Barry Bogs'  1/22.5  scale Union Pacific  Big Boy  4018 Boiler Build - Apr. 17th, 2021

The basic boiler of the G scale BB is four inches in diameter. It is also thirty five inches long! This is the largest boiler the BLW shops have ever had to fabricate. With that being said, I searched for some basic tube with the four inch size in mind. Nothing stood out as saying this is what I need, so walking the isles in Home Depot, I came up with some PVC couplings that had the four inch OD size. With those in hand, along with a piece of pipe, I delivered them to the boys in the shop to assemble the basic shape of the boiler. This is the first time that the boys have had to form a tapered smoke box on a boiler. The boiler is not straight, and also is sloped at the rear. With all this in mind, the final size of the boiler was completed in sections, starting with the smoke box. I directed the boys to add spacers glued on to the base tube to increase the diameter to the correct size, and then wrapped 20 thou sheet material around each section, gluing them at the bottom of the boiler, with a half inch wide gap. The casting shop then poured resin in the gap to fill the area between the base tube and the wrapper. When the resin is set, it is very strong and solid, not to mention heavy. The firebox was formed in the rear of the boiler and and a wrapper covered the entire area.   - Barry

 

skip to other pictures in this project series

to the Big Boy project page

the C&W home page

Page created  4/18/2021