Whats up with that 3rd photo? Lots of issues with the ends of those feathers... bbs' are nothing, but the porosity is another animal. Now the real work is here. You'll need to tig those and then grind back to shape. Anything can be fixed, it all comes down to the time to make it right.
Yeah that's what I was wondering too. It's only on that one side. I see these little damages fairly often. Would be nice to track down the issue causing them. I seem to have ironed out all the other major issues over the last 8 or 9 years with the forum's help.
C'mon you have to have gone by now! Ideas? Yeah might be the gating but it's strange because the sprues were symmetrical and the damage is only on the one side.
Alright.. give me a minute to wipe.... I've looked over your images and I cant wonder if your bronze was too hot? Everytime I look back at stuff I've poured that had any kind of surface issue, it came down to me overheating my metal. Case in point.. look at the tips of the feathers. If there was a metal shortage caused by spruing etc, you would have had gaping holes. Ya didnt. Just tiny imperfections. I would like to know if there was shell INSIDE those tiny holes... If not, what's the chance of tiny air bubbles being present in the very first slurry layer? Those are some real tiny voids and could only be created by something sticking out of the slurry as the wax was removed and remained behind to leave you with this issue? Some of this I'm just blowing air out my ass, but I still think the temp was too high.
The side with damage was at the same level as the side without. There was shell inside. And yes I did pour too hot. I saw burned shell clinging to the eagle after breaking it out but not on the subsequent 2 shells from the same pour (cooled by then). Maybe it contracted too much and ripped off shell from the walls? Strange because I poured at 45 volts on the thermocouple which is below 2150F. Maybe something was off about the measuring? Repairing the small defects is a bitch. The shell inside needs to be ground out otherwise it causes any more metal to blob up at weird angles and won't seal. By the way a hammer drill and concrete bit helped clean out the inside of my shell easily. Very surprised how well it worked.
Any loose shell inside will cause this. If you hear anything rattling around inside after dewax, I suggest to rinse the shell out with water. It's easier to grind back than add metal and have to reshape. Whatever was loose, floated into those areas and prevented the bronze from filling completely. sux man. I would bet any unremoved shell material on remelted bronze could produce the same result. I always bead blast my scrap clean before remelting as cheap insurance.
Makes sense. There was a bit of rattling in this shell. Must have just floated to the top on one side. Hmm. I'll have to try washing with water if I hear rattling next time. I haven't had issues with remelting shell. It is made of quartz which has a much lower density than bronze and so it floats to the surface where it is skimmed off. Not a problem. I'm a bit concerned about the chest plate. I attached it with about 1/8" of bronze. It will look ok but I wonder about strength. Hmm.
After dewax, the shell firing is mostly complete. I'm always stuck patching holes so if I have junk inside, I'll hear it. A fired shell can live on the shelf for years before pouring bronze. A quick trip back up to 1700 and its metal time. The first time you fill a shell with water, you will get to see firsthand how this stuff is permeable. Water will begin to soak through the shell. Try it sometime.
Before you set your mind on it being loose shell particles watch this video at the 16:30 mark. The inclusions at the tail area makes me think that its still a gating problem more than anything else...
Maybe. But why would shell be in the bronze? How would this be sprues better? Still need to repair a lot of feathers on the bad side. Not looking forward to it. Very tedious. I ground down the weld lines and re-sandblasted it. Tidied the beak up too. The feet go on tomorrow.
Was there shell material in all those spots?? Or did those spots occur in a centered location above the thickest parts of the casting??
There was shell material in all the defects. There was some shell jingling around in the shell before casting. I shook as much of it out as I could but some bits were still inside. I figured they were too big to exit the sprues so it is surprising that so many feathers are damaged instead of a couple here and there. Maybe there were more shell bits that I had thought? I think I still have some of the shell material that fell out that I could show you. I have also noticed a second problem with several sculptures. It seems that the shell material is delaminating between layers 1 and 2 or 2 and 3 and a thin sheet of metal forces it's way between layers. This is hard to remove. I'll shoot a quick video later today to show you where they appeared and the delamination. It's hard to explain with pictures. Easier with a 30 sec video.
I'm really not sure about the layer issue. There is a thin layer of shell trapped beneath the thin layer of metal. You can kind of see it here.
I'm not in love with your slurry... just saying man. Hit up their tech department on the phone. The solution for now is to never pour into a shell with loose shit rattling around in there. If it cant float up and to the top, it's going to end up where you dont want it everytime.
