|
|
#11
|
||||
|
||||
Re: Drill Bit / screw sizes
You are fine drilling one or two sizes smaller then the screw, but you MUST counter sink the hole to stop spider cracking!!!
__________________
1986 V20  Old Fishermen never die, we just SMELL that way!! 
|
|
#12
03-16-2007, 03:02 PM
|
||||
|
||||
|
Re: Drill Bit / screw sizes
You are fine drilling one or two sizes smaller then the screw, but you MUST counter sink the hole to stop spider cracking!!!
__________________
1986 V20 Old Fishermen never die, we just SMELL that way!!
|
|
#13
03-17-2007, 05:41 PM
|
||||
|
||||
|
Re: Drill Bit / screw sizes
I take the screw and hold a bit up to it...if I can see "a little bit of the edge of the threads" stickin' out wider than the bit-shank, that's the one ... and use a cone-shaped bit or counter-sink edge of hole like MJ says above...fiberglass does not take screws like wood does... ;) ...
__________________
'74 V-20/ BF 150 '95 V-21/ BF 150 '84 V-20/ 200 2.4 Merc '87 V-20/'18 F150 Yamaha 
|
|
#14
03-17-2007, 05:41 PM
|
||||
|
||||
|
Re: Drill Bit / screw sizes
I take the screw and hold a bit up to it...if I can see "a little bit of the edge of the threads" stickin' out wider than the bit-shank, that's the one ... and use a cone-shaped bit or counter-sink edge of hole like MJ says above...fiberglass does not take screws like wood does... ;) ...
__________________
'74 V-20/ BF 150 '95 V-21/ BF 150 '84 V-20/ 200 2.4 Merc '87 V-20/'18 F150 Yamaha
|
|
#15
03-17-2007, 08:21 PM
|
|||
|
|||
|
Re: Drill Bit / screw sizes
Thanks To All Who responded,
Thought for sure there was a fiberglass screw/drill bit chart. There should be one. Have seen to many people crack their fiberglass by forcing a screw. Appears that a 1/32 to 3/64 of an inch less than the thread diamater will be about the right size pilot hole. Always remember to put petroleum jelly on the screw threads.
|
|
#16
03-17-2007, 08:21 PM
|
|||
|
|||
|
Re: Drill Bit / screw sizes
Thanks To All Who responded,
Thought for sure there was a fiberglass screw/drill bit chart. There should be one. Have seen to many people crack their fiberglass by forcing a screw. Appears that a 1/32 to 3/64 of an inch less than the thread diamater will be about the right size pilot hole. Always remember to put petroleum jelly on the screw threads.
|
|
#17
03-17-2007, 08:30 PM
|
||||
|
||||
|
Re: Drill Bit / screw sizes
The petroleum-jelly sounded good at first...but most screws that go in boats should be coated w/ marine grade silicone... or at least that's the way I do it ...nothin' works for everybody ;) ...
screw-threads in fiberglass...it doesn't take much BITE to get a good, firm hold :D ...
__________________
'74 V-20/ BF 150 '95 V-21/ BF 150 '84 V-20/ 200 2.4 Merc '87 V-20/'18 F150 Yamaha
|
|
#18
03-17-2007, 08:30 PM
|
||||
|
||||
|
Re: Drill Bit / screw sizes
The petroleum-jelly sounded good at first...but most screws that go in boats should be coated w/ marine grade silicone... or at least that's the way I do it ...nothin' works for everybody ;) ...
screw-threads in fiberglass...it doesn't take much BITE to get a good, firm hold :D ...
__________________
'74 V-20/ BF 150 '95 V-21/ BF 150 '84 V-20/ 200 2.4 Merc '87 V-20/'18 F150 Yamaha
|
|
#19
03-17-2007, 10:24 PM
|
||||
|
||||
|
Re: Drill Bit / screw sizes
I kept dropping my countersink bit in the water, in a pinch, i took the screwdriver bit and used it to bevel the hole before I ran the screw in, worked pretty good
|
|
#20
03-17-2007, 10:24 PM
|
||||
|
||||
|
Re: Drill Bit / screw sizes
I kept dropping my countersink bit in the water, in a pinch, i took the screwdriver bit and used it to bevel the hole before I ran the screw in, worked pretty good
|
 |
| Thread Tools | |
| Display Modes | |
|
|
Linear Mode
