Larryhagmansliver Posted February 23, 2011 Share Posted February 23, 2011 Hey guys, I just finished casting my first car ever, and was wondering how my method compares to others... I took an existing model body shell to get the rough shape and roofline, and then grafted and sculpted non-hardening oil based clay to it to get the details I wanted and to transform it into a different car. How do all the other guys go about doing it? Quote Link to comment Share on other sites More sharing options...
jeffs396 Posted February 24, 2011 Share Posted February 24, 2011 Welcome to the site Neil!!! I think you can use anything you like for transforming something into a master...styrene is the material of choice, but diecast pieces work well, fiberglass, just about anything that'll stand up to the mold-making process. You mention "non-hardening" clay? I guess as long as you don't obscure or disturb the soft material during the rubber pour, you'd be OK. But a durable master is preferred, then it can be used again after the first mold wears out! Show us what you built! Quote Link to comment Share on other sites More sharing options...
MADD FABRICATOR Posted February 24, 2011 Share Posted February 24, 2011 Hey guys, I just finished casting my first car ever, and was wondering how my method compares to others... I took an existing model body shell to get the rough shape and roofline, and then grafted and sculpted non-hardening oil based clay to it to get the details I wanted and to transform it into a different car. How do all the other guys go about doing it? You didn't say what brand of RTV you plan on using to make the mold, but most manufactures recommend that you don't use regular modeling clay, which I believe is oil based, as the silicone RTV will not cure properly. I recommnend that you create the modifications out of Sculpy clay which needs to be baked after the modeling is done. Make it so the modification pieces can be removed from the plastic model, then baked as per the Sculpy instructions, and then reattached to the model before making the mold. ( Oil based clay and silicone RTV just don't work together. That is why Smooth-on, Alumilite, and other manufactures of casting products sell their own brand of clay. Hope this answers your question. CHEERZZZZ !!!!!!!!!!! MADD FABRICATOR Quote Link to comment Share on other sites More sharing options...
Mike Kucaba Posted February 24, 2011 Share Posted February 24, 2011 Most manufacturers of RTV recommend a Sulphur- free non- hardening oil-based clay.At least the ones I used. Some artsy types who do figure sculpting an such like gaming pieces use all kinds of materials for the master. As long as it won't inhibit the RTV cure,or can be sealed to prevent it, it's pretty wide open. I've read about Bondo being used even for a mold master. Quote Link to comment Share on other sites More sharing options...
Larryhagmansliver Posted February 24, 2011 Author Share Posted February 24, 2011 (edited) Welcome to the site Neil!!! I think you can use anything you like for transforming something into a master...styrene is the material of choice, but diecast pieces work well, fiberglass, just about anything that'll stand up to the mold-making process. You mention "non-hardening" clay? I guess as long as you don't obscure or disturb the soft material during the rubber pour, you'd be OK. But a durable master is preferred, then it can be used again after the first mold wears out! Show us what you built! Thank you for the welcome folks! The durability factor is actually why I'm asking. As soon as the first mold was mastered, the original was basically destroyed. Also, with clay it was very hard to get straight lines to stay straight, so I'm hoping that I can find something that's as easy to sculpt and shape, but more durable and still able to be worked without a time limit. I used all Alumilite products, so the one good thing is that the compatibility was not an issue. As far as showing what I cast - I'll try to post some pics today. Because of the clay's distortion, I had to do a lot of finish work with a dremmel on the resin cast piece, and I'm not entirely satisfied with it just yet. Still, it was fun and I learned enough to do a better job next time. Oh by the way - it's a mid-nineties Bonneville SSEI that I made. I'm a Pontiac freak! Edited February 24, 2011 by Larryhagmansliver Quote Link to comment Share on other sites More sharing options...
