File:UnkaJesse VerticalBoilerWithWoodLaggingAndBrassBanding.jpg

Unka Jesse's "Newbie Project" locomotive as featured in Live Steam magazine uses 5/16" thick American Black Walnut both for its insulation and appearance. From http://www.chaski.org/homemachinist/viewtopic.php?f=8&t=72960&hilit=lagging