[kelly]

One more thing you might need to know for an answer. My lead is for plumbers most of the time and is almost pure lead and very clean. I never fluxed untill this thead. I will for hear on out.

[cadman]

Originally Posted by kelly

You have changed my out look on fluxing. Thank you. Not to change the subject but how dos smoking the mold help. I am having trouble seeing a difference in my pour and do not any change. I would think all the prep would be during the flux proses. One last thing A past post cadman having good pouring when cold out (close to sea level? no moiture in air). I am lucky to have alot of pouring like that and live in utah. Can altitude or lack of moisture in the air change the properties, change like boiling water at high altitude it needs to be hoter to boil.

Kelly, I was just thinking about that thread I started, and I was going to bring it up in a couple of days. But since you brought it up, I'll give you my feedback. All winter I poured a lot, as I was really busy. You know that I don't recall ever walking away from my pot frustrated. Everthing poured great. Yesterday I was pouring, and I had a mold that poured really well, and then 100 hooks later nothing worked. I got frustrated, and just stopped and walked away. I figured I pour the rest tomorrow. Today I poured in the morning and everthing poured flawlessly. I'm stumped. Both days were hot and humid. I read somwhere that moisture and or humidity definitely affects pouring. My question is this I poured both days consecutively. One day was horrible, and the next was perfect. What gives?

Sagacious or anyone else, I'm curious if you have any insight on this. If I have to pour like I did yesterday, then I better give this up, or buy myself a big meat cooler and pour in there.

[sagacious]

Originally Posted by kelly

You have changed my out look on fluxing. Thank you. Not to change the subject but how dos smoking the mold help. I am having trouble seeing a difference in my pour and do not any change.

Smoking the mold is good general practice, and good advice for anyone using metal molds. However, you're right-- in some cases it doesn't seem to make a noticeable difference. I always smoke a new mold, just in case.

Smoking the mold does several potentially critical (potentially very helpful) things:
First, it helps 'break in' a new mold. The surface of the cavities of an aluminum or steel mold may not be completely anodized, or coated with 'bluing' (steel mold), and the lead may tend to stick in the cavities until the mold has been used for a few times. The soot layer functions as a very good non-stick coating for the cavities.

2) The soot (carbon) layer is a thin insulating layer in the cavity. What that does is allow the lead to 'slosh and slide' into the cavities freely and fully for a fraction of a second before it starts to solidify. That's always good. It can be particularly helpful in getting a mold to fill out in a narrow collar area.

3) The soot layer helps prevent hollow areas or voids in larger molds, as it reduces the potential for the lead to freeze in the gate, or to freeze where it contacts the side of the mold cavity.

On some molds, such as smaller jig molds, or molds with tight tolerances, I'll smoke the entire face of the mold halves. Sometimes a speck of lead, or many specks will hold the mold open a tiny bit and cause flashing on the jighead. I'm sure that's happened to many of us. If the mold face is silver, it can be a real pain to track down and scrape off all the lead bits-- and they often stick really tight. If the mold face has been smoked, and bits of lead that get splashed on are instantly visible, and easily removed.

I'm sure there's other benefits that I haven't listed. Maybe someone will chime-in with their thoughts or experience.

I would think all the prep would be during the flux proses.

Well yes, but part of the prep is prepping the mold cavities (if necessary), pre-heating the mold, organizing your pouring space, preheating your hooks and forms (if necessary), etc. No doubt you do all that stuff without thinking about it any more, but there's a lot of folks new to lead pouring that haven't worked out all the kinks. Smoking the cavities is easy, and it will definitely help in many cases. There's enough frustration to be had in learning to pour lead, so every bit of prep that will save grief later is good general advice. I can recall a few people here on TU that replied they had better pours after smoking the cavities. So, you're right, it may not be important for you with your mold(s), but it's a good thing to keep in mind, and a good thing to do to head off potential problems.

One last thing A past post cadman having good pouring when cold out (close to sea level? no moiture in air). I am lucky to have alot of pouring like that and live in utah. Can altitude or lack of moisture in the air change the properties, change like boiling water at high altitude it needs to be hoter to boil.

I'm not sure, I haven't seen any data on elevation re lead pouring, and have no experience with pouring lead above 1000'. Could be, but my guess is there's probably little affect due specifically to altitude.

Humidity? Now that could just be a significant factor, as increased humidity can increase the amount of surface oxides formed, and so could adversely affect mold fill-out. Plumber's lead is 'pure' lead, and pure lead is more prone to develop a significant amount of surface oxide than hard lead-- so you may have something there! So, if you pour soft lead, high-humidity days may not give the best results. And, if you pour soft lead when humidity is high, flux the lead every now and then to keep the melt fluidity high and to remove the lead oxides-- so that you don't run into problems. Also, adding some ww lead to the soft lead when humidity is high is another option, as that will reduce surface oxide formation too. Lower humidity during wintertime sounds like it might make more than enough difference to offset the cold air (it's relatively low humidity all year where I pour).

Good questions, good stuff-- you guys may have gotten to the bottom of a frustrating phenomenon! Flux early, flux often is a good solution to many problems.

[sagacious]

Originally Posted by cadman

...
All winter I poured a lot, as I was really busy. You know that I don't recall ever walking away from my pot frustrated. Everthing poured great. Yesterday I was pouring, and I had a mold that poured really well, and then 100 hooks later nothing worked. I got frustrated, and just stopped and walked away. I figured I pour the rest tomorrow. Today I poured in the morning and everthing poured flawlessly. I'm stumped. Both days were hot and humid. I read somwhere that moisture and or humidity definitely affects pouring. My question is this I poured both days consecutively. One day was horrible, and the next was perfect. What gives?

