Hollow Point Troubles

[Wilson]

Thanks to you all we've pretty much mastered high volume 9mm and .40 casting with LEE 6 cavity molds.
I'm sure someone can help me master HP casting. We started last night with our new Mihec molds and one Lyman 330 Gould. We had good results with the Lyman, but are having fits with the Mihec molds!
I've read a lot on this forum and I read chapter 13 in Glen Fryxell's book. I ordered tin and added 2% to my clip on WWs as suggested in the book and got started.
I was working in low light last night so I quit and brought the boolits inside to check them out. I was stunned that only about 1 in 4 were marginal keepers! As said above all the 45/70s from the Lyman mold were good.
I cleaned the Mihec molds, a four cavity .44 and a two cavity .40 with Acetone and lubed the sprue plate and pins per instructions.
#1 there is a lot of crud floating in my pot. I haven't seen this before. Could this be the tin? If so why won't it mix? I keep trying to flux and mix it back in, but it persists floating on top. Is it something else that should be scooped out?
I preheated the molds on a hot plate for 40 minutes and cast about 30 cycles. I am getting all bullets like those seen in the photo below. I think the mold is still too cold, but it seems very hot to me. I'm working the sprue plate with my gloved hand and am not having to hit it with my mallet. The pot is set on 800.
Suggestions?
http://castboolits.gunloads.com/imagehosting/4885502a777752a3f.jpg[/IMG]
http://castboolits.gunloads.com/imagehosting/4885502a77936441b.jpg
http://castboolits.gunloads.com/imagehosting/4885502a77b69a219.jpg

[paul h]

Not sure why you have so much crud in your melt, but something is off with your alloy. Looking at the boolits your mold is definately not hot enough.

I've only cast with one mp mold, a 359640 two cavity. I cast straight ww's and the bullets are fully filled out. Even with the mold heated by dipping in the melt I probably needed 10-15 casting cycles before the mold got up to temp. Once up to temp and casting quickly I got very few rejects.

The rheostat on my Saeco is off so I don't know how hot my melt is, but I can tell when it's hot enough, and when it's not.

[Iron Mike Golf]

Do you have a thermometer? Just because the knob points to 800 doesn't mean it's so.

A half an hour on a hotplate set on full, with the mold resting on a circular saw blade gets the mold hot enough for me when casting 380, 44, or 45 cal HPs using a Mihec cramer mold.What's the wattage of your hotplate?

Alloy not hot enough could also be explained by your pot being under temp. Boolits definitely look like not enough heat. Do they drop off the HP pins easy?

[tomme boy]

Where did you get the tin? It might have been Zinc.

[ilcop22]

I've seen that when aluminum gets in the pot, too. Something is very wrong with your mix. I'd suggest skimming off everything that doesn't melt below 800 and tossing it out. First, though, verify the pot temp is actually 800.

[captaint]

Wilson - you need to spend some time fluxing that pot. Actually, it's more like cleaning the pot. Take a kitchen spoon and keep pushing the dirt against the side of the pot. Keep doing that until you just have dirt, then scoop that out. Repeat until the pot is clean. Then flux with sawdust or similar. I personally like sawdust. Normally, I leave a spoon of sawdust sit on top until it burns up completely (just black ash left), while I'm casting. Then give it a good stir and start over. enjoy Mike

[Wilson]

Thank you very much for the replies.
The boolits are dropping off the pins.
I got the tin from Roto Metals.
I do have a thermometer, so I will check the actual temp.
I'll go ahead and bring it to a measured 800 degrees and skim off everything. Then I'm going to empty the pot into ingot molds and use them for sling shot ammo.
I'll make sure the pot is clean and start all over again. If I get the same crud floating on top I'll skip the tin and try pure WW. I was trying the tin because I had read that it works well with HPs.
I'll let you all know how it turns out.

[MBuechle]

I have a Mihec 9mm HP mold, you definitely have to run these warm. Hot plate on high side of medium, set sprue plate down between casts once brass is hot to get good consistent base fill out.

[Fishman]

What Mbuechle said. I'd preheat the mould a bit hotter.

You may also have lube contamination if you lubed the pin tips themselves. I have but one Mihec mould, a .380/9 mm mak combo Cramer and I preheat exactly like Mbuechle and I get perfect boolits in a couple of casts. I initially scrubbed with a nylon brush and soapy water, preheated, and lubed the sprueplate and pin slides with bullplate. No issues in two long casting sessions.

[tek4260]

I have 4 Mihec HP molds and I can tell you that good boolits require casting at high temp and a very fast pace. It is almost like the HP pin is a big heat sink because if you slow up any, you will get wrinkles. Even after casting for over an hour.

[runfiverun]

Wilson - you need to spend some time fluxing that pot. Actually, it's more like cleaning the pot. Take a kitchen spoon and keep pushing the dirt against the side of the pot. Keep doing that until you just have dirt, then scoop that out. Repeat until the pot is clean. Then flux with sawdust or similar. I personally like sawdust. Normally, I leave a spoon of sawdust sit on top until it burns up completely (just black ash left), while I'm casting. Then give it a good stir and start over. enjoy Mike

here's the ticket....
i like to add some fire to the burnt sawdust.
clean the oil from your molds and get/keep the hollow point pin hot.

