Odd problem with Accurate Mold

[igolfat8]

I received my 1st mold from Accurate Molds a couple days ago. Its a thing of beauty! Its a 5 cavity, aluminum, 115 grain, 9mm mold without lube grooves.


The cavity closest to the handle is dropping bullets with a defect. See attached picture. I have tried filling it first or filling it last but it makes no difference. I cast 60 pounds of lead today. The other cavities are dropping flawless bullets so its got me stumped. I also cast Lee 120TC bullets with the same lead mix and I didn't have this defect with the Lee mold. I am confident its not the lead mix. Its not a problem with every cast and only happens sporadically but its ALWAYS on the same cavity. The defect is always on the lower flat portion of the bullet where the lube groove would be located. I probably had 250 bullets with similar defects. Its not a wrinkle due to lube in the cavity. Could it be a venting problem? Do you have any ideas?

169056

[mozeppa]

try cleaning the cavity with lacquer thinner.

awe heck...clean them all!

[Tar Heel]

Very interesting. I will be eagerly awaiting other comments. I would bet it is an alloy/temperature/cadence/cavity position issue. Is this cavity on the end of the mold? Position 1 or 5? Call position 1 closest to your hand.

[500MAG]

D you fill that cavity first or last? Are you using a bottom pour pot or ladle?

[pdumont01]

Had a similar issue but mine was with the middle cavity, I took one perfect boolit drilled a home in the base and put a tec screw in it, closed it in the mold, put a little toothpaste on it and went over all the cavities, carb cleaned, and retested, no longer had problems and they were perfect and fell right out with no help.

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[243winxb]

Return to manufacture, its defective.

[igolfat8]

I use a bottom pore Lee 20 lb furnace. All cavities were thoroughly cleaned, then smoked. The temperature is held constant at 700*F with a PID.

[igolfat8]

I've tried filling this cavity first and filling it last and it makes no difference. Its the cavity closest to the handle pivot bolt.

[igolfat8]

Return to manufacture, its defective.

I've tried contacting Accurate Molds but they are not responding?

[Dan Cash]

Picture of the mould cavity needed. If there is supposed to be a lube groove in that bullet it seems someone sold it as it is gone.

My most recent mould from Accurate seemed more difficult to degrease as it did not come totally clean with my regular method. After several casts, it acted right. Perhaps the manufacturer is using a different machining lube.

[igolfat8]

Picture of the mould cavity needed. If there is supposed to be a lube groove in that bullet it seems someone sold it as it is gone.

I ordered the mold without the lube groove because I powdercoat my bullets.

[country gent]

It could be a venting issue or some cutting fluid / preservative left in the mould. With an sharp ice pick, awl, scribe, or exacto knife gently pull the point thru the vent lines from cavity to edges when possible. It dosnt take much to plug these vent lines off. You dont want to remove any metal just any crud in them. A bamboo skewer from the grocery store works good here also. After this reclean the mould first with a solvent acetone, paint thinner, alchlol, or other solvent. With a tooth brush really owrk this in and around scrubbing good to remove anything. hen with hot water and dish soap scrub again good really work up a lather to remove any residues left by the solvents. Some times a good boiling in hot water dish soap mix works wonders also. Before doing any lapping or polishing try the above cleaning and see what happens. I would also recomend exaimineing the cavity in question under magnification for rough spots burrs or off areas. Lapping polishing is a last resort. I would even contact the maker before those are done. I believe clearing the vent lines and the above cleaning will cure your problem.

[runfiverun]

try filling that cavity first.

[Mk42gunner]

Looks like either a venting or contamination issue to me. Both can be fixed by you.

First off, I would try to clean the mold half that is doing this a few more times with a non deposit leaving solvent such as acetone or alcohol, maybe both.

Then wash it with hot water and dish soap.

Next step would be to heat cycle the mold a few times, either on a hot plate or in an oven. Get it to casting temp then let it cool to room temperature a few times.

Try casting with it. If that didn't work, try rubbing the offending cavity with a pencil eraser and make sure the vent lines are clear.

Good luck,

Robert

[popper]

More than likely a venting problem you created by smoking the mould. Clean it with non-clorinated brake cleaner, use a toothpick to clean out the vent lines. With no L.G. it is harder to get the air out. You might try a little hotter mould and alloy also. Actually, just really huge wrinkles.

[runfiverun]

those are voids.
they just happen to show up on the side of the boolit instead of internally.
get more heat in that cavity and give it enough sprue to pull extra lead from and it will go away.

