Help with molding model car tires

Darthsideous · Post by **Darthsideous** » Thu Jan 12, 2012 12:56 am

Hi, just thought I'd put this out there to see if it is possible. I recently picked up a fiberglass 1/8 Keaton batmobile car kit with resin wheels and tires. I was wanted to make vinyl tires (I believe this is what normally comes with 1/25 scale cars). I have a solid resin tire that I could use to create a mold, but can anyone recommend a product to create the soft vinyl tire casting?

rpauly · Post by **rpauly** » Thu Jan 12, 2012 6:38 am

Tire Casting Rubber

Darthsideous · Post by **Darthsideous** » Thu Jan 12, 2012 10:12 am

rpauly, thanks for pointing me to that product. I didn't think to check Micromart!

Stu Pidasso · Post by **Stu Pidasso** » Thu Jan 12, 2012 11:05 am

Tip from your Uncle Jimi: LOTS AND LOTS of mold release! Not talc.

Darthsideous · Post by **Darthsideous** » Thu Jan 12, 2012 2:53 pm

Thanks Jimi, Will do!

Umi_Ryuzuki · Post by **Umi_Ryuzuki** » Thu Jan 12, 2012 3:57 pm

Interesting, I use no mold release and talc...
But then I am using a Polytek polyurethane.
Of course we are also trying for that chewed up look on tugboats.

http://www.rcgroups.com/forums/attachme ... id=4326501

Darthsideous · Post by **Darthsideous** » Fri Jan 13, 2012 11:35 pm

Do you use micro mark products Umi?

Umi_Ryuzuki · Post by **Umi_Ryuzuki** » Sat Jan 14, 2012 1:23 am

Darthsideous wrote:Do you use micro mark products Umi?

No, I typically don't buy such small quantities.
Polytek 74-30 is what I am using, I wait a week for molds to cure before pouring.

Rogviler · Post by **Rogviler** » Sat Jan 14, 2012 1:58 am

More importantly, how about some pictures of this kit?

I've heard of it but have never seen it.

-Rog

Darthsideous · Post by **Darthsideous** » Sun Jan 15, 2012 12:51 pm

I'll see what I can do for pictures. I've never posted pics on the internet before. What's the best site to post them to?

With respect to the batmobile the tires are 3 to 4 inches across and about 2 to 2.5 inches thick. Bear in mind I have never casted anything before can you guys tell me approximately how much micromart tire resin I will need, also which product can you recommend for the mold material?

Darthsideous · Post by **Darthsideous** » Sun Jan 15, 2012 1:23 pm

Ok, hopefully this will work I have tried creating a photbucket account and sharing it. Here's the link:
http://s1244.photobucket.com/albums/gg5 ... ld_Hitman/
Besides trying to cast rubber tires. I also have to repair the wheels which were extremely damaged during shipping. I'm thinking I'll need to repair the wheels and then recast them so they will not break apart? I was think of using aves apoxy sculpt to repair the wheels has anyone had experience with this sort of repair? will Aves work?

Once the wheels are repaired I'll mount the rubber tires I mold on them.

Umi_Ryuzuki · Post by **Umi_Ryuzuki** » Sun Jan 15, 2012 2:27 pm

The issue I see, seems to be that the wheel and tire are one piece in some
fashion. How will you separate the tire form the wheel to make your molds?

If you calculate the cubic volume of your tires, you can then
calculate the number of ounces of material you will need to cast them.

Rogviler · Post by **Rogviler** » Sun Jan 15, 2012 2:51 pm

Umi_Ryuzuki wrote:The issue I see, seems to be that the wheel and tire are one piece in some
fashion. How will you separate the tire form the wheel to make your molds?

It comes with separate wheels, so all you have to do is drill out the wheel part of the one-piece wheels/tires. There are certainly worse things to have to fix.

That really is an awesome model though. It doesn't look overly detailed, but at that size it would be easy to do that yourself. I'll have to keep my eye out for one of those. I have the smaller kit and that looks like a Matchbox car in comparison!

