Under pressure! (David Bowie, Pro-Melt, and bottom pour)

[ohland]

I tried to configure my Pro-Melt bottom pour. What I learned is when liquid lead is under a lot of pressure, it doesn't want to form a lead puddle. It flows fast enough to make a stream that deprives the boolit to be of a puddle to draw from when cooling.

So... when I set up the RCBS mold guide, the nozzle is about 3/16 " from the top of the sprue plate. I cranked down the adjustment socket screw far enough to freeze the nozzle (another issue).

It is expected to possibly rain this afternoon, so no casting outside. My plan for world domination:

Use the shipping box, suitably modified, as a wind break. Remove the top, take out one side, create an enclosure with three sides. True, cardboard is combustable, but it does not conduct electricity.

Run Pro-Melt up until the external (stick er in the pot) thermostat settles on 725. Add @ 6oz of tin to the full pot. Flux. Stir. Enjoy.

Boolits from Tuesday looked pretty good, but while ladling, there was a skein of alloy flapping off the ladle. This flap would interfere with the velocity and volume of the pour. You could see the lines in the boolit, either from the halting pours, or mold temp.

Does anyone make a ladle which does NOT attract any normal component, like lead, antimony, or tin? One less thing to have to contend with.

[Maximumbob54]

Not hot enough. Crank up the heat. Lead will stick to anything if it cools fast enough.

[bhn22]

Bead blast your tools, and spray them with mold prep. This will cut way down on the alloy sticking on the ladles, and other tools.

This is the only practical use I've ever had for mold prep. It's sure death for most moulds.

[ohland]

Not hot enough. Crank up the heat. Lead will stick to anything if it cools fast enough.

That's where the windbreak and 725 come in. Tuesday was pretty windy (amazing how heavy a mere 10mph seems while casting) and the pot seemed to bounce in the 625-700 range. Once loaded, I got it to settle at 700, it cast fairly well, but the skein was ready to form at the lower end of the temps. The spout freed up towards 700, but I just stayed with the ladle.

What is a normal distance from nozzle to sprue plate? Dropping the guide down would keep the sprue puddle from catching on the nozzle.

NOTE: The present pour rate would be the cat's fuzzy buttocks with the 300-500 grain boolits... 462560, here we come!

[Maximumbob54]

You can "pressure cast" right from the nozzle and just let some puddle at the last second for that bit the mold draws in as it cools. I usually hold the mold just far enough away to be able to see the lead pour. The tip on the mold prep spray is spot on as well. I use some in my ingot mold just so it's that much easier for the ingots to fall free. This is just guessing but I bet you are still getting at least minor deformities casting at 700.

[country gent]

I ladle pour all my bullets still. Several things help with keeping the ladle clean and working as it should. I lightly polished the outside of mine with a wire wheel then dremel tool and nylon brush with valve grinding compound working everywhere I could get to. The smoother surface dosnt allow lead to adhere as easily. Ocassionally I boil the ladles in dish soap and water, use an old pan dedicated to doing this. I also occasionally unscrew the handles and throw them in the vibratory case poliher over night with corn cobs, walnut might work better being a little more agressive. Sand blasting with fine sand will smooth out alot also. To help with the uneven flow of lead I opened the spouts on mine to .205 dia. Another trick to keeping ladle working properly is technique. I have fitted stop rings handle shafts allowing ladle to set in pot with handle still away from it. ( just a nut drilled to press fit on handles shaft). This helps to keep ladle hot. I pour a mould full, dip ladle to bottom of pot to fill with hottest metal hooking stop on edge of pot letting it float just under the surface, WHen next pour is made dip to bottom of pot with a swirling motion and lift spilling a little out the spout and then refill mould. Keeping the ladle as hot as the alloy or almost helps cut the sticking down also.

[mongoose33]

If I understand what you're asking, what I think you're looking for is one of these:

http://www.rotometals.com/product-p/...le_bottom2.htm

A Rowell ladle, one that pours from the bottom, not the top. They come in various "poundages." What I've read (here on CB) is that the 1# is too small, the 3# is too heavy, and the 2# is just right.

[cajun shooter]

I have found that when I ladle pour from my Wagge pot which is my only way I cast bullets now, I have to have a few things in line before I start to make my perfect bullets.
I use a RCBS ladle which to me has the perfect design for casting as the spout mates with the sprue plate perfectly.
I don't start until my lead is at least 725 min to my preferred 750
I wash my ladle when it's new to remove any factory protective coatings and allow it to skim over in a light rust. This is to me the best way to have your ladle.
I push the entire ladle into the melt and allow it to reach the same temp as the melt. When it's lifted, no lead should be on the outer surface.
You are now ready to ladle pour.
Good Casting David

PS MY MOLDS ARE SITTING ON A SINGLE LARGE HOT PLATE TO COME UP TO TEMP

[EdS]

Re: mongoose33's Rowell ladle recommendation - I think the "ideal" diameter will depend a lot on the diameter of your lead pot. My small Lyman ladle pot would be overwhelmed by a 2-1/2" ladle. I've used a Lyman ladle for decades and clean it by using it to stir the alloy during occasional fluxing. Then a couple of taps of the shaft against the top of the pot before skimming dross. As was suggested, keeping your melt temp high enough helps too. -Ed