Pyrolysis is word someone uses when they don't think just burning something sounds impressive enough. Not trying to educate anyone, just questioning whether any of those enhancing chemical reactions actually occur from something that's mostly carbon....and information and misinformation aren't the same thing, that's all . Now if as Mark suggests, it's merely an inexpensive and expandable means to control the surface of the pour, that seems reasonable and practical. Do you use wood in your melts and metal conditioning? Best, Kelly
How much zinc is in that bronze? I've never seen bronze poured in person, to my knowledge (nor have I seen brass) but that stuff looks uncommonly fumy.
I don't have enough brass experience having been focused on iron casting to the point of cross-eyedness. I've been skimming my brass like crazy just before pouring and still having problems with oxide skin getting folded into the casting and even below the surface that gets exposed with machining and just assumed flux would be the end of my problems. It is LG2 leaded gunmetal bronze: 85 and three fives, 85% copper, 5% each of lead, tin and zinc. As mentioned before it was poured hot, as sections of the castings are around 1/4" thick in places and the smaller crucible of around A16 roughly was giving flow problems compared to the usual A25 crucible with it's slower cooling.
Is there a less fumy version? I do not wish the zinc fever, especially given that I must wear a respirator when welding stick. (I suspect I might be more sensitive that way than most.)
I simply stay upwind as much as possible and keep the doors open to get natural ventilation or also cast outdoors.
That is not fumy (sic) at all, watch some of my videos pouring 60 40 brass but 85 5 5 5 is really bad to breath because of the lead you need a respirator rated for welding fumes V/r HT1
#2097 p100 filters, correct? Sounds like less lead and zinc might be a good idea. Also tells me why 90-10 bronze is so popular in the group (that I do foundry with) - no lead/zinc to get fumed up with. 87Cu-10Sn-2Zn-1Pb? (Machinist's Handbook)
yes! but the explanations I found for Pyrolysis where much more relevant then the ones for Hydrolysis I use Sawdust on Aluminum as mentioned in other threads, and it seems to work very well, much better then pool shock the issue with pool shock is it absorbs moisture and once it does that, it ads rather then removes gas, and if you use too much you will get brittle aluminum( No idea what is going on chemically there, but i have seen the results a lot . on brass( A proper Yellow brass 60 40 or 70-30) no degassing or flux is used , just skim off all the oxides with a proper skimmer, and pour on Tin Bronzes like the above mentioned 85 5 5 5 or 86 8 4 you may need a flux if your metal is nasty , or you are pouring slowly, lead and tin will continually create dross ( Looks sort of like black small curd cottage cheese you will see it on top of the ingotsoften) , you need a flux or an active skimmer (The third person on a pouring crew not the tool ) his only job being to ease back the dross the tiniest bit from the lip of the crucile and hold it there creating a clean stream of metal , the rounded edge a proper skimmer is best for this, not a piece of bent over flatbar , but the flatbar works well with a flux, because the flux creates a larger clump and you actually just ease back the whole clump ( Im kind of in the weeds here trying to describe "technique" and there are tons of variables that make one technique work well in one place or with one material, but not others) tin bronze will almost always need to be degassed most commonly with Phosphor copper but there are other degassers Everdur Silicon Bronze needs nothing, but there are commercial degassers for it if you think it is gassy Aluminum Bronze Has commercial degassers https://www.belmontmetals.com/product/26-aluminum-bronze-degasifier/ V/r HT1
that is the correct respirator have not seen anyone advocating C92600 here??? the artists all want Everdur Silicon Bronze UNS C87300 super easy to cast, no fumes, and it is readily weldable seems the most talked about alloy here Your choice of metal really should be based on aplication, that is what matters, in the video, they where making Heat exchanger end bells? 85 5 5 5 is a perfect alloy for that water tight,, corrosion resistant against salt water easily machinable, and brazes well I make Plaques bright shiney cast thin, inexpensive 60-40 is perfect ( I add a lil silicon, to get it extra fluid, for the thin stuff) some of my pieces break the minimum thickness rules if someone asks me for a more traditional "red appearance" i run 85 5 5 5 just because it is readily available as scrap plumbing fittings in the Navy we ran G metal 86 8 4 for marine applications or Manganses Bronze for Plaques M Bronze is known as High strength Yellow brass , it is commonly found as brass gears its very wear resistant V/r HT P.S. ill shut up now V/r HT1
What I'm after, loosely speaking, is: 1) No/low/minimal fumes. 2) Readily cast and machined. (90-10 is grabby. I've extracted broken drill bits from this stuff - others put them there. Luck, good and bad. Good, that I could extract the busted bit - it was not easy. Bad, in that someone else was unlucky enough to break a drill bit off in the casting.) 3) Solders readily, hard and soft. 4) Works passably as a bearing surface. 5) Reddish color is a plus, but not required. Have secured phosphor copper, and am accumulating the other supplies(?). I take it the picture is a "proper" casting skimmer? (No, no insults intended. If it is, I'll assay as close a copy as I can manage! I did download the picture.)
I hope I don't pollute this thread but it reminds me the sad story of Paw-Paw in the early 2000's. Zinc fumes are nasty, it's relatively easy to work safely though if you're cautious enough. Fumes are visible, it's not a danger you're aware of when it's too late.
Well, zinc is the only metal in usual alloys with such a low boiling point, below the melting point of the alloy. When it is melted together it is OK, but when putting a piece of zinc in metal over the bp of zinc, it is just like putting a piece of ice in hot oil or other liquid above 100 C. For the fun I tried once pouring copper over a piece of zinc and it really made a lot of noise and green flames.
I've mentioned it before but I've had zinc fume poisoning and it is seriously unpleasant. I was brazing galv for a day hanging over the work and not enough ventilation. I was a lot younger then and it took a week before I could get out of bed, these days it would probably finish me off LOL! Imagine the worst case of proper flu with pounding migranes.
Some might well treat metal-fume-fever lightly. I was born with breathing problems - no, I don't have emphysema, as far as I know - but pollution makes me really sick, and being near stick-welding is a whole lot worse. I'm not inclined to chance such matters more than I need to.
It is just a poison, someone here will give you a proper medical/biological type response (the diversity of knowledge here is amazing) It's akin to CO posioning in affects, don't ask me how I know. Good ventilation and staying down-stream, as HT1 suggests, mask if you feel the need.
Im one of those people it just doesn't bother much, if I Pour several days in a row I get the 48 Hour immunity , otherwise a glass of milk, some fresh air, I'm fine V/r HT1
The description I’ve seen is, it’s unlikely to kill you, but for a few days it’ll make you wish it had.
It killed at least one person, Paw Paw from Anvilfire. Not something you may encounter as a hobbyist, a safety reminder, though. https://www.anvilfire.com/iForge/tutor.php?lesson=safety3/demo
Uh, looked that one up, and it roughly corresponds to 87Cu-10Sn-2Sd-1Pb - with a hint, perhaps, of Nickel. I have the nickel. Now just need to get a few (pounds/kilos) of Tin. (And make a set of tongs to fit an A4 salamander...)
This get a mention in an article on Hackaday: https://hackaday.com/2021/04/12/zin...-risks-of-working-with-hot-metal/#more-469245
