Flux

[Harry]

Just wondering if any of you guys that I have sent the flux I use have tried it out?

I came across the bottle with the Mortons lite salt chunks that I melted up a couple years ago on the advice of using it as flux and it jogged my memory on this. I have not used it since getting real flux because of the differences in my own impression of how they work. I never much liked the way the salt flux went to a watery liquid that would soak into a SiC or Graphite crucible. The foundry flux does not melt, at least that I can see. It seems to create a reaction with the dross that causes it to get hotter melting the aluminum metal out of it and leaving a crumbly, dry sort of dross.

Awhile back I had tossed a good handful into my scrapping furnace at the end of a scrapping run, when I cleaned the furnace out all of the dross was scooped into a steel pot. The reaction was still running in the dross for a half hour or more, the top would skin over as it cooled but when disturbed it was clear down inside it was still near yellow hot. The next day the pot full of alumina was all crumbly pieces like coarse sand and there was a puddle of aluminum in the bottom that had leached out of the dross.

Anyhow, wanted to post this because I would not recommend the use of salt as a flux, it might work but you will not get the same results and I have to wonder what it would be doing to a crucible or hotface when direct melting if enough was added that it could soak into it. I dont even flux often, I think by using good metal to begin with and keeping the temperature and atmosphere correct it just isnt needed. You might skim off a little extra metal but whats an ounce or two when pouring ten pounds? I do use flux when ending a scrapping session, mainly because it makes it so easy to clean out the furnace with the dross ending up crumbly and the metal pretty much all removed.

[dallen]

I've been using it but have yet to figure out how much to put in like and A4 crucible, I have gone as far as to put some in when I start the melt with the first charge, then add some more later on top. I have noticed that there is a lot less metal left in the dross when using it, I have also been using the degassing tablets I made a flux tool but I didn't make it big enough for my larger crucibles, with this I put some paper in it and ram it into the other end then pour in the crushed degass table, I don't need a whole one in an A4 plug the tool with paper and plunge it in seems to work ok I get a lot of bubbles, I found a weld on fence top that I am going to drill a hole in and weld a rod in it then, take and make some small like life saveers our of the degass tablets with SS and see how it will work, someone on one of the other fourms mentioned doing it. the tablets don't do any good if you don't get it to the bottom of the pot.

Small Foundry supply has a flux that says to be a furnace cleaning flux for cleaning the walls.

I find that lot of people that are into this as a hobby don't really want to get the proper tools, crucibles, and fluxes I guess they think that 10 dollars worth of flux will break the bank, But I woulde rather spend 10 dollars on flux then on propane redoing botched melts.

I have been trying some grain modifers that I got off evil bay, but haven't messed with them enough to know if they are making a differance. I also have some degassing tables from Asbury chemicals one is a degassign tablet and the other is a titanium modifier, It would be better if I could melt more, but my requirements are sort of on hold till I get the muller finished. I found out yesterday that the earings for the wheel had to be backordered adn didn't ship till yesterday, so I should have them in the next ten days HOPEFULLY, or I may expire as an ole gray headed man before I get the damn thing done.

And Harry your right it doesn't melt as far as I can tell, unless you put it in and get it hot enough to melt then back the melt temp down to pouring temp, from what I been reading in this book that "jammer pointed me towards, The other day the last melt I did I had put the flux in the curcible with the inital charge wehn I lite the furnace and what was up towards the top fo the pot looked like it was melting onto the metal, retco has a pretty good article in their catalog about using fluxes and degassers with aluminum. I'll see about scanning it wait I already scanned it and sent it to a guy in oregon. I'll find an post it we got a file sections

Remembered that the article that I mentioned was on the computer that crashed so it may be a few hours before I get it rescanned and posted informitive article or I thought it was
David

[Harry]

As I said I do not flux most of the time. In my mind the biggest benefit of fluxing is to release the dross from the metal on top of the pot, I just take a little metal with the dross and discard it (well I keep a pail next to the furnace and toss the chunk into a barrel when it gets big enough so I am not throwing it away). After pouring about two tons of aluminum I have probably close to 100 lbs in the barrel. I will most likely run this through the scrapper and flux it then to recover the metal. I like the dross provided after using this flux, it is a granular aluminum I am thinking could be used in a refractory.

