fins and rims.....

[acemedic13]

I just got done casting some 230 gr. .45's from my lee 2 banger mould. Some of the boolits had a fin on the nose and some had a rim left on the base....Some had both. It was pretty easy to just knock of the protrusions with a thumbnail, but it is still not a good thing... What is causing this? I tightened the sprue plate screw and made sure the blocks were aligned when closed, and still had a few isuues after that. Out of all the boolits cast (around 200) almost half of them had these issues. Of those hundred or so, only about 15 were comlplete rejects. How do I fix this?!?!? Thanks in advance for the input.....

[opentop]

It could be that you are pouring way to hot, or the mold halves are not closing completely. Check to see if there any lead on the faces of the mold halves that would keep them from closing.

[acemedic13]

I just did that.....all clear......Thanks for the advice.....

[JIMinPHX]

I'm going to guess that either you didn't lube up the alignment surfaces well enough or else you have a burr somewhere on the molds that keeps them from closing all the way. They don't need to be very far out of place to give you the results that you described. I'd look for burrs around the pressed in steel alignment pins & the ends of the aluminum alignment ribs first, then I'd clean the mold real well, then I'd lube it up & try it again. For the next 20 or 30 pours, after you close the two mold halves together & before you close the sprue plate, hold the blocks up to a light for a second & make sure that you can't see light between them, then close the sprue plate & pour. If you see a crack pf light, then you know where your problem is coming from.

If your boolits weren't frosted, then they probably were not over temperature when you poured them.

[runfiverun]

if you tighten the sprue plate it causes the back of the plate to push down and the front to lift causing the fins on the base you need to hold it up to a light and adjust it so it's even.
even if this means slightly loose and floppy.
everytime i tighten a plate on an aluminum mold i've galled the top of the mold.
you might just be hitting the sprue cutter with your finger/thumb when pouring and slightly opening the mold.

[Mk42gunner]

Since you were using a two cavity Lee mold; my bet is you either got in a hurry and didn't close the mold properly; or you need to lube the aluminum alignment v's.


Robert

[acemedic13]

Thanks Run five and Jim. I just cleaned the mould and cast a few, the points were great but still goofed up bases. Then I loosened the sprue plate screw and cast a few. The bases came out perfect. I guess from the mould heating and being worked that screw tightened up. It is casting great boolits now and I am going to make a bunch tonight. Thanks again for the advice, Joel......

[acemedic13]

Spoke too soon. I just ran a few more and started having the same issue. Just not as extreme. I looked really closely at the inside of the mould through a really bright light, and from several angles. It appears that the mould is warped ( thats the only word I can really think of to describe this) at the center section that seperates the two cavities. It looks like its a goner...Rats...... I guess I will just order another one after I get back, and start all over!!! Thanks for the help guys... Joel

[JIMinPHX]

I've messed with a few that I thought were warped, only to find out that they had a burr someplace. Don't throw it out just yet. Let someone else take a look. Post some pictures if you can.

[bigboredad]

It could be something as simple as to much pressure when pouring. If you bottom pour hold the mold closer and slow the stream down and if ladle poring same thing hold the mold closer slow your stream down and try not to over flow too much>. I had the same problem with the bases and that is how I fixed the problem I am now able to have skirt free boolits good luck