Smoothing out the Engine Bay

Welding the holes and then using a little filler is the only good way to do it.

correct. they're just holes, so they're not hard to weld in at all. hell, i would even skip on the thin layer of bondo unless it was a hrdcore show car.

Me as well as a few other guys including Mansonozz have used a product called All Metal. Its a filler like bondo but much stronger. I'm in the process of smoothing out my engine bay right now. I have the filler layed on and sanded down on both sides. In addition to the filler, I'm also using some spot puddy to fill in the little tiny areas that the all metal didn't get.

It's very important to weld up the holes, if you don't weld and only use filler, its going to crack.

About 6 yrs ago I welded up the holes in the engine bay. I then used the all-metal as thin filler to fill in the grinding marks from welding and to fill in any low spots to make everything level in the engine bay.
I then shot the engine bay with a etching primer, and the last thing I did was to use the evercoat finishing putty to fill in all the really- really small pin holes that may have been left in the all-metal.
After that I shot the engine bay with a single stage paint.
As I said that way about 6 yrs ago and I never seen a crack in the engine bay.
My theory was to do it once and do it right.

However there is a person on Corral that used some sort of 3M tape and says he’s never had a crack either.
Here is the link.
http://www.corral.net/forums/showthread.php?t=810250

I also used the 3M tape. No cracks and my car is not garaged.
Obviously welding is the best but I have no welder or welding skills...PB

that 3M tape is pretty trick stuff.