Frustrated!!!!!

[GARCIA]

I am very, very frustrated at this point!!!!!

I have cleaned this mold with Dawn, using both hot tap water and boiling water.
Have tried brake cleaner, even used 97% alcohol while the mold has been both cold, hot and have still ended up with what looks like pitting on my boolits.

I have casted from one end of the temperature range to the other with still the same results.

So yeah, I am just a little frustrated at this point.

My mix that I am using is WW's with a little 95/5 mixed in for fill out.

Anyone have a clue as to what I might be doing wrong or where I am screwing up?

Tom

[Doby45]

Looks like the start of frosting to me. In other words, that is a very shootable boolit. Load it and send it down range.

[JonB_in_Glencoe]

Need more info.

could be the mold...Pics of mold ?
Have you looked with a loupe or other magnifing lens at the mold
cavities ?
Is there more than one cavity ? If so, are they all the same ?
If they look OK and all cavities are droping the same problem boolits,
then it's probably your pouring technique.
sometimes, putting the stream off-center and giving
a swirling effect as the Lead fills the mold will fix a problem like that.
Jon

[GARCIA]

Ruger only mold from MP-Molds, double cavity.

Looked through a magnafying glass and could not make out any differances.

Have tried canting the mold in all four directions and still getting the same effect. Plus varying the height. Results are still the same.

Tom

[BABore]

Get the mold hotter, not the alloy. Run your alloy in the 725 F range. It looks like you need to fill the cavity faster. Flow rate!

[songdog53]

I have had same thing as photo shows and is on few boolits but i just lube size and shoot them...looks like maybe little frosting but shootable bullet. Remember what ever your target is will never notice difference.

[badgeredd]

I am inclined to believe your mold is a bit on the cold side as Bruce said. It appears you're get reasonable fill with some freckling. To me that indicates your lead is hot enough but your mold is a little cool. AND remember that frosting is not a bad thing if it is moderate. Shiny boolits shoot no better than frosted ones.

Edd

[GARCIA]

I can run the mix at a low temp or a high temp, the effects are still the same.

Even tried running the mold from one end of the spectrum to the other heat wise, the effects are still the same but more pronounced the higher the temp is. It may be something in the mold itself but that is a real far stretch considering the quality of MP-Molds.

I do have a message to Miha about it but I am still awaiting a responce.

Tom

[waksupi]

I would try emptying the pot, cleaning it well, and try a different batch of alloy.

[BABore]

Are you running a BP pot or a ladle? If the blocks are hot enough, you need to get the lead in the cavity faster. If you have a ladle, pressure pour the mold by turning the mold to the side, putting the spout tight to the pour hole, and then turning the mold upright. I prefer a ladle to have a spout hole of around 0.160 diameter and the sprue plate holes to be about 0.155.

[GARCIA]

Going to be a BP, want to say a Lee 4/20.

If I need a faster pour can I drill out the spout a little to make for a faster fill?

I am ready to try just about anything at this point!!!

Tom

[BABore]

If you have a ladle, just dip from the BP pot to see if your problem is resolved first. With the BP pot, have you tried different pour styles? Height differences? Straight through the hole and leaving the flow swirl off the hole edge? IIRC that boolit design is around 270 grains and is a bit long. It should pour fine as you don't run into big-time flow rate issues til your alot bigger than that.

As this is a M-P mold, I hesitate in giving out this advise, so it's your decision. I do give this advise for my molds. I dip the mold corner and free end of the sprue plate right into the pot for 30-40 seconds in extreme cases. Wipe it off good, open it and wipe the inside edges that were dipped, and cast. The first pour should take 15-30 seconds for the sprue to solidify. The boolits will look like fully galvanized sheet steel. Your mold is now way too hot. Run a slower casting cadence til the boolits are just slightly frosted and the sprue takes 3-4 seconds to solidify, then maintain this cadence. It is much faster and efficient to start up a mold this way that starting with a cold mold and working up in temperature.

[Maven]

Tom, Lots of good advice above. However, if emptying & cleaning the pot and trying a new batch of alloy doesn't work, try these suggestions: Keep the temp. constant, say 750 deg. F, then smoke the mold with either a BIC/butane cig. lighter or several wooden matches (best to do this when the mold is too warm to touch so as to avoid condensation problems). If that doesn't work, try loosening the sprue plate a bit for better venting. If these two don't work, try casting with a ladle rather than with the bottom pour feature of your furnace. Hope this helps!

