Castable mold question

[Richard Huntrods]

I have a question for those who routinely cast stuff out of castable. Way near the bottom of this post, but first some background info.

I'm finishing up the new shop, and am at the stage of getting the furnace back up and running. Pulling the lid "cold" destroyed during the move most of the maintenance lid and gathering port, but it's no loss - a goodly glass tag the year prior had it needing replacement anyway.

(refresher - Lauckland style 40lb top gather wire melter.)

This time I'm going to cast a gathering port so that any tag will drip back into the pot. Yea, that may mess up the glass, but better that than requiring a rebuild every time.

I have a pristine bag of Fractocrete 3400. Nothing on the internet specific to that product (except the hazmat sheet), but Yokefellow Enterprise Corp. has a comparison chart that shows it roughly equivalent to Greencast 94 and 97. I checked the archives to see how that is prepared and used.

My gathering port is a slightly cone shaped opening. I have a stainless steel pail that is much too tall, but the perfect size and slope. I will build my form out of OSB and 2x4. 2x4 sides, OSB bottom. I will cut a hole in the OSB for the pail to sit in such that obtain the exact diameter I want (it's about 2" from the bottom of the pail).

Finished port will be 3" thick, 12" square with the approx 9" hole in the center. It will be fitted inside the existing maintenance lid (K23 brick in a frame) and is fully supported by the furnace brick and an alumina board.

Here's my question (finally, eh?) - is something like PAM (the cooking spray) a good release agent to prevent the castable from sticking to the SS pail? What about the wood? I was going to put something like wax paper or cling wrap on the OSB to prevent sticking (and give a smoother finish). Anything special for the 2x4 sides.

Thanks in advance all you castable workers! :)

-Richard

[Jordan Kube]

Crisco.

[Richard Huntrods]

Originally posted by Jordan Kube
Crisco.

How much? Thin coat OK?

Thanks,

-R

[Sky Campbell]

I really hate greasing up molds and pam isn't always enough on plywood. I've taken to saran wrap and tin foil. I just rebuilt our small glory hole. I laid plastic visqueen in the mold and used saran wrap on the inside positive of the retention ring. My color furnace crown still has tin foil on it from the casting 2 years ago.

[Henry Halem]

A mixture of vaseline and kerosene, pg. 295, Ver. 4.0. 1 part vaseline 2 parts kerosene. Heat vaseline in old pot till it melts. Take off heat and add kerosene. Stir, baste chicken and broil, oh wait that was something else.

[Marc Leva]

Originally posted by Henry Halem
A mixture of vaseline and kerosene, pg. 295, Ver. 4.0. 1 part vaseline 2 parts kerosene. Heat vaseline in old pot till it melts. Take off heat and add kerosene. Stir, baste chicken and broil, oh wait that was something else.
Henry, I know you love that separator - but the idea of pouring kerosene in a hot pan doesn't thrill me. How do you measure? Volume? Weight? Also, how do you store it? Won't it congeal if it gets too cold? If it congeals do you have to put it back over heat?

[Jordan Kube]

Yeah, thin coat. You just need to make sure it's coated that's all. cover wood with some kind of plastic. Everytime we turn around the dogs are all over the molds.

[Allan Gott]

Originally posted by Richard Huntrods
a goodly glass tag the year prior had it needing replacement anyway.

:headbang: :headbang: :headbang:

[Steve Stadelman]

Coat rough wood molds with spray adhesive and plastic.

Crisco

Crisco

Crisco

Releases every time, Jordan cannot count how many TONS......yes....Tons of castable he has helped me with, Dakota has done more.

Crisco.

[Richard Huntrods]

Originally posted by Allan Gott
:headbang: :headbang: :headbang:
Yea. Actually cooked through the alumina board and started on two of the main furnace bricks. One on top, one at the bottom.

Took a bit of delicate surgery to excise just the glass-eaten part without touching a coil and then cut and fitted a small bit of replacement brick. No fun - but glad I caught it before it ate the element.

-R

[Richard Huntrods]

Originally posted by Steve Stadelman
Coat rough wood molds with spray adhesive and plastic.

Crisco

Crisco

Crisco

Releases every time, Jordan cannot count how many TONS......yes....Tons of castable he has helped me with, Dakota has done more.

