Author Topic: Can't get a perfect pour  (Read 690 times)

Offline David_C

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Can't get a perfect pour
« on: 12/15/19 00:52 UTC »
Hi guys

I've been pouring down rigger bombs but for some reason, I can't get them as smooth as they sell them in the shops.

I've tried pure lead, and lead with tin. I've tried using a cold mould and a hot mould - and even different pouring speeds but for some reason, I just can't perfect them. I've even tried spraying some silicone spray (as I thought it was a release issue but that doesn't seem to help.

Has anyone got any tips to help me out? I'm in Australia and can't find anyone here to help me out. I was thinking about getting a small metal funnel, so when I pour, it's near the bottom of the mould but that will just complicate the pouring process.

I have the 8 and 10 mould :)

Kind regards

David

David

Offline smalljaw

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Re: Can't get a perfect pour
« Reply #1 on: 12/15/19 04:37 UTC »
There are two things you can do, try using Frankfurt Arsenal Dropout which is a graphite based mold release or smoke the mold. I don't know how long it will take but a heavy coat of soot will help smooth that out. I pour a lot smaller stuff and it is painted so I don't have much of an issue but when I spray or smoke a mold the head looks like it was machined, not a single wrinkle. Good luck and let us know what works or doesn't work.

Offline 21xdc

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Re: Can't get a perfect pour
« Reply #2 on: 12/15/19 06:18 UTC »
I think you need to use a bigger ladle... It's cooling too fast. Larger cavities need faster pours.
« Last Edit: 12/15/19 06:19 UTC by 21xdc »

Online ctom

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Re: Can't get a perfect pour
« Reply #3 on: 12/15/19 08:38 UTC »
I have the ten pound mold and there can be a learning curve here.

I use pure lead, nothing alloyed or wheel weights. Todays alloys are hard to control, especially wheel weights. I clamp the mold with a heavy c-clamp and place it in the oven at 250 degrees, THEN start the melting pot. The clamp is not placed anywhere over the ball cavity or fin, only on the edge of the mold to keep it closed securely. The melting pot is cast iron and has a pouring lip and a heavy wire bail handle. I can melt 15 pounds at a time in the pot. I use a heavy propane hot plate to melt the lead and when its hot - been melted and heating for 20 minutes beyond melting - I bring the mold down then quickly pour to mold using really heavy weight heat resistant gloves so I can handle the pot's bail handle and the pot. Pouring should be done as smoothly as possible, one complete non-stop pour with the sprue area topped off when the mold has filled. I leave the mold closed for an hour after filling.

Alloys and wheel weight lead are miserable to work with because the metal can cool so quickly and un-evenly, hence the wrinkles in the finish. Some of this trash lead will start to set up as soon as it hits any part of the mold even though its been pre-heated.

The smoke or drop-out will help in smooth filling. The biggest thing is to have that mold blistering hot when you start to pour so the lead will not set as it is poured into the mold. Using really hot pure lead and preheating the mold and clamp will produce balls that are spotless.

Offline David_C

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Re: Can't get a perfect pour
« Reply #4 on: 12/26/19 06:41 UTC »
I do apologise for the delay in response. We've been having some fire issues here in Australia. Our place is safe but unfortunately for my mate, his property has been lost - not great just before Christmas but as least his family are all safe.
Thanks guys, I will give the suggestions a try and let you know.
David

Offline Kasilofchrisn

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Re: Can't get a perfect pour
« Reply #5 on: 01/13/20 22:13 UTC »
I too recommend the Drop Out spray.
Works great for me.
I also pour from my pot all in one shot.
I never preheat my downrigger molds.
If my molds get too hot I end up with dents so I cool the mold between each pour.
I do 8 & 10 pound fish shaped ones and 8, 10, &12 pound finned round balls.

Sent from my S41 using Tapatalk


Offline David_C

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Re: Can't get a perfect pour
« Reply #6 on: 01/16/20 15:26 UTC »
Thanks guys for all the tips.

Based on the advice, I'm now pre-heating the moulds on a ring burner (elevated) and speed pouring the lead. I would have thought that pouring that quick would have developed crease marks but it doesn't. Amazing!

With my pot, I can normally pour 4 10lb and 4 8lb before I have to reheat more lead. Pouring takes around 10 mins and then another 20 - 30 mins before the lead is ready for the next pour (time depends on the outside temperature).

I haven't been able to locate the drop out spray here in Australia but am trying to source a different type of graphite spray.

Really appreciate your help with this one - I'm still blown away with the speed I can now pour!

David