[454PB]

I agree that the alloy and/or mould are not hot enough. I've seen this before with dirty alloy. It appears as "sand" in the mix. Several thorough fluxings will usually clean up the alloy and fix the problem.

[Larry Gibson]

"My mix that I am using is WW's with a little 95/5 mixed in for fill out."


I that "5" tin or antimony? WWs already have enough antimony in them. Hard to tell from the picture but it could very well be antimony crystalizing before the lead. A 3.5% of antimony is about the max amount that is soluable in a lead alloy. More than that will solidify before the lead/3.5% alloy does.

Many batches of WWs will need close to 2% tin for best fillout.

Larry Gibson

[BABore]

"My mix that I am using is WW's with a little 95/5 mixed in for fill out."


I that "5" tin or antimony? WWs already have enough antimony in them. Hard to tell from the picture but it could very well be antimony crystalizing before the lead. A 3.5% of antimony is about the max amount that is soluable in a lead alloy. More than that will solidify before the lead/3.5% alloy does.

Many batches of WWs will need close to 2% tin for best fillout.

Larry Gibson

Common 95/5 solder is 95% tin, 5% antimony.

[GARCIA]

Maybe too much 95/5?

Going to clean the pot out in the morning and start fresh.

Going to try 50/50 WW's and soft lead with just a touch of 95/5.

I appreciate all the help and insight that everyone has provided in this frustrating matter.

Tom

[geargnasher]

I can run the mix at a low temp or a high temp, the effects are still the same.

Even tried running the mold from one end of the spectrum to the other heat wise, the effects are still the same but more pronounced the higher the temp is. It may be something in the mold itself but that is a real far stretch considering the quality of MP-Molds.

I do have a message to Miha about it but I am still awaiting a responce.

Tom

You missed it, Garcia!

Now listen. BABore already told you what to do, get the MOULD hotter, NOT the alloy. MOULD temp governs boolit quality, degree of frosting, and fillout quality. POT temperature is dictated by the melt point of your alloy and amount of tin in there. You can pour 900 degree alloy into a 150 degree mould and get a shiny, wrinkled, round-edged disaster for a boolit. You can also pour 625 degree wheel weight alloy into a 450 degree mould and get frosting so bad it looks like you sandblasted the surface of the boolit. If you don't get anything else out of this thread, please at least understand this, it will make your casting experiences much more enjoyable.

The mix you're running shouldn't need to be more than about 675 degrees to work. 700 is fine, but you need to understand the properties of the alloy you're using. Here's a pretty good rule: Run your alloy about 100 degrees above the point that it's fully molten, maintain it there, and forget about it, it's ok. Focus on other things, like casting THREE TO FOUR POURS A MINUTE FOR 20 OR MORE POURS until you get that mould HOT.

Some people try for shiny boolits, and get frustrated when they can't balance good fillout without getting the mould hot enough for a light frost. If you get good boolits with slight frost that will wipe right off with a rag when cool, then quit worrying about it and go shoot them.

The boolit in the pic shows a mould temperature that is right on the brink of frosty, just above the limit of the shiny boolit point. So cool your alloy, cast faster, until your boolits form a light frost on the surface a few minutes after dropped, and see how that goes. You can always slow your pace to cool the mould and try for shiny boolits, but that's up to you to experiment with.

If you do indeed have large pits from dross inclusions in your boolits, empty the pot, clean with soap, water, and a Brillo pad, rinse, and start over with clean ingots.

Gear

[BABore]

One more thing to add on your alloy, most any common boolit alloy. Pure lead and tin play very well together. You can add as much tin to your Pb as you want and can afford til you only cast with tin. It will all cast great.

You can also add a whole bunch of antimony to Pb and you can cast great boolits. Hard and brittle, but good boolits

It's when you have Pb and antimony alloyed together, then add tin to it, that you can run into problems. Antimony has a certain affinity for tin. It can only tolerate so much. Excess tin in an antimonial lead alloy will give you grief and fugly looking boolits. The excess tin migrates to the boolit exterior and will bind with any crappage still left in the supposidlly clean alloy. Ugly, dirty looking spots on the boolit exterior are a dead giveaway. It will also form soft spots outside of the Pb-antimony matrix. I've found that % tin should never exceed % antimony and is best left at 1/2 to 3/4 the amount of antimony present. Most add and depend on too much tin because they fail to run the mold precisely the way Geargnasher recommends.

