Casting 101?

[KnifeMaker]

I know what you mean, it is always kind pucker time.

[Wayne52]

I recently dabbled a little with tin sorta, what I did was add about 30 GTO pellets in a small mix in my pot and the whiskers were a little out of control at times but I did get over half as being good.  I know for sure that if I start using tin in my mix I'll need to control the temperature more closely because without doing that there's always going to be problems.  I guess it time I finally picked up a new pot with temp control on it and I'll have to get me a thermometer as well.  The simplicity of the pure lead casting sure is nice though.

[triggertreat]

Wayne, with your success I wouldn't change a thing. 

[triggertreat]

I have received a number of PMs asking what my casting setup consist of.  I'm putting this post together to avoid retyping so much.  Feel free to add your recommendations, too.

I would like to avoid input on dip casting.  This particular post is focused on bottom pour pot casting.  That said, I will caution anyone to not to use your bottom pour pot for smelting dirty lead, or using sawdust to remove dross from the lead (which is popular) in your bottom pour pot.  Both will clog the exit spout.  It's best to use another pot for cleaning heavily soiled lead first.

I use paraffin wax to render my lead, which basically mixes the tin back into the lead.  This brand can be found cheap at most grocery stores.  Many other products can also be used like bees wax.  These products will smoke you out and also ignite when the pot is hot enough.  I would recommend outdoor casting or a very well ventilated area.  I cast very near the entrance door to my shed with a large fan drawing out the smoke and fumes.  You really don't want to inhale this stuff.
 


I use Frankford-Arsenal-Cleancast-Lead-Flux to clean my lead of minor dross.  I also use it to coat the top of my lead while casting to prevent oxygen from entering the lead once clean and separating out the tin again.



The melting pot I use is this one.  The Lee Precision model 90947 Pro 4-20.  It's a 110 volt 20lb bottom pour pot.  20 pound capacity is far easier to work with than a 10lb and last longer between refills of the lead supply.  The spout shaft on this one is vertical and not angled, which helps to seal better and limit leakage.  It is easy to adjust the flow rate, which will be required to keep the same flow rate as the lead level drops.  I would call having to adjust this a con when using this pot, but at least it is easy and quick to do.

I would recommend starting your lead temps for casting around 800°.  lead starts melting at around 626°.  I usually cast around 825° to 850°, which works for my 150gr slugs.  Don't be afraid to experiment to find what temps work best for your cast.



I would not recommend this pot or any other pot without it having a PID temperature controller.  This pot only comes with a rheostat, which is awful at controlling lead temps consistently.  As the lead level drops, the lead temp increases with just having a rheostat.

To remedy the rheostat temp control issue, I built my own DIY PID controller.  Now my lead temps stay consistent regardless of the lead level, so my cast are now more consistent, too.  The pot is plugged into the PID controllers output, and the pots rheostat is turned to its highest setting and ignored.





Here are some YT links that are good to use as a how to to build your own DIY PID controller if you choose this route.  It's a very easy build and the parts are listed at the bottom of the video(s).

https://www.gatewaytoairguns.org/GTA/index.php?topic=158723.msg155780761#msg155780761

I went a different route and purchased this kit on eBay

https://www.ebay.com/itm/Digital-F-C-PID-Temperature-Controller-TA4-SNR-K-Type-Probe-40A-SSR-Heat-Sink/292039794173

My project case was a used PC power supply from eBay.  The switches, fuse holders and terminal strips, etc. were from various other sources like WM.  Whichever was the cheapest.  None of my casting setup equipment came from Amazon (too expensive).

Another option is purchase a built-in PID controlled bottom pour melting pot like the Lyman model 2800382 Mag 25.  I did not choose this route based on the cost of this one at the time, plus my thoughts were, with my route taken, if the Mag 25 were to go bad in any way I would be out a PID controller and a melting pot.  With my setup, I can simply replaced just one component and would not have to replace all components.



The remaining components of my casting setup include a digital thermometer for monitoring the temps on my NOE moulds.  This is the one that I use.  You can find this one on the NOE website.  I found one much cheaper elsewhere, but can't remember where, but is the exact same one offered from NOE.  I order all NOE moulds drilled so I can use the digital thermometer to keep up with the mould temps.



