Stubborn screw

Have you tried some of the finer penetrating oils like Liquid-Wrench?  How about a little heat and cold to break it loose?

Sometimes slight tightening the screw will break it loose.

for these situations I will use a ratchet screw driver where I can put a lot of downward pressure on the screw axis while I turning the screw driver.

Here is a picture of the ratchet screw driver. It has different size drivers for phillips and slotted screws

The "finest".

Sometimes you can grab the screw with side cutters. Move/twist it back and forth, CW/CCW, slowly with patients.  As it loosen add more pentrating oil.   

You are going to have to be brave and just put a lot of pressure on the screw using a good flat bladed screwdriver and turn it. It looks like the unit has either been overfilled in the past and the fluid has run down to the bottom or there has been a leak of the bottom gasket. The yellow stuff is the cedar oil that has been left after the original carrier oil has evaporated. Over time it has solidified around the screws and is holding them tight. At worst you will shear the head off and will leave a portion of the screw sticking out which can then be removed with pliers.

Using a solvent to dissolve the residue is the path to take.  I believe Goo Gone will to the trick.  I have use cleaner called Carbona on old smoke units to soften solidified wicks… it would probably work to loosen the stuff around the screw.

Tom Stoltz

in Maine

Use your smallest drill-driver with impact setting on lowest torque with the best fitting screw bit.  If you just put a lot of torque with a hand driver you stand a good chance of twisting the head off.   The light tapping from impact will likely loosen it.

What that is in your photo, is old masking tape. Gilbert used it to insulate the lugs on the top. Its flaked off at the top due to age and handling. It's gotten crusty with age an some old smoke fluid. Just scrape it off with a screw driver or old pen knife. To get that screw out, use a sharp blade and remove any residue from the slot and around the head. Place the smoker so the bottom is on a hard sturdy surface, and unsung a good square screw driver that fits down into the slot, use as much pressure you can muster and try to screw it in then out. That at action should break the gunk and allow you to remove it. 

Worse case, if it happens to snap off you should be able to get a vice grip on the stump after you get it off and back it out.

gandy

Good! Now on to the next challenge... Breaking into that smoker!

gandy

Boy, this really takes me back ! 

TrainDave...thanks for the info.  I was just getting ready to "revive" the smoke unit and  your info is helpful