[FN in MT]

I cast some 230 RN slugs today out of an old H&G mould...I almost have to TRY to make a bad slug. I was running the electric pot from 650 to 700 degs.

Yet I could NOT get a decent slug out of the new Miha #68 mould. I wrote it off as not cleaning the mould as well as I should have...so quit casting with it. Not before taking the lead temp up to 850 or so. THAT wasn't working so I quit.

Wonder If I need to get a hotplate and simply keep the mould warmer and run the pot at my normal 650-700??

Gearnasher has been down the road with this stuff far more than I. Or maybe the RAT is the brains of the outfit?

FN in MT

[geargnasher]

"Tin blotches" is what I call them. Little dull patches on the boolits due to sheets of tin oxide from the surface of the pouring stream that get pushed against the sides of the mould cavity when pouring, like llittle floating bits of wet tissue paper. Much less of a problem with ladle-casting than bottom pour for some reason. For the new folks, overtinning the alloy is discussed in Lyman #3, pp. 47.

Brass, aluminum, and iron alloy moulds all have their preferences, as indeed each individual mould does. Look up the specific heat of the metals, compare them, and you'll see. Brass conducts heat faster than any other common mould material, and massive blocks like Accurate Mold's and Miha's soak up a lot of heat, thus require a brisk casting rhythm to keep the heat supply from your alloy up. With brass and large aluminum moulds I find it essential to preheat them. I use a mould oven made from a 6x6x4 galvanized steel electrical box with a door cut in the side, hotplate, and grill thermometer, and keep it going while I'm casting so I can park the mould in there if I need to get a drink, add ingots, flux, stretch, or for any pause longer than the next pour.

Gear

[stubshaft]

Try cleaning it with Kroil. I regularly use it to clean my molds and have not had any problems at all. There is a sticky somewhaere around here about using it. Not going to dispute what Gear and Babore have to say, but will add that you lead does look to me like it is still dirty and yes you can drill out the spout of a ladle. IIRC I drilled out my RCBS ladle with a 3/32" bit.

[GARCIA]

Well the pot has been cleaned and is awaiting a new batch of WW ingots.

I took the mold apart and took it down to the man cave for further study. I plugged in a high intensity work light and inspected the mold. I discovered that there was some kind of contaminant that was adhering to the offending cavity. It appeared to be an almost white(?) in color crystalline substance. It was hard as heckto see unless the mold was held in acertain position to the light.Broke out the Q-tips and some Eagle brand nano polish. Took a little while and lots of inspecting under the light to ensure that it was removed.

Going to get the pot going after the wife heads to work. Will follow the recommendations on melt temp and of the mold temp and report back.

Sure hope that I got that offending junk out!!!!

Tom

[Bret4207]

Sometimes it takes 3-4 casting sessions for the contaminants to "burn out". Myself, I don't get too bent over the blotches and freckles and even slight "acne scars" on my boolits as long as they are filled out nicely and of as close to even diameter as I can get them. As someone else noted, the slight frosting and cosmetic imperfections shine up with a rag or 4/0 steel wool. It's what they do in the gun that matters.

[Moonie]

I worry about sharp bases and bands, slight cosmetic issues such as this don't worry me and they generally shoot just fine.

[GARCIA]

First off a big hearty "THANKS" to everyone that provided their insight.

Just got done casting some with the errant mold and things worked out good. The pot is cooling down and I just need to clean up my mess before the wife gets home.

Again guys "THANKS"!!!

Tom

[alamogunr]

"Tin blotches" is what I call them. Little dull patches on the boolits due to sheets of tin oxide from the surface of the pouring stream that get pushed against the sides of the mould cavity when pouring, like llittle floating bits of wet tissue paper. Much less of a problem with ladle-casting than bottom pour for some reason. For the new folks, overtinning the alloy is discussed in Lyman #3, pp. 47.