I agree wholeheartedly that spending a few bucks where they give good returns is a wise idea. I got over using steel crucibles very quickly using my home made refractory crucibles but even though those worked great I did not feel like it would be a good idea to make them of much size with the ~A7 being about as big as I would consider using. After spending $100 per for SiC #10s and seeing how long they held up (well over 200 melts on the current one) that sealed the deal with me. Even for someone who is not looking to make money in their foundry the right tools will be safer and make for better castings with less problems to try and sort out and in the end not be much at all per pound of aluminum poured. This is the same for source material too, use good known alloys to get the properties you want in your casting and you will spend very little over using found scrap of unknown or unwanted alloy.

Anyhow, good to hear your observation is the same on the flux. I was very impressed with how long the dross held heat and actually continued to make heat when a lot of it was placed into a container. When scrapping out wheels I saw a volume of maybe half a gallon of dross after about 20 wheels (~400 lbs). After scooping this out of the furnace into a steel pot it continued with an intense glow for quite a long time. I will have to get some video of this next time I scrap, it was pretty fascinating.

[4cylndrfury]

I found a local foundry supply place (local being in the same state lol) and Im going to see if theyre interested in shipping me a decent SiC crucible, and I think Im going to look into some real flux after reading this. I have noticed that the rims of my refractory crucibles do get brittle over time (maybe a few dozen melts) and Im guessing its the lite salt flux...still for now, the cheap factor is a big one for me on ref crucibles.

I have gotten better about keeping the right atmosphere in the furnace and have noticed a decreased amount of Dross, so I have been fluxing less. Still, actual foundry flux would be nice. Do you have a brand name for the flux you get Harry? Also, IIRC, Starbide is the brand of crucible
you use correct?

-Drew

[Harry]

Yes Starrbide (with two r's I believe). Dont remember the brand on the flux but I was told the stuff BCS sells is the same, Ashbury something.

If you are going to have a crucible shipped then it really doesnt matter if it is in state or not. The quote I got from MIFCO was reasonable (product price and shipping) but I was able to get a deal through my local supplier (like you local = same state, 3 hr drive each way) so I went with them, same brand on the crucible.

I liked my refractory crucibles, they lasted longer than the clay graphite ones I purchased and just generally felt better than the clay ones did. The only thing is I would not want to use them for larger pots and maybe they are not quite as efficient with heat transfer though I never saw that as an issue because I can make as much heat as I want.

[dallen]

4CyllinderFury, I was going to say the Retco was in Ohio, but after looking at the address on the Catalog i find that they are in Illinois. Ohio is pretty big so it might not be very close to you.

4CF their not close to you but they do have some pretty good prices on fluxes and they carry cover fluxes and drossing fluxes in differant temp ranges thats Small Foundy Supply outside of St Louis Mo. They also carry cover fluxes which as we all know air is what causes the oxides to form on the surface. I keep meaning to order from them but haven't gotten around to it yet. Freemans Foundry Supply is in Ohio I have done business with them nothing bad to say about them.

Harry, I agree with what your saying about the flux and crucibles, I bought mu silicon Carbide for Iron and thats all I use it for, I had one in an A6 that I did melt some aluminum in before I started in melting Iron but once you put iron in one its pretty much not any good for anything but Iron. Because of the mess that gets left in the Crucible. I buy most of my clay graphite crucibles from Legend Mining Supply, they have decent prices on there crucibles and the Fire Clay ones that they sell are made by A P Green, I'm not sure who makes the Clay Graphite ones, and the Silicon Carbide ones are Morgansite I belive. Mifco sells as you say Starbrite, they are good. I have always gotten good service from Mifco and the shipping from them isn't too bad.

One thing that I would like to see is some tongs and shanks at a reasonable price that a persone could afford to buy, I make all of my own lift outs and pouring shanks, but its pretty easy when your dealing with the small size crucibles that I am using right now, Even the A 10 that I pour Iron with, the pouring shank wasn't hard to make. but when you get into shanks for two people or ones that are used by overhead cranes you better go to the bank and take out a second mortage on your home to buy one.

One thing that does happen with using the flux with all melts and using it in the manner that it was made for is that it washes the oxides out of the melt that is below the surface of the crucible, now this is what I have been reading and its not just in one atricle but basicly in all the books and articles, What this means is that if you use the flux correctly you won't end up with oxide inclusions in your castings. the one thing I can say is that if you don't have problems don't change what your doing.
I tried the Lite Salt and I tried a mix of Salt and Borax, and I didn't really see where it did anything, for one if your using the salt without premelting it, its not going to melt on top of the molten aluminum because most people are not going to have the molten metal hot enough to melt it. Once its been melted and mixed together and it cools off the chiemicl change that goes on lowers the melting point of the salt so that it will do what its suppose to do.
The first commercial products that I used was degassing tablets from BCS, I didn't know how or how much to actually use so I didn't get very good results with it, still have the stuff and have been using it, along with the Degass Tablets that I received from you and some that I got directly from Asbury by emailing and askig for a sample, they sent me some degass tablets that are by conparison to Harrys pretty small and are Gray in color and look to have metal in them, they also sent a sample of a grain modifier which The one time that I used it and tracked what I was doing cause a major differance in the way my metal was after pouring, It machined 100% better than what it had been doing.

