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Sparrow

making molds
I use Room Temperature Vulcanizing (RTV) rubber for my molds. I get it from Micro-Mark. It’s easy to get and use.
There is a great feature on ModelGeek.com that shows detailed instructions on making molds. You can read more here Mold Making and Resin Casting
I use basically the same techniques as Steve does in the feature.

Making the molds is an important step. A poor mold will yield bad parts. One key to making a good mold is to have a thick one. I would recommend at least .5” all the way around the master if possible. If you look carefully at my mold I am on the boarder and I had to be very careful. I actually poured about 8 barrels and only got 2 good ones. It’s a learning process.

In addition to the thickness of the mold I learned that you should make the air escape route as large as possible. I made mine out of some wire scraps and then I carved it a bit larger with a hobby knife. The excess resin flows into this larger area easier and even though you are wasting a bit more resin, the excess is worth a good pour.

A few pointers I will add include make the pour hole as large as possible. This allows the resin to pour in easily and smoothly. If you pour too fast the resin momentarily fills the hole and pushes air down into your mold. This is not good. The air creates hollow pockets in your part which will ruin the part or at best leave you with holes to fill with putty.

TIP:Vaseline is the other key ingredient to a good easy two part mold. RTV material will adhere to itself so you need a barrier between your first pour (bottom half) and your second pour (top half). I used a QTip lightly dipped in the Vaseline then rubbed over the cured 1st half.

TIP: Another tip I found helped is to save the exterior container if possible. I use old “blister packs” or styrene boxes from toys and kits as my mold container. There are other things you can use; building block custom made boxes, kitchen foil containers. All are fine; it boils down to personal preference. If you can save the container, use it when you pour resin. The extra strength and rigidity it offers ensures a better end piece. Another area to be aware of after your mold is made is when you prepare the mold for pouring. The method I used is to put the mold back in the original container, then gently warp it with electrical tape (electrical tape is not affected by the resin and is easily removed). Be careful not to compress the mold at all, this could result in odd shaped or oblong pieces.

TIP: When I pour I usually get a long thin implement like a chop stick, coffee stir stick, or toothpick. I insert one end as deep into the mold as possible and pour the resin down the implement slowly so the resin flows down the stick and easily into the bottom of the mold. This helps distribute the resin and avoid air bubbles.

Pouring the resin pieces was very straight forward. I have already mentioned the major points above. With the pieces removed from the molds I was left with simple cleanup. Sanding down a bit of over-pour on the carriage pieces was easy. The barrel was a bit tricky simply because it is round and you have to be careful to retain the shape without sanding in any flat spots.

At this point I did some basic assembly to give me a final size and shape.
  • 8_1_DSCN1344
  • 8_2_molds
  • 8_3_pour_resin
  • 8_4_pour_toothpick

About the Author

About Scott Lodder (slodder)
FROM: NORTH CAROLINA, UNITED STATES

I modeled when I was a teenager. College, family and work stopped me for a while. Then I picked it back up after about 12 years off. My main focus is dioramas. I like the complete artistic method of story telling. Dioramas involve so many aspects of modeling and I enjoy getting involved in the ...


Comments

Excellent article Scott.
OCT 07, 2006 - 08:09 PM
GREAT article Scott!! And great subject/model too! well, 14 pages is a lot for my english skills and i will have to start all over again but you prove that dioramas is the king of modelism genres because here you can really DARE, you are only limited by your imagination!
OCT 07, 2006 - 08:21 PM
Arrrrr!!! Nice work matey! It's got a great sense of action/motion. Excellent job documenting the build too! Cheers, Jim PS: About those links... try putting them back in. I need to see them in action to figure out why they are failing.
OCT 07, 2006 - 11:55 PM
Thanks for the complements It was a blast to build and I hope some people can learn a tip or trick. PS - the links are on page 14
OCT 08, 2006 - 12:46 AM
Hi scott, As somebody who has an interest in the subject of the time of the Pirates and often enjoy playing a variety of games, I have really enjoyed both the review and the pictures that accompany the text. I have often looked at the Pirates series by Verlinden and may well look again with an intention to buy as I feel a little inspired by the work that you have done. Many thanks, and this is my first visit to Model Geek, so I may now visit again. John
OCT 08, 2006 - 02:13 AM
Great article Scott, well written ,easy to follow with and great photography. I always wanted to do something with water and waves and I had read many others on how to achieve such, but your has a bit more since to it. You put in a ton of time and effort into this article feature, you deserve a round of applause. Joe
OCT 08, 2006 - 09:28 AM
Thanks Joe - the encouragement makes the work worth it Hopefully you jump in and try some water - just ask any questions, I'd be happy to help. John - pirates are Great, a bit of color, a bit of 'fantasy', total creativity, and you keep a bit of military base too. Hope to see you around MG more often - it's a fun place
OCT 08, 2006 - 04:12 PM
Great article and well executed dio. It's well worth reading and learning a few new tricks and also getting a reminder of a lot of features already showed on Modelgeek. Well done Scott Cheers Claude
OCT 08, 2006 - 06:03 PM