View Full Version : advice for ranch dog mold
12-02-2010, 10:35 AM
Please look at the following pics.
Two different bullets, cast from Lee 6 cavity molds. The 3 bullets on the left are from a group buy and the 5 on the right are from a ranch dog 30 cal mold.
The smaller 30 cal bullets were cast first, then the rd bullets.
Both molds were pre-heated on a hotplate. The hotplate coils were red.
The alloy was the same, the temp was the same. Alloy was similar to Lyman #2.
The smaller bullets casted well right away. The ranch dog bullets show a wrinkle on the grooves and an occasional wrinkle on the nose for the entire session.
The alloy was hot enough to start frosting on some bullets. The casting was done from a Lee 10# bottom pour pot.
My only guess is the rd bullets, being larger, needed a more plentiful supply of alloy. I am suggesting the sprue holes are too small to deliver the larger supply of lead to the larger cavity. Would opening the sprue holes help?????
I can easily open the sprue holes, but I would like some feedback first.
The sprue holes are .154 -- #23 drill.
Is the RD mold new? If you havent' washed out the mold with something (I use hot water and dawn dish soap for a good 5 minutes) then it is entirely likely that the cutting oils from the factory are causing you fits.
Also, I don't feel the sprue plate holes are too small as I've cast 300 to 400 grain slugs just fine from Lee molds. You are getting good base fillout it looks which probably wouldn't be the case if the there weren't enough lead flow.
12-02-2010, 11:09 AM
I did wash with dawn.
The mold is not old. This was its second use.
I've read about cutting vent lines on the underside of the sprue has helped.
Thanks for the response.
Cutting vent lines in the sprue plate would help if you weren't getting good base fill out, but it looks like the bases are sharp and square. I would turn up the heat some more and see what happens as not every mold is the same. The mold may need a few castings before it starts to act right or normal and I use "normal" loosely.
With the Lee 10 lbs pot there is not a flow adjustment other than by the operator opening up the valve more or less, but it could also be that there just isn't enough lead flow from your pot. I've seen this from time to time and it happens with older pots that haven't been cleaned out very often as the spout becomes partically plugged with crud. A means to cleaning out the spout is as simple as draining the pot and then taking a paper clip or drill bit the same diameter as the spout hole for cleaning. The 20lbs pot I acutally opened the spout hole up a drill bit size to help with more flow volumn which as helped a great deal with the large molds.
12-02-2010, 12:27 PM
More heat! My RD molds wrinkle until the boolits start to frost, then they do just fine. Raise the pot temp and cast faster.
12-02-2010, 01:18 PM
Got a ladle??
12-02-2010, 02:29 PM
The suggestions pointing you to more heat and mold degrease are positive. Another step often overlooked is flow length. If you are using the Lee 4-20 adjust the mold guide to the highest possible position that will allow you to get the mold in and out, thus shortening the flow length to the sprue. An 1/8 to 1/4 inch flow length to the sprue is ideal and loses the least temperature from a bottom nozzle pour. Casting speed alone may cure the problem too. DO crank up the pot heat incrementally till you are sure it is too high and just frosts bullets slightly, Then you can easily slow down a little or back off temp a little to get the best bullets. I prefer a little frost. Mold heat is important but even a cold mold will come up to operating temp in 4 to 5 cycles if the metal temp is correct and your work speed is not sluggish. A ladle will easily stop the the flow length cooling problem too but many find work speed more critical with a ladle and fluxing annoyingly frequent with a ladle. In general I watch to see if the metal remains remains fluid on the last poured sprue plate puddle for 4 whole seconds. If it solidifies earlier than 4 seconds CONSISTENTLY, I raise the pot temp no matter what the thermometer says because there is not enough heat because of something going on.
The pour itself also has a peculiar quality you can control for better castings. Don't pour dead center into the sprue hole. This causes turbulence in any mold pour that can and does result in a variety of inconsistent voids. Vent lines are a design feature to allow air out in harmony with metal coming in but a turbulent flow will cut off vents and nullify vent effect. A good swirling pour works well into a mold with NO vents. Pour off center to the sprue hole by half the diameter of the flow, even tip the mold, 5 degrees or so, also and this asymmetry will set a good swirl to your fill of the mold and give good consistent pours when all else is good thermally.
gary ( retired casting analyst--really)
12-02-2010, 06:06 PM
I'm in the "more heat" corner.
12-03-2010, 03:18 AM
Classic cool mould indications. Cast faster. Turn up the pot is that doesn't help.
12-03-2010, 12:31 PM
Yeap, more preheat from the mold. You indicated that the mold was washed and your alloy was hot as you had frosted bullets. So, either the flow is extremely slow or the mold block wasn't hot enough.
I always dip the forward corner of the mold in my heated alloy. Leave it for a few seconds and then lift it. The alloy should flow immediately off the blocks. Sometimes after letting my mold sit 30 minutes directly on top of my pot, it still needs a couple of dips to be at the proper temperature. I also only work with one cavity until I see a good bullet. No sense in wasting alloy if they are not dropping well. When I get the first cavity/bullet right, I add the next, and then the next. Usually by the time I'm at the third cavity things are right.