[sw282]

That frothy mess is zinc. Skim it off and throw the junk away. Then add lead only

[StratsMan]

That frothy mess has got to be insulating your pot, too.... The melt temp is probably lower than you think...

That said, I was having trouble with my MP hollows wrinkling. So I added 50% pure lead to the mix... They are much prettier now, fall right off the pins, and have no wrinkles...

Can't wait for my 359640 to arrive!!!

[leftiye]

Flux first (sawdust/shavings), then stir/scrub with hardwood dowel. Get some flames going, maybe use some boolit lube (helps get the carp hot too), and stir and rub the carp on the pot walls. If it doesn't give up its metals and end up looking like gray dirt, scoop it out and throw it away. Your boolit metal looks good, with no visible inclusions. Way too cold though. Look up threads about mold heaters, and see if you like them. I always use them. I take the wooden handles off of my hollow point molds so that I can heat the pins in the molds on the mold heater between casts. Other casters here throw a ton of boolits in a bucket of water and sort them out afterwards, them remelt the culls and go after it again. You need some light so you can see what you're making and adjust temps and flow rates. I even wear reading glasses (magnification) and inspect what I'm making as I go. Two ways to go fast. One you make a ton of boolits, and sort them out later (if none are good you don't go too fast). The other is to make only good boolits, and quit when you have enough. Doesn't usually happen this way, but you can get your reject rate way down.

[303Guy]

Carp? That's one way of getting past the auto sensor!:mrgreen: Otherwise spelled cr@p. [smilie=l:

[KYCaster]

Seems to me, if your pot or mold was too cold you wouldn't have such nicely formed edges around the hollow point cavity. And you say they're dropping off the HP pins without sticking......that's a good indication that you're near the ideal temp.

So that leaves contaminated mold as the cause of the wrinkles. Aluminum molds seem to require a few heat/cool cycles to drive out all the machining lube.

That crud on your melt doesn't look like Zn to me. Flux properly and all the metallic looking stuff will reduce back into the melt. From the looks of your ingots, you need to do a better job of fluxing while you're rendering your alloy....quite a bit of crud trapped in those ingots.

So.....CLEAN UP YOUR ACT, WILSON!! :kidding:


Jerry

[geargnasher]

As others have said: SAWDUST AND FIRE will clean up that crud on top of the melt. Your alloy is filthy and loaded with oxide scum. Sawdust and and stirring with a dry stick will clean all that junk up and turn most of it back into useable metal. Work the crud against the sides of the pot with a paint stir stick or similar until only a fine powdered ash is left, then skim the ash with a spoon. Don't scrape the bottom with the stick because it will trap ash under the melt and make pits in your boolits. Use a spoon only on the bottom.

After you get the alloy cleaned up, the other issue you're having is with your MOULD TEMPERATURE. Wrinkles are caused by a cold mould, and poor HP fillout is caused by cold pins. Overheating your alloy won't fix this. Your alloy should be about a hundred or so degrees hotter than the point that it's fully liquid (end of the "mush" phase).

Preheat your mould and cast FAST to keep the mould hot. If your boolits aren't lightly frosted, they probably won't fill out sharply.

Making a mould oven like this and preheating it for half an hour at 400F before casting will help greatly.

http://castboolits.gunloads.com/imagehosting/thum_89094e5ad65ae2e31.jpg

TRUST ME on the sawdust and casting with a HOT mould. You'll be amazed how well sawdust will extract the goody from the scum, absorb the bad stuff, and make the metal more castable.

Here's what a "lightly frosted" hollow point should look like if your mould is hot enough. The alloy was wheel weights and pure at only 700 degrees, but the mould was over 400 from a pour rate of four pours per minute:

http://castboolits.gunloads.com/imagehosting/thum_89094eed574690075.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=3051)

Hope this helps,

Gear

[Marlin Junky]

What Gear said with one addition:

Don't forget to lube your mold with something at least the quality of Amsoil Saber Professional. A quick pour rate at 500F* will be hard on even an iron mold if not lubed properly. Keep a swab handy with a trace of lube on it and every 1/2 dozen or so casts, check underneath the sprue plate for traces of alloy. Alloy that may start to collect there should easily be wiped off with the swab, assuming your mold is at the proper casting temp. The alloy will deposit underneath the sprue plate before it starts to smear on the block top. If you wait until alloy starts to collect on the block top, you may inadvertently introduce lube into the cavity when removing the alloy with the swab.

When you first apply sprue lube to a hot (pre-heated) sprue plate, put enough on so that it smokes and wipe the sprue plate with a clean swab after most of the lube has burned off. Keep the latter swab handy during the casting session and use it to keep your sprue plate clean.

MJ

P.S. *That's 500F mold temp. The alloy can be around 700F or perhaps a bit less. Like Gear said, about 100F over slush temp should be fine for the alloy.

