15 replies to this topic

[Lone Wolf]

I want to cast some drivers heads and maybe a few bumpers in 2 piece molds. I have not done this in years and last time I bought way too much material and it went bad before I could use it all. Looking for a small quantity of supplies to do a few parts like drivers heads etc.

 

Tell me what you are using, how you like it and where you got it please. 

 

Post pics if you got em'

 

Thanks

[MattD]

Joe go to Hobby Lobby and buy  the  Alumilite Quickset plastic and the extra strength rubber.      They are $29 I think, but you can get an online coupon to get 40% off.    Less than $20 each.   you can only use one coupon at a time.

 

You will find that you can make driver heads in a one piece mold  Just add some sprue to the neck and glue it in a box, cover it with rubber.   The rubber stretches enough to allow you to pull the head out thru the neck opening and  it is finished!    Might keep a straight pin handy to stir the plastic in the mold a little to release any air caught in the nose or chin area.   

You can probably make bumpers in a one piece spilt mold depending on  what the bumpers look like.    I can send some pictures if you want to see exactly what I am talking about.

[Lone Wolf]

Thanks Matt,

 

What is the quickset plastic? Is it 2 part? What color does it become when cured?

[Jairus]

I used Alumilite before too.  Uses a hardener so yeah, I guess you could say it's two part.

 

[MattD]

 

It's two part 50-50 mix for the plastic which is white and  the rubber is  10-1 mix using a scale like you get at Harbor Freight for $6-$8.

[drrufo]

I know this might be a bit much for a casual home builder, but we used to use an glass bell jar and a vacuum pump to pull the bubbles out of the aluminum casting resin we used to make ski molds. The molds were six to seven feet long and the vacuum pump worked really well.

 

John Andersen

[MattD]

Really good casters use pressure pots and vacuum.   I think they pressure rubber for the mold and then pressure the mixed plastic or put the mold in a pressure tank after plastic is poured.     Those guys make stuff way better than me.   I'm just a hack, but I am determined!

[Dave Crevie]

You can get a kit from Alumilite which includes all you need to make a few small molds for driver's heads. You don't need to

vac out small quantities. I make small molds in Dixie cups. You can make two-part molds in them as well. Just make sure

you provide some kind of alignment pins to line up the two halves. Vacing the plastic can't be accomplished after the two

parts are mixed, there isn't enough pot time. And vacing before mixing serves no purpose. And you may still get a few

bubbles just from the catalizing process. Some gas is created during it.

[MattD]

Dave, I beg too differ, having known Chris Etzel (Etzel Speed Classics)  pretty well and learning from him, I learned most of the pro casters poured mixed plastic into the molds and then put them in either pressure tanks or vac pots.    Lance Sellers  used pressure with all his great Indy car kits. 

 

Of course all their molds had vent holes.  They didn't sue the quick set plastic like most of us amateurs use

 

see this

https://www.smooth-o...vacuum-chamber/

[idare2bdul]

Micro Mark can be a good choice for stuff like this too, check out their website. They have a ridiculous amount of tools and supplies for modelers. You might check out their decal making supplies to add the personal touch to your cars. 

[munter]

I use an Australian product so that is no use to you but I haven't seen anybody mention Smoothon product range yet.

They are from the US, no?

 

Casting heads successfully without vacuum chamber or pressure pot can be done.

 

The enemy is air trapped in the mould...release that and let the resin go off and you are underway.

[MattD]

Smoothon makes excellent products and their sampler packs were my "go to" when I first started.   Back then they were $30, an incredible deal, now I think they are $60.  The Alumilite products are great and are readily available at HL and they are the cheapest you buy.   At that cost, if product goes bad, you have not lost much money.

 

Obviously you can buy 1 gallon/5 gallon  products from Eager,  Smoothon, Vagabond and other companies and get a cheaper price per ounce, but unless you are going into the business of making and selling in volume, that is a lot of product to have go back setting on a shelf.   Alumilite is still the cheapest way to get some product to experiment and see what you can do.

[Dave Crevie]

]The Alumilite plastic resin only has about a 90 second pot life to where it won't fill well. I have been working with two-part resins

since the early 70's, first making detail parts for plastic model railroad items, then model cars. I have run the gamut of types,

from epoxies to polyesters, and more. I found that the Alumalite resin usually doesn't need to be vaced out for small parts. Not

for scale drivers, or wheel inserts, of which I made many styles. Plus it it pretty much the only brand where you can purchase

small quantities. I used to get resin and silicone rubber in five gallon pails from Eager Plastics in Chicago. That would last me

about a month of making castings.                                                                                                                                                            

 

 

 

 

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[MattD]

Dave, I agree that many parts like heads, drivers, trim and even some bodies don't need vacing of the plastic.  I have never done more than simple pours in open air.   A lot has to do with mold design and mixing and pouring techniques.   

 

But most  "pro" guys use vacuum or pressure.  They don't use  fast cure resin as posted above.   Alumilite, Smooth on and all the resin companies make resins that can take up to an hour or more to cure.   That's what guys use in vac molds, they don't use fast cure resin for that work.   

 

I think we agree the Alumilite is a good product to play with and experiment with.  Enough practice and you can make most anything you want at home.   All this stuff was made with the above products and some simple two part molds,  and  I'm just a hack.   I do like seeing what I can make.

 

[slotcarcol]

G'day Matt,

 

Is that a Nichimo Manta Ray? Looks very nice. I have trim pieces if you need, and a clear resin canopy.

 

Col.

[MattD]

Col, it's good to hear from you.  I been trying to see if I could get your email from a mutual friend down under, but he kind of lost touch with a bunch of you guys.

 

I've seen pix of some of your work around the internet and you are doing nice, neat work.   I share Nichimo stuff with another guy and he just sent me a motor last week.  I had the rest of it.    I'll message you later.

 

matt b