I cast a lot of the TLC311 bullets as I'm feeding a number of family rifles and shooters. I recast 20# worth of them three weeks ago and had keeper bullets dropping after molding 5 individual bullets by following the procedure I outlined above. This week I cast my 380 Auto and 9mm bullets but I had keepers after 3 bullets with those shorter bullets.
12-03-2010, 12:51 PM
get a ladle learn it you'll love it
12-03-2010, 01:12 PM
Good advice you've gotten so far. I put a steel plate on my hotplate coils to preheat my molds, that way I don't have to worry about getting them too hot. That being said I am in the "mold is too cold" corner.
Not all molds are going to be the same, mine are certainly not. Some molds like the outside cavity filled first and some like the cavity closer to the handle filled first. I do not have an explanation for it, just know it works for me.
With my aluminum molds (BRP, NOE) they like to be heated up until the bullets frost and then I back off a bit on the heat and the speed of my casting. I have a 432-265grain NOE mold. Put it on the hotplate, heat up the lead, get to casting. I've got an NOE 432-300 grain mold, heat up the mold, heat up the lead, cast like crazy for about ten casts until the bullets are frosting and the sprue it taking too long to cool. Then I back off a bit, slow down, and it throws perfect bullets every time.
My BRP aluminum mold is a 458-420 grain mold -- it does NOT like my bottom pour pot and I get much better bullets by ladle casting with that method --- actually ALL my molds *seem* to cast better and release easier with ladle pouring and I have many fewer culls by using the ladle but I can adapt to the bottom pour when I need to.
Mostly I use BP for pistol bullets and six cav molds but prefer ladle for my big rifle bullets, it just works for me. Don't lock yourself into any hard and fast rules for casting. Try it hot, try it cooler, speed it up, slow it down, find out what works then use it.
I still think the wrinkly bullets are from too cold a mold though man...............
12-04-2010, 05:37 AM
What Michael says!
12-04-2010, 03:31 PM
I've cussed Lee 6 cavity moulds 'til my wife would not allow me in the house!
I purchased a 230 .45 standard SWC Lee mould a month or so back and learned most of the words I had forgotten all over. Dirt spots, wrinkles, poor fill-out and oh my - oh my - not allowed to say here.
In final desperation I tried modifying my procedure as follows:
Lee 4-20 bottom pour pot.
33% certified 94-4-2 alloy.
33% certified(?) 95-2.5-2.5 alloy.
remainder stick-on wheel weights.
I set the block to leave only 1/4" between the bottom of the spout and the top of the sprue cutter plate.
Set the flow rate about half way between slowest continuous dribble and full flow.
From cold, ran the pot at "10" (full speed) until alloy was fluid and would pour through the spout (700 to 750 on my "Rotometals" thermometer.
Turned the heat control down to "7" (which later stabilized at about 650 degrees).
"Floated" the mould on the alloy until the alloy did NOT stick to the mould.
Started pouring first cavity from handle to cavity furthest away from handle.
Watched for "grey" cast - indicating solidified alloy - and then cut sprue(s).
Allowed "de-sprued" boolits to remain in the mould perhaps twice the amount of time that it took for the sprues to harden.
In about 20 minutes after the first pour, I had 240 boolits and after inspecting them had only 3 rejects! Now, that's a personal first for me! I think I better quit while I have this experience behind me.
onondaga has a point - in my opinion.
Hope there is something in this message that might help someone here.
12-04-2010, 03:37 PM
I agree about the Lee 10lbs bottom pour. I was blaming a mold maker that the mold (Hollow point 32 cal) wasnt any good Solids O>K i heated the living **** out ot the mold. It was my Lee. After getting the Lee Pro 20lbs Most rejectes dropped . No more Lee drip o Matic. R.I.P old friend
12-04-2010, 03:39 PM
Speed up the casting until the mould warms up. Then slow it down to a steady pace.
12-04-2010, 04:50 PM
I have never cast a wrinkled frosty boolit.
If they frost they have enough tin. If they frost you have enough heat.
New moulds need some experience being filled and emptied. Or cleaned
or lapped or Lee mented someway or another.
New casters need some experience turning the heat control clockwise.
In very few instances has it helped to enlarge the sprue holes for me.
Life is good
12-09-2010, 05:56 PM
I recast the bullets. Heat turned up all the way. Casted quick. Bullets were frosty and not wrikled. Very good fillout. Also, the weight variation between bullets was less.
Thanks for the advice.
12-10-2010, 07:23 AM
I've found that each of my molds seem to like a different temperature to pour right. I even have two Lyman molds for the same bullet that require a 50 degree difference in what makes them pour a good bullet consistantly. And I have absolutely no idea why!!!
Try messing with the temps and see what happens.
Powered by vBulletin® Version 4.2.1 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.