For sizing my cast, I use the Lee Challenger Press.  It works great with the NOE sizing die kit and their sizing bushings.  It can be mounted upside down which makes sizing very easy and fast.  The slugs/pellets drop down into the Lee cup that I order separately off eBay.  I added some foam to the bottom of the cup for a soft landing.



I use NOE handles on my moulds.  The Lee handles are cheaper, but the NOE handles are of high quality.  You will be beating on your handles to knock out the slugs on occasion, especially before the moulds are good and hot.  You'll need quality handles like the NOE handles.  Mine have never given any trouble through my learning curve.  I would suspect the Lee's would have separated having gone through my newb torture sessions.

The only other tool I use is a Lee ladle.  It's cheap but works great.  it allows me to dip out dross and stir the lead up from the bottom.  It also allows me to add a quantity of rejected slugs at a time back into the pot safely without getting splattered with hot molten lead.  I would caution you to rest the ladle on top of the molten lead before diving into the lead with it.  Any condensation below the lead surface will explode violently beyond what you may think.  Never allow any moisture below the lead surface.  This includes your sweat droppings.  It's really bad to do so...



That's about it on my casting setup.  My process and advice is to not add any lead, like from sprue cuts, lead dripping, or any rejects back into the lead pot until it is time to resupply the lead pot.  This will prevent you from breaking the top surface and allowing oxygen back in.  Add all this lead back in at one time.  Then add a small amount of paraffin wax back in and stir well to render the tin back into the lead.  After that add just a small pinch of Frankford in (or whatever) and stir to remove any dross.  After that add a couple of more pinches of Frankford to cover the top surface to block out oxygen.  Don't break that seal again until it's time to resupply the pot again due to low lead levels and poor pour spout performance.

Now that you are well on your way at casting, why not recycle as much lead as you can by building a lead trap to shoot at.  Here is a link to the one I built for use with capturing lead indoors using my up to 300 FPE .357 Slayer.  It will stop a 300 FPE slug at only 10 feet away from the muzzle indoors.  I use it every time I can along with all my other guns.  It's like shooting for free, but does take some time to sort the lead from the rubber mulch.

https://www.gatewaytoairguns.org/GTA/index.php?topic=152077.msg155685378#msg155685378

I hope at least some of this helps someone else.  Much of my knowledge came from others here on the GTA sharing their knowledge.  I am by no means an expert, but have had some good success at casting using the above equipment and procedures.

[Hobbyman2007]

Great write up Keith. I think you may have solved one of my problems with oxidizing . I always cut the spru and it went directly back in the pot . I never had a barrier between the lead and air . I’ll have to get myself some sort of barrier agent . Thanks .

[KnifeMaker]

Yep, good stuff Keith!


I also never introduce lead while actually casting. Only when time to replenish and bring back up to heat. Putting the spru cut off in chile casting also changed the temp at the bottom of the pot. Exactly where you don't want it changed.


I used the F. Arsenal white powder of ryears. Until I learned the the 20 mule team Borax at he g. Store was the sam thing, and a fraction of the price. LOL!


When using tin n the mix, I try to keep the  temp under 745-50 to prevent tin separation.


If pure lead, I raise it to 825 for best base squareness. It they start to round even a little on the based, I will hit the spru plate with a touch of propane torch, or dip the end of the plate in the melt. You want the plate  HOT!!!


Knife
Closet Caster

[Hobbyman2007]

Borax you say , I’ll pick some up on the way home tonight .

[triggertreat]

Thanks for chiming in Knife.  It's always good to get confirmation and additional tips from closet caster masters.

[KnifeMaker]

Thanks for chiming in Knife.  It's always good to get confirmation and additional tips from closet caster masters.

Man, I've got to stop posting when asleep. I can't even read my writing. LOL

[Wayne52]

Borax is amazing stuff for a whole lot of uses.  A guy I worked with treated the salmon eggs he got when cleaning fish with borax to preserve them, they worked fantastic for catching steelhead too.

[Insanity]

Next time Im in my local IGA I will pick up a box of borax and try it.

[Airgunhunter73]

I have a Lyman Mag25 and have found I have more consistent boolit pours with it set at around 790 degrees I had been running it at 810+- and it would start dripping a little