PDA

View Full Version : The Ideal Casting Furnace (pun intended)



Bradley
09-21-2014, 07:27 PM
For as long as RCBS has been making them I've been using a Pro-Melt furnace. Love it. Still, there are clearly things that could be improved. So what I'd like to discuss is what changes I'd like to see and what features I'd like to keep to make this as close to an Ideal casting furnace as possible.

First for the pluses.

* I REALLY like the mould guide rod. I've got maybe two dozen different brands of moulds and that guide rod works
perfectly with all of them. That feature can not be improved.
* I also really love the fact that RCBS will repair their units. No other furnace maker that I'm aware of does that.

Then there are the things I'd like to see changed.

* the on switch lights up when the heating element is actually on. I would far prefer a small light on the front of
the unit where it would be far easier to see.
* the screws that hold the nozzle shut-off pin in place and hold the handle in place are WAY to short. If those
screws back out then the handle and shut-off pin literally float in hot alloy and the furnace empties with no
way of stopping the flow. Longer screws would significantly reduce this problem. I'd also like a nut on the
end of those screws to limit the chance that the screws can back out.
* get rid of the mould guide collars. they serve no useful purpose.
* I'd also like for the area that contains the actual alloy to be easily removed so if you want to switch alloy you
would not have to drain the furnace. Instead you could just pull out the "container" holding the alloy.
* I'd like to see some absolutely positive way to stop alloy from going through the nozzle at the bottom of the
furnace so if the furnace does start to uncontrollably drain that that can be stopped.
* I'd like the actual heating elements to go up higher around the "container" that holds the alloy. As it is, if the
furnace is full and empty, when that heating element comes on it heats only the alloy at the very bottom
of the furnace. That leaves a solid plug of alloy above the reach of the heating elements. That plug will
eventually be melted IF the expanding alloy does not push up on that plug thereby raising the shut-off
pin and causing the liquid to go out the nozzle. If that happens there is no way for the heating element
to melt that plug. If you ever have that happen you know it is a real problem. A practical way to avoid
this is to always make sure the furnace is half empty when you turn it off but I'd prefer for the heating
elements to come up higher in the furnace.

And finally I'd like:

* digital readouts of not only furnace temperature but also the furnace temperature setting as Lyman has just
introduced on their new model.


ANY OTHER SUGGESTIONS?

Mk42gunner
09-21-2014, 08:25 PM
I haven't used my Promelt all that much, and overall I am satisfied with it. Oddly enough one of the gripes I have is the mold guide. I had a H&G 4 cavity the handle mounting screws protruded from, this was a bit of a PITA if I tried to just pull or push it while resting on the guide.

While I don't have any experience with a PID, a lot of people that I respect like them; so maybe RCBS could make two versions of the Promelt???

1. As it is made now.

2. As the Promelt deluxe with a PID.

I don't believe that Lyman has actually started shipping their PID controlled model yet; I mean it has only been what three years since they announced it?

Robert

dikman
09-21-2014, 08:49 PM
* I REALLY like the mould guide rod. I've got maybe two dozen different brands of moulds and that guide rod works
perfectly with them all. That feature cannot be improved.


Actually, I have to disagree with you there, the first time I used it I didn't like the rod and it didn't get any better! A member on here makes a kit for the Lee pot which includes an adjustable shelf for supporting the molds. I pinched his idea and made an adjustable shelf from aluminium plate. MUCH better.

After adding a PID I'm happy with it and can't see anything else that needs doing - it works well.

Springfield
09-21-2014, 09:01 PM
I really don't see how you could make a removable pot and still have the heating element touch the pot. As for the mould collars, just remove the set screws and toss them if you don't like them. Personally I like them. And not sure that putting the "on" light in the front would make life any easier, except for maybe relieving the boredom some. Magma pots don't even have an on switch, just plug and unplug them. Funny how nobody ever asks that RCBS up the wattage of the pot. IMHO that would be the most useful change, especially for those of us who cast large lots or larger then normal bullets.

dragon813gt
09-21-2014, 09:08 PM
Let me know when that Unicorn of a Lyman pot is for sale :laugh:

dikman
09-22-2014, 03:01 AM
You're right about the wattage, Springfield, I noticed that my Lee 20 lb'er heats up noticeably faster than the RCBS. Still, I can live with it as it's only a minor inconvenience.

Springfield
09-22-2014, 03:58 PM
After using my 1500 watt Magma I am totally spoiled. I have to restrict myself to 1 lb ingots with the RCBS or the temp drops so much the spout freezes. I use LEE 6 cavs mostly so I can drain a pot pretty quick. I use the RCBS for all my pure lead casting, like balls and conicals, and the Magma for most everything else.

sdcitizen
09-23-2014, 10:11 AM
So add a PID and a removable pot to a MAG 20 and you have the ideal pot? Of course it too could use more wattage, though you can add 4lbs of cold alloy at a time before spout freeze up becomes an issue. Truthfully though I have been more than happy with the mag 20, if only the pot held 40 lbs.

