Ghetto casting

[Rebo]

Hey guys...

I'm just experimenting with the chaulk and glycerine method to see if I can get it to work for me, can you give me a rough idea how long it takes to set?.
I've only mixed up enough to cover one of the nippers matchboxs cars and smoothed it over with an ice cube.

One last thing is it glycerine or glycerin, or are they the same thing?.

<div class='quotetop'>QUOTE(rigormortis @ Jul 31 2006, 04:40 PM) [snapback]1291242[/snapback]</div>

Sets up quick, but remains workable for about 10-15 minutes. Smooth with icecube while setting (water will not effect the curing).

Hope that helps.
[/b]

Okay I should learn to re-read stuff. :rolleyes

 

[frosty]

Recaster. how will a little company like matchbox survive with you casting there products for profit...,

Never tried this myself i will have to give it a whirl

 

[Rebo]

<div class='quotetop'>QUOTE(frosty @ Dec 17 2006, 04:01 PM) [snapback]1379772[/snapback]</div>

Recaster. how will a little company like matchbox survive with you casting there products for profit...,

Never tried this myself i will have to give it a whirl
[/b]

Oh's no, busted. :cry

I will destroy molding and mold upon completion of experiment

 

[kdawg1]

I think Michales Crafts has silicone for molding.

 

[Rebo]

<div class='quotetop'>QUOTE(kdawg1 @ Dec 17 2006, 04:27 PM) [snapback]1379785[/snapback]</div>

I think Michales Crafts has silicone for molding.
[/b]

Ah....just one problem with that, well two actually, im in the Uk and im a miser. :lol

Ive just had a cruise round the bay and came across a product call "gelfex" meltable rubber.
Can this be melted down in a pan on the stove (shh... the Missus is close by) and used with a polyester resin?

 

[exoray]

Unless someone knows a shop in Cincinnati that consistently sells silicone.[/b]

I suggest doing it "right" unless it's not a big deal to replace the sculpt you made, cutting corners and going cheap has more risk then it's worth in most cases...

Check your local Hobby Shops for Alumilite stuff

http://www.alumilite.com/index.php?page=dealers_OH

 

[Rebo]

Hmmm.. 2hrs on....

Mold has skinned over, but with gentle taps I can feel its still gooey underneath.

Maybe I haven't added enough glycerin. At a rough guess I mixed 50ml to 5ml.

I'll keep checking it every so often.

 

[patsmear]

You could also use mold latex. I get it at Michael's. It is usually next to the resin. you paint it on about 3-4 coats thick. Drying inbetween coats.

Kinda like this stuff:

http://www.modeltrain.com/rubbermold/rubbermold.html

Although I use a plaster jacket. If you do the plaster route, you need to make sure there are no straight edges or undercuts or else it will lock in the mold. I know this from experience.



Pat

 

[Boba Frett]

I'm just experimenting with the chaulk and glycerine method to see if I can get it to work for me, can you give me a rough idea how long it takes to set?. [/b]

Are you using 100% silicone rubber?

 

[Rebo]

:confused Probably not, it's bathroom sealant.

Still aint set...

 

[Admiral Vaughn]

<div class='quotetop'>QUOTE(Rebo @ Dec 17 2006, 02:57 PM) [snapback]1379898[/snapback]</div>

:confused Probably not, it's bathroom sealant.

Still aint set...
[/b]

Here Is The Correct Way To Do It.

((4 Drops BabyLax and 4 Drops acrylic paint Per Tube of %100 Silicone Rubber is Perfecto.))

2 Tubes get 8 Drops of each etc..

(smaller amounts?)..1/4 Tube gets one Drop of each..1/2 Tube gets 2 Drops of each etc..

and don't forget to MIX IT REALLY WELL

Never layer more than 1/4" thick, or you Will have problems.

I Know it stinks

Have Fun.

~Russ

 

[jedi5150]

So what's the viscosity of this mixture? Is it pourable, or brushable, or do you just "moosh" it all over your piece??

