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| Author | Post | ||
| daves |
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 Registered Member #105 Joined: Wed Jul 15 2009, 12:01pmPosts: 3560 | I was from the start and still am a loose cannon in the hobby of model ship building and I fell strong about breaking the old school ways of no plastic, got to draft plans by hand, got to use only traditional boxwood and swiss pearwood in your model, got to be within .005 on an inch, got to be historical accurate. I say hog wash with all the tech today 3D printing, polymer materials, and all the different methods you can use I say model ship building is wide open for creative thinking. | ||
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| Gary M |
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| Registered Member #4198 Joined: Tue May 07 2013, 10:50pmPosts: 904 | Dave, what about Durham's Wood Putty? You could try a slightly moist mix and see if it would fill the molds. Just a thought. G | ||
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| dave1254 |
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| Registered Member #2647 Joined: Fri May 25 2012, 08:08pmPosts: 405 | When I did model airplane fuselages I used polyester glass and some in epoxy because of the carbon fibre required. On some of the models like the p51 the transition area from the fuse to the wing is a deep thin fillet. Normally you would want the glass or west systems epoxy to have a slow cure to get into these tight areas, and also no air bubbles. I was wondering if maybe this would help. You could use a vibrator then to move the bubbles and increase work time. The west systems did dry clear. Now that I think about it the west system did not have an odor as much as the polyester resin although the polyester did flow better. Dave | ||
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| daves |
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| Registered Member #105 Joined: Wed Jul 15 2009, 12:01pmPosts: 3560 | the latex molds are so small it is hard to get anything to flow into the thin areas. Also the molds are very flexible something like Jello I did think of pushing a polymer clay into the mold but that distorts the mold. An idea is to make a stiff backing mold for the mold that way it will hold its shape and you might be able to press in a clay or putty. another thought is to make the molds out Micro Mark RTV silicone molding rubber. Thing is there is a fine line when making molds to much flex in the mold and it distorts the piece but make it very easy to pull the piece out of the mold, to stiff and the mold holds it shape and you can press clay into it, but difficult to get the piece out. Some of these pieces have under cuts and you have to stretch the mold to get the part out. viscosity is everything Easy Cast is temperature sensitive the higher the temperature the thinner it is and the better it flows into the tiny detail but That means that the higher the temperature, the quicker the cure and less time to get bubbles out. [ Edited Sat Aug 16 2014, 04:41pm ] | ||
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| daves |
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| Registered Member #105 Joined: Wed Jul 15 2009, 12:01pmPosts: 3560 | do you think a standard vacuum cleaner would work if I hooked it up to a jar and sucked out the air and air bubbles in the casting resin, I would need to invent some way to prevent the mold from being sucked up. [ Edited Sat Aug 16 2014, 04:32pm ] | ||
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| dave1254 |
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| Registered Member #2647 Joined: Fri May 25 2012, 08:08pmPosts: 405 | What if you made a simple box frame around the mold. That way you stiffen the sides but when it cures you could remove the mold and press out your part. It would also allow you to use a vacuum to suck the air out. It would possibly give enough strength to support when using a simple household vacuum. If you are going to put it into a plastic type bag and suck out the air I would build the frames high enough to stop the plastic from touching the casting. Or put something over the frame to prevent that. If you check out the west systems site they used to sell a bagging system for laminating plane wings. I tried the system but I made my own and it worked quite well. I used a small vacuum pump that I bought in a store called Princess Auto. They sell just about anything cheap. Dave | ||
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| dave1254 |
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| Registered Member #2647 Joined: Fri May 25 2012, 08:08pmPosts: 405 | Dave you stated that you were a bit of a rebel. When you entered a scale competition (aircraft) in Canada it used to be "builder rule" You lost points for everything that you did NOT build. We had guys who built the retracts, some even cast there own tires. Even the engine was part of the deal. I started my own business like most who enter these competitions for 2 important reasons. To get the max points and also to be able to afford it. Now in these competition today I see they are allowing premade parts and in some cases kits. It was a very elite group that did this and I am glad that they opened their eyes to the everyday builder. So what you are saying makes me smile because the "average guy" may never enter a competition with his boat because he/she didn't build everything from traditional materials or methods. Hopefully enough people would pressure the convening bodies to open it up to changes the establishment a little. My thoughts Dave | ||
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| daves |
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| Registered Member #105 Joined: Wed Jul 15 2009, 12:01pmPosts: 3560 | moving on to the figurehead I need to make a two part mold. [ Edited Mon Aug 25 2014, 01:17pm ] | ||
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| daves |
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| Registered Member #105 Joined: Wed Jul 15 2009, 12:01pmPosts: 3560 | here is the results of dabbing the resin into the mold and painting the mold surface. There are no air bubbles. so I would say rather than pour the resin in a mold slowly dab in into the mold. Also the resin was tinted the color of boxwood. this is a soft latex mold and the problem with pressing a clay into it are the delicate high and low areas in the mold. These ridges will distort or flatten out from pressing on the mold with clay. Now this carving might work with a stiffer mold like RTV silicone for pressing a clay into it, but I don't think you will get the clay sofy enough.   | ||
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| daves |
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| Registered Member #105 Joined: Wed Jul 15 2009, 12:01pmPosts: 3560 | the figurehead has open areas behind the legs and arms which would lock the piece into the mold and I would never be able to get it out. I filled these areas in with clay. I made a resin master for the two piece mold because I did not want to risk damage to the original carving. I did end up ripping the latex mold getting the original out so I did some repair work and cast the resin piece. To get this out I ended up totally destroying the mold. Next step is making a two piece mold.  | ||
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