Yes, I've researched Alvin stuff, up to & including finding it at a welding supply place right around the corner............
then, in talking to my brother who's been in the automotive industry for many years, I hear this:
" The guys that know bodywork & heat area repair that I work with hate the stuff"
Why, I ask, 'cause I'm on a quest to fix some things like you've got there & do some other, more creative, special, almost sculptural type stuff...............
The stuff applies OK, but then, anything that's not of the same metallurgical ilk as the original material it's applied to will EXPAND & CONTRACT at a different rate than the original material.....
Over time ( no idea how long or what intensity of conditions that might mean? ) the stuff will flex differently enough to at least undermine the paint & later then crack apart itself......
Now, all this bullshit I'm spoutin' may not mean a whit, 'cause I stopped short of actually buyin' the stuff & doin' the deed(s)
I could ask some more questions on this end & see if there's any more expansive info than just that ^^^^
I'm pluggin' for a cure for these poor, chipped up kettles as much as the next person !!!!