H&G casting problems

[wv109323]

I have a H&G 68 mold which is a six cavity. I have used the mold very little but it is around 30 years old.
I got it out last week and cast some boolits with it. I had trouble getting fully filled bases and many times the cavity was 1/2 filled. The mold has the trough on the sprue plate. It appears as when one cavity was filled the lead would spilled over into the next cavity the lead would solidify before the cavity was full. I got the best results if I filled each cavity individually but it was impossible to keep the lead from spilling between cavities. I was casting at 720 degrees F.
With a mi-hec 4 cavity mold this was the right temp. I could cast better and more boolits with the four cavity mold than the six cavity H&G.
Any suggestions that would help?

[prs]

Run the mold a little hotter, esp. the spru plate. If your pot (I assume bottom pour) has room, tilt the mold slightly so that the first pour is a bit down from the next and so on. Maybe a slight tilt to the side too. The plate trough helps you have a nice reserve to feed the mold as it cools, but it can also lead to flooding of the adjacent cavities.

prs

[HeavyMetal]

it's also a bit bigger mold which means you need a little more heat to get it to do what you want.

I have been using Accurate mold with the trough, 5 cavity, and have found that when using my Lee 20 pot I need to start at the fathers cavity and have the mold slightly tilted with the far end higher than the rear, the trick is to pour fat enough to fill a city and then move the stream to the next with out over flowing.

Takes a little practice but is not real hard to do and use the mold guide if you pot has one, just remember to have the lead running down hill toward you and fill front to back on the cavities.

HM

[Jack Stanley]

I typically run my six cavity H&G molds at eight hundred depending on alloy . Start pouring the alloy at the lowest end of the mold and maintain a puddle in the trough much like a welding bead .

Jack

[John J]

I agree with Jack as about what i do when using the larger molds..get the mold hot before you start is the key
Back in the day they cast over a caldron and used a ladle.

John J

[quail4jake]

It seems that using a mold oven would be of value with these heavy molds, does anyone make a ready made, good to go mold oven?

[lightman]

Many of us use a cheap hot plate and a few have built "garages" to cover the mold. Most often from a tin can. My hot plate came from Walmart for about $12.00.

[dragon813gt]

It seems that using a mold oven would be of value with these heavy molds, does anyone make a ready made, good to go mold oven?

You don't need anything more than a can cut in half.
https://farm5.staticflickr.com/4427/36231032880_d8b394ca62_o.jpg

[LenH]

I have 6 & 8 cavity H & G and I run the melt at 725 and get the molds hot on a hot plate. They take a bit longer to heat up but I have noticed that
the molds need to be lined up directly under the stream and the mold needs to keep moving. The over pour into the next cavity can lead to problems
but those molds make great bullets. Also a mold shelf makes life easier.

[The Lord Flashheart]

You don't need anything more than a can cut in half.
https://farm5.staticflickr.com/4427/36231032880_d8b394ca62_o.jpg

You sir, are a genius! ::D

[reddog81]

I got the best results if I filled each cavity individually but it was impossible to keep the lead from spilling between cavities.

Only do one cavity at a time. Most mold makers have abandoned the trough because it doesn't really help much and is kind of a pain. Keep the mold tilted so the lead runs away from you and start at the far end of the mold.

[wv109323]

Thanks for the advice. I will try tilting the mold. With my setup I may need to make some way of resting the mold at an angle. The problem is with my pot(Lyman 20 lb) i modified the mold shelf and reduced the distance under the bottom pour spout. I will also up the lead temp. and try again.

[Jack Stanley]

With my Pro-melt I nailed two 2x4's together and screwed it to the bottom plate . Two pieces of flat iron act as guides to center the mold . It works real well for the heavies .

Jack

[376Steyr]

Try using a Rowell 1 lb. ladle. https://www.rotometals.com/casting-ladle-bottom-pour-rowell-1-2-1-4-bowl-diameter-9-handle-length/
In my experience, big multi-cavity moulds are just plain finicky about how the lead is poured into the cavities. I generally have to try a couple of different techniques, up to the "Bombardier" method, before I can get consistent results from a 5 cavity mould. Run it hot, with a good sprue plate lube, and life should be better.