Do I have to predrill before running screws into fiberglass - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 


Like Tree9Likes
Reply
 
LinkBack Thread Tools
  #1  
Old 08-01-2013
Senior Member
 
Join Date: Apr 2006
Location: Michigan
Posts: 613
Thanks: 33
Thanked 4 Times in 4 Posts
Rep Power: 9
abrahamx is on a distinguished road
Do I have to predrill before running screws into fiberglass

I will be replacing the wood on my boat. The new wood is made up and the old wood is off. I am going to fill the old holes and then install the new wood. Do I have to drill a pilot hole into the fiberglass first? Also if anyone has done this job I will take any other advice before I start.
Reply With Quote Share with Facebook
  #2  
Old 08-01-2013
Tim R.'s Avatar
Senior Member
 
Join Date: Mar 2003
Location: Portland, Maine
Posts: 1,541
Thanks: 1
Thanked 27 Times in 26 Posts
Rep Power: 12
Tim R. is on a distinguished road
Re: Do I have to predrill before running screws into fiberglass

Yes, pre-drill and chamfer the top of the hole so you do not crack the gel-coat.
__________________
Tim R.
Out cruising
1997 Caliber 40LRC

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

-----------------------------------------------------
Reply With Quote Share with Facebook
  #3  
Old 08-01-2013
Senior Member
 
Join Date: Aug 2006
Location: wherever
Posts: 5,261
Thanks: 8
Thanked 17 Times in 16 Posts
Rep Power: 11
xort has a spectacular aura about xort has a spectacular aura about xort has a spectacular aura about
Absolutely. Must predrill. And it has to be a relatively large hole compared to what you can do with wood pilot holes.
Also, after drilling pilot hole, put a small chamfer on the hole to prevent chipping of the glass
Reply With Quote Share with Facebook
  #4  
Old 08-01-2013
Senior Member
 
Join Date: Apr 2006
Location: Michigan
Posts: 613
Thanks: 33
Thanked 4 Times in 4 Posts
Rep Power: 9
abrahamx is on a distinguished road
Re: Do I have to predrill before running screws into fiberglass

So I have to chamfer? That sucks. So now I have to line up my hole pattern? I was hoping to go through the wood and glass at the same time. I know from being a metal worker that lining up hole patterns is not easy.
Reply With Quote Share with Facebook
  #5  
Old 08-01-2013
Senior Member
 
Join Date: Apr 2006
Location: Michigan
Posts: 613
Thanks: 33
Thanked 4 Times in 4 Posts
Rep Power: 9
abrahamx is on a distinguished road
Re: Do I have to predrill before running screws into fiberglass

what about bedding the wood? Any suggestions on what I should use?
Reply With Quote Share with Facebook
  #6  
Old 08-01-2013
BubbleheadMd's Avatar
Chastened
 
Join Date: Nov 2009
Location: Edgewater/Annapolis
Posts: 2,836
Thanks: 0
Thanked 54 Times in 50 Posts
Rep Power: 5
BubbleheadMd will become famous soon enough
Send a message via Yahoo to BubbleheadMd
Re: Do I have to predrill before running screws into fiberglass

Dude, a chamfer (counter-sink) bit is cheap and takes only seconds for each hole.
For bedding deck hardware, butyl tape is the best thing for 99% of applications.

You can buy it from Maine Sail's website: Compass Marine "How To" Articles Photo Gallery by Compass Marine at pbase.com

He sells the best, white butyl tape. A roll will last forever. Proper application is described in text and photos on his website. If you really are in a hurry, you can buy black butyl tape at NAPA as "windshield tape" or windshield sealant.

