If you want to easily model a typical heavily weathered covered phosphate hopper then this paint method may work for you. First make sure the model is clean of wax residue, soak in Bestine for best results. Then paint the the car a dark red color (the paint job doesn’t have to be great). I used Krylon Fusion Burgundy. Next I cut a template of SCL letters. I sprayed flat white spraypaint over the template. Then I weathered the whole car with mists of flat white spraypaint. I have yet to add reporting marks, which are usually patches of cleaned off areas. Overall, this simple technique renders a realistic heavily weathered covered phosphate hopper quickly. (Model shown is a U14 prototype slightly different from what is currently for sale at Shapeways.)
A variety of N scale phosphate hoppers (wet rock and dry rock) are now available here from Shapeways.
Bone Valley Scale Models has gone digital.
In 2005, I produced a run of HO scale resin freight car kits of equipment found in Florida’s phosphate mining region. Those models have since sold out and I’ve been looking for ways to make the kits better (easier to assemble) and easier to keep available. Well, I have found a solution with a company called Shapeways. Shapeways uses 3D printing technology to print custom products, such as model train related products.
For the time being, I am only going to be releasing N scale rolling stock models through Shapeways. The cost to quality and reliability ratio of the available materials is not yet sufficient for HO scale models in my opinion. But for N scale it is great. As the technology improves, HO will eventually be available. If I make anything available in HO scale anytime soon (other than HO accessories) it will be a GE MATE model. But that project is still a work in progress with no guarantee yet that current materials are sufficient to make it viable.
Here is a breakdown of the Good and Not-so-Good of using 3D printing to make model railroad items. These things do not apply to the bridge component which are printed in a different material.
Pre-Assembled: All you have to do is wash, paint, decal, and put on a pair of Micro-Trains Barber Roller Bearing Trucks and a brake wheel.
Lots of Detail: The printing process allows a level of pre-assembled detail that cannot be achieved with injection-molded plastic or resin.
Not Incredibly Expensive in N Scale: Considering that the models come assembled, around $20 per car is not very expensive for a unique custom car.
No Limited Availability: Unlike with resin kits that are produced in limited run batches, these are made to order.
The Not so Good
Texture: The model material is not perfectly smooth like injection molded plastic or resin. Some areas end up smooth but many have a slight texture, especially curved or angled surfaces. The texture can be remedied with some brief, careful sanding with 500 grit paper. Once the model is finished and weathered, any texture becomes inconsequential without a magnifying glass.
Wax: The support wax used to print the model freight cars lingers on the model sometimes. So you have to clean the wax off for painting. The best method discovered thus far seems to be to use a product called Bestine.
Paint and Decals: You have to paint and decal the model yourself. Standard Microscale decals will work.
Limited to N Scale for now: I look forward to making HO scale models available using 3D printing, but considering that an average HO scale freight car would currently run over $60 without any guarantee that it would hold up without breaking or warping, HO is not really viable yet.