Mounting instruments in cockpit bulkhead - 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? 
  #1  
Old 01-27-2007
Senior Member
 
Join Date: Jul 2006
Posts: 225
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
geary126 is on a distinguished road
Mounting instruments in cockpit bulkhead

Aloha.

Replacing 4.5 inch dead instruments with something requiring 5 and 1/16th diameter hole. Anyone have any suggestions on making this happen?

The notion of using a gigantic hole cutter on a power drill scares the hell of of me. Plus, I have nothing for the bit (as in, the center guide bit) to sink into, thereby ensuring that my 5" cutter doesn't go awry.

Debating the jig saw route as another option. That, followed by sanding bit on drill, perhaps?

Help!

Thank you.
Reply With Quote Share with Facebook
  #2  
Old 01-27-2007
paulk's Avatar
Senior Member
 
Join Date: Jun 2000
Location: CT/ Long Island Sound
Posts: 2,534
Thanks: 4
Thanked 20 Times in 19 Posts
Rep Power: 15
paulk is on a distinguished road
Jigsaw route might be the simplest, since the edges are going to be covered by a trim ring anyway. Just scribe an additional 9/16" out from the existing edge and go for it. Don't forget to seal the edges of the hole with epoxy if it's cored, btw. To use a compass bit, you'd have to attach a temporary board over the existing hole on one side, and drill from the other, once you found the center... tricky and a hassle. KISS.
Reply With Quote Share with Facebook
  #3  
Old 01-27-2007
Faster's Avatar
Just another Moderator
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 14,937
Thanks: 76
Thanked 214 Times in 206 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
The jigsaw will work if you have the room to swing the body of the saw as you cut. Sometimes the hole is too close to a companionway molding or a coaming for the saw to clear.

Using a Holesaw - clamp a temporary piece of plywood behind the hole , mark the center and use the holesaw in the normal fashion - the ply will guide the pilot bit.

Alternatively cut a hole the right size in a piece of ply, clamp it in place on top, and use a router to cut the hole with the ply as a guide. (this way you can shift the center slightly if that's desirable)

Good luck
Reply With Quote Share with Facebook
  #4  
Old 01-27-2007
S/VNirvana's Avatar
SONNY
 
Join Date: Jan 2004
Location: Wilton, CT
Posts: 69
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 11
S/VNirvana is on a distinguished road
Make sure you mask the area that the jig saw is going to move over. I have done similiar job ages ago and you can't tell that I enlarged the whole with a jig saw. If you are on the small side when you are finished or it's uneven you can use a dremel tool to smooth out the edge or to make it a more symetrical circle.
__________________
Sonny
s/y NIRVANA, SO49
Reply With Quote Share with Facebook
  #5  
Old 01-27-2007
Member
 
Join Date: Oct 2006
Location: Katy, TX
Posts: 72
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
Culinary411 is on a distinguished road
When I changed my compass on the bulkhead I used the "roto-zip" tool. I put the new compass over the existing hole and marked it with a dry-erase marker, then, took off 1/16 at a time until I got it to fit tight...a little marine caulk and that was it.
I prefer the rotary tool because it allowed me to make a perfect hole with almost no effort. Had I used a saw or a semi-round file to open the existing hole I doubt that I would have made it as nice.
Reply With Quote Share with Facebook
  #6  
Old 01-27-2007
Faster's Avatar
Just another Moderator
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 14,937
Thanks: 76
Thanked 214 Times in 206 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
Just one caution I've found with the rotozip - it has a lot of torque for a small tool and can be difficult to make it track straight without a router-style template to follow.
Reply With Quote Share with Facebook
  #7  
Old 01-27-2007
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
If the cabintop is cored, and most are nowadays... don't forget to remove the core for about 1/2" and then fill the gap between the two layers of laminate with thickened epoxy... this is to help prevent water from getting into the core and causing delamination/rot. Also, if the fasteners are outside of the hole you'll be drilling... drill them oversized and fill with thickened epoxy, and then re-drill for the fasteners... for the same reasons.
__________________
Sailingdog

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

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
Reply With Quote Share with Facebook
  #8  
Old 01-27-2007
Member
 
Join Date: Oct 2006
Location: Katy, TX
Posts: 72
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
Culinary411 is on a distinguished road
Sailingdog....good point. I did the same thing only filled the 1/2" gap with marine caulk. Not sure if that's proper but I know it will keep moisture out.
Reply With Quote Share with Facebook
  #9  
Old 01-27-2007
pigslo's Avatar
Senior Member
 
Join Date: Nov 2004
Posts: 804
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
pigslo is on a distinguished road
Use a painters mask as the fiberglass dust is rough.
pigslo
Reply With Quote Share with Facebook
  #10  
Old 01-27-2007
sailingdog's Avatar
Telstar 28
 
Join Date: Mar 2006
Location: New England
Posts: 43,291
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 13
sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice sailingdog is just really nice
Quote:
Originally Posted by Culinary411
Sailingdog....good point. I did the same thing only filled the 1/2" gap with marine caulk. Not sure if that's proper but I know it will keep moisture out.
Probably not a good idea... caulk will eventually dry out and shrink...leading to the problem you're trying to avoid in the first place. Also, the filled epoxy adds strength to the area that has been weakened by the hole—essentially becoming a small structural reinforcement, which the caulk can not do. I would highly recommend cleaning out the caulk and re-installing with a good epoxy and high-density filler.
__________________
Sailingdog

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

Telstar 28
New England

You know what the first rule of sailing is? ...Love. You can learn all the math in the 'verse, but you take
a boat to the sea you don't love, she'll shake you off just as sure as the turning of the worlds. Love keeps
her going when she oughta fall down, tells you she's hurting 'fore she keens. Makes her a home.

—Cpt. Mal Reynolds, Serenity (edited)

If you're new to the Sailnet Forums... please read this
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.

Still—DON'T READ THAT POST AGAIN.
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
Cockpit Camping on Crossings Joy Smith Cruising Articles 0 08-12-2004 08:00 PM
The Cruising Cockpit Sue & Larry Buying a Boat Articles 0 07-08-2003 08:00 PM
The Cruising Cockpit Sue & Larry Gear and Maintenance Articles 0 07-08-2003 08:00 PM
The Cruising Cockpit Sue & Larry Cruising Articles 0 07-08-2003 08:00 PM
The Cruising Cockpit Sue & Larry Her Sailnet Articles 0 07-08-2003 08:00 PM


All times are GMT -4. The time now is 01:21 PM.

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.