With penetrants, the rule of thumb I've found
essential is, if you have the time, take your time. A shot of stuff, several times, each time you're at the boat, over the course of weeks, often will work, even tho it seems hopeless at firt. This requires that you not strip or mangle the fastners, needless to say, and as always, your milage may varry.
If that fails, and you go the impact driver route, you want to make sure you have a very snug fit between your bit/socket and the cap screw in question. While an impact driver can do wonders, it can also shred a nut or bolt
in amazingly little time. (He says, recalling the single slam it took to turn a ten year old hex nut on a NY-36 into a perfectly smooth, nicely rounded bit of stainless. (We ended up drilling that sucker out, eating four drill bits and several hours in the process)
- David Levine