Is this the one from the Howard Studios shell? I thought that was pulled directly from an original studio scale one. If so, it's probably the most accurate one you can get, aside from buying the real full-size car.

-Rog

EDIT: I'm wondering, though, if you've taken a trip to your local RC shop to see if there are any pre-made tires that would fit the rims? It might be worth a try, since there's really nothing special about the tires where you have to worry about some special detail.

Darthsideous · Post by **Darthsideous** » Sun Jan 15, 2012 4:38 pm

Umi_Ryuzuki wrote:The issue I see, seems to be that the wheel and tire are one piece in some
fashion. How will you separate the tire form the wheel to make your molds?

If you calculate the cubic volume of your tires, you can then
calculate the number of ounces of material you will need to cast them.

Thanks for the advice Umi! I'm thinking that I will cut out the centres of the rubber casting, and insert the resin replacements. i have never tried this before so i don't know if cutting out the ruber will work, but I figured I'd give it a try.

Ziz · Post by **Ziz** » Sun Jan 15, 2012 4:56 pm

Plan ahead, then back up and plan further ahead.

Start by cleaning up the parts and making molds of one of each front and back wheel & tire as is. That will give you the ability to cast more if your attempts to drill out the ones you have go wrong somehow. Secondly, it will give you a way to back up and use resin tires & wheels if you can't find or make suitable rubber or vinyl replacements.

Also investigate what http://www.smooth-on.com carries. I'm sure they have something standard for casting tires and such and they'll probably be cheaper then MicroMark. MicroMark carries a lot of unusual stuff but they've never exactly been a bargain.

Darthsideous · Post by **Darthsideous** » Sun Jan 15, 2012 5:00 pm

Hi Rogviler,

Thanks for the feedback. I was told that it was came from the The Magic Model Company, which was the second unit for the 1989 Batman movie. I haven't done any research to determine how acurate this is. I just wanted a big batmobile without spending about $2000.00 for a prebuilt one.

I've built lit 1/25 scale versions of this car before so I'm pretty sure I can do the same with this one in a larger scale. The cockpit will be the spot for detailing as well as the machine guns, not sure if I can do a pull out the engine. the body will take alot of work. Hopefully i can post it on this site even though it's not a starship.

Joseph Osborn · Post by **Joseph Osborn** » Sun Jan 15, 2012 5:35 pm

Ziz wrote: Also investigate what http://www.smooth-on.com carries. I'm sure they have something standard for casting tires and such and they'll probably be cheaper then MicroMark. MicroMark carries a lot of unusual stuff but they've never exactly been a bargain.

Tell me about it

... The "tire" casting rubber from Micro-Mark is just firm urethane rubber that has to be tinted black by the user. Probably something like Vyta-Flex from Smooth-On.

I hope you got a good deal on that kit, Darthsideous! It looks like those wheels have been through a woodchipper. Better than starting from scratch, though

Darthsideous · Post by **Darthsideous** » Sun Jan 15, 2012 9:34 pm

Joseph Osborn wrote:
Ziz wrote: Also investigate what http://www.smooth-on.com carries. I'm sure they have something standard for casting tires and such and they'll probably be cheaper then MicroMark. MicroMark carries a lot of unusual stuff but they've never exactly been a bargain.
Tell me about it ... The "tire" casting rubber from Micro-Mark is just firm urethane rubber that has to be tinted black by the user. Probably something like Vyta-Flex from Smooth-On.

I hope you got a good deal on that kit, Darthsideous! It looks like those wheels have been through a woodchipper. Better than starting from scratch, though

Thanks ZIZ & Joseph, I'm totally new to casting so your help with products is really appreciated. I did get the kit at a decent price and I'm asking the seller for some money back due to the wheel damage from shipping, but I am under no illusion, this model will take alot of work.

I've also going to take Rogviler's advise and see if I can find RC tires that will fit the wheels.

I'll probably start a new thread when I start work on the body to ask for help working with fiberglass.