F.I.R.E. 2019 on the River (Foundry Invitational & River Exhibition)

There will be a F.I.R.E. Exhibition at the Metal Museum May 16th - May 19th.

I had the Metal Museum folks over a few months ago to demonstrate crucible iron melting, and they had not seen that before (they do cupolette iron melts), and so they asked me to do a demonstration at their FIRE event.

I will be an unofficial guest demonstrator.

The folks at the Metal Museum have been extremely helpful in showing me all their foundry techniques, especially their bound sand molding process, so I really owe them.

I will have to transport the new furnace, but luckily it is not that heavy; probably under 200 lbs total.

And if nothing else, this will give me an opportunity to get caught up with some iron castings, such as bearing caps, windmill gears, etc, if I don't get to that before the exhibit.

It should be fun.
Hopefully I won't drop the crucible or something, but those folks are use to slinging iron all over the place when they tap the cupolette, so no big deal.

https://www.metalmuseum.org/fire

Here are a couple of iron pours done at the Metal Museum a few years ago.





Edit:
I was talking to the guy who did the seminar on backyard casting at the NAMES show the other day, and said they use to do an aluminum demonstration at NAMES outside the building, but he was all nervous about how dangerous it was. I told him that he would have a heart attack if he saw how much iron the Metal Museum people sling around on a regular basis.
Iron pours are not for the faint of heart.

.

 

Hopefully the weather will cooperate.

I have encouraged the Metal Museum folks to make a permanent crucible furnace so they can do iron work on a more routine basis.

As it is, they only pour iron a few times per year, and put on a big show with the cupolette, but it would be nice to do iron more than just a few times a year.
The do aluminum pours/demonstrations/classes pretty much year around, and some bronze work mixed in to.

I will set up a power supply and plug in my dash cam, so that I can take a very long video of my entire melt/pour.
I could probably mount it up on a pole, perhaps 8 feet in the air.

If I get burned, somebody needs to upload the video to y-tube so I can at least get some view counts while I am recovering in the hospital.

.

 

Will do.

They will be running two cupolettes at once during the events.
They anticipate using 7,000 lbs of bound sand and I forget how many lbs of iron, maybe one or two tons.

Artists come from around the country to make stuff, and they do some serious iron work.

.

 

That is one of the coolest videos I have seen in a while.

Here are some photos I took today at the Metal Museum while I was down there getting ready for the FIRE show.

They bought a new muller.
I think it is a MIFCO.
It runs extremely smooth and very quiet; you can barely hear it running.

(I will upload some photos in a minute).

 

That casting demo at names was great to watch but they let people wander around the furnace while it was running. I would have thought that they would stop people getting too close to the furnace.

 

They usually rope those sort of things off.
They did not do a casting demonstration this year.

I did not find anyone at NAMES that did their own iron castings, other than a guy who cast locomotive parts.

More photos from the Metal Museum.

 

Quite a place. Interesting using a cobbler's nail tray for making ingots.

 

They probably cast it too.

 

The last four photos are the smith shop.
The foundry is a separate building.

.

 

I made a 3D printed scratch block sized plaque for the F.I.R.E. exhibit which is coming up next week.

I did not have much time to spend on this, and thus the comic book style font (that is all I had time to do).

And the 3D printer filament ran out in mid-print, but luckily the Prusa printer allows a recovery, and I grabbed some orange filament, and the effect was pretty interesting.

Hopefully I have enough draft in it.
I could not get as much draft as I wanted due to program restrictions.

 

Nice looking block for sure. No reason to apologize for the font which I think looks quite cool.

BUT, tell me/us about machine restrictions that limit draft. That sounds very concerning for printing patterns. Or is it somehow related to the font/machine interface?

Denis

 

Solidworks allows you to use a draft angle when you are extruding shapes, but........if you have wonky shapes like those curved letters, the program would only allow 8 degrees on some shapes, and less than that on other shapes.
I went back and used some fillets, and that helped a bit, but the program still struggled trying to fillet the compound curves.

I can manually fill it in a bit with sheetrock wall patch compound, if necessary, to get more draft angle, but am hoping to avoid that.

I am also trying a new product used for pattern release, which is a liquid similar to "Zip-slip", but a different brand (Alumapart).
It is alcohol based (I think), and is silver in color.
You paint it onto the pattern, and it helps with release from the sand.

There was one guy on the other forum who worked in a foundry, and he said he HATED !!!! products like ZipSlip, because if you have to modify a pattern, then nothing will stick to it ever again after Zipslip has been applied.
But I have noticed that commercial foundries often use the stuff, and so I am going to try it.

I have been using paste wax as a release again, but you have to keep waxing after every mold is made, and the wax does not seem to be long lasting.

.

