Various past projects

[J Hall]

First off a couple photos of a 1/25 Euclid TC-12 in 1/24 scale...Some wood, some resin castings
More models to come as I find them..

[J Hall]

A Cat DD-9G in 1/16 scale...Mostly wood, brass cast tracks

[J Hall]

some D9Gs and 666s in progress...1/24 scale,

[J Hall]

A couple of better shots of the DD-9Gs and a 657E in 1/16 scale

[J Hall]

A resin cast Cat D8-2u in 1/24th and some 657Es in 1/16 scale

[J Hall]

A couple of older 657s in 1/24 scale this time...

[J Hall]

Cat 666 in 1/24 scale and a 1931 Packard.., just for the fun of it...

[J Hall]

I do a little mould making and casting from time to time..
A Cat RD-8 with solid nonmoveable tracks and a partially completed resin D8 13A, all in 1/24 scale

[J Hall]

A partially comleted 1/8 scale D7G...and after 3 years it is still not finished..I gotta get it done someday, I need the table space...
Also a no frills ecomomy D6C in 1/24

[J Hall]

D-11R CD in 1/16 scale

[sneaky-pete]

Wow,very nice work!

[Iron Art]

J Hall, Great job, you mentioned that you cast some parts for your models, is it alum. casting? I just took a class in sand casting alum looking for a way to cast some blocks but I'm not sure if thats the way to go. Any advice is appreciated. Fred

[modelman]

Amazing work jerry! They look real!!

[J Hall]

Thanks guys...Glad you like them..

Iron Art...
The casting I do is in urethane resin..I start out with a wood pattern and put as much detail into it that I want..Then I build a mould box to put the master in... allowing for expansion of the moulding rubber to come next...I mix RTV rubber with a hardner and put the mix in a vacuum chamber to get all the air bubbles out..I usually pour the rubber right over the pattern and then de-air it..It expands as the air leaves the mix, and that is why the over size box...once the air is re-introduced back into the vac chamber the rubber returns to it's original volume...
Let the rubber "kick off" or cure out...then remove the rubber off the master and you have a mould..

The urethane resin is a 2 part. equal parts A and B..It needs to be mixed completely for over a minute, or untill you sense heat building up...Pour it into the mould and it "kicks off" withn 5 minutes and you have a reproductoin of the original pattern..

The urethane is white when cured resembling ivory...I have made pistol grips before and they look good...The urethane should be used for decorative pieces only and it is no where as strong as metal where powered models are concerned....It works well for almost all static models though..

Here is a link to Smooth-on products for getting silicon rubber and casting resin and more

http://www.smooth-on.com/

I hope this helps..

[Iron Art]

J Hall, Thanks for the info and the link. Your write-up on the process is very informative. I'm kinda stuck on building with metal and thats why the interest in alum. casting. Thanks again, Fred