Originally Posted by
W.R.Buchanan
I have one more suggestion on this topic. I have done this extensively while working on F4's and on just about any larger screw that is stubborn. I use this technique frequently when working on Navy stuff that has been out in the weather along time and virtually glued together with corrosion.
You use a 3/8 drive Speed Wrench, hopefully one with a fairly big knob on the end.(like a Brace) This way you can lean into the tool and then wiggle the handle back and forth which will MOST ALWAYS break the screw loose.
On the top of the wing of an F4E there is a stress panel that has nearly 400 Offset Phillips screws (wormy head) holding it in place. Normally it requires a machinist to drill out a large portion of those screws, as none of them give up easily. I have gotten all but 2 out on that panel three different times using my technique of simply wiggling the screw back and forth until it breaks loose. These screws were all held in place by corrosion, and the combination of having your body weight on the tool to hold it in perfect contact with the screw so it doesn't work the head, and the ability to jiggle it back and forth quickly so it breaks the corrosion loose is a winner.
As far as drilling the screw out the hot tip is a left hand twist drill. What happens is the drill generates heat and eventually the remnant of the screw breaks loose and the drill backs it right out of the hole. The kicker with drilling out screws is that you absolutely must drill thru the center of the screw. Otherwise you FU the host piece, which is a negative experience.
This is why I recommend having someone who knows exactly what he is doing do it for you. That way you have someone else to blame if it goes badly.
Randy