I think you nailed it: humidity. Low humidity during winter, plus with pouring high-volume, you go through the lead before entrained lead oxides and surface oxides build up to a deleterious point.

As the summer day wears on and the temp rises, so does humidity.
As the humidity rises and time passes, the melt eventually develops a significant amount of surface oxide, as well as entrained oxide. (You know when you get that hazy grey scum on the melt, and you stir it back in, and the melt surface is shiny again? Well, you've just stirred in all those oxides so they can cause lots of problems. Better to flux the melt and just remove the bad stuff. )

You pour 100 jigs. As humidity increases and time passes, more oxides form and collect in the melt until it becomes sufficient to prevent good pours. You stop and start over again when the humidity is low, and everything is back to normal........... until the humidity rises and enough time passes.

The soution to directly address this problem is, of course, fluxing the lead. Maybe fluxing twice, if you had a frustrating pouring session and you want to be sure. Flux early, flux often.

So, as my gramdma would say, "the proof of the puddin' is in the tastin'!" Next time you pour when the humidity is high, flux the lead once every hour, or more often if you're adding a lot of lead ingots per hour. Try that, and get back to us. Should be, "problem solved!"

Sagacious or anyone else, I'm curious if you have any insight on this. If I have to pour like I did yesterday, then I better give this up, or buy myself a big meat cooler and pour in there.

Or get a de-humidifier! Better yet, just flux early, and flux often!

[gat0r]

Wow.. Best thread/posts I've read in a while. Thank you all for the contributions. I shall go back in my closet of non-fluxing, non-smoking mold pourers now.

[cadman]

Originally Posted by sagacious

I think you nailed it: humidity. Low humidity during winter, plus with pouring high-volume, you go through the lead before entrained lead oxides and surface oxides build up to a deleterious point.

As the summer day wears on and the temp rises, so does humidity.
As the humidity rises and time passes, the melt eventually develops a significant amount of surface oxide, as well as entrained oxide. (You know when you get that hazy grey scum on the melt, and you stir it back in, and the melt surface is shiny again? Well, you've just stirred in all those oxides so they can cause lots of problems. Better to flux the melt and just remove the bad stuff. )

You pour 100 jigs. As humidity increases and time passes, more oxides form and collect in the melt until it becomes sufficient to prevent good pours. You stop and start over again when the humidity is low, and everything is back to normal........... until the humidity rises and enough time passes.

The soution to directly address this problem is, of course, fluxing the lead. Maybe fluxing twice, if you had a frustrating pouring session and you want to be sure. Flux early, flux often.

So, as my gramdma would say, "the proof of the puddin' is in the tastin'!" Next time you pour when the humidity is high, flux the lead once every hour, or more often if you're adding a lot of lead ingots per hour. Try that, and get back to us. Should be, "problem solved!"


Or get a de-humidifier! Better yet, just flux early, and flux often!

I would need a big de-humidifier in my garage.......Thank You for your wealth of knowledge, your insight and all of your help. If you ever need any help down the road PM me.

[hawnjigs]

"gat0r", sup to you but after 10 years of blundering I'm staying out of the closet! Second flame flux session today with softer alloy again produced quality castings at a lower temp than I thought possible. And in a 150+" rainfall climate with 90% humidity normal. "cadman", I too have had frustrating WTF! days so you're not alone. How are you other born again fluxers doing?

[cadman]

Originally Posted by hawnjigs

"gat0r", sup to you but after 10 years of blundering I'm staying out of the closet! Second flame flux session today with softer alloy again produced quality castings at a lower temp than I thought possible. And in a 150+" rainfall climate with 90% humidity normal. "cadman", I too have had frustrating WTF! days so you're not alone. How are you other born again fluxers doing?

I saw an advertisement about your jigs in In-fisherman magazine. Well I'm impressed. Very nice looking jigs if I don't say so myself. Just out of curiosity, do they all come out so perfect. Very nice, and a vey nice plug hopefully for you business.

[kelly]

Thank you. I am a born yesterday fluxer. Never fluxed before this thread. I love it. Sagacious thank you for all the info. Now I need to think of another question, but I still wonder about altitude?Flux Flux Flux

[reeves]

OK, it is official! I am out of the closet and never going back. You guys would have given good money to be a fly on the wall watching this operation. I used some parafin I had laying around, cut it into about the size of a sugar cube. Got some chunks of paper towels to light with and my lighter. The melt was ready to go. I dropped in the cube of wax, not sure of what exactly to expect. Grabbed the chunk of paper towel and the lighter and lit it. Now I have to admit, I really thought Sagacious had lost it when he said to light the smoke as I had never seen or heard of that being done. Thought I was performing one of those magic shows when I introduced the burning paper towel over the melting wax cube. Poof! Scared the tar out of me. It flamed a bit higher than I expected, which worried me some. Grabbed the long handled ladle and commenced stirring. Got a ton of smoke with the parafin, so will try to get some bees wax for future use. Once the smoking died down, I skimmed the sludge off the top and started casting. Oh yeah, I also lowered the pot temp. Casting went flawless and the melt was sludge free. No more dross whatsoever throughout the entire casting session. Can't believe I have been doing it wrong for so long.

Sagacious, I want to really thank you for sharing and teaching. Without your help I would still be destined to a life of mega-dross. Wow, I am so impressed. Anyway, thank you a thousand times over. If ever you need something that I may be able to help you with, you just ring the bell and I will answer.

Guys, this has been an amazing post, that I think (from what I am reading anyway) everyone has learned from. I would love to have Sagacious come to my shop and show me what else I may be doing wrong, but that is just wishful thinking, but you are invited if you ever get to Oklahoma.