 

[Admiral Vaughn]

It's Brushable..and mooshable too

Repeating some good advice already in the thread:
Brush in the 1st detail layer avoiding air bubbles and thick spots. every layer after that can be troweled on so you don't waste brushes..build it up how you want it, and make a plaster(or whatever)backing support, if needed.

If mixed and applied well, it should cure quickly...I've never timed it.

If you use it on regular clay, or a clay with a sulphur base, spray a coat or two of (Acrylic) clear coat on your sculpt...I clear coat everything made from clay.. just in case.

((Don't use clear coat with petroleum products on clay))

Plastics like items(toy cars etc..) should not need a clear coat.


~Russ

 

[motman241]

Or the even cheaper, easier way (as posted before):

Coat the item in petrolium jelly, squirt on the clear 100% silicone caulk. After about an hour, you can smooth out the outer part of it with your finger. No mixing. No muss. No fuss.

depending on the item size, and thickness you applied, it could take several days for the silicone to cure.

 

[EchoLeader]

For small applications you can find Silicone gasket making materials at auto supply stores. Below is a sample of what can be used.

Gasket Material

Slow drying, non-hardening sealant designed for sealing cut gaskets and stamped parts. Allows for easy disassembly if required. -65 to 400 degrees Fahrenheit temperature range. Resists common shop fluids and fuels. Use where sealing is more important than adhesion for valve cover and oil pan gaskets. Use on gaskets, flanges, pipe joints and threaded connections.
Product Details
Price From: $2.70
Manufacturer: Permatex
Model Number: 80016
UPC Number: 686226800169

 

[Rebo]

Ah sod it, it didnt set so I binned it..... Probably would have, had I left it a few days. It was only a little experiment anyway.

Thanks to a UK Rpf member who gave me info on a uk supplier for all my casting needs. :thumbsup

The supplier has suggested that I use a medium hard rtv with a polyurethane fast cast (1/1 mix) resin and filled with blr 2 filler powder.

Now, I didn't want to look too dim while talking to him, as I understand how to use the first two (maybe), but how do you introduce the filler?.

Is there a straight forward ratio I can follow for mixing it in and when you add it does it change the viscosity much?.

One more thing, will I have to move fast with this stuff as he quote this "Expect set within around 5-10 mins and demould tack free within 30".
Now i'm thinking, mixing resin and then adding filler takes time, any method you lot care to share, just so I don't end up with cups of un-pourable resin?.

Oh one last thing (I know, I should have opened a new thread), do I need to order a release agent?.

 

[Rebo]

Bumpty...

Guys, I'd like to get an order in, so any info/suggestions on the above questions would be great.

Just discovered a chaps thread, he has used the same ingredients as im thinking of ordering, but he says it too brittle for his needs.

Where as he is making a large wearable prop, I am planning on making smaller parts, airfix size. Will I suffer the same problems with smaller casting?.

 

[Boba Frett]

<div class='quotetop'>QUOTE(Admiral Vaughn @ Dec 17 2006, 11:53 PM) [snapback]1380147[/snapback]</div>

<div class='quotetop'>QUOTE(Rebo @ Dec 17 2006, 02:57 PM) [snapback]1379898[/snapback]

:confused Probably not, it's bathroom sealant.

Still aint set...
[/b]

Here Is The Correct Way To Do It.

((4 Drops BabyLax and 4 Drops acrylic paint Per Tube of %100 Silicone Rubber is Perfecto.))

2 Tubes get 8 Drops of each etc..

(smaller amounts?)..1/4 Tube gets one Drop of each..1/2 Tube gets 2 Drops of each etc..

and don't forget to MIX IT REALLY WELL

Never layer more than 1/4" thick, or you Will have problems.

I Know it stinks

Have Fun.

~Russ
[/b][/quote]


Nice work Russ

 

[Admiral Vaughn]

Thanks, Bud.

I Learned From A Master

~Russ

 

[BlindSquirrel]

What's the concensus? 4 drops of Glycerine or 50 drops per tube?