CP9302
Member
Its been a long time since I posted anything, but I thought it was about time to share some of what I've been working on again, so here goes. Hope you all enjoy.
As a modeller of Canadian Pacific in the 1990's and a lover of intermodal trains, I was confronted with a lack of accurate well cars to build my trains. While CP was an early adopter of Intermodal freight, they were slow to adopt the 'double-stack' car that is now common place. CP relied mainly of flat cars to carry their container traffic. In 1986 they took delivery of their first double-stack well car, a 3 unit, draw bar connected set numbered 524000/524001/524002 (yes, each car was individually numbered) It wasn't until 1993 that they would take delivery of their first group of cars from National Steel Car (NSC), and they were on lease! This experiment went well and CP ordered their own cars in 1995, again from NSC. This thread will follow my attempt at modeling these two batches of cars. The 1993 group will be referred to as the 'Early car' and the 1995 group as the 'Late car'. Both groups are very similar in design and construction. The Early car has angled sides around the trucks while the Late car has the rounded edge common to today's NSC cars. The Late car is also characterized by inspection 'port holes' in the car sides.
This is a photo of one of my first completed Late style cars. Note the curved side near the wheel and the round 'port hole' inspection openings in the side.
For additional information on building these cars and scale drawings, please see the November 2001 issue of Model Railroader. My efforts here are based heavily on the article by Jonny Barnstorf and the scale plans by Jonny and Rick Johnson.
Since no model of either of the cars is currently on the market, I was left with no choice but to build my own. Since the cars operate in 3 unit draw bar connected sets, to build one car I had to build three. And one set would just not be enough. I decided to make a mold and cast the cars in resin. Since I've only done one sided molds, I broke the car down into pieces that I could cast in flat, one sided molds and glue together after to complete the car. In the end I broke the car down into 7 pieces, 2 sides, two bolster/walkway ends, two well ends and the well bottom. I built masters of these parts using styrene and the plans referenced above. Take your time building masters, any errors, goofs or close enoughs will be faithfully reproduced in every part you cast.
To create the molds, I glued the masters to a sheet a styrene and built a wall around the masters using styrene strips. Make sure the walls are taller than your master so the mold compound can cover it completely. Also make sure and the joints are sealed, on the walls and your master part. I then mixed the mold compound as per the instructions and poured it into the mold. You can start by pouring a small amount into the mold and use a brush to paint it over the fine details. Use a pin or toothpick to release any trapped air bubbles. Pour in the rest of the mold compound until the mold is full. It is best to pour in the open areas of the mold, not directly onto the master, and allow the compound to flow over and around the master. This will help reduce the number of trapped air bubbles. Leave the mold to set on a flat level surface. If you have a vibration table, it would be good to let the mold set on their to help shake out any air bubbles. I let mine set on the dryer while running to shake the air bubbles out
This is the master for the sides and well end plates of the Early car. The pink in the lower right is some overflow from the mold compound.
Once the compound has set, you can peel the mold off the master and you're ready to start casting parts!
I used Mold Max 20 from Sculpture Supply Canada to make the molds for this project. I found it very easy to work with. It produces very durable molds and de-gases well. The molds have a very high tear strength, so they are good for many castings. It has a 10 to 1 mixture ratio, so some measuring and math is needed
http://www.sculpturesupply.com/list.php?sf=subcategory&vl=Mold+Max+20&cat=Rubber+Silicones
I've also used Micro Mark mold compound in the past. It is also easy to work with. The 1 to 1 mix ratio is easy, but the molds are not as durable and tend to tear/split easier.
http://www.micromark.com/one-to-one-and-rapid-mold-rubber-32-fl-oz,7883.html
Next up, casting parts...
As a modeller of Canadian Pacific in the 1990's and a lover of intermodal trains, I was confronted with a lack of accurate well cars to build my trains. While CP was an early adopter of Intermodal freight, they were slow to adopt the 'double-stack' car that is now common place. CP relied mainly of flat cars to carry their container traffic. In 1986 they took delivery of their first double-stack well car, a 3 unit, draw bar connected set numbered 524000/524001/524002 (yes, each car was individually numbered) It wasn't until 1993 that they would take delivery of their first group of cars from National Steel Car (NSC), and they were on lease! This experiment went well and CP ordered their own cars in 1995, again from NSC. This thread will follow my attempt at modeling these two batches of cars. The 1993 group will be referred to as the 'Early car' and the 1995 group as the 'Late car'. Both groups are very similar in design and construction. The Early car has angled sides around the trucks while the Late car has the rounded edge common to today's NSC cars. The Late car is also characterized by inspection 'port holes' in the car sides.
This is a photo of one of my first completed Late style cars. Note the curved side near the wheel and the round 'port hole' inspection openings in the side.
For additional information on building these cars and scale drawings, please see the November 2001 issue of Model Railroader. My efforts here are based heavily on the article by Jonny Barnstorf and the scale plans by Jonny and Rick Johnson.
Since no model of either of the cars is currently on the market, I was left with no choice but to build my own. Since the cars operate in 3 unit draw bar connected sets, to build one car I had to build three. And one set would just not be enough. I decided to make a mold and cast the cars in resin. Since I've only done one sided molds, I broke the car down into pieces that I could cast in flat, one sided molds and glue together after to complete the car. In the end I broke the car down into 7 pieces, 2 sides, two bolster/walkway ends, two well ends and the well bottom. I built masters of these parts using styrene and the plans referenced above. Take your time building masters, any errors, goofs or close enoughs will be faithfully reproduced in every part you cast.
To create the molds, I glued the masters to a sheet a styrene and built a wall around the masters using styrene strips. Make sure the walls are taller than your master so the mold compound can cover it completely. Also make sure and the joints are sealed, on the walls and your master part. I then mixed the mold compound as per the instructions and poured it into the mold. You can start by pouring a small amount into the mold and use a brush to paint it over the fine details. Use a pin or toothpick to release any trapped air bubbles. Pour in the rest of the mold compound until the mold is full. It is best to pour in the open areas of the mold, not directly onto the master, and allow the compound to flow over and around the master. This will help reduce the number of trapped air bubbles. Leave the mold to set on a flat level surface. If you have a vibration table, it would be good to let the mold set on their to help shake out any air bubbles. I let mine set on the dryer while running to shake the air bubbles out
This is the master for the sides and well end plates of the Early car. The pink in the lower right is some overflow from the mold compound.
Once the compound has set, you can peel the mold off the master and you're ready to start casting parts!
I used Mold Max 20 from Sculpture Supply Canada to make the molds for this project. I found it very easy to work with. It produces very durable molds and de-gases well. The molds have a very high tear strength, so they are good for many castings. It has a 10 to 1 mixture ratio, so some measuring and math is needed
http://www.sculpturesupply.com/list.php?sf=subcategory&vl=Mold+Max+20&cat=Rubber+Silicones
I've also used Micro Mark mold compound in the past. It is also easy to work with. The 1 to 1 mix ratio is easy, but the molds are not as durable and tend to tear/split easier.
http://www.micromark.com/one-to-one-and-rapid-mold-rubber-32-fl-oz,7883.html
Next up, casting parts...