Gjac wrote:
My approach for screws that won't budge is as as follows. First try a screw diver with a wise grip or wrench for added leverage. If the screw driver tip comes out of the slots with the added torque I spray Kroil oil and let it sit over night and capillary action will allow the oil to penetrate on horizontal screws . You can put plastic under the screws to protect the rubber roof. If they still don't budge I use Matt's approach with heat except I don't have a high wattage iron so I heat the shank of an old screw driver with a propane torch and let the heat transfer to the screw. The glass transition temperature for most epoxies and polyesters is 350 degrees or less. As Matt said it does not take a lot of heat to break them free. They are only threaded into a piece of sht mtl that is .030 to .050 thick so there is not a lot of surface area to hold that screw into. Let us know how you are making out.
I usually have good luck with a screwdriver and channel locks. You can put a ton or force on the top of the screw driver to keep the head in the grooves on the screw and then apply torque using the vice grips to turn the screwdriver. If that doesn't work, you are going to have to try heat then drilling the darn things.
If you have a good soldering iron, you can set the temperature. Even if you go a little too hot, you are just going to have a little deformation on the shroud. That is if you are careful and pay attention to what is going on.
In any case, it looks like the OP has moved well on so... whatever.