Where did I wrong go ?

[SmuvBoGa]

OK Gents,



http://castboolits.gunloads.com/picture.php?albumid=402&pictureid=2743

Asking for help - -

Facts: Have a Lee Pro - 4-20. Moulds (2) 1. NOE 360-180 GC, 5 hole & 2. MP 359-640, 2 hole. Casting tem. approx 700 - 720. Using a mix of WW's, isotope lead, shotgun pellets, & some pure lead. The cast boolits are BHN 12 (75 in Cab Tree).

Had problems with the bottom pour clogging up (6 or 8 times) - had to use a small torch to get the lead to flow - stop the extra heat & the flow would slow then stop. I tried wire punch, steel picks, & cussing. :holysheep

I would like to hear what ya'll think. Pls note the dis-colored cores in addition to the cavities. Maybe a trip to the dentist ?

Thanks for you views (another picture on my album page of another bloolit butt)

JohnMc

[CiDirkona]

I'm definitely new to casting, but when I had problems like this, it was either from pouring straight in from the bottom pour spout (not hitting the 'cone' of the sprue plate to cause a little bit of vortex action,) the mold not being hot enough and causing some lead to harden up before the entire cavity was full, or from not piling the sprue high enough that it could 'suck' in some molten lead as it cooled. Since these boolits are quite a bit taller than what I'm used to, there's probably something else I'm missing that I haven't seen yet.

[seppos]

Maybe some zink involved..

S

[HORNET]

The wrinkles look like the molds are too cold and the shrinkage voids hint at the same thing. The nozzle freezing up indicates that your melt is too cold as well. Try turning the pot temp up a little, running a bigger sprue puddle, and casting faster to get the mold temp up. A couple of members claim that it should take 6 seconds for the sprue puddle to harden. I assume that the molds were cleaned and the alloy doesn't have any zinc in it? That can raise the temp. requirements a lot.
You might be able to turn the melt temp down once you get the mold temp up.

[Blammer]

I'd try it hotter.

Don't hold the mould so far from the bottom of the spout, and reduce the pour speed (if you can) I suspect you're getting "fly out" best I can describe it.

when the lead goes into the mould it "fly's out" like a geyser after it's full.

[jimb16]

Looks like zinc to me too.

[docone31]

I am going to guess you melted wheel weights in your bottom pour pot.
From there, a couple of zinc wheel weights got in the alloy. Notice the dark streaks on the two in the lower right area. You also referenced to haveing to unclog the nozzle.
I have run into that in some of my melts.
I run my pot at 8 or 9. I keep my mold hot also. Just enough that it takes six seconds for the sprue to freeze.
Welcome, and keep trying. You will get it.

[geargnasher]

If you 4-20 spout freezes at 700* YOU HAVE ZINK. Try cranking the heat up all the way and see if it starts to flow better and fillout. That will oxidize the tin like crazy, but possibly make the zink flow better. Looks like the boolits are "coring", another symptom of zink.

FYI you're casting at what should be an ideal temperature for what your alloy should be, so don't take the "more heat is better" as a rule if your alloy contains a significant amout of tin (more than .5%), just try it in this case. Tin loses it's effectiveness as an oxidation barrier and viscosity modifier at about 750*, so normally you don't want to exceed 725* or so.

If more heat won't make it cast, try "freezing out" the zink by lowering pot temp until it separates in to slush on top of the melt, try to skim it off. Also, check for the sticky on using sulfur to remove zink from the melt, but you'll need to empty the pot and do this outside, preferably not anywhere in town or near neighbors.

Gear

[Charlie Two Tracks]

New to casting myself but when I had problems with the spout clogging, it was that the lead was too cold. At 700 everything was ok. As far as the mold goes, I got a heating plate and put the mold on it as the lead is warming up to pour temp. It has made a world of difference in casting. It has taken me a long time to get to the point of casting nice looking boolits. These guys will help a lot. I would try a new mix of just wheel weights and see if it is the mix or not. I try to sort all the zink out first and then take my time with melting the wheel weights. If you turn the heat up too fast, the bottom is real hot and the top is not melted yet. If a zink WW is at the bottom, well, not good. I hope you are using all the safety gear. 700+ deg. will melt skin. Takes a long time to heal. IMO

[SmuvBoGa]

Folks,

Many thanks for the ideas ! ME thought that I was casting too fast,maybe. I never thought of the "Z" word !! NOT in my house err, basement. This zink thing does blow my skirt up ! Afraid that I have WELL mixed mess. :evil:

I shall crank up the heat & try to cast the mix I have & then start over with clean lead. :?

[WHITETAIL]

Yes, I agree with what was said. +1
But I would start with crank up the heat.
If that does not work, then try recleaning your mould.
Then if that does not work.
Clean out your pot and try some straight WW and make sure
you melt them in a pot outside and not in your bottom pour pot.:cbpour:

[home in oz]

Too cold, the melt and the mold.

[XWrench3]

i have to run my lee (same model) pot with the lead around 725-750 degrees to keep the silver stream flowing. anything less, and i get the same problems. i guess it is becase of the cooling effect of the "spout" hanging out in the air, which allows the lead there to solidify, while the lead in the pot is still molten. no big deal, just got to go with the flow (pun intended).

