New style Lee 6 cavity problems

[brotherdarrell]

I am having a couple of issues with the new style 6 cavity molds. I just tried out my second one today and am having the exact same problem as I had with the first one.

I would swear that the mold blocks are warping. The first one was a 452-200 rnfp. I ran a couple thousand boolits and then they started fining on the nose and dropping around .457" opposite the parting line. I have tripled checked for lead on the mold faces but none exists. When the mold is closed I can see light between the two halves. I assumed I got it too hot and warped it.

Today I tried out a brand new 452-230 rnfp. Before ever warming it up I checked for light and could see a little that would go away if I squeezed the handles. I cleaned it up, cycled it a couple of time yesterday on the hot plate never going any higher than I usually do to pre-heat a mold.

I started casting @ 725 according to my brand new thermometer and as soon as the mold starting warming up to temp I started getting fining on the noses and diameters around .455". Light is also visible between the blocks. After letting the mold cool down the fining went away and diameters were spot on. After the mold started getting warm after a couple of casts the problem repeated.

If I cam the sprue plate too hard I can induce a gap so I was very careful not to put too much pressure. This did not help. It only takes a couple casts and the problem arises.

I may not have been casting since the Truman era but I also am not a rank amateur. I have a couple old style 6 cavs. that have well over 10K boolits through them that are still going strong.

I don't know if I have problem molds or if I just can's see the forest for the trees.

I have crying for help here. Any ideas?

Thanks to all

Darrell

[w5pv]

If you have a hydraulic press take and press the two haves together and let it set for a while using 12 to 15 thousand psi.Be sure that the halves are supported by a heavy piece of flat iron.I repaired a double cavity this way.It was finning/flagging and a machinist friend told me how to do this. Good luck if you try.

[PS Paul]

The very FIRST thing I consider is "what have you been using to lube the mold"? I've found that Lee's recommendation to use the 50/50 alox-beeswax stick creates a residue buildup on the mold that can and will prevent the mold halves from fully closing.

I had a .356-124 mold do that very thing and found just a really good scrub with comet took care of most of the problem...... BUT, even after cleaned, it still would not closed fully, so I just padded it between the jaws of a vise and closed the vise on the mold and let it sit for a while. Seemed to fix the issue. Perhaps the hydraulic vise might be a better solution, provided warpage IS the issue?

[Lights]

This has came up before. The sprue plate grows more than the mold when heated and the sprue plate stop bold helps it warp a bit. You need to remove some material from one side of the slot that is closest to the pivot bolt.

[brotherdarrell]

This is a brand new mold used for the first time today and the only lube used was Bullplate on the alignment pins. When the mold is at room temp there is no gap between the blocks.

Thanks for the ideas.

Darrell

[Old Caster]

I recently bought a brand new 38 105 grain 6 cavity mold. Before using it I checked it and it was warped. I called Lee and wound up paying for shipping to send the mold to them. I recognized the mold as being the same one when I got it back and it was flat. I have no idea whether they bent it or re machined it. If the faces were re machined, the bullets won't be round. The biggest kick is why did I have to pay shipping to get the mold fixed when it was brand new never used condition. Some warranty.

[jules]

I recently bought a brand new 38 105 grain 6 cavity mold. Before using it I checked it and it was warped. I called Lee and wound up paying for shipping to send the mold to them. I recognized the mold as being the same one when I got it back and it was flat. I have no idea whether they bent it or re machined it. If the faces were re machined, the bullets won't be round. The biggest kick is why did I have to pay shipping to get the mold fixed when it was brand new never used condition. Some warranty.

Even though it's no fault of the buyer Warranties for the most part never cover shipping.

[Frozone]

Check the alignment pins/sockets. They get larger when hot.
Is the light you see only in the middle of the blocks or all the way across?

'all the way across' is the pins not letting the halve close fully.

LEEs are 'famous' for having the pins walk out. Be sure to stake em with a center punch when you are sure they are adjusted.

[Old Caster]

Unless the warranty is from a real company like Dillon.

[bangerjim]

Even though it's no fault of the buyer Warranties for the most part never cover shipping.

MOST companies that deal with the general public on consumer grade products provide warranty, but it is the responsibility of the customer to get the product back to the manufacturer for service. Your car dealer does not pay for your gasoline for you to drive your car to them for warranty service. But they may give you FOR FREE a loaner! My Lexus deal does. Very few companies will cover RETURN for warranty shipping. I provide industrial equipment that can cost upwards of $10,000 and carries up to a 5 year warranty and we still expect the end user to pay one-way shipping for warranty. Shipping on a $30 mold is nothing out of the ordinary.....Priority Mail FRB?


I had a skewing problem on one 6 banger and it was just a bit of lube/crud build-up in one alignment pin hole. A quick clean with a small brass bristle brush and all is good! At first I thought warping too, but is was not.

Good luck...........and happy casting!

bangerjim

[brotherdarrell]

Check the alignment pins/sockets. They get larger when hot.
Is the light you see only in the middle of the blocks or all the way across?

'all the way across' is the pins not letting the halve close fully.

LEEs are 'famous' for having the pins walk out. Be sure to stake em with a center punch when you are sure they are adjusted.

I can detect no friction when closing the blocks. I keep the pins loobed with bullplate.

The light starts at the pin area away from the handles and as the mold heats up moves down the mold until I can see light almost the entire distance.

I have experience with the "walking pins" and, as far as I can tell, this is not happening. I haven't had to stake pins yet on the molds I already have but if I can get this one to cast properly I may give it a try.

I am getting ready to try it again. I will try a different set of handles and maybe relieve the area on the sprue plate that fits under the stop pin. We will see what happens.

Thanks again.

Darrell

[Frozone]

I can detect no friction when closing the blocks. .....

You may not feel friction.
But if the inserts are out too far they prevent the mold from closing properly.
I still think it's a distinct possibility that's the problem.

[Dave C.]

After you close the sprue plate do NOT touch the sprue plate handle until you are ready to cut the sprue. DO keep the mold block handles lightly squeezed until you are ready to cut the sprue. Try it, you have nothing to lose.

Dave C.

[brotherdarrell]

You may not feel friction.
But if the inserts are out too far they prevent the mold from closing properly.
I still think it's a distinct possibility that's the problem.

Preliminary results are showing you may be correct. I drove the female half in far enough so that there is almost no light showing, and once up to temp there is no light showing. I cast up about 150 and spot checked a few along the way with a mic and they seemed good to go. I will know tomorrow when I run them through the Star.

I am keeping my fingers crossed.

Darrell

This is the mold

http://leeprecision.com/new-452-235-rf-6-cavity-mold.html