This is a really interesting post.......I've been loosely following this thing since it started.

The last post sparked my chemistry side (what I do for a living) so I felt like its time for me to add some additional complexity to the discussion!!! Haha.

Alkyds as noted in the last post are old as the hills chemistry. Here's my .02 worth: Alkyds have free hydroxyl groups, which offer the possibility of crosslinking them using IPDI and HDI (Isophorone Diisocyanate and hexane diisocyanate) trimer(s), these isocyanates are usually used in most modern 2k clears urethane along with acrylic polyols as the main resin.

Problem is... one has to have an idea of how much isocyanate to add to the alkyd. Unless you can get a precise recommendation from the alkyd maker on how much of these isocyanates to add, I dont suggest doing this. There is a chemical balance that should be obeyed called stochiometry, this is the balance between the isocyanate and the free hydroxyls in the paint. Unless you match these fairly closely you can create alot of problems, bubbling peeling etc. However, if you are successful you will have created a urethane modified alkyd car paint. Something that is commonly used in 3rd world car repair, either that or your local Earl Scheibs..haha. Anyway keep in mind that if you do add isocyanates to your paint, the pot life (or application time before hardening) will be reduced to several hours regardless of whether the paint is closed can or open.

What will really annoy everyone about car paint (or any paint for that matter) is how cheap the raw materials are, and how bad the public gets gouged. Don't ask.