MADD FABRICATOR Posted February 24, 2011 Share Posted February 24, 2011 Most manufacturers of RTV recommend a Sulphur- free non- hardening oil-based clay.At least the ones I used. Some artsy types who do figure sculpting an such like gaming pieces use all kinds of materials for the master. As long as it won't inhibit the RTV cure,or can be sealed to prevent it, it's pretty wide open. I've read about Bondo being used even for a mold master. Mike, you're right. I meant to say " sulfur free" not " oil based". My mistake. I guess it's back to the whipping post and 40 lashes again. As for using " Bondo" for the master pattern for the mold, it works great and is realitively easy to shape,carve, and sand. I've used it many times. just make sure you seal it, before applying the RTV to it. CHEERZZZZ !!!!!!!!!!!!!! MADD FABRICATOR Quote Link to comment Share on other sites More sharing options...
shucky Posted February 24, 2011 Share Posted February 24, 2011 Hi Neil, IMO Sculpey clays are too brittle and delicate for this type of work. You'd want to ensure your master holds up to the molding process in the event you need to make a new mold. I'd suggest using styrene of various shapes to permanently modify or scratch build. You can use bondo or body filler for smoothing out the work. However, something that has served me very well is an amazing product from Aves called Apoxie Sculpt. This stuff can be shaped into endless varieties, air dries, dries rock solid, adheres to nearly any surface, can be drilled, tapped, can hold a sharp crease, etc. Its also very easy to work with and shape as well as sand smooth. No cracking whatsoever, and zero shrinkage. Its really amazing for body work and holding specific shapes. Good luck! Quote Link to comment Share on other sites More sharing options...
Mike Kucaba Posted February 24, 2011 Share Posted February 24, 2011 Mike, you're right. I meant to say " sulfur free" not " oil based". My mistake. I guess it's back to the whipping post and 40 lashes again. As for using " Bondo" for the master pattern for the mold, it works great and is realitively easy to shape,carve, and sand. I've used it many times. just make sure you seal it, before applying the RTV to it. CHEERZZZZ !!!!!!!!!!!!!! MADD FABRICATOR Hey don't be so hard on yourself.I am a practicing member of the group in my signature! Quote Link to comment Share on other sites More sharing options...
Larryhagmansliver Posted February 25, 2011 Author Share Posted February 25, 2011 Being from Cleveland, I know a thing or two about Bondo, LOL! Seriously though, you guys who are using the stuff, what do you do since carving tools wont work? Shape a rough outline with your hands and then use files to detail it? Also found some stuff called "Balsa foam". Sounds like it might be useful for this as well. Quote Link to comment Share on other sites More sharing options...
MADD FABRICATOR Posted February 26, 2011 Share Posted February 26, 2011 (edited) Being from Cleveland, I know a thing or two about Bondo, LOL! Seriously though, you guys who are using the stuff, what do you do since carving tools wont work? Shape a rough outline with your hands and then use files to detail it? Also found some stuff called "Balsa foam". Sounds like it might be useful for this as well. When using Bondo, you need to start working ( carving, and etc), as soon as it's still somewhat soft. It works pretty easy in that state, even with Exacto knives and gouges. If you let it sit overnight, it will be much more difficult to carve, unless you use a Dremel type tool with some good quality grinding bits and sanding drums. You'll have to do some experimenting to get the feel for working with it in such small quantities. As also remeber different brands of bondo types of materials will work differently. So PLAY away and see what best works for you. CHEERZZZZ !!!!!!!!!! MADD FABRICATOR Edited February 26, 2011 by MADD FABRICATOR Quote Link to comment Share on other sites More sharing options...
Mike Kucaba Posted February 26, 2011 Share Posted February 26, 2011 You can shape bondo fairly easily if you catch it just as it's kicking. Believe it or not ,but in the foot care section of most large stores is a callus tool for feet that works just like the surform(cheese grater) that is used on the 1:1. It's smaller though and just right sized for model work. And even after Bondo hardens, it's no match for a 36 grit flap wheel in a drill. Quote Link to comment Share on other sites More sharing options...
Larryhagmansliver Posted February 28, 2011 Author Share Posted February 28, 2011 You can shape bondo fairly easily if you catch it just as it's kicking. Believe it or not ,but in the foot care section of most large stores is a callus tool for feet that works just like the surform(cheese grater) that is used on the 1:1. It's smaller though and just right sized for model work. And even after Bondo hardens, it's no match for a 36 grit flap wheel in a drill. Thanks for all the great advice guys. Ok, much to the dismay of my wife, I spent the majority of this weekend redoing my original. This time I used USC metal glaze, which is a finishing putty that I've used with success on real cars. I'm pretty pleased with the way it's going this time around. I changed my approach into making more of a "conversion kit" than a full body. It's the back part of the car that's taking the most reworking time. I'm really looking forward to sharing it, even if it's less than perfect. Quote Link to comment Share on other sites More sharing options...
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