switching from 2 cav to 6 cav mold question

[sdelam]

I have made several hundred 230g RN with a 2 cavity mold. It was slow going so I bought a 6 cavity mold to speed things up.

I cleaned the new mold, smoked the cavities and tried to cast. I could not get the mold to fill out. its the same alloy that works fine with my other mold.

I use a lyman 4lb pot and ladle. I've tried everyway I can think of but I cant seem to get all 6 cavities completly fill out. They seem to fill 1/2 to 3/4 and then the spruce plate plugs. I thought the spruce plate was not hot enough so I filled the cavites and turned it upside down on the pot. After a few minutes I tried again but got the same results.

What am I doing wrong?

[Bret4207]

Mould isn't getting hot enough. Turn the heat on the alloy up, preheat the mould on a hotplate and cast as fast as you can.

A 4lb pot won't last very long at all. I use a pot that holds over 30 lbs and for my big 35x250 Bator I use a dutch oven and a 1 lb Rowell ladle. You might want to look for a bigger pot soon.

[sdelam]

my pot doesnt have a temp adjustment, I will probably get a bigger pot within the next year or so, for now however i just run my smelting pot to refill the casting pot.

[NuJudge]

Heck, I run a 20 pound pot to cast from, and a 10 pounder as a melter to back it up. I'm slipping the occasional small ingot into the 20 pounder, and when the 20 pounder gets half empty I pour the 10 pound into the 20 pound furnace.

Can I suggest you also use some Tin to help with fill-out.

CDD

[opentop]

Start by filling only the first two cavities, then after a few cast, fill the first 4 cavitys, then move to all six cavities. that should help your mold warm up. Once you get your mold hot, its going to retain heat longer than your two cavity mold.

[NSP64]

I too tried to switch to a 6 cav mold and found my rejection rate too high. I was using a 10# pot and could not cast fast enough to keep it hot. So I stick to 1&2 cav molds. It's slower but they all come out great. I don't shoot that much so production rate is not that big of a deal.

[EDK]

my pot doesnt have a temp adjustment, I will probably get a bigger pot within the next year or so, for now however i just run my smelting pot to refill the casting pot.

I just bought a LEE Magnum Melter 20 pound pot for about $50 + tax. It melts in about half the time my LYMAN bottom pour pot does! I wish I'd gotten it a lot sooner. The LYMAN has been a PITA and needs the bottom pour stuff re-worked...and possibly some other repairs. I've never had very good luck with bottom pour pots, but use an aged Hensley & Gibbs ladle with 4 or 6 cavity moulds. I only use the LYMAN/RCBS dippers for single cavity moulds for boolits for my BIG 50.

You need to run a little hotter for big boolits or multi cavity moulds.

[mooman76]

I probubly wouldn't even bother until you get a bigger pot. By the time you get going good you will run out of hot lead and this will be frustrating. You could get a cheap cast iron pot until you get a bigger electric if you want to go that route or just get a cast iron and use it for the 6 cavity only!

[MT Gianni]

The rest have covered most of it. I would add that the mold needs to be cleaned really well. Boil it for a bit, scrub it with an old toothbrush and make sure all oils are out of the cavitys before you smoke it. Gianni

[Will]

I had the same problem with a 4# pot. It just can't keep up with more than a 2 cavity mold.

[sdelam]

thanks guys, i guess I'll go back to the 2 cav until I find a bigger pot.

[LqChrome]

Im with RDK a Lee 4-20 bottom pour is the way to go for 6-cavity moulds,as is a wet cooling cloth for*speed casting*