Edit:
I am getting everything sorted out to take down to the F.I.R.E. exhibition on the River.
I am also sorting out everything needed to make resin molds again.
I got all the Mizzou cleaned out of my mixing bowl, and cleaned off of the mixing wand.
Power wire brushing that stuff creates a cloud of dust (use a good dust mask).

I am going to try to make a test mold tomorrow with the resin binder, and be sure it is still usable. I think my resin material must be at least 3 years old, maybe older.
I have new type of binder standing by, but I would like to stick with the old resin binder for the windmill gears and bearing cap since I know exactly how to mix and use it, and the results using it are excellent.

I am also going to try a mold wash, which is "Velacoat ZA 9078", and it is an alcohol-based mold coating that is sprayed on.
I will try this material on my test mold before I start making the parts mentioned above.

 

Comments:
1) It is interesting that Solidworks struggles a bit with draft angles. 8 degrees would be a lot of draft. Just 2 or 3 should be more than enough especially since you are using a bound sand. Even on green sand just a few degrees should be enough.

2) Sheetrock compound would be OK I guess, but bondo sticks so much better and is so much stronger.

3) Just plain silicone spray has worked perfectly for me on bound sand molds and cores and is so easy to apply and so available---corner hardware. If you have not tried it, I would suggest you give it a whirl. My guess is you have already tried it.

4) The guy who complained that ZipSlip or other silicone-containing products once are applied to a pattern will subsequently prevent sticking anything to the pattern is really exaggerating the problem. It is true that release agents do, indeed, try to release stuff applied to them. But, I have had to make modifications to my patterns countless times after the commercial foundry I used to employ applied ZipSlip to my pattern. I just sanded and scraped off the silvery slippery stuff and then used SHELLAC sprayed onto the pattern and then applied Bondo and/or lacquer. Often the lacquer would "birdseye" for the first coat or two, but a little more spot sanding and another coat of shellac or lacquer solved the problem. Shellac seems to be a very good bridging agent between silicone contaminated surfaces and subsequently applied finishes and fairing agents or even glues.

5) It might be interesting and instructive to just try casting the block with the simplest approach---silicone spray to the pattern, coal dust in the bound sand, and no mold wash or ZipSlip and then, if needed, add in the fancy stuff. A side-by-side would be really interesting.

Denis

Denis

 

It does that with compound curves.
With a more normal shape, it works fine.

I have had trouble with bondo being too strong, and I end up gouging the wood pattern when trying to sand the edges smooth, since the bondo is much harder than the wood.

I have a can of silicone spray in the shop, but I never use it, and don't recall why I bought it.
I think I used it once, and it just coated everything with this super slick finish that seemed to migrate to every tool handle in the shop.
So it is the super slickness of the stuff that may indeed make it work so well for a release agent.
I have not tried it as a release agent, but I will do that, and compare it with the silver stuff.

I use shellac religiously on patterns because it dries very fast (like 15 minutes), sands easily, and seems to be compatible with most other coatings and pattern materials.
I don't think the Alumapart will be a problem if a pattern has to be modified.
Any problems caused by Alumapart will be minor compared to an uncoated pattern sticking in bound sand and causing damage to the sand when the pattern is pulled.

I do have some coal dust, but have never used it.
I bought it to use with green sand.
I think either the coal dust or the mold wash should be used, but not both.
The mold wash is going to negate any effect the coal dust would have, since the mold wash will seal the mold.
I think coal dust is a green sand thing, although it may work with bound sand if a mold wash is not used.
The bound sand is going to seal the coal dust, and it will be solidified in the binder, so I am not sure if it will have any effect with bound sand.
You would need to add additional binder to compensate for what would be absorbed by the coal dust, assuming you mixed coal dust in with bound sand (which I would not do).

I think the silicone and the Alumapart will work about the same; they seem to have about the same slickness.
The Alumapart gives a bit of a visual indication when it is getting thin, since the pattern color starts to show in places that need recoating.

I am not a fan of mixing additives into sand if they are not needed, and so far I have not needed to add anything to either the molds or the cores.
If it's not broken, don't fix it.
I have seen more than a few people do stuff as a matter of routine, and also had others debunk the need for that same stuff, and I have run the same tests and also proven that the stuff is totally unnecessary and ineffective (this is not referring to melterskelter, but refers to others who shall remain namless).
So I don't use anything or any method unless I can prove it personally, and repeatedly.

I have had surface finish problems.
The resin bound sand produces a pretty good finish, but there is a slight variation between the top and bottom of the mold, with one being slightly rougher, and so I hope the mold wash gives a finish superior to what can be obtained with just bound sand.

Below is from a coatings brochure:

 

Here is a photo from a white paper by Anton Gieniec comparing furan binder with PepSet binder.
This has nothing to do with core wash, but this is the level of improvement I hope to get by using Velacoat with bound sand.

 

Coal in silicate bound sand works very well and prevents burn-on and burn-in.

Here is a Coal/Silicate core falling out of an iron casting and the casting finish.