Metal Melter

[prepman]

Looking like we're heading for a fail!

View attachment 345988

I won't know until all the PLA is gone but at a guess the wax was a bit hot and blew through the thin walls of the mould.

I'm wondering if when I "grilled" it, an air bubble(s) in the wax exploded?

Seem to be going backwards here!

Typo PLA ...PVA?

 

[Onoff]

Typo PLA ...PVA?

Whoops! Yes, typo!

 

[Onoff]

This morning:

There's excess wax around the lower half of each side of the face, the left ear and snout. It maybe some bizzare wax/PLA sandwich as there is possibly a layer of PVA between the model wax and excess wax. Difficult to tell. More soaking required

 

[Onoff]

Looking better than expected. The excess, certainly around the sides of the face seems separated from the main wax body by a layer of PVA. I'm not going to look a gift horse etc but am struggling to see the mechanics of how this occurred.

This "protective" PVA in the wax sandwich is clearly the original mould walls. The excess has gotten behind this into the lighter infilled areas.

How?

 

[prepman]

Looking better than expected. The excess, certainly around the sides of the face seems separated from the main wax body by a layer of PVA. I'm not going to look a gift horse etc but am struggling to see the mechanics of how this occurred.

This "protective" PVA in the wax sandwich is clearly the original mould walls. The excess has gotten behind this into the lighter infilled areas.

How?

View attachment 346045

What are the 2 substances glass points? PVA is The glass transition temperature of polyvinyl acetate is between 30 and 45 °C depending on the molecular weight.
Is the wax just too hot for the PVA?

 

[Kram]

Text is looking much sharper. A bit more soaking and that excess wax should come off.

 

[prepman]

Well tried a very short burn test to check swirl pattern. All ok. Managed to use up a fair bit of scrap. Won't win prizes for looks. If it works that's all that matters. Tacked a piece of angle iron
as a protem foot pedal. The lift mechanism works ok. Should leave it a week to dry out and then a very slow ramp up to full fire over days. Probably start on another one and make chamber bigger diameter....or maybe not.

 

[Kram]

Nice swirl.

@Onoff did the wax survive?

I did some wax carving, and I'll have a go casting it tomorrow in sand.
I found syringe can build up wax quite nicely, just small amount at a time, like 3d printer. Stays hot for a minute or two.

 

[prepman]

Nice swirl.

@Onoff did the wax survive?

I did some wax carving, and I'll have a go casting it tomorrow in sand.
I found syringe can build up wax quite nicely, just small amount at a time, like 3d printer. Stays hot for a minute or two.

Carving was the traditional way and then into clay...I have read. I've never done it.

 

[Onoff]

@Onoff did the wax survive?

Amazingly not too bad! Currently having it's very last warm water soak to get rid of the last PVA residue within the letters. Here's a few taken just now in natural light. Still a few water droplets on it.

The ring came out well. Then, this time, the smaller, rectangular side features came good, more meat at the edges. One "R" appears OK, the other has lost its middle bit. I might try and carve that detail in. The "A" seems alright too.

The head does have a crack running from the right ear down across the face. I can probably smear some hot wax into that on a fingertip.

The rear is slightly concave reflecting the post pour shrinkage:

Basically I'm done then with this I think, ref the Great Wax Experiment! I mean I know I can do it etc.

What we've not got yet is an actual PLA (yes I do mean PLA) model of this. One that reflects the letter font and spacing changes then the smaller, single, side rectangles. That's quickly printed though.

What's next then?

 

[prepman]

Amazingly not too bad! Currently having it's very last warm water soak to get rid of the last PVA residue within the letters. Here's a few taken just now in natural light. Still a few water droplets on it.

The ring came out well. Then, this time, the smaller, rectangular side features came good, more meat at the edges. One "R" appears OK, the other has lost its middle bit. I might try and carve that detail in. The "A" seems alright too.

View attachment 346198

The head does have a crack running from the right ear down across the face. I can probably smear some hot wax into that on a fingertip.

View attachment 346193

View attachment 346194

View attachment 346195

View attachment 346196

The rear is slightly concave reflecting the post pour shrinkage:

View attachment 346197

Basically I'm done then with this I think, ref the Great Wax Experiment! I mean I know I can do it etc.

What we've not got yet is an actual PLA (yes I do mean PLA) model of this. One that reflects the letter font and spacing changes then the smaller, single, side rectangles. That's quickly printed though.

What's next then?

Cast it?

 

[Onoff]

Reality check time. Being really critical now on the wording. The following letters in bold are imo not good enough!

THE RISING SUN

DEXTER CATTLE

Hmmm...

 

[prepman]

Reality check time. Being really critical now on the wording. The following letters in bold are imo not good enough!

THE RISING SUN

DEXTER CATTLE

Hmmm...

View attachment 346227

Your original 3d PLA print was bang on. Lost PLA?
Burning refractory in now.....extremely carefully....so might be able to give it go as well.
Couldn't repair furnace earlier as I use it as a workshop heater.

 

[Onoff]

Your original 3d PLA print was bang on. Lost PLA?
Burning refractory in now.....extremely carefully....so might be able to give it go as well.
Couldn't repair furnace earlier as I use it as a workshop heater.

You're welcome to have a crack at it. I could send you one already printed? Saying that we haven't yet printed the final, "final" PLA one.

 

[Kram]

Fill in the letters with wax and use it as a test peice? Can etch the text after casting?

What's next then?

Try a PLA investment shell?
If theres one thing messier than melted wax, its plaster
It would be good to have a few ready to try when you bring the stuff down. Im not expecting the cast to be perfect first time..

 

[Onoff]

Try a PLA investment shell

You mean a negative/female mould like this PVA one but in PLA? How does that work then? I mean the PLA won't dissolve?

You couldn't pour brass straight in so...I'm lost!

 

[Onoff]

It would be good to have a few ready to try when you bring the stuff down.

A few what, PLA positives? No problem.

 

[Kram]

I mean dip/paint the positives in investment plaster, to burn out, then and pour brass into.

 

[Onoff]

I mean dip/paint the positives in investment plaster, to burn out, then and pour brass into.

Didn't know you could dip in investment plaster!

Thought you had to bury/encase the model.

Infilling with wax works! I was just melting it with a soldering iron tip and dripping it in.

 

[prepman]

Took the furnace up to max in stages. One good thing about using kaowool is it isn't explosive. So drying out isn't as fraught. Water vapour from the refractory can escape easily. Drilled a couple of holes. Top temp 1150C base temp light straw bordering white 1300C ?
Added a foot pedal and tidied the welding up some....don't want to be ostentatious
Need to level lid to stop blowout.