Crisco.

Is this anything like...

"SPAM SPAM SPAM SPAM SPAM SPAM..."

???

-R:p

[Steve Stadelman]

Yes, now you remember! Monty Python sticks...........Crisco releases!

[Allan Gott]

Not sympathizing at all. Referencing your rant the last time you hosted glassmaking "guests". One :headbang: per guest.

You were cautioned against using board when you built it the first time.

Shit happens............get over it.

[Henry Halem]

Originally posted by Marc Leva
Henry, I know you love that separator - but the idea of pouring kerosene in a hot pan doesn't thrill me. How do you measure? Volume? Weight? Also, how do you store it? Won't it congeal if it gets too cold? If it congeals do you have to put it back over heat? Oh yea faint of heart. Melt the vaseline and take it off the heat. It takes practically no heat to melt vaseline. You can put your hand in the melted vaseline the temperature is so low. Pour in the kerosene and stir. By volume, and it is very liquid during the summer and a tad congealed during the winter. No, don't store it in the refrigerator. If it's too cold for the seperator then your studio's too cold. Marc just do as I say and don't question me. Would I steer you wrong?

[Hugh Jenkins]

For board and foam mold parts, packing tape or duck tape make a great moisture proofing. Plastic wrap laid out flat also makes a good water proof for casting flat on the floor or on a board. I don't think grease is enough on wood. It is perfect for metal or plastic bucket (inside or outside forms) as release. Creases need to be clay filled. Water leaks leave weak areas in the casting where the cementing agents wash out.

[Richard Huntrods]

Originally posted by Allan Gott Not sympathizing at all. Referencing your rant the last time you hosted glassmaking "guests". One :headbang: per guest.

I remember. That was not my finest moment, by a long shot.

You were cautioned against using board when you built it the first time.

Agreed. The cast gathering port should protect the board and the bricks from now on.

Shit happens............get over it.

Yep.

Cheers,

-Richard

[Richard Huntrods]

Slight update...

I will be casting the gathering port in place - tomorrow.

It turned out to be quite easy to prepare the lid for the casting. I'll use tinfoil or tape to keep the bricks from sucking moisture from the castible so it can set properly. Saves building a form and then I know it's a tight fit.

The gathering port opening (mold) will now be made from styrofoam to give me the best shape, and I'll cover that with foil or saran.

Thanks one and all for your suggestions.

Cheers,

-Richard

[Scott Novota]

Ok newbie alert****


If you knew that you would be backing a casting with fiber board could you not make the mold out of it and not give a rats ass about the sticking at least on the largest away facing side anyway. Then again I guess the stuff would seep into the fiberboard and cause issues maybe. I think I just answered my own question.


Scott.
.

[Ben Rosenfield]

Originally posted by Steve Stadelman
Crisco releases! It's true. Crisco certainly is a safe product for the application at hand. Buy a lot of it. What you don't use when making castings can be great for tasty pie crusts. Failing that, I hear it's great for when you feel the need to act out some of the scenes from Caligula in the comfort of your own home.

[Richard Huntrods]

Originally posted by Scott Novota
Ok newbie alert****


If you knew that you would be backing a casting with fiber board could you not make the mold out of it and not give a rats ass about the sticking at least on the largest away facing side anyway. Then again I guess the stuff would seep into the fiberboard and cause issues maybe. I think I just answered my own question.


Scott.
.

From what I understand, you would still need a barrier between the fibreboard (or brick, in my case) and the castable. Both brick and fibreboard will suck water out of the castable, which is not good for curing characteristics of the material.

In my case, I'm casting into a brick maintenance lid, so I'm using tinfoil to keep the brick from sucking water out of the castable while it cures.

Cheers,

-R

[Brent Hickenbotham]

We will spend hours greasing molds for casting and not pay attention to my dogs, go to lunch and the molds will be clean when we get back.

[Randy Kaltenbach]

Originally posted by Richard Huntrods
... I'm using tinfoil to keep the brick from sucking water out of the castable while it cures.
... and you can use the leftover tin foil for a hat! :D

[Richard Huntrods]

Originally posted by Randy Kaltenbach
... and you can use the leftover tin foil for a hat! :D

Sorry, Randy - could you repeat that? I have tinfoil in my ears!

