Tube Life - Heat Fins

I am moving forward my project. The room I have to listen in is smaller (12 x 16) and I also need to keep 'hands' off the amp and other equipment, so it is all next door in a closet. This is fine, and I have resonable amount of air space around and above it (3'Wx2'Dx-3'H space). But I purchased thermal heat gun and noted temps a few times when I am listening for a few hours at medium to high levels.. it is Summer.. and all that together means tubes run 210F

Online googling and seems normal operating temp for main
power tubes is 200-240F. Once they reach operating temp, the glass is a terrible conductor so saw notes about "extending life" by using fans or even copper tape etc.


Question
1) Is their anything wrong with using copper "radiator" on main power tubes to help radiate heat? (it can look dorky.. but in my case, it is in closet anyways)
2) Will this increase lifespan and do it without impacting quality

I did quick test and it does seem to help operating temp. I made a quick "crude" test one to see.. but can make ones that don't look as ugly later

Anything clamped on tubes could create cracks due to thermal differences. A fan would be a better alternative.

IME the only thing that noticeably increased the lifespan of my power tubes was incorporating auto biasing boards. I was lucky to get 6 months prior to this mod, tube costs were starting to really add up. Since this mod am closing in on 2 years with current tube set and still going strong. Also using 120 mm fans to cool my amps, but just cooling the glass does not do much for the temp of tube internals, mainly benefits the PT's. Without the fans PT's are almost too hot to touch, but with the fans the PTs are lukewarm.

Don't expect too much from this mod.

I got one of these for my 5AR4 on my ST120. I thought that was the hottest running tube because of it's location. I've since installed auto bias and a weber WS-1t. I then put the tube cooler on the weber because I didn't want to see all the copper. I seems to have a positive effect. It did take a very long time to arrive from Canada to NYC though.

https://www.pearl-hifi.com/03_Prod_Serv/Coolers/Coolers.html

Not really in vein you were seeking but good read and info
http://tronola.com/html/maximize_tube_life.html

this is a very interesting question.
Do the valves need to be at a normal temp? too cool might not be better but I'm sure thats not going to happen. I assume you open the closet door while the amp is fired up and its in a low position. I think Bob Latino would say still stick with the 3000-5000 hours for power tubes
and then save them for back-up. Would running hotter than normal degrade them sooner? what is the temp in the closet? If it's 60-80 deg I would think that would be normal. I run my Dan Steele/Lance Cochrane amp 14 hrs a day so I do think about these things. I was burning through rectifiers in 8mo. or less. Luckily Lance Cochrane fixed the rectifier circuit problem by modifying the mfd off the rectifier and installed a RCA JAN CRC-5U4GB. Lance also “fixed bias arrangement that was in there and put in a automatic cathode bias set up. Each output tube now automatically sets its own bias. Each one has a dedicated power resistor and capacitor." I do think that balanced bias is probably more important than temp. ok I guess I only brought up questions not answers, but personally I would not put anything on the glass ... glass really does transfer heat well