barts wrote:Imron recommended continuous service temp. is 200 F.
Imron 3.5+ HG(formerly known as Imron 333M) has continuous service 250F, intermittent 300. It has a "failure"-mode that doesn't matter much for a black stack- it says, "Some yellowing of light colors may occur at elevated temperatures." Jeff Lund also did line it with some insulation but the forced draft I added ripped it up and it would occasionally throw out a chunk of insulation up the stack so I removed the rest of the insulation.
I can just say that I haven't had any issue, and I know that they use Imron on steam traction engines with good results. My buddy Tom Diehl has it on his replacement boiler made by Johanas Stutzman for a 6HP Russel traction engine.
barts wrote:Imron recommended continuous service temp. is 200 F.
Imron 3.5+ HG(formerly known as Imron 333M) has continuous service 250F, intermittent 300. It has a "failure"-mode that doesn't matter much for a black stack- it says, "Some yellowing of light colors may occur at elevated temperatures." Jeff Lund also did line it with some insulation but the forced draft I added ripped it up and it would occasionally throw out a chunk of insulation up the stack so I removed the rest of the insulation.
I can just say that I haven't had any issue, and I know that they use Imron on steam traction engines with good results. My buddy Tom Diehl has it on his replacement boiler made by Johanas Stutzman for a 6HP Russel traction engine.
Note that firetube boilers run at the steam temperature, so that's a lot easier on paint than a single walled stack. Measure your stack temperature under load at the dock w/o wind. Double wall stacks are easy. I've seen stacks w/ blistering paint on boats where the boiler is forced during a race.
A 200 psi boiler has steam temps of near 400 F - which means unless there's an economizer the gas temps are above that.
barts wrote: I've seen stacks w/ blistering paint on boats where the boiler is forced during a race.
A 200 psi boiler has steam temps of near 400 F - which means unless there's an economizer the gas temps are above that.
I'm not doubting this. However I have never seen Rustoleum bbq spray last. Maybe it's all in the prep but I can tell you the stack on mine which is stove pipe that I did with Rustoleum "High temp" 550 or whatever it claims to be just flakes off and needs almost constant application. The top of the bonnet which is the bottom part of the stack with no double insulation and imron looks great.
Mike,
How about graphite and boiled linseed oil like was used on loco smoke boxes? My not count as dressing things up, but it does have some tradition with it.
On my boiler/funnel, I just used Sherwin Williams industrial flat black enamel - same as the hull. Still on there after 5 years. If the boiler/economizer is transferring (absorbing) heat efficiently, the flue gases should be in the 350 range at the pressures we run.
The top of Otter's titanium stack is painted w/ flat black bbq enamel; it's developed some scratches over the last 25 years, but the stack bounces around in the boat when trailering.
I'm not that excited about sand blasting my SS stack. I hate blasting!
I wonder if going at it with an orbital sander would be enough. Or some sort of acid thing like Hydrochloric acid. I just don't want the paint to peal off. Actually i thought that nothing would stick to Titanium. Hmm.
I would like to be able to paint the stack with a gloss color. Maybe with a stripe or two.
Probably I should have a sheet metal shop roll me up a new one out of black iron. This one is too heavy.
If you think you are too small to make a difference, try sleeping with a mosquito.
Dalai Lama