[geargnasher]

The Lee pots do get cooler on the bottom since the heating element is up the sides a bit, but I've never had one get anywhere near freezing until about 575* with a half-full pot that I was experimenting with.

+1 on too cold mould also, but 700-725* is MORE than hot enough to make beautiful, perfectly sharp, lightly frosted boolits IF the mould is hot enough AND there is no Zink present. If Zink is present, all bets are off with the temp, run it as hot as you can (800-900 if possible) and you can probably get away with the alloy you have.

Gear

[454PB]

The "coring" is caused by a partially clogged spout. I know you said you tried clearing it, but it is still partially restricted. Whatever device you use to clear the spout has to be at least an inch long to properly clear the nozzle. The clogging problem is amplified by using dirty alloy, like non-smelted wheelweights. The metering rod will also get a buildup of crud, and needs to be removed and cleaned occasionally. I chuck the rod in a cordless drill and then place it in the spout recess and give it a good lapping.

I use a modified dental pick that is about 1/16" in diameter and bent at a 90 degree angle. I use it in a filing motion, give the spout about 6 full stokes every 150 pours.

[Crusty Deary Ol'Coot]

Now first off, just clear the deck, I am not a bottom pour user or liker, so be that as it may, years back I did try that system.

I did then as now, smelt my WW down into what I thought to be nice clean, casting ready alloy before putting the metal into the casting pot.

I just didn't have any luck, except bad with the bottom pour and that was years before this or any internet forums, so there was no go to source of people in the know as here on the Cast Boolit forum.

Pluging up the spout was one of the problems I came up with, so I wrote to the NRA about the situation and rec'd the answer that you could never get WW clean enough for use in a bottom pour.

Well I doubt that is true from all I read here and on other forums, BUT I'll probably never again try the bottom pour method of casting.

The tried and true use of a large lead pot on an old Colman gas stove along with the use of the very good Rowel (SP?) bottom pour ladle, gives me no reason to try again. :castmine: :cbpour: :cbpour:

Keep em coming!

Crusty Deary Ol'Coot

[TCLouis]

I only see that when I cast with too cool of a melt or when I cast into too cool of a mold.
If the nozzle of the pot is plugging I can almost bet that the metal is not hot enough.

I have no idea what temperature I am running when I cast, I let the pot and mold tell me what to do.
That said, I just bought one and may well regret it.
Maybe the safe thing to do with it is leave it in the package and let the wife sell it for 50 cents in a yard sale after my demise

[fryboy]

as stated if ur nozzle is freezing up ur too cold for the alloy ( zinc or not ) if it's clogging it wont work until u have the "silver stream" i would give it the college try of turning up the heat but that would be to empty the pot , i would re-smelt it and clean the pot before putting it back in , by re-smelting it i mean at least one flux past where no trash comes up when stirred properly , a thermometer would help in this case to help see for sure where the alloy melted , it would also give u the best idea of where ur pot's control numbers are for certain temps , from time to time ( about every 10-20 cast ) i like to open up my spout by pouring a bit out into a ingot mold just to help keep it clear and flowing good , usually on my 4-20 pot i have to adjust the flow down with a full pot and the open it up a lil as i use it , i understand exactly what blammer is referring too by flyout - worse i cant describe it any better :P

[geargnasher]

Would "Cow peeing on a flat rock" describe it better? :kidding:

Gear

[44fanatic]

Ive had holes in the core when my pot pours lead to quickly. Seems to fill the cavity then spray out of the mold. Sometimes I will get a glob of lead, other times, a cavity similar to the picture above. Slow down the pour and my problem is solved if the mold is up to temp.

[fryboy]

Would "Cow peeing on a flat rock" describe it better? :kidding:

Gear

ummmm actually that covers the rock better than his lead covered the holes :-P

[RSOJim]

I couldn't help but notice in your post that you are casting between 700 and 720 degrees. I once had a lyman thermometer, since then dropped it and broke it, that read extremely high. For instance, I had to get my lead temp up to 950 to 1000 degrees before I could cast good boolits. Everyone knows a Lee pot will not get lead that hot. Some thermometers cannot be believed. thanks Jim

[Bret4207]

Cold mould, pot needs more heat for the nozzles sake.

Lee BP are tools of Satan.

[SmuvBoGa]

When casting with bottom pour I place the mould next to the bottom spout, touching. I have drilled out the flow hole one step larger. I DO use a Lyman thermometer - that is the source of the 700 - 720 pot temp. The pot has been cleaned out for the "drilling".
Next time I fire up the pot I'll go up 800 - 900 according to the Lyman thermometer
& make sure the mould is hot. I keep ya'll informed how it goes.
30 lbs of lead inter mixed with the ham zink - its not that much [smilie=b:

I should say thank you to all for the ideas & help - - somehow I'm just PO'ed about the "z" stuff.

[docone31]

When I have had zinc in the melt, and did not want to discard the melt, I poured it out. From there, I made muffin ingots. These I kept aside. I think I poured 2/3rds of the melt out.
I then added Roof Boots. These thinned the zinc contaminant so the spout cleared, and I could cast. I then slowly added the muffin ingots to my mix. I mean slowly. That kept it all thin so the zinc was not really an issue.
I have had it happen when I did not want it to.
This way, I can keep the heat modestly down to incorporate the zinc in the melt.