Molds Won't Close

[BlueNorther]

I was casting today with two single cav. Lyman molds and ran into trouble right away. On the first mold I cast about 30 boolits and started to get finning, thought maybe I didn't get the mold closed. So I cleaned the lead off the face and any where else there was lead. No go, the mold will not close. I'm thinking a pin needs adjusting? The second mold did the same thing but I was able to cast about 70 boolits before it was hard to open and close. After cooling they are still not able to close tight.

I did all the required pre cast stuff, cleaned molds, lubed the pins and sprue plate and preheated them on a hot a plate. Casting was @ 650 to 700 degrees. These are both new molds. I was also ladle casting.
I had to tap the mold handles to get the bullets to drop, can this cause the alignment problem?

[jtaylor1960]

You probably need to adjust the pins.You didn't get finning right away because the mold wasn't hot enough.I have molds that only fin when they get real hot.Add a little gap and it just magnifys the problem.I'd guess that if you adjust the pins and try again with everything else the same you should be OK.I also have a set of RCBS handles that get tight after they get real hot.I got them too hot when preheating them on my furnace and they warped a little.Good Luck!

[Bullshop]

Check those blocks both on and off the handles. If they close while not on the handles then it is the handles.
BIC/BS

[HeavyMetal]

+1 on Bullshops statement!

I have found Lyman handles to be to tight on some molds and, when heated, they bind.

If this isn't the issue take a magnifiy glass and examine the alignment pins and the mating holes. Your looking for burrs or possible lead blockage.

If these do not appear to be the problem I think returning them to the place of purchase is in order.

[462]

Hold the moulds up to a light source, you should not be able to see any light between the two blocks. If light is visible, check for burrs in the holes, as mentioned. If the holes are okay, tap the pins in a bit and re-check, repeat until the blocks mate properly After the pins are aligned, the blocks should not move when you twist one against the other.

Seems moulds always need a bit of initial TLC. The secret is to not let it get you frustrated.

Good luck.

[BlueNorther]

Thanks for the advice and help gentlemen. I was able to resolve the problem. A small amount of lead got into the pin holes. With some careful scraping I was able to remove it and now the molds are back in working order.

I've learned a couple of things from this incident and with your help I'll learn more as I stumble along.

[462]

Good deal.

I stumble, too, but consider it part of the learning process. In fact, I'm currently stumbling with a new mould.

[Echo]

I'm sure most of us stumble along - but there are forum members who prop us up, and we are both better off for it...

[Suo Gan]

What brand of mold and how many cavities are we talking about?

[HeavyMetal]

I always look for something simple first, glad it was only a bit of errant lead.

Good luck with casting.

[justingrosche]

I'm having a bit of trouble with a mold I just got off Evil-bay. It's a two cav. 452460. Right off the bat I was less than impressed with the condition of the mold. Screws buggered, Small splotches of rust on the outside of the cavities and one of the pin holes was gouged, where it looked like the alignment pin was striking the face. when I closed the mold halves I could see light between them So knew I had some work to do.I redrilled both the pin holes, to true them up and removed the burrs, then cleaned every surface with Bar keepers friend but still has light between the halves. I really dont want to stone the interior of the mold if I dont absolutely have to. The vent lines on this mold are too shallow for my liking as it is.
Any ideas?

[HeavyMetal]

The vent line are deeper than you think.

I've had a few molds that were in about the same condition.

Go to a good hardware store and buy some 1500 grit sand paper.

Remove the alignment pins and place the 1500 grit on a piece of glass set on a flat surface and put a little oil on the sand paper thgen move each mold half in a figure 8 pattern. you want to count each complete pass and make the same number of pass's on each half.

The goal is to make each half completely "shiney" with no hidden depressions. Then re install the pins slowly you want to remove slop from the half's as they mate but you don't want them going far enough into the other half of the mold to hold them open!

[Doby45]

Make sure you lube that hinge pin on the mold handles too. I had my Lee 2cav freeze up this past weekend. A drop or two of Bullplate right in the hinge area and within about 15sec it was slicker than owl snot. I had not lubed that hinge since I got the mold a few weeks ago.

[justingrosche]

The vent line are deeper than you think.

I've had a few molds that were in about the same condition.

Go to a good hardware store and buy some 1500 grit sand paper.

Remove the alignment pins and place the 1500 grit on a piece of glass set on a flat surface and put a little oil on the sand paper thgen move each mold half in a figure 8 pattern. you want to count each complete pass and make the same number of pass's on each half.

The goal is to make each half completely "shiney" with no hidden depressions. Then re install the pins slowly you want to remove slop from the half's as they mate but you don't want them going far enough into the other half of the mold to hold them open!
Thanks for the advice Heavy Metal, I guess there is no easy way out of it, like I hoped. I'll have to break this mold down into its components and start from scratch.
It definitely isnt the handles, is suffers from the condition w/o the handles installed as well.

[HeavyMetal]

Let us know how it turns out.

[justingrosche]

Re inspected it right before I tore it down and found a tiny bit of smoltz (technical term) on the inside corner that I had missed.
Cleaned it off and it shut like a vault door. Cast a couple hundy this afternoon with it. Beautiful.

[MtGun44]

The dressing of the face is a good idea, but 1500 grit is going to make you crazy.
Try 600 at least, and a light polishing will not hurt anything.

Bill

[94Doug]

....and follow up with the 1500 if you want for a super finish. 1500 and up is used a lot for wet sanding clearcoats.

[chuebner]

Since we are on the subject of mold maintenance, how are the pins removed from a Lyman mold. I have a 457125 that rocks about .004-.005 at the locating pins on the vertical axis. There are no evident protrusions or burrs at the female pin holes but it is hard to tell on the male side. I would like to remove the pins and lap the mold faces with 600 wet/dry paper. So far I have tried to whack the pins out with the mold half lying face down on a vise between two pieces of 1" aluminum angle stock as protectors on the vise jaws. The pins are not moving and had a prior soaking in Kroil for 24 hours. Suggestions appreciated.

charlie

[HeavyMetal]

First on the 1500 grit the old saying is measure twice cut once! 1500 give me something to do and more control on close tolerance surface's.

As for the alignment pins on a Lyman mold. Some of those babies can be really stuck! Continue with Kroil and keep tapping until the pins move.

Some times the female holes are wallowed out. I have taken a 10 degree taper reamer and tapered the first .050 of the alignment hole. Then set the pin out further until the rocking goes away but the half's don't stick on opening.

[462]

Chuebner,
If the mould halves are moving about, the pins aren't extended out far enough. As odd as it may sound, use a bigger hammer. A 32-ounce ball peen finally moved a pair that I was adjusting.