mold is suddenly finning

[longbow]

"I have one Lee mold that will fin unless I invert it and smack it with a wooden dowel every so often" what he said!

My NOE moulds tend to be stiff at closing due (I think) to the blunt alignment pins so the moulds do not close easily even when sprue plate lube is applied to the pins. I just give the edge of the handle a gentle tap as I close the mould and that does it.

Could be that when you are working with the mould it starts binding a bit on a pin so the blocks don't quite fully close. Try sprue plate lube on the alignment pins and if that doesn't do it then try a gentle tap just as you close the mould halves.

Longbow

PS: I love my NOE moulds so don't misunderstand. It is just a quirk I solved and continue to do. The moulds cast perfectly as long as they are closed.

[jeff100]

"I have one Lee mold that will fin unless I invert it and smack it with a wooden dowel every so often" what he said!

My NOE moulds tend to be stiff at closing due (I think) to the blunt alignment pins so the moulds do not close easily even when sprue plate lube is applied to the pins. I just give the edge of the handle a gentle tap as I close the mould and that does it.

Could be that when you are working with the mould it starts binding a bit on a pin so the blocks don't quite fully close. Try sprue plate lube on the alignment pins and if that doesn't do it then try a gentle tap just as you close the mould halves.

Longbow

PS: I love my NOE moulds so don't misunderstand. It is just a quirk I solved and continue to do. The moulds cast perfectly as long as they are closed.

Yes, I've lubed my alignment pins and sockets. The mold seems to close with no effort. I also have NOE molds, I love them, they cast excellent boolits. That said, I find them difficult to open, usually taking several cycles of opening pressure, closing pressure until I finally get it worked open. I lube the heck out of this alignment hardware too. They close fine, just the opening that is difficult. I think it's the boolits themselves causing the binding when trying to open and I just live with it since the mold casts such perfect boolits. JJ

[jeff100]

Would you post some close-up pictures of the mold halves

Also, check the leading edge of the sprue plate where is fits around the stop pin for any burs that might be keeping it from closing properly.

Occasionally I will gently tap the handle (with a small leather mallet) where it contacts the mold with the mold fully closed to assure complete seating of the alignment pins/closing

Here you go, dang if I didn't notice a small piece of lead near one of the alignment pins as I was prepping the photo. JJ

[vzerone]

I dunno I have had some LEE molds in the past that putting them in a vice and hammering them into shape sure made me feel better about things.

Ditto done the same thing and it trued them.

Have you held the empty mold up to a light with the halves closed and been able to see light anywhere they meet?

[jeff100]

Ditto done the same thing and it trued them.

Have you held the empty mold up to a light with the halves closed and been able to see light anywhere they meet?

Yes, I have inspected the mold under strong light and do not see any light breaking through. When I posted the picture of the mold I thought I saw a small amount of lead near one of the alignment pins. I looked at the molds to clean off that lead and found no lead, just a small area near the pin that was marred from a deposit of lead that had been previously cleaned off, scarring the mold face in the process. I took another close careful look at the mold faces under good light and high magnification and I now believe that there is some damage to the face of one of the mold blocks at the nose of a couple of the bullet forms where lead would probably flow no matter how tightly the blocks are held together. The damage is very slight, but it's there. In the past I did find some lead splatter on the mold faces that I had cleaned off with a dental pick. The finning started some time after that. I now believe the mold has been damaged by casting with that lead spatter on the faces and what's done is done, I will have to either live with trimming off the fins (done that, don't like it) or replace this mold. Many thanks to everyone who took the time to help me, I learned a lot about molds and inspecting molds and what to look for. Although it seems I'm not going to be able to fix this mold, this thread has been really helpful to me. Lesson learned, don't keep casting when you know you have lead splatters on the face of the mold blocks. - JJ

[vzerone]

Yes, I have inspected the mold under strong light and do not see any light breaking through. When I posted the picture of the mold I thought I saw a small amount of lead near one of the alignment pins. I looked at the molds to clean off that lead and found no lead, just a small area near the pin that was marred from a deposit of lead that had been previously cleaned off, scarring the mold face in the process. I took another close careful look at the mold faces under good light and high magnification and I now believe that there is some damage to the face of one of the mold blocks at the nose of a couple of the bullet forms where lead would probably flow no matter how tightly the blocks are held together. The damage is very slight, but it's there. In the past I did find some lead splatter on the mold faces that I had cleaned off with a dental pick. The finning started some time after that. I now believe the mold has been damaged by casting with that lead spatter on the faces and what's done is done, I will have to either live with trimming off the fins (done that, don't like it) or replace this mold. Many thanks to everyone who took the time to help me, I learned a lot about molds and inspecting molds and what to look for. Although it seems I'm not going to be able to fix this mold, this thread has been really helpful to me. Lesson learned, don't keep casting when you know you have lead splatters on the face of the mold blocks. - JJ

You know if you feel it's that far gone, you might warm it up a little and clamp it in a vise. Nothing lost if you're going to replace it.

