New Pattern in Progress, for Casting an Aluminum Bronze Pipe Hawk

I bet you could use a follower like that more than once if you tried to be a little bit careful ramming it up... It might chip a little but even then it would still save a lot of coping down.

Or you could make a double shrink pattern, cast and use a plaster follower to mold and cast the pattern, then cast a copy of the follower to match it... I think.

Getting some ideas now... Maybe I could cast metal copies of my coreboxes the same way!

Jeff

 

Thanks, good tips!

Jeff

 

I added some more putty after someone on the internet pointed out pix of forged steel pipe-hawks that are beefier than my pattern was at the blade-to-eye connection. It has been sanded and repainted since, I think I'm just about done making the pattern... For real this time.

I used up all my nice clean silica this summer making greensand, so I picked up another small bundle (75 mesh) from the pottery supply around the corner from my office to make cores with. Noticed they also sell sodium silicate while in was there, but the girl could not figure out how to print a label for one of their pint containers, so she wouldn't sell me any. Oh well, it is really close by, so I don't mind going back after her boss gets it all ready for me. I still have plenty of wood stove gasket cement, but it should be fun to try the proper stuff for a change.

Muller is all greased up and ready to go, so maybe I'll start freshening my sand up after work today. With this cool weather, I expect it won't dry out again before the weekend. Which is when I am hoping to cast it.

Jeff

 

Lol, good idea

 

It does. A little more setup is needed since the handles are tapered, but that does seem like a good approach!

Jeff

 

New pix of completed pattern modifications:




Picked up the sodium silicate from the pottery supply place around the corner as well. I have enough sand mulled to make the mold; I'm gonna use my old Smelko Foundry Products blend for facing and the homemade stuff for the rest. Still on track to cast this thing this weekend. Woohoo!

Jeff

 

That deserves to be on a match plate with some good gating.

Best,
Kelly

 

I made one something like that a few years ago, but the geometry of both blades was all wrong. A friend has that one now, and says he does use it on his farm (all crops there are legal since long before October 17). But I'm thinking it's making him work harder than he ought to have to...



Maybe I will make a match plate for this (the pipe hawk). I've never done one before, it would be a fun project.

Jeff

 

Well, one of my coreboxes cracked a bit because I baked the cores still in them. Because the 'real' sodium silicate ate from the pottery supply isn't thick and gooey like the woodstove gasket cement I'm used to using, so the cores won't demold clean until they are cured.

I think I can get both coreboxes to survive sanding some draft on them and casting them in Al. Aluminum coreboxes would survive baking. And slightly shrunken cores that would come from the cast coreboxes would fit coreprints made by a cast aluminum pipe-hawk match plate better anyhow. I think. Right?

Anyhow, the cores got plenty hard. Maybe next time I will add a little bit of the leftover dextrin I have to see if burning it out will make the cores collapse a bit easier, I had to bash away at them for a while to chip them out of the casting.

Got out there this morning to cast it. It went pretty well, but I used up the last of my wvo, in fact I would have run out mid melt in less than a minute probably. Close call! Guess I could have turned the propane back on if I needed to...

Pictures!

Just poured. After the last runout, I decided to weight the mold this time:



Looks like the feeder fed...



C954 ingots turning rainbow coloured as they cool in their greensand ingot molds:


Cope side of raw casting with gating still on. This weighs 1850g, just over 4lbs.


Drag side:



The eye came out nice and smooth inside. And yes, I accidentally cast some aluminum bronze wire in the core vents again:



The bowl too. There is a small thick spot at the base of the bowl that had no feeder. Looks like the shrink behaved itself and stayed right where I have to drill a hole anyhow!



There's always one of these damn boogers! This one seems shallow enough to grind out I think:



A few funny spots from where I ended up futzing with the mold a bit, again I think it'll all grind out, and they can be avoided next time.




All in all, I think it'll clean up nice.

Gotta get a new blade for my bandsaw to chop off this gating before I can see how the handles are gonna fit. Heading to the hardware store to get that after dinner.

Woohoo!

Jeff

 

Thanks Mark. I still haven't gotten the booger just like it in the last axe I cast tigged shut yet! Lol.

Jeff

 

Casting looks good, pretty shiny right out of the mold. Bad news though.. I heard Canada is completely sold out!!

 

Looks pretty darn good Jeff but think you would do better if you separated the sprue from the part with some additional length in the runner and gate. Looks to me like the mass of your sprue introduced some issues near the contact area.

Best,
Kelly

 

Yeah, you're probably right, I'll keep that in mind for next time. That area also got messed up a bit when I broke the sand a bit there while cutting the gate and then clumsily tried to repair the mold.

You might also notice that when I cut a bit of sand away from the fat end of the main coreprint in the cope to make room for a vent that would be connected to the vents in the core itself, I inadvertently cut it so it overlapped the top of the runner, filling the vents in the core halfway up with bronze. I don't think that really hurt anything, just something else for the list of ways to try and do it better next time.

As for Canada being sold out and all that, well, right now at least here in Ontario all the medicinal users are stuck waiting in line with/behind a couple hundred thousand recreational users and novelty purchasers whose plain brown parcels from the government-run monopoly were already late showing up a week ago. Poor bastards. The dealers that legalization was supposed to drive out of business have got to be laughing their asses off right now.

It may be going more smoothly in other provinces, as they are each dealing with it differently. To be honest I'm actually getting bored of hearing about it every time I turn around. Hopefully the novelty will wear off soon and everyone will figure out it really just means that some of the people who were pot smokers all along are trying out new dealers.

Jeff