# First try at a mold



## SFC_Allen (Aug 19, 2007)

Well tried my best to make a mold of a diecast nascar that fit on the Mega G chassis. Did a bone head thing and forgot to add the release agent but luckly i had a layer of clay down so it wasn't so bad.

Was trying someones theory on how to make the molds fool proof, but got side tracked and forgot what i was doing and starting pouring the second portion of the mold.

First car is on the left, went pretty bad. Second car had to bad bubbles in it. Decided to try and paint (rattle can) it anyways. Looks pretty bad to me, i see about a 1000 flaws in it. Do i need to sand the resin down with a certian grit before painting? And how do i stop the bubbles that you see? The large one and the group of smaller ones. 

Had to make the pour spout in the back after i screwed up. I think i'll try again but the mold stuff is so expensive it may take alot more trys to get it down. Is there a cheaper way than alimnite out there?

Next is how to i get it to mount to the chassis? I want to make a bunch of this one so the kids and me have more racers to have but i want it to be an easy transition between mounting and not having to use double sided tape everytime.

Also when pouring alimnite resin i was going slow, but by the time i got the warm mold full the plastic cup was getting warmer and the resin was becoming hard real quick. then about 10 secs later it was rock hard. Any idea's?

Thanks in advance. Hopefully i have a few different cars to make shortly. Earle


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## kiwidave (Jul 20, 2009)

Keep at it Earle! And thanks for posting this. I'm keen to learn more about this as well!


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## bobhch (Apr 22, 2007)

*Smack them to pieces....the Moles that is.*

Hey Earle,

Keep plugging at it...

Sometimes my bodies get bubbles and messed up to. My solution is this. (see picture below)










I am going to rust this bad boy out next. Then will be drilling some holes in the hood with a couple of little moles peeking up in a few of them. Yep a traveling SMACK A MOLE car.

I use the Smooth-On resin starter kit. Lots of people use different resins with success  and failures  alike.

Bob...Smasher drives with his knees...zilla


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## 1scalevolvo (Feb 5, 2004)

:thumbsup:They say a journey of 1000 miles begins witha 1st step. I'm proud of you !

Neal:dude:


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## bearsox (Apr 22, 2006)

*Hi Earle ,
always the 1st few efforts are learning tools and usually costly. It's great you wish to continue on as loads of folks just toss in the towel and say it's not worth it . If i may make a couple of suggestions that may help . 1st visit and follow the info available on sites that sell the products you use as they have a vested interest in trying to help you succeed as they sell more. Tap plastics http://www.tapplastics.com/info/video.php has loads of helpful videos as does youtube oddly enough. Smoothon also has videos http://www.smooth-on.com/media_video.php?category_id=1&category_name=Basics Of Moldmaking Videos to help . Now for your issues .... looking at the molds and not the body i see issues that can be helped AND limit some of the blems , pits and holes as they are caused by the mold rather than the resin . So take a look at this video and use it as a way to remove air from molds cheaply and get a better result. http://www.metacafe.com/watch/930417/how_to_make_a_simple_silicone_mold_part_2/ Now as for the resin issues ... what i see from pics is some trapped air so some of this can be from how you mix the resin ( go back to video to refresh ) the other part is again the pour. Ideally cutting in sprues and vent holes will remove alot of the air so find a good video you can go back to over and over to reference. 1st though start your pours from 1 location like a corner and slowly rotate the mold to allow the resin to flow into all areas and push it's way along . This limits trapped air . If your molding a tjet use the posts as a vent hole if molding other cars a tire slot ( cut a v slot atop the male mold ) is usually a good location . Once undercuts are filled place male part of mold in place and gentily press allowing gravity to do most of the work . If you find your running out of time change the resin you use to a slower setup like Smoothon's smooth cast 305. Hope all this helps in the end but regardless there is no substitute for trail and error. Have fun in the end as it a hobby 1st ! 

Bear :wave: *


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## bobhch (Apr 22, 2007)

Bear,

I am so going to try that "Bombs Away" method, shown on your last link,next time I cast a body or parts!

Bob...some day will be able to afford the BIG SUCKER!...ZILLA


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## vaBcHRog (Feb 19, 2003)

SFC_Allen said:


> Well tried my best to make a mold of a diecast nascar that fit on the Mega G chassis. Did a bone head thing and forgot to add the release agent but luckly i had a layer of clay down so it wasn't so bad.


Explain the above. Did you forget the release when you poured the second half?

Roger Corrie


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## joegri (Feb 13, 2008)

sfc you are way braver the me.taking that 1st step must be awsome!think i,ll go to school in yer thread.dennis all the info you posted will have to studied further. thanx for posting that!


