Just a data point: I need to replace the "gasket" on my carb heat "butterfly" so I just called Dynamic Propeller and ordered one. This got me to thinking about: A dozen or so years ago, when I first bought my 182, the pre-buy revealed that the carb heat box had seen better days and had a numerous cracks. The worst were around the "neck flare" that attaches to the carb. I bought a Dynamic Propeller reinforcing kit and pondered my options. The price for both replacement and overhaul of the box were pretty salty. I don't remember exact prices as it's been a dozen years but it seems like it was $1,000 to $1,500 or so. So, I stopped by a reputable local steel fabricating shop and asked if they welded aluminum. "Sure" they said, we have one guy who is our aluminum specialist. He practices on beer cans. Hmmm. Do I want to spend $50 or $1500? (or whatever it was) I was active in CPA at the time and posted my dilemma. The prevailing opinion was that I had lost my mind, that the type of aluminum the box was constructed of couldn't be welded, that it would set up stresses and re-crack, etc. I took the box into the local shop, had their aluminum guru look at it, and he assured me that "this was no hill for a stepper." So I decided to give it a try. The stiffening kit from Dynamic Propeller was installed when the box was re-installed on the airplane. 12 years later, at last month's annual, it's still whole and no cracks have redeveloped. Like I said above, just a data point.