This stuff is WAY cleaner, and easier to use than 3M 4200/5200, is more effective, and lasts longer.
__________________
S/V Old Shoes
1973 Pearson 30 #255
Reply With Quote Share with Facebook
  #7  
Old 08-01-2013
Senior Member
 
Join Date: Apr 2006
Location: Michigan
Posts: 613
Thanks: 33
Thanked 4 Times in 4 Posts
Rep Power: 9
abrahamx is on a distinguished road
Re: Do I have to predrill before running screws into fiberglass

I got free butyl tape at work. thought I read that it was kind of sloppy for doing wood rails. I figured I would just use a larger bit for a chamfer. My point was that I will have to pre drill the holes in the glass in able to chamfer. Meaning I can not just set the wood there and drill through both at the same time. Making it much harder to layout and line up the hole pattern on my wood to the holes in the glass. Unless I am missing something.
Reply With Quote Share with Facebook
  #8  
Old 08-01-2013
jimgo's Avatar
Asleep at the wheel
 
Join Date: Sep 2011
Location: Pennsylvania
Posts: 2,916
Thanks: 71
Thanked 108 Times in 106 Posts
Rep Power: 3
jimgo is on a distinguished road
Re: Do I have to predrill before running screws into fiberglass

Lining up the holes isn't THAT hard (and I'm lazy):

Drill the holes in the wood.
Put the wood over the fiberglass and tape it in place.
Put a bit in the drill that is the same size as the holes in the wood, so you're using the hole in the wood as a guide.
Slip the bit into the hole and just kiss the surface of the fiberglass.
Repeat for the other holes.
Remove the wood.
Put the proper sized bit in the drill.
Drill the pilot holes at the point where the drill kissed the fiberglass.
Chamfer the edges of the pilot holes.
Put the wood back over the newly drilled and chamfered holes, and add the screws.
__________________
- Jim
Home: Western Philly 'burbs
1980 Allmand 31
1975 Albacore 15


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
The Following User Says Thank You to jimgo For This Useful Post:
abrahamx (08-01-2013)
  #9  
Old 08-01-2013
Senior Member
 
Join Date: Apr 2006
Location: Michigan
Posts: 613
Thanks: 33
Thanked 4 Times in 4 Posts
Rep Power: 9
abrahamx is on a distinguished road
Re: Do I have to predrill before running screws into fiberglass

Thanks. I'm glad I thought of that. Guess thats why they pay you the big bucks. And I'm a metal fabricator for 19 years. To used to measuring everything I guess.
Reply With Quote Share with Facebook
  #10  
Old 08-01-2013
BubbleheadMd's Avatar
Chastened
 
Join Date: Nov 2009
Location: Edgewater/Annapolis
Posts: 2,836
Thanks: 0
Thanked 54 Times in 50 Posts
Rep Power: 5
BubbleheadMd will become famous soon enough
Send a message via Yahoo to BubbleheadMd
Re: Do I have to predrill before running screws into fiberglass

Quote:
Originally Posted by jimgo View Post
Lining up the holes isn't THAT hard (and I'm lazy):

Drill the holes in the wood.
Put the wood over the fiberglass and tape it in place.
Put a bit in the drill that is the same size as the holes in the wood, so you're using the hole in the wood as a guide.
Slip the bit into the hole and just kiss the surface of the fiberglass.
Repeat for the other holes.
Remove the wood.
Put the proper sized bit in the drill.
Drill the pilot holes at the point where the drill kissed the fiberglass.
Chamfer the edges of the pilot holes.
Put the wood back over the newly drilled and chamfered holes, and add the screws.
Oops, sorry I didn't answer your original question. Yes, this procedure seems fine. Just chamfer the holes, and bed with butyl.

Um... I'm a real stickler about water intrusion and core rot. If this area isn't solid glass, I'd over-drill every one of these holes, fill them with epoxy to seal the wood core, then re-drill them to the proper size for the screws, and bed them with butyl tape.

If the area is solid fiberglass, then just carry on with your procedure.
__________________
S/V Old Shoes
1973 Pearson 30 #255
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Epoxy screws davidpm Gear & Maintenance 7 06-22-2013 12:44 AM
How Do you Organize screws? SaltyGirl Gear & Maintenance 19 08-25-2009 02:31 AM
Screws into fiberglass floatsome Gear & Maintenance 6 04-29-2009 08:14 PM
Loose screws bmcald Gear & Maintenance 13 05-29-2002 11:57 AM


All times are GMT -4. The time now is 05:43 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.