[John Boy]

I use a bottom pore Lee 20 lb furnace. All cavities were thoroughly cleaned, then smoked. The temperature is held constant at 700*F with a PID. If you note where the bullets in this cavity are not filled out - it's because the melt & mold are not hot enough for a complete fill!
And I'll bet ya, the sprue puddle is frosting in 2-3 seconds if that.
So, heat the melt in the pot and the mold to a temperature so ALL 5 CAVITY SPRUE PUDDLES FROST IN 8 - 10 SECONDS
Am also betting that you are drizzling the melt into the cavities ... STUFF the pot spout into the cavity and hold it there during the COMPLETE pour for each cavity

[Echo]

I'm betting on a venting problem, so my suggestion is to thoroughly scrub the blocks in this area with a toothbrush and acetone, use a toothpick and go over every line intersecting that cavity. And pour it in faster...

[igolfat8]

try filling that cavity first.
I've filled it first and last and it makes no difference.

[reddog81]

Looks like a venting problem to me. I had the same thing happen with an NOE 9mm no lube groove mold. I cleaned out the vent lines with a box cutter and the problem magically disappeared. Just make sure your gentle when cleaning out the vent lines.

[dubber123]

In my opinion it is a venting or fill technique problem. I'd clean out all the carbon smoking introduced into the cavities. I believe smoking causes way more problems than it solves, and is just a band aid solution for a real mold problem. I doubt Accurate cut a cavity that produces that divot on the boolits, in fact I doubt it's possible, It's a big air bubble from poor or clogged vents, a cold mold, or too slow of a pour is my take on this one. Clean it well, skip the smoking, run it hotter and don't dribble the lead in. Let us know how you make out.

[igolfat8]

The lead isn't dribbled in, its streamed in under the force of a full pot. Having said that I did notice that the pore holes, in the sprue plate, are not centered over each cavity but rather offset nearly to the edge of each cavity. I doubt that is a problem but its worth mentioning? I'll scrub the mold and inspect the vent lines later today. Thanks for all of the suggestions.

[John Boy]

I've filled it first and last and it makes no difference.
... but you haven't done this!

So, heat the melt in the pot and the mold to a temperature so ALL 5 CAVITY SPRUE PUDDLES FROST IN 8 - 10 SECONDS
Am also betting that you are drizzling the melt into the cavities ... STUFF the pot spout into the cavity and hold it there during the COMPLETE pour for each cavity

[igolfat8]

I received a reply from Accurate Molds and they suggested the problem may be a small bit of residual contamination in that cavity.

[GWM]

Having said that I did notice that the pore holes, in the sprue plate, are not centered over each cavity but rather offset nearly to the edge of each cavity. I doubt that is a problem but its worth mentioning?

That is not normal. The sprue plate cannot be positioned right. It would need to be adjusted.

[dubber123]

The lead isn't dribbled in, its streamed in under the force of a full pot. Having said that I did notice that the pore holes, in the sprue plate, are not centered over each cavity but rather offset nearly to the edge of each cavity. I doubt that is a problem but its worth mentioning? I'll scrub the mold and inspect the vent lines later today. Thanks for all of the suggestions.

No offence meant, and in fact "dribbling" the lead in is only 1 possibility. I have molds that actually need a slower pour to fill well. Accurate is likely right, clean the mold again very well, I use an old toothbrush and dish detergent myself. I do suggest skipping the smoking, it can mess up venting or produce undersize boolits.

[Digital Dan]

It's Al Gore's fault

[Maxx]

That's so funny!! I have the same mold but in a 4 cavity and mine does the same thing from time to time, it goes away after the 20th fill or when the mold heats up, adding tin helps out a lot. But even then, it happens from time to time,

[Walter Laich]

from Maxx's reply I 'could' entertain the thought that with all the other cavities hot with lead the lack of a lube groove causes this.
But remember I'm only cleared for rumor and gossip.

[runfiverun]

think about it.
if the sprue hole is off center and the alloy is rushing in there then rolling up the wall of the cavity from the bottom it's cooling down before the cavity is full and air is getting trapped right there.
this is creating the void.
I have seen pigs of linotype do the same thing from being filled too fast and they are open ended molds.

try pouring that cavity first and slow down the fill speed you need to let the air out.

[TomAM]

Turns out the holes are off center because I mounted the sprue plate backwards.

I think the culprit has been found!

[runfiverun]

Tom.....
your accuracy level just went down to 99.99%,,, c'mon man :lol: