all of that typing, and beyond what you indicated in your post, one is perhaps still inclined to believe that your problems are much simpler: the mold was not preheated adequately. Before you take unbrage at that assertion, when one is struggling with difficult pours, or stopping to admire the beauty of a rare perfect pour, he often unintentionally interrupts the casting session and the mold temp varies wildly-- and fill-out can suffer. Keep that in mind during your next casting session.

Hope this helps, keep us posted.

[XWrench3]

i have to agree with gearnasher, it sounds like the mold needs to be cleaned. i use brake cleaner with a q tip inside of the cavaty(ies) of all of my molds. then spray the snot out of the rest of it and make sure it is thouroughly dry. then i get the mold pretty warm, and just touch the pins and pivots with lee stick alox (that i cut into slivers) so everything moves correctly. you need to be very stingy on the lube. if it migrates into a cavity, it will screw up the fill out. smoking seems to help a bit when the mold is new, but you should only have to do it once after the cavities are CLEAN. once you have cast a hundred or so boolits, all you will ever have to do is occasionally touch the lube points with lube. 800 degrees seems to be a bit hot to me. but i will say this. none of my molds (all of them are lee) want to cast well until the mold is THOUROGHLY heat soaked. i usually run the lead up to 750 degrees, then back it off and let it drop to around 650-700. i start casting @ 750 and let the mold soak up as much heat as possible for the first 10-15 casts. after that, the mold is hot, and will cast quite well. good luck, and keep us posted if you are still having trouble.

[dragonrider]

With any aluminum mold the first thing I do is toss it in the dishwasher with a load of dishes, freaks the wife out but works great. Then I lement it, you will find the process in the stickies section. Then I cast some, don't care how they come out just use them for lappers. Lap it, clean it thouroughly, then it should be ok to cast with.

[Recluse]

With any aluminum mold the first thing I do is toss it in the dishwasher with a load of dishes, freaks the wife out but works great. Then I lement it, you will find the process in the stickies section. Then I cast some, don't care how they come out just use them for lappers. Lap it, clean it thouroughly, then it should be ok to cast with.

Yep, +1. The dishwasher makes a fine supplemental casting and gun cleaning tool.

I Lee-ment the mould. I do this, however, to EVERY mould--Lee or otherwise--to a certain extent.

I've had some Lee moulds in longer boolit styles that I just couldn't get good fillout on, no matter what. I found two things that worked like a champ:

1. Heat the mould in the melt to burn off any stubborn, residual oil or junk, and

2. Use a ladle rather than bottom pour.

I've never been able to get consistently good rifle or extremely large boolits, every time, every run, using bottom pour--not on the Lee Pro 4 20 or the RCBS Pro Melt. But the ladle works every time.

[mooman76]

Are you using a bottom pour? Some have better luck with those big heavy bullets using a ladle. I only ladle pour so I can't state a difference myself.

[Gee_Wizz01]

I am wondering if you are running the mold to hot. When you take the time to smoke the mold it has cooled off a little and produces a good boolit.

G

[Greg in Malad]

Thanks guys, I should have included more details but I type slow.
I cleaned the mould with brake cleaner and preheated it for a couple minutes in the melt. I have a RCBS thermometer and I think the calibration is off, because even at 800 deg. the bullets wont frost and my other moulds work fine at that temp. I didnt lee-ment this mould because the bullets simply fall out when opened.
I will try a different brand of cleaner and heat soak the mould really good. This bullet is cutting one hole groups at 50 yds in the 45/70 so I dont want to give up on it.

[HeavyMetal]

Checking to see if the mold is clean would be my first step but my experience with big single cavity molds is they like heat!

I would clean it with another brand of brake cleaner, then rub the cavity with a q tip soaked in alcohol two or three times.

Then I'd ladle cast. Since your only making one at a time anyway speed should not be a goal here! Dip the mold blocks and then dip the sprue plate then pour your boolit!

Don't be afraid to turn up the heat if you still get some wrinkles after all this!

[Maven]

"With any aluminum mold the first thing I do is toss it in the dishwasher with a load of dishes...."

All, While I agree that dishwasher powder is an excellent degreasing agent, it is highly corrosive to aluminum. (Don't ask how I know this!) Ergo, use the dishwasher or dishwasher powder on iron (meehanite) molds if you wish, but NEVER on aluminum blocks.

[Greg in Malad]

Well I tried it again tonight and several of you were right, it was too hot. I've never had a mould get too hot to fill out in the lube grooves, untill now. I backed off the temp to 700 deg. and it worked great. Just to make sure it was the temp causing the problem, after 100 bullets I cranked up the temp and they stopped filling out. Every mould has its own personality. Thanks for the help