Dale53
09-23-2014, 11:08 AM
I have two RCBS Pro Melts and have been more than satisfied with them. I have cast several hundred thousand bullets from mine. Now, being a "Certified Old Fart" I only cast one full pot at a time (20+lbs.). There is one modification that I have thought about doing. I would like to put two small ball bearings on the mold rest. That would allow me to position the mould (front to back) easily without drag across the mold rest. The PID would be nice but a bit expensive for what you get.

Just a thought or two...

Dale53

Springfield
09-23-2014, 12:28 PM
Dale; Why don't you find a tube that fits over the mould rest tube and use it as a roller bearing? Easy enough to do. I just keep Bullplate on the rod to keep it slippery. I tend to like to do big batches. I will do maybe 2000 .451 balls for my C&B guns and not have to do any again for a year or two, so it is nice if the spout doesn't freeze on me and hold up production. I COULD just empty my Magma and fill it up with pure but I am too lazy! Same reason I have 2 Dillon 550's, one with small primers and one with large.

BruceB
09-23-2014, 12:35 PM
Good grief, folks.

Spout freeze?

Hold your hand just above your furnace when it's full of casting-temperature alloy. What do you feel?

HEAT!

That is waste heat which could be used to pre-heat the metal which will be going into the pot.

My ingots weigh three pounds, cast in an angle-iron mould about 10.5 inches long. I place four or five of these in a front-to-back row atop my RCBS furnace.

When the front-most ingot is put into the pot, the row is moved forward and a cold ingot added at the back. I add an ingot as soon as the alloy level drops enough to accept a new ingot. Therefore the pot stays full, and flow pressure is consistent.

The front ingot gets VERY HOT, and as a result........

I NEVER STOP CASTING! Adding the pre-heated ingot doesn't drop the melt temperature enough to worry about. I do NOT stop casting to flux the melt, either. The alloy being added was well-cleaned when the ingots were cast.

NO freeze, NO delay, and we also save some of that waste heat (i.e.: MONEY).

If your ingots are too short to span the pot, fabricate (or find) a wire rack to go across the top. Ensure there's an opening large enough to allow an ingot to pass through into the melt. A small kitchen roaster rack would likely work for this.

Mk42gunner
09-23-2014, 03:46 PM
Listen to Bruce folks. I have been using his method since I bought my first electric pot, a Lee 4-20. Waste heat used to preheat my ingots is one reason why I haven't gotten a hotplate yet. The other reason is I live in an old farmhouse with 14 ga wiring, and few circuits. It is kind of fun to stick a hot ingot in the pot at an angle and watch it self feed.Robert

DaveInFloweryBranchGA
09-26-2014, 09:23 AM
BruceB has the right of it folks. Pay heed and if you can find his process for speed casting, read up on that as well. It's called doing the BruceB. Some of the best advice on making cast boolits and getting enough of them done to reload on a progressive I've ever read.

Walter Laich
09-26-2014, 09:46 AM
I sit mine on a small shelf with the PID under the shelf (think two sides and a top piece for the pot to sit on)
Gets it up a bit higher so I can see the flow going into the spout--not really a mod on the machine itself
did the tubing acting like a roller on the horizontal guide rod--works great
used guide collars to hold the roller on the guide rod.
do preheat ingots on top before they are added
still working a way to hold the probe in the pot. have a removable cover now but want to come up with something more elegant--mostly because I have the time and like to fix things that aren't broke.
.
with PID below the pot facing me the light in the on/off switch isn't an issue

jeepyj
09-26-2014, 09:54 AM
Good grief, folks.

Spout freeze?

Hold your hand just above your furnace when it's full of casting-temperature alloy. What do you feel?

HEAT!

That is waste heat which could be used to pre-heat the metal which will be going into the pot.

My ingots weigh three pounds, cast in an angle-iron mould about 10.5 inches long. I place four or five of these in a front-to-back row atop my RCBS furnace.

When the front-most ingot is put into the pot, the row is moved forward and a cold ingot added at the back. I add an ingot as soon as the alloy level drops enough to accept a new ingot. Therefore the pot stays full, and flow pressure is consistent.

The front ingot gets VERY HOT, and as a result........

I NEVER STOP CASTING! Adding the pre-heated ingot doesn't drop the melt temperature enough to worry about. I do NOT stop casting to flux the melt, either. The alloy being added was well-cleaned when the ingots were cast.

NO freeze, NO delay, and we also save some of that waste heat (i.e.: MONEY).

If your ingots are too short to span the pot, fabricate (or find) a wire rack to go across the top. Ensure there's an opening large enough to allow an ingot to pass through into the melt. A small kitchen roaster rack would likely work for this.

This is a good tip. I'll be trying it next casting session.
Jeepyj