Best way to cast 1/700 scale?

[jpowers_01]

Sorry for all the questions today. Has anyone made a cast of vehicles and or accesories in 1/700? What did you use and how did you make the cast?

I have seen rubber you paint on, then pour plaster. I've seen clay you form, then use hot molten metal. I've even seen the science experiments using composits and resin. What is the best for detail, easiest to do, and cheapest on the purse?

Thanks
James

[Charlestonguy]

I'm no expert but I have had a great deal of success using RTV for a mold then fiberglass resin for casting. The resin is quick and easy to use and you can set your drying time based on how much hardener is used. Too much and you get air pockets, to little and your drying time may take weeks, but after a little effort you will get the hang of it.
The reason I used fiberglass resin is cost. You can get so much more out of a quart can of fiberglass resin then the traditional model resin.
I would not try to build large parts with it unless you mix a bit of ground up glass fiber to add strength.
I use a light coat of oil (a very light coat), on my mold as a release agent.

The crewmen of this diorama were made from fiberglass resin.

[RNfanDan]

I cast all my 1:700 kits and PE into boxes and shipped them away to other builders; does that count?

[jpowers_01]

HI,

Charlestonguy, thanks for the tip. Is there any particular brand of fiberglass resin you use? Wondering if auto repair resin would work as good and be cheaper?

Anyone else have a favorite method, and cost?

Thanks
James

[Charlestonguy]

Yes, I buy the resin from my local automotive supply store. One quart will last for years.
One more note, I have the best results when using the black RTV or high temp brand. I also use the clear home bathroom caulking RTV for some of my molds.
If you have never made molds before here are a few suggestions.
1. Build a box from plastic styrene, don�t worry once you have the RTV mold you can remove it and use it again.
2. Fill the box with RTV and smooth the top surface.
3. Coat the part you wish to copy with a light film of oil and press it into the RTV, make sure you have good contact on all sides, if you wish to copy the upper part only press half way down leaving the upper part exposed. Let this dry before the next step.
4. Now, make a second box and after you have applied some Vaseline to the first mold and part, push or mate the two RTV halves.
5. Drying time on the RTV may take some time; give it a few days and check. When its ready pull the two mold haves apart and remove the part. Now cut a small �V� from the part to the outer part of the mold with an Exacto knife, making sure you do the same for both sides of the mold (top and bottom).
6. The V acts like a funnel to pour your resin.
I normally cut two of these, one to pour the resin the other to let air pass out. When the resin starts dripping out of the second I know it is full.
I use a rubber band to hold my two molds together.

For most parts you can hold the mold with your hand, but if you use a lot of hardener, say three drops to � of a Dixie cup of resin then it may be a bit hot to hold.

Practice and after a while, you will have the mix and drying time down to what works best for you. I've had the same molds now for over 10 years so you will have an endless supply of parts.

[arnobiz]

The same as just above but with pictures, enjoy!

http://www.modelshipwrights.com/modules ... &artid=469

[raser13]

i use legos to build my boxes for molding. i also use the dollar a tube of bathroom caulk(100% silicone) baby powder for a release. and the five minute appoxy that comes in the seringe like tubes, you can find them at wal-mart in the hardware section.