My 30 year old Burnham Wood boiler has four 4" by 17" long 1/4" thick steel baffles that form a shelf that sits above the fire box and reflects heat back into the fire along with redirecting the hot gases to the front of the boiler before going above the baffle through a bank of vertical heat transfer tubes with the remains of turbulators. I have no idea what they originally used for baffles as it was a used and abused boiler when I got it for free. My guess is they were not standard A36 plate but over the years as they burned out I replaced them with A 36. I would get a few months before they started losing thickness and drooping to the point that the fell into the fire, meaning I would have to fish out red hot plates in order to load more wood in and see a further decrease in efficiency. I have them cut up by a local supplier and usually have two sets made up. They have no technical folks and are pretty limited on what they stock so no options of going with anything beefier from them.
I was out of spares and the ones I have are getting pretty thin so its a PITA. So I ordered up some 410 Stainless plate today. Not cheap but going to give it try. It definitely has a higher temperature rating and is also supposed to be corrosion resistant so maybe It will not thin out as quickly. I bought a piece from an online seller so I will need to cut it to size. I expect my angle grinder is going to be going through a fair share of cutting wheels.
I was out of spares and the ones I have are getting pretty thin so its a PITA. So I ordered up some 410 Stainless plate today. Not cheap but going to give it try. It definitely has a higher temperature rating and is also supposed to be corrosion resistant so maybe It will not thin out as quickly. I bought a piece from an online seller so I will need to cut it to size. I expect my angle grinder is going to be going through a fair share of cutting wheels.