Gear

This is why I try to read as many of these threads as possible. I have never worried about too much tin. I have a large stash of solder and tin rich alloy, so have been somewhat cavalier about adding to my castiing pot. I have a tendency to follow the adage that "if a little bit is good, a lot is better". I'm going to back up and get out the Lyman #3 and review it. Thanks, Gear

John
W.TN

[mroliver77]

This is exactly what I have been seeing on some of my boolits. I attributed it to contamination. I am so tight I cannot imagine that I would use too much tin. ;) I guess I have to re evaluate.
Jay


"Tin blotches" is what I call them. Little dull patches on the boolits due to sheets of tin oxide from the surface of the pouring stream that get pushed against the sides of the mould cavity when pouring, like llittle floating bits of wet tissue paper. Much less of a problem with ladle-casting than bottom pour for some reason. For the new folks, overtinning the alloy is discussed in Lyman #3, pp. 47.

Brass, aluminum, and iron alloy moulds all have their preferences, as indeed each individual mould does. Look up the specific heat of the metals, compare them, and you'll see. Brass conducts heat faster than any other common mould material, and massive blocks like Accurate Mold's and Miha's soak up a lot of heat, thus require a brisk casting rhythm to keep the heat supply from your alloy up. With brass and large aluminum moulds I find it essential to preheat them. I use a mould oven made from a 6x6x4 galvanized steel electrical box with a door cut in the side, hotplate, and grill thermometer, and keep it going while I'm casting so I can park the mould in there if I need to get a drink, add ingots, flux, stretch, or for any pause longer than the next pour.

Gear

[geargnasher]

As has been mentioned, you're ok as long as you don't put more tin in your alloy than you have antimony, by weight. Most of us don't know exactly how much antimony is in there, so just add enough extra tin to get the fillout you need, and it doesn't take very much. If you add a full 1% tin to an alloy and it doesn't help, lack of tin isn't the problem.

Due to the intermetallic SbSn that forms in our PB/Sb/Sn alloys, you will have at least two phases of solidification going on depending on ratios, sometimes three. With common WW alloy, the elemental Pb freezes at one point, the SbSn at another, and free Sb at still another point. These freeze temps and the order in which they freeze depends on the percentages of each element. If you have more Sn than Sb, the extra tin doesn't have anything to bind to, and due to it's low melting point, the free tin freezes last, causing pure tin nodules to form throughout the boolit. Oversimplified, but that's the gist.

This is not necessarily the cause of the tin patches on the mould, I think that has more to do with surface temp of the cavities and fill rate. I get it worse with brass, quite a bit with aluminum, and rarely with steel and iron. I think the aluminum and brass loses it's surface temp almost instantly when the boolits drop, and the tin oxides freeze on contact with the surface, and after the cavity is filled the surface of the cavity conducts the heat fully again between the blocks and the boolit metal, allowing good fillout.

If you want a sure cure for tin patches, purge your cavity with argon gas immediately before filling, and keep the stream as short as possible. The gas purging out of the cavity will swirl up and around the stream, momentarily protecting it from oxidation as the cavity fills with lead. Keep the stream less than 1/4", or pressure cast with a ladle. Makes PURTY boolits!

Gear

[Jailer]

Well the pot has been cleaned and is awaiting a new batch of WW ingots.

I took the mold apart and took it down to the man cave for further study. I plugged in a high intensity work light and inspected the mold. I discovered that there was some kind of contaminant that was adhering to the offending cavity. It appeared to be an almost white(?) in color crystalline substance. It was hard as heckto see unless the mold was held in acertain position to the light.Broke out the Q-tips and some Eagle brand nano polish. Took a little while and lots of inspecting under the light to ensure that it was removed.

Going to get the pot going after the wife heads to work. Will follow the recommendations on melt temp and of the mold temp and report back.

Sure hope that I got that offending junk out!!!!

Tom

Do you have a water softener? I noticed today after cleaning my new NOE mold that it left a bit of residue on the mold and in a few cavities. It looks just like water spots on glasses that come out of a dishwasher. The only thing I can figure is it was salt left over from the water evaporating off so fast from the boiling water final rinse. All of my molds have exhibited the same sort of spot frosting and poor fillout, especially for the first few casts, as yours has. I'm betting there is a little left over salt residue that is buggering things up when you go to cast with it.