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## pshoe64 (Jun 10, 2008)

There are many ways to make the molds work. The guys here do incredible stuff! I create relief vents in the bottom of the 2nd half of my molds so the air bubbles can work their way out. I also use a paint pressure pot to help force the air bubbles to rise out of the resin. I have had really good results with applying around 20 psi. I have started using the pressure pot for degauzing the silicon when making the molds as well. This became a necessity, because the pressure used when making the resin body, forced the resin into any void in the mold, including several i couldn't see. Pressure casting the silocon has resolved that issue. My next project is aimed at making pit crew personnel in HO. So I will be building a completely different 2-part mold, that I haven't done before. I'll get a new thread started when I begin this project and document the steps and misteps (there will be many). Maybe some that will apply to my car molds later down the line.

-Paul


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## pshoe64 (Jun 10, 2008)

*A Pictures Worth?*

After my last post i dug up a couple of photos of my last car mold I made.










Here I have the internal cavity of the car filled with clay and sitting on a Glad container lid with the container's bottom cut out.










Here's the finished exterior mold. I will get slathered with vasoline as will the body(with the clay removed and cleaned) so the interior mold will not stick when poured.










Here are the 2 halves finished. Notice i have cut away the silicon from between the wheelwell extensions. This makes a vent for trapped air in the resin to escape. It is best seen in the picture below.










Here you can see the venting on the sides and front and rear of the mold. It doesn't take much, especially if you are using pressure to help force the bubble out. I picked up my pressure pot at Harbor Freight for about $25. I have not had a bubble blown out body since. Hope this helps.

-Paul


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## SFC_Allen (Aug 19, 2007)

vaBcHRog said:


> Explain the above. Did you forget the release when you poured the second half?
> 
> Roger Corrie


Yes, got alittle ahead of myself and was rushing it ...dooh


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## SFC_Allen (Aug 19, 2007)

Wow..thanks guys lots to digest, but hey i'm game and burning money is my thing 

I think i'm quite sometime away from a pressure pot. I still have to learn to airbrush after i get this down.

Paul, all i see is x's for your pics. VR Earle


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## resinmonger (Mar 5, 2008)

*No pictures?*



SFC_Allen said:


> Paul, all i see is x's for your pics. VR Earle


Same for me Paul. I see the pictures are from Windows Live and one has to logged in to Windows Live. That may be the issue...


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## pshoe64 (Jun 10, 2008)

Sorry guys, my screw up. I upgraded my website on Live and changed the folder name that housed these photos. Wouldn't think I do this for a living?:freak: Brainfade big time today. Post is updated and the images are up.

-Paul


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## SFC_Allen (Aug 19, 2007)

Still X's, but it may just be me now Earle


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## pshoe64 (Jun 10, 2008)

Guys, I checked from 2 different laptops (windows and mac) and I can see the pics. Let me know if they aren't showing for you and I'll repost the links again. All my images are posted from my site and I haven't had any issues, except those caused by me 

-Paul


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## slotcarman12078 (Oct 3, 2008)

I only get blank spaces where the pictures are supposed to be. I know they should be there because if I click Quote, I can see the html.


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## pshoe64 (Jun 10, 2008)

*Safari Issue on My Side*

Thanks guys. It's on my end. Apparently the last upgrade to Live is messing with Safari's view and access to my own site! I'll repost the pics with my windows PC in the morning. I guess I need to watch for the next set of patches:drunk:

-Paul


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## pshoe64 (Jun 10, 2008)

*Image Test*

These are the same images in order. Let me know if these pop up. I may have had the resolution too high.

-Paul


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## bobhch (Apr 22, 2007)

:thumbsup: I can see the pics now!!!!!!!!!!!! BZ


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## 706hemi (Oct 23, 2009)

*my 2 cents*

hey earle

good first attempt, in agreement of everything said so far, whilst thinking of keeping it on a budget, i will say use the cheapest rtv silicone you can find, you find you can make the mould last longer by using a wax or silicone based release agent, not so important though when starting out. i would highly recomend the use of brushing on the silicone to the body prior to final pouring, especially on highly detailed areas and any undercut areas, this will prevent any air bubbles occouring, 

my own opinion is to stay away from pouring in the resin through a single hole, as mentioned by others, i would use vent holes to expell any resin excess and air bubbles, i would pour the mix into the main part of the mould, spread it around with a mixing stick so it gets into all awkward areas then press in the plug/centre part of your mould, to slow the curing process slightly, i drop the temprature of the resin by putting in a fridge first to cool, its been my experience that the quicker the curing time the better (more flexible/stronger) the resin, nearly always the slower setting resins are more brittle and more vicious to the mould (i.e reducing its life expectancy) but this just might be a u.k thing! i have been casting for a few years now and its still a "black art" to me, some tricky moulds i have made produce excellent results all the time while some simple moulds still pop out air trapped bodies nearly all the time! anyway good luck, any more probs i'm sure people here will be happy to help 

take it easy
tony


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