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I'm working on a canopy for a 1/32 T-38A Talon. A little experimenting has proven that I cannot make it from 2 canopies alone. Looks like I will have to cut a 3rd to go betwen them to get everything to line up. If I make the blank for a mold, could someone form the finished canopy for me? I'd of course cover all materials and whatever you'd like for your efforts.

 

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Mongoose,

 

If you can make the master for a vac canopy, why not vac it yourself? It's not too difficult. There're a number of how to videos on the process. It's fairly affordable too. Unless you want to buy a high dollar machine. The hardest part would be making the master and make sure it fits right. Look at it this way. By you making your own vac canopy you've just added a new skill to your modeling.

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  • 3 weeks later...

Lots of setup here in preparation for the question 😠most from my wip thread.

I went back to the original canopy pieces I glued together and finished the inside as smooth as possible. Had a small crack in the bondo from all the handling but i filled it with clay and the put vaseline on it so the clay would come out. Ruined one because I forgot the vaseline.

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When i put the mold on the bottom of the tuperware it kept moving around and material got under it in places and made it uneven.

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The solution I thought was to press the mold in from the top. Now i just needed a way to keep it from settling to the bottom. 🤔 So i made it a lifejacket 🤣

I cut slits in the side so no air would be trapped. I put the screws through the platic sheet and into the clay while it was still inside the canopy so the clay wouldn't distort. This also made it easy to remove the clay without messing up any corners. I mixed up the perfect cast and poured it in the tuperware, sprayed the clay with a windex type product to minimize air bubbles, and then angled it into the casting material so the slanted rear of canopy was filled first. And presto it floated!

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Here's my finished product.

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It has to dry for 24+ hours so I'll wait till Monday to try a mold from it that i can use to form petg over. Tomorrow I'll probably make another one so I have a spare. I will probably have to make several molds anyway So I don't get caught short in the forming stage. One of the guys from the local club is goingg to help me with that as he does them all the time for his paper models.

 

Any upfront advive on this next molding step would be appreciated for sure. I need to make the final blank that i will form petg over. Reading the book i bought on it. That'll get me started but I know some real world experience would help me out alot.

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  • 3 weeks later...

I have this over in my WIP on the T-38A Talon to if you're interested in the application. This has been super fun to learn 🙃

Thanks for all the positive comments. I'll work hard to keep this build at a high level. Trying to put all I've learned, and still am learning, together at once 🤓

tonight I learned to vacuum form. It's to late for me to do anything with them tonight but I'll post the pics of the process here and in the tips forum for all to see now. This wouldn't be so easy without the great help I got. Isaac from Cincinnati Scale Modelers looked over my form and gave me advice on improvements before we did our forming. He does this alot for his paper models (wonderful work btw). Kudos to him because we got good parts the first time!

Started out with the basic mold on his vacuum box. Hooked up to a small shop vac. I tapered the sides of the balsa wood base to match the flare at the bottom of the canopy. I drilled holes in the balsa wood for additional vacuum due to that flare just to make sure the plastic pulled in there.

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We're using the kitchen oven here. Gas stove set at 350F. Firebrick on each side to support the frame.

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The frame is metal picture frame style held together with aligator clips. Yep that's me doing my best Vanna, the correct letter was T...-38A

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It took 1min 20 sec for the 0.020†petg to sag and be ready to form. The first canopy was really good we thought. A little later we found it didn't quite form completely in one corner so it will be my test fit piece and the one I use when i try to cut my first canopy out of the plastic form!

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We did 3 good ones out of 0.020†petg and 2 out of 0.030†petg. The 030 petg was really really hard to get off the mold. We stopped after the 2nd one. I was worried we'd break the mold trying to get it out. We had to do a lot of cutting where the plastic pulled in around the edges and then pry it up with a stick between the plastic and the balsa wood.

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