[40Super]

Yep, once the pot is a little hotter than what it takes to keep your lead completely molten, it's all about mold temp. Both of the MP molds I have, need to be beyond hot. If your looking for shinny bullets, forget it. The only way to get good usable hp with those molds is to have it so hot the bullets will be frosty. I've also taken a torch and brushed it over the pins every eight to ten casts to keep the pins hot enough, but use caution to not get the tips turning colors.

[Blammer]

alloy temp is pleanty hot, get that mould hotter, I mean SMOKIN hot.

git it so hot it takes 10 sec for the sprue to solidify then wait another 5 and cut it and then drop them, then slow the pace till you get to about a 3 sec sprue cooling time and then another 3 to open the mould. You'll find a rythem, just don't expect it to be any rythem your used to.

on my mihec mould it takes a sprue cooling of 3 sec another 3 to crack the sprue and dump then do it over again. It's a slower pace but each time it's 2 HP boolits, so that's worth it.

[Wilson]

Very good information. I greatly appreciate you all working to get us through this learning curve.
I got home early from work today and fired up the pot.
Check the temp. on 800 it was 755 on my thermometer.
Scooped all the crud off the mix and discarded it. Dumped the entire pot back into ingot molds and set them aside for other stuff.
Put in ten pounds of WW lead and 2% tin after I made sure there was not crud in with the 10# of WW. I was too scared to load the pot with 20#. Everything melted together with no problem.
Used saw dust to flux and covered the melt with it. There was a lot of smoke for a while.
Preheated the molds and went to work. After about 10 cycles I started getting good boolits!
I'm glad you all mentioned frosted booliots 'cause that's what I was getting. It wasn't long before I ran out of the 10# batch. I'll try and get some photos up tomorrow. Once again thanks a million!

[MikeS]

I must be doing something wrong, when I cast HP boolits I don't have to heat the alloy any hotter than say 675F or so. I keep the mould fairly hot, but not so hot that I get frosted boolits, they have the same satin finish (not shiny, but not frosted, sort of in between) as my other boolits have. I've cast HP boolits from the Mihec 45 cal 200gr mould, Mihec's copy of the H&G #38 (Ness Safety Bullet), and a couple of Lee 2 cavity moulds made into HPs by Erik of hollowpointmold.com. For me the key is to properly preheat the mould, heating it till it gets up to temp is not enough, you need to let it sit on the hotplate at the proper temp for a while so the heat gets into the mould blocks completely.

[Wilson]

Thanks for the tips. The .44s sized and checked were from the first batch and were not as frosted as the ones from the second batch. I will do more experimenting with temperature and try for a less frosted boolit.
I've got more to do later this week, but I think I'm on the right track.
Thanks, again!
http://castboolits.gunloads.com/imagehosting/4885502d9c80983e8.jpg
http://castboolits.gunloads.com/imagehosting/4885502d9c80aa417.jpg
http://castboolits.gunloads.com/imagehosting/4885502d9ca26a32e.jpg
http://castboolits.gunloads.com/imagehosting/4885502d9c80b6b3b.jpg

[snuffy]

I've seen that when aluminum gets in the pot, too. Something is very wrong with your mix. I'd suggest skimming off everything that doesn't melt below 800 and tossing it out. First, though, verify the pot temp is actually 800.

There's no way aluminum can melt with a lead alloy. Unless that alloy is at 1220 degrees or over ,(the melting temp for aluminum). The most I've ever seen on my thermometer is 920 degrees.

Think of it this way; if the lee pots were capable of reaching 1220 degrees, they would melt into a puddle with only the steel parts remaining solid.

Looks like you're getting the experience level where it belongs. Takes a while with the Miha cramer HP molds to learn their quirks. I have to turn my hotplate to high, then leave the mold on it for at least 20 minutes to get good boolits, then the first couple of casts are rejects even then.

[geargnasher]

Snuffy, aluminum can certainly be in the alloy, same as antimony or copper, note the temperature at which they melt. Wheel weight metal often comes pre-alloyed with aluminum contamination, and I have a strong suspicion that the aluminum in some of the WW paint gets absorbed by the melt when "smelting", although I haven't had any of those samples tested to be sure. Sawdust does help remove the aluminum.

Gear

[HORNET]

Snuffy, the aluminum doesn't have to get above the melting point to dissolve. It has a limited solubility in molten lead, just like zinc. If you leave it there a while, some will dissolve in. Ever put sugar into coffee? It doesn't have to melt first either.

[40Super]

Just like lead/copper alloys.

[snuffy]

Damn, I only wish I was as smart as I sometimes think I am!:popcorn:

Dissolving without going into a liquid state? Sort of like ice turning to vapor without going through a liquid water state? I wish I knew a lot more about metallurgy, guess I should keep quiet and learn.

[Wal']

Nah, if the questions weren't asked, the answers wouldn't be forthcoming.

I wouldn't have thought aluminum could dissolve into lead at those temp's either. :cbpour: