Bunkers - more experiments.

[Sangennaru]

Ok, then it's only here in Guelph. I've searched almost everywhere, but maybe I should look for Pledge?
I will try another run today, i'm curious to test it!

[Mr. Peabody]

Well, they have gone and changed the name. Again.  You are looking for: Pledge Floor Care Multi-Surface Finish You can tell it's what you want because the label has the old 'Future' logo in the bottom right corner.

You can find it at your local (Guelph) Canadian Tire, Home Depot and Lowes.

I've used Future several times to seal multimedia masters before pouring my moulding compound. I've had no loss of detail and it has allowed me to work with materials that would normally react or fail in contact with urethane rubber compounds like VytaFlex.

It's a multi-use hobby acrylic medium. Best known as a gloss-coat or paint additive. Clean-up is with Windex or any other ammonia based cleaner.

[Sangennaru]

I bought it, and tonight i'll make some experiments to test the differences! Three small identical molds are ready: one will be coated with Future, One will be wet and one will be left as it is! Science FTW!

Anyway, tomorrow i'll put the sculpt for sale on the bazaar! I still haven't figured out a price, of course it's meant to be molded and produced by a company, so i'm mainly selling the reproduction rights!

[maxxon]

Wow, you really made a plank mold... excellent!

To stop the balsa sucking up water, you could simply paint it.

[Andym]

Excellent tutorial bud! Is your mould destroyed after your one cast?

[Sangennaru]

Wow, you really made a plank mold... excellent!

To stop the balsa sucking up water, you could simply paint it.

Yeah, emulating sometimes is the way! Although that implied many technical difficulties, the result worth the effort.
For the paint: acrylic are not really waterproof, unless you paint a thick layer, which will reduce the grain too much. =(

Excellent tutorial bud! Is your mould destroyed after your one cast?

I'm afraid yes, the mold was quite devastated. However, if you keep the mold simple you can hope to save the mold box for another cast or two... but since i'm sculpting masters for production, i wouldn't use it in any case more than once! ^^ that's against my "rules".

The three identical boxes to test the future are ready, today i'll make the test!
and in a couple of hours i'll put te piece on the bazaar!

[Sangennaru]

The piece is now on the Bazaar!

http://leadadventureforum.com/index.php?topic=67822.msg821260#msg821260

cheers
Jack

[Sangennaru]

that's the quick preview of my tests: basically, the future was GREAT to prevent the pouring and to preserve the mould, but the non-wet surface (and kind of hydrophobic) generated a lot of bubbles. I don't know how to resolve this issue, for now.

That's with the wet mould:


That's with the future:


I tried to keep the conditions as constant as i could, and i even used a control for the test, with a non-wet and not future-treated mold:



any suggestion to resolve this problem is welcome!

[Capt. E.W. Brimmage]

Nice work. Could you use plastic for the outside frame of the mould? Maybe combine that with replacing the balsa with a thin veneer of a harder wood, or just use a harder wood for the entire mould. This should make it durable enough to be cleaned and reused.

[zizi666]

Maybe try to laminate the balsa with acrylic floor polish (Klear / Future / Johnson's...) or would that soften the details too much ?

*edit*
Doh ! that's what you meant with the future mold. I guess it really is time for me to go to bed... *massive facepalm*

[Mr. Peabody]

Try wetting the Future coated mould and / or try to 'settle' it more aggressively.

Air bubbles aren't uncommon with plaster moulds, especially where there is lots of fine detail. Dental labs use vibration tables to deal with this sort of thing.

[maxxon]

any suggestion to resolve this problem is welcome!

You know, the other one isn't bad either. It's different but not bad. It kinda looks like heavily weathered concrete you might find on docks etc. where water gets into contact with the concrete.

Hmmm... Maybe you could try coating the outside of the mold, so it will still suck up some water but not too much since it won't leak through?

[Slayer]

as others have said I think the second one looks fine, bit more weathered is all

[DELTADOG]

I´ve done that same work for my Fallout Vault project a few weeks ago. IMO Future isn`t that good idea for your Problem. I´ve used spayable Moldrelease from Smooth-on and that worked the best! To avoid the microbubbling in the plaster you have 2 possebilities.

1. Use a Vakkum-System to de-gas the ready mixed plaster before casting.

2. Use LEFAX! LEFAX is a common medicine against exhalation in Germany and Europe in general. I don`t know if you know it or its available were you living. Maybe a similar product under another name would work too. Those medicals use ezymatic incredience to break surface tension of bubbles. LEFAX works fantastic to de-gas Plastermixtures, but not resin! Just pestile it to fine powder and mix it directly in your water you will use with the plaster. Warm up the water a bit will increases the effect.

[Sangennaru]

Cheers Gents! I'll try to group-reply by points:

- Plastic for the outside: That's an option, but it requires to switch glue to a super-glue or cyanacrilic which is much less practical than PVA. I would rather avoid that.

- Wetting the future coated mold, or vibrations to de-gas it: That's an option. In my opinion it's still time consuming, but it definitely worth a try.

- Coating the outside of the mold: that's a neat idea, i'm not sure it will work but it surely doesn't damages!

- The LEFAX solution: seems interesting, i'll study a bit this option! Maybe now with a medicinal, but there must be several other products with a similar property, no?

- Keeping the mold with the bubbles? Nope: it does look as a damaged concrete, but the damaged concrete does not have bubbles, but holes. If i want to make a damaged concrete, i will rather carve holes in a bubble-free piece!


cheers again and thanks for all the suggestions, really appreciated!
Jack