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Awesome Dave, always looking for the KISS method and so far this is KISS.
Looking forward to Chapter 2
Bob

I have one dumb question that hopefully you may answer in the next instalment. Why not just use the Fly box lid the other way up, then the silicone can be poured anywhere in the box and the car can be stuck to the inside top which is now the bottom of the box.

The two cars I moulded for the Panam and LSR/Drag proxies, I built the box out of Lego, and just took it apart brick by brick once the silicone was set. The Lego method allows for easy sizing of the box.

As you said, this is your method and it works.

Thanks for posting this.

Keith

Yep, one question. Is that special paint on the model or does it have a coating so the silicon doesn't stick to it?

Any type of mold box will work fine. I have found cardboard and tape will work, legos can make any size box. Just be sure that if you use tape, hot glue or otherwise make a box, you must be sure there can no silicone leakage. Nothing worse than pouring your silicone and coming back 20 minutes later and seeing it has partially leaked out and you have to scoop it up and pour it back in! Ask me how I know. I did save that project though.

That Alumilite high strength is really a nice product and will last for a lot of castings. I have done a mold or two that actually spread some due to the softness of the silicone. Those two molds have small blocks of wood that fit against each side with a rubber band around the mold to hold the wood in place and keep the sides straight.

One last thing about silicone mixing ratios. For years I stayed with Smoothon silicone which was mixed 1 to 1, so it was easy to get the ratio right. When I started using the 10 to 1, I got a small scale off Ebay for $6-$7 with free shipping and it weighs several ways, from ounces to grams. I use the gram setting for sil and can mix little or big batches with proper consistency. I use the throw away plastic cups that go in a bathroom dispenser. I put the rubber in and then pour the activator in until I get the 10% that is required. A friend bought a similiar scale at Harbor Freight.

For just a couple bodies a slosh cast is fine and I have made plenty that way. Last time I did it, I got tired of mixing and pouring and rotating to get smooth coverage. Wait a few minutes and do it again. I was doing this 4 times or more. I got tired of all the pouring and mixing and went ahead and finished off the inside of a slosh body and poured an inner mold. Then I could make one body with one pour and in 15-20 minutes demold and make another body. I spent a lot less time mixing and playing with the mold. I pulled 20-30 bodies from each of the last Indy car molds I made and it saved me a lot of time.

Do what works for you and you will be surprised at your results. Just take a look at your project and think backwards about your mold and it all gets easy. Follow Daves advice and you will be surprised at what you can make.

This type of silicone will not stick to anything!

Do you paint your body after you stuff it full of clay?

Has anybody ever used a palm sander without sandpaper in it to vibrate bubbles out? I have several, and the pads are packed felt, so there wouldn't be a violent vibration, just a gentle, but strong vibration.

I have another Q, have you made a '38 Chevy coupe? 'cos I'd buy one.
I really like your thread so far as it's something I've read about heaps but never been confident to try and this is proving to be very encouraging for me.

delete

Air bubbles are really no problem. All this silicone is self de-gassing and the air will rise to the top and be released. Sometimes a two part mold may have an area that is hard to get resin into and that area may have bubbles in the resin. The trick here is to cut vents in the mold that allow the plastic to flow where you want it.
Air bubbles are no problem with a slosh casting.

Here is a link to an article I did back in the 90's when I first tried making a body. Much of the same info as Dave posted. The original article with pix has been copied and some of the pix are no longer there, but it is just a little more info about casting. http://hodrags.com/EntpCasting.html

I always use an open top box, and I run a screw up thru the bottom into the clay to hold the master in the bottom of the box.

A little further info if you are interested in two part molds. When Dave mentioned mold release, he wasn't referring to the stuff that is sprayed into a mold to allow easy removal of a body. The release he is talking about is a liquid you paint on your outer mold, 2 coats 12 hours apart. After it dries, It will keep the inner mold rubber from sticking to the outer mold when you pour the inner. You can get the Alumilite brand at Hobby Lobby.

What a great thread and final product.

Just got home and nice to see this on a hot, muggy, otherwise miserable day.

Congrats Dave on a great new car NO ONE has done. Just one more choice in the line up. Making my "Pre-Pre Order" now :)

A quick caution regarding materials: As Dave has laid out, IF you are using the materials shown above, it will work fine. IF you are using another brand of silicone, be aware that if you use a platinum catalyst type, normal "hobby" clays contain varying amounts of sulphur and will inhibit the cure of such silicones. With the platinum (non-condensation) cure silicones, you must use a sulphur-free clay, commonly sold as "Klean Klay" here in the US, or any other sulphur free clay. An alternative is to COMPLETELY coat any clay surfaces with a wax or other sealant. In the distant past, condensation cure materials were not really suitable for mold making, as they cure form the outside in, and take a long time doing so, witness attempts to make molds using common silicone caulks, which are condensation cure. Obviously Alumilite (and likely others) have figured out new formulations which offer the best of both worlds, i.e., fast cures, good tear strengths, low shrinkage, compatibility with most any substrates, which previously were the exclusive realm of the platinum cure silicones, and low costs. Mold on!

That is cool Dave!

This is a great new section. Next time I do some molding I will try and take some pictures as well, although really nothing much different then has been shown.

I use Smooth on products as I have had good luck with them and they degas really easy, both the silicone and the resins.

I am a lego user for the build box and I use hot glue to seal the perimeter. Found it much easier to use then clay

With respect to resin I slush cast as I am only doing these for myself. I have done a couple of two part molds, but currently am happy slush casting. I will usually have four molds going at once, and I keep myself hopping as I pour and slush one, and once the initial set up starts I move to the next one. I use a 10 minute resin so you don't have to wait long.

Being in 143 scale I usually use diecast cars as masters. 143 is really spoiled when it comes to subject matter in this regard.


Cheers


Dan

That is going to make a great looking build!

Excellent tutorial, Shotgun! I'm bookmarking this one for future reference.

Thanks!
Rick V.