Hey what's up guys, we are back.
Huge success with the pokeball castings
except from the bubbles.
The bubbles are our number one enemy and we need a way to get rid of them.
I 've got a lot off suggestions in the comments saying we should build a vaccum chamber
so we can extract the bubbles,
So our silicon and plaster castings are as perfect as they can be
so that is exactly what we are gonna do today
So I've gathered up these materials and we're going to spend our afternoon together
Building ourselves a vacum chamber.
This here is a twelve inch stainless steel cooking pot
And we're not going to need the lid, we just need the pot itself
I also stopped by a hose supply company and picked a bunch of various fittings.
We have a couple of quarters inch shut off valves,
We have a quarter inch cross,
Three quarter inch male to male nipples,
(That's actually what they're called)
A quarter inch hose barb
And a fitting just to connect them up to a vacuum pump.
And just for fun, I picked up a liquid filled vacuum gauge as well
This isn't really necessary, it's just going to show us what pressures we're holding inside the vacuum.
So we have got our pot, we've got our fittings,
We've got our vacuum pump
And now it's time to put them together,
And for our lid, I'm using some of this three-quarter inch, crystal clear acrylic.
I'm using this stuff because we're gonna be able to look down inside the chamber,
and see what's going on.
Now, acrylic is pretty brittle,
and under vacuum pressure it can implode.
but three-quarters of an inch thick should be more than we need.
That should give it enough integrity to hold up to the pressures we're gonna put it under.
I'm also using some clear poly tubing for the vacuum hose,
But if you look closely, you can see the stuff has really thick walls.
So when we pull a vacuum it's not gonna suck in on itself and collapse the tube.
Now this sheet of acrylic is way bigger than we need,
And frankly it's quite expensive,
This piece right here probably costs about $100.
But all we're gonna need is a section just bigger than the mouth of the pot.
So we're gonna flip this thing over, use a sharpie marker
And draw around the edges,
Leaving about a quarter to half inch overlap all the way around.
Let's go grab ourselves a jigsaw, and cut this thing out.
This is a vacuum pump I picked up from Harbor Freight,
It was one of their higher-end models, but still really cheap.
This one goes down to 22 and a half microns which is honestly overkill for this project,
But I got it just in case,
But you never know what might be down the road, it might justify the expense.
Vacuum pumps are designed to suck air out of objects,
And the air gets sucked into this little port here.
So to make it a little easier I picked up this little fitting
And that's gonna screw on
This is a ninety degree elbow
that'll connect to our hose,
So we can swivel it any direction we want.
Once our ninety degree hose barb is attacked, we can take our hose and just press it over top.
So we've got our three quarters inch acrylic lid, we've got our pot, we've got our vacuum pump,
This is the part where we put them all together.
This little tool here is called a tap
And it's for making the little ridged grooves for screw holes.
This is a quarter inch NPT, that stands for national pipe thread,
And for this one we need a 7/16ths drill bit to drill a pilot hole for it.
now to drill the suction hole in the lid, we can really put it anywhere we want,
But I'm gonna put mine closer to the side, and here's why:
If we ever wanna flip this thing over and use it as an acrylic base,
We can put something like a glass bell jar over top so we can see the reaction happening.
However if our hole is in the middle, any object we put in the middle is gonna block the suction.
But if we have the hole near the edge, it should still be able to work in either direction.
So there you go, now we have a threaded hole in our acrylic lid,
And at this point we can go ahead and remove the paper,
because we're not gonna be machining it anymore,
So let's go ahead and throw on some thread tape,
Get all these things connected together, and get ready to finish up.
So here's the idea of how this works:
We've got our pot with the lid
And when this thing is closed,
The vacuum pump will suck air out of the system.
Now we've got these little ball valves here so we can actually close off the vacuum,
turn this thing off and it should stay.