I think my next mold I'll try a different cleaning technique to see if it cast better from the get go. Maybe an initial cleaning with mineral spirits followed by a final rinse with contact cleaner.

[Doby45]

Dawn and boiling hot water. Scrub with old toothbrush rinse with same hot soapy water and immediately place on my hotplate. Never had a problem after that routine with mold being oily or bleeding oily residue..

[beladran]

i had similar issues with my MP mold and was not use to casting with brass. i set the bottom of the mold on top of my alloy to get its temp up. after its at temp cast quick and fast. I usually count to three and hit the sprue. Like the others are saying.. paper nor critters are gonna stop and say "hey was the boolit frosted you just shot me with?"

[leas327]

I am a firm believer in pre-heating a mold on a hot plate. I would rather have the mold too hot to start than too cold. For me it seems that it doesn't take as long for a mold to drop down to the correct temp than it does to get it up by casting a bunch of bad boolits. I also don't care if they are a little frosted. With my only m-p I run the temp between 750-800 degrees. I am using an unknown alloy. The lady I bought it from said that her late husband told her it was good for pistol boolits. I am pretty sure it is mostly ww. My casting speed is as soon as the mold is filled I wait until the frost wave go's from the outside to the middle of the spru and crack it open. I flip, dump, refill, and repeat at that pace. Occasionally the spru seems like it is taking to long to harden I will fill the mold and press it upsidown on a wet rag. There is now way I could cast one of my iron molds at this speed. Some of my 6 cav lees can do it some can't. The bullets out of the m-p look very bright and shiny. That mold loves to run hot and I have quit trying to fight it.

[geargnasher]

Leas327, you make a good point about it being easier to get an overheated mould down to temp than a cold one up to temp. Sometimes I miscalculate my mould oven temp and the first sprue takes 10-15 seconds to set up. If I see that, I refrain from cutting the sprue until it's good and firm, and observe the boolit bases for super-shiny-still-slushy before opening the blocks. With a brass mould it only takes about 30 seconds for it to drop down to proper casting temperature.

I tried something last night that worked very well, I used some truck wheel weights cut with about 40% roofing lead (in other words very little tin content), ran it at 800 degrees, got good satin boolits from one of my brass Accurate Moulds with no splotches at all. Normally I would want a little more tin and a lot less heat so the tin would do it's job (700 or below) but this alloy was liquid at 605 degrees and the mould blocks work best when very hot, so I cheated a little and had good results.

Gear

[Dale53]

I am a big fan of using a hot plate to pre-heat my moulds. They are ready to cast when the metal is ready.

However, you CAN use the molten metal to heat the mould as is stated - I just prefer using a hot plate at a pre-determined temperature (just under full casting temperature for the mould).

Dale53

[Bulltipper]

I just set my MP molds on the top of the old lyman bottom pour and let the whole thing heat up together. when the alloy hits about 750 and has been there a couple minutes, the MP molds start throwing good boolits right away.

[GUINEAPIG WITH AK47]

What approximate temp on the hotplate thermostat? Medium? High? I have a thermometer and have seen a pic of one being held between the blocks, is that accurate enough?

Newbie questions!

[Dale53]

'AK47,
Hotplates do vary in their setting from different manufacturers. However, I set my hotplate just above Medium. The perfect temperature, in my opinion, is just under casting temperature, then let the first cast or two bring it up to speed.

I made a mistake one time with an iron mould and heated it too long by touching the molten lead. The bullet metal soldered to the mould cavity. This was NOT a good thing. So, you CAN overheat the mould.

Set it on Medium, cast with it and you can judge very quickly if YOUR hotplate needs to be a bit hotter or a bit cooler to operate properly.

I also, very strongly, favor using a small $7.00 manicurists fan (small 6" fan available from Target Stores or Walmart) for maintaining proper mould temperature.

Dale53

[geargnasher]

I made an oven from a steel elecrical box w/ blank cover and a hole cut in the side. Installed a grill thermometer through a 1/2" hole in the top so I can monitor air temp inside. I stole this idea from another member here, Montana Charlie. He posted pics a time or two here if you care to search.

Gear

[Doby45]

I love mold ovens. Mine is ghetto but works like a stinkin champ.