Firebox for Brinkmann Trailmaster

Hey all, Dad has put thousands of miles on his Trailmaster and has mastered bbq on it (he smokes a killer brisket and mine sucks lol) and his firebox has rusted out. The main cook chamber is in great shape minus a little surface rust on the outside but the firebox is shot. Georgia humidity is rough on our outdoor cookers; it destroyed the firebox on my Old Country Ranch Hand. Dad would oil his down after every cook and keep the outside of his seasoned like I do my Smokehouse Vertical and it went a good 3 years before the metal just rusted through. We did everything right and I'm just going to wager it's the thinner metal they use on them.



Sorry for the long intro, I'll get to the point-where can we get a firebox for this cooker? No point in tossing the cooker when it's just the firebox. Thanks in advance!