You know I've had a number of the Lee molds over the years and even though I say they are the softest aluminum I've ever seen, I've gotten some of the most accurate bullets from them. They are very affordable and once you doctored them up and take care of them they can las a long time.

I wish you luck with whatever you do.

[jeff100]

You know if you feel it's that far gone, you might warm it up a little and clamp it in a vise. Nothing lost if you're going to replace it.

You know I've had a number of the Lee molds over the years and even though I say they are the softest aluminum I've ever seen, I've gotten some of the most accurate bullets from them. They are very affordable and once you doctored them up and take care of them they can las a long time.

I wish you luck with whatever you do.

I love my Lee molds. They usually work great for me. This one is a problem because I abused it through my ignorance. Not the fault of Lee or the mold. Just saying...JJ

[John Boy]

also check for wear where the sprue handle goes against the mold it might be 'over camming' and pushing the blocks apart when closed.

Then for starters, close the mold block and with a tight squeeze and plate out of the way, hold the mold up to a bright light to determine where any light can be seen in the cavities

[Grmps]

Those are some clean blocks. if the faces are clean I'd suspect an alignment pin.

clean and dry the mold. hold it together and hold it up to a light pinching it together. rotate it around at all angles to see if you can see light through it

If you can't tap the offending pin back a smidgen, clamp the mold halves together between two flat solid blocks of wood might re-seat the pin(s),.

.

[OS OK]

Any new developments on this post yet? OP...what have you done to correct the problem thus far?

How do you monitor the pot temperature? Where do you try to keep it?

Do you hold a medium firm grip on the mould handles as you fill the cavities?
Do you incorporate the sprue handle in your grip as you fill the cavities?...You should not...

[jeff100]

Any new developments on this post yet? OP...what have you done to correct the problem thus far?

How do you monitor the pot temperature? Where do you try to keep it?

Do you hold a medium firm grip on the mould handles as you fill the cavities?
Do you incorporate the sprue handle in your grip as you fill the cavities?...You should not...

No light can be seen through the mold using very bright LED light and rotating the mold blocks as I inspect them under the light. I do not hold the sprue handle as I fill the mold, I use moderate pressure on the two mold handles as I pour. I DO use a thermometer in my pot and of late have been casting at 600-650 degrees F.. I used to cast hotter but once I started really paying attention to my alloy composition, I've been able to dial back the temperature of my melt and cast at cooler temps and still get good fill out. Nice shiny boolits are the result. I did clamp the blocks together for a 24 hour period but I did not preheat the blocks before clamping.

My last ditch effort here will be to try ladle casting with this mold. If I still get finning while ladle casting, I'll try heating my mold and clamping under pressure again and then try ladle casting one last time. If that fails to fix this, I'm DUN.

[Walter Laich]

I had a Lee mold that won't close completely--sliver of light between the halves

Each time I would close the mold I would turn it 90° and tap the mold sides together which would close the mold completely.

After doing this 20 or so times the mold came back into specs and has worked without problems from then.

[Walter Laich]

another quick possible fix came to mind:
remove the handles and flip them over, reinstall. Could be they are canting a bit when closing.

or try another pair of handles. If mold was dropped could have twisted them


and there is always the option of sending it to another caster and letting them see what results they get. Cost of postage would be about it

[Echo]

Yes, I've lubed my alignment pins and sockets. The mold seems to close with no effort. I also have NOE molds, I love them, they cast excellent boolits. That said, I find them difficult to open, usually taking several cycles of opening pressure, closing pressure until I finally get it worked open. I lube the heck out of this alignment hardware too. They close fine, just the opening that is difficult. I think it's the boolits themselves causing the binding when trying to open and I just live with it since the mold casts such perfect boolits. JJ

I had that problem, bad, with an NOE mold, so I called, and Swede suggested using a chamfer reamer to touch to alignment inserts. Did, no joy. But I had another reamer from my electronics days that has a sharper included angle, and tried it. Worked. Mold opens and closes like a champ, no play when closed.
My take on your problem is some kind of obstruction in the locator holes/inserts...

[Dusty Bannister]

No light can be seen through the mold using very bright LED light and rotating the mold blocks as I inspect them under the light.
------------
You may be doing it right, but not saying it right. Close the blocks, and hold them between you and a light source. Maybe just hold them in front of a window and then look to see if there is any light coming through between the block halves. Also, it was suggested that you check to be sure the handles are not damaged. I have had the hinge bolt loosen up which will allow the blocks to be misaligned when closing.

[MT Gianni]

You are checking for a warp at room temp that might appear at casting temps. I am of the opinion that Lee molds are as great as BIC lighters. They are useful, inexpensive and we should not be overly concerned when they are dead.