Did you know that tinfoil earplugs are the preferred poor man's tinfoil hat substitute?

:p

-R

[Eben Horton]

I like vasaline.. never tried henry's kerrosene trick though.

Nothing is more funnier than to send your assistant if you have one to Walgreenes to buy vasaline and kneepads before you do your mold casting. They always come back sooo flustered. :D

[David Patchen]

Brent - your dogs on statins now? Their cholesteral must be through the roof.

[Rich Samuel]

Dear Dr. Glass,

I'm out of Vaseline and kerosene. Can I substitute Vicks VapoRub and whale oil?

Signed,

Congested and Greasy in Seattle :D

-----

By the way, I've been reading V.4.0, and it's brilliant! Thanks again for "putting it all together." A friend was wondering if it can be ordered with a spiral binding, so it can be opened flat.

[Richard Huntrods]

Originally posted by Rich Samuel
Dear Dr. Glass,

I'm out of Vaseline and kerosene. Can I substitute Vicks VapoRub and whale oil?

Signed,

Congested and Greasy in Seattle :D

-----

By the way, I've been reading V.4.0, and it's brilliant! Thanks again for "putting it all together." A friend was wondering if it can be ordered with a spiral binding, so it can be opened flat.

KY & brandy?

No wait. I have other uses for that...

:D

[Henry Halem]

Originally posted by Rich Samuel
By the way, I've been reading V.4.0, and it's brilliant! Thanks again for "putting it all together." A friend was wondering if it can be ordered with a spiral binding, so it can be opened flat. No it cannot but someone once took a copy of V. 3.0 and went to a place that had a cutter and had the binding carefully cut off and then had it spiral bound at a Kinko's. Actually I just made that all up but I think it could be done.

[Brent Hickenbotham]

David, no statins but a killer case of the runs, love to clean it out of my carpet. Rich don't know about the vapo rub in the castings, but a handful in the respirator while I'm fraxin is great. and I use whale oil for the same reasons as Richards KY.... UHHH.....never mind.

[Scott Novota]

Whale oil and KY should never be used in the same sentence. Ever.


Scott.
.

[Brent Hickenbotham]

no it really shouldn't.;)

[Ted Trower]

Crisco is being reformulated to (almost) completely eliminate the transfats. What do you suppose that will do for its' performance as a mold release?

[Richard Huntrods]

Further update:

Didn't cast the port yet. Yet another change of plans as it seemed there would be too much castable in the finished lid (13" x 12" x 3" area with an 8" gathering hole in the middle).

Instead I've rebuilt the lid to almost original specs, although I cut the hole "octagonal" rather than round (rough cut).

I have now secured a box of rammable and will build the desired protection ring for the gathering port inside the existing lid. This will give me the shape I want (round) but retain all of the insulating brick in the lid to save energy.

Because rammable doesn't stick to K23 all that well, the ring will be removable for maintenance as well.

I'm going to make this ring "in place", so now I need to finish up all other maintenance on the furnace so I'm ready to go once the ring is done.

-R

[Steve Stadelman]

Originally posted by Ted Trower
Crisco is being reformulated to (almost) completely eliminate the transfats. What do you suppose that will do for its' performance as a mold release?

There is always Manteca.

[Henry Halem]

Originally posted by Steve Stadelman
There is always Manteca. Gillespie's version with Chano Pozo was the best.

[Brent Hickenbotham]

since that, the castings are done at room temp or below, and have nothing to do with digestion and nutrition. I don't think that the molds are gonna retain any adhesiveness or cellulite.:D :chuckle: :chuckle: :chuckle:

we should make a slip and slide out of the old crisco and the new, and have lots of naked girls test them out, we'll see if the friction lossess are significant and we'll disclose the results in due time.:clap: :toast: :cool:

[Richard Huntrods]

Another update.

Hammered up the rammable casting ring and it went quite well for a first try.

Heated the furnace to 200F to remove moisture as per the instructions, then heated slowly to 1300, faster to 2100.

Charged last night & cooked, glass at 1850 this morning.

The casting ring looks great so far. Now to test it in use.

-R