My greatest problem after pouring is that the metal acts gummy, heck the flask sides I got a better finish with a Vixen File then I did with a Brand new cutter in the mill.

Sorry for being so long winded, thats what happens when you get old and have nothing else on your hands.

I received the Bearings today so maybe this weekend I will try to mix some sand. I have put off work on the flask till I get the muller done that way I don't have to empty it out.


David

P.S. think I'll go to the junk yard tomorrow and see if i can find some 6 inch square tube to make a flask out of. for small items like vibrators and buckles.

[Harry]

I did not notice any huge difference in machining after using the strontium and tibor grain modifiers but then I am not much of a machinist so you can take that with a grain of salt. It does seem to help a lot though just letting a casting set for a couple of weeks before machining it. I believe I have read that in a years time natural aging will bring cast aluminum to the same hardness as precipitation hardening. I know very little about all of this but I can see it something like concrete where the big changes happen in the first month then it continues to slowly change for the rest of its life.

[4cylndrfury]

Thanks guys for the info. The starrbide crucibles seem like exactly what I want for the long haul...probably will try to get one for Al, one for bronzes, and when the time comes, one for Iron...one day!

I did find a foundry supply place in Ohio, in Dayton specifically:

Dayton Foundry Supply
1531 Keystone Avenue
Dayton, OH 45403-3335
(937) 258-9531

Dayton is about an hour drive more or less for me, so its not too bad. I have a co worker who lives near there, I may try to get an order paid for over the phone and see if this guy would be willing to bring it by...likely just a crucible, and some flux...maybe some ingots or perhaps some petrobond clay if Im feeling really crazy. (a lot will depend on what they carry and their pricing...).

And for degassing. Im going to try to whip up a 10" long x 1" wide tube with a 1/2"wide bore, made of refractory. I will cast it with some thin gauge wire running through the walls. Once set up, I will attach it to a longer steel rod. The idea is that i will place some degassing material into the open end of the bore, and the small holes left by the wire will allow the degasser to escape and bubble up through the melt. The tool being made from refractory will keep steel from contaminating the melt.

[Jammer]

That would be about 2 hours for me. They don't have a website??? Tell them to come to the 21st century, I don't care for all this pooter stuff (was rooting for Y2K), but if I were a business, I would sure try to get my info out there.
Maybe they have a catalog.

[dallen]

Thanks guys for the info. The starrbide crucibles seem like exactly what I want for the long haul...probably will try to get one for Al, one for bronzes, and when the time comes, one for Iron...one day!

I did find a foundry supply place in Ohio, in Dayton specifically:

Dayton Foundry Supply
1531 Keystone Avenue
Dayton, OH 45403-3335
(937) 258-9531
I haven't heard of this one before but then there are a lot of places that are not on the internet.

Check the locateing supplies thread I posted a listing for an outfit that is located in Orrville Oh.

And for degassing. Im going to try to whip up a 10" long x 1" wide tube with a 1/2"wide bore, made of refractory. I will cast it with some thin gauge wire running through the walls. Once set up, I will attach it to a longer steel rod. The idea is that i will place some degassing material into the open end of the bore, and the small holes left by the wire will allow the degasser to escape and bubble up through the melt. The tool being made from refractory will keep steel from contaminating the melt.

All you really need is a short piece of 1/4 or 3/8 inch pipe welded cross ways onto a say .125 X .750 flat bar, no longer then it will be in the aluminum it won't contaminate the melt with iron and the flux and degass power is rolled up in a piece of paper and plunged to the bottom the melt holds it in the tube when the bubble stop pull it out.
One thing BCS did was to put a good discription on their site about how ot make and use one, I saw a youtube vid that showed a guy fluxing brass or bronze with one that had a cone on the end of a long rod handle that he put the flux in and plunged it into the crucible.

BCS also sell copper nickel shot which is used ot degass brass and bronze, C.W.Ammens expounds on this in his brass melting book about what the shot does.

I gotta find that other foundry outfit that I emailed the other night hunting VG-69 powder. Can't remember if I marked it or not.

David