Reply
 
Thread Tools Search this Thread
 
Old 02 April 2007, 08:32   #1
Member
 
Nasher's Avatar
 
Country: Other
Town: Principalite d'Chaos
Boat name: The Nashers Revenge!
Make: Ocean & Bombard
Length: 6m +
Engine: Suzi DT200EFI, DT9.9
MMSI: "Mmmmm SI" she said!
Join Date: Jan 2004
Posts: 4,147
Transom Fitting Hole Saw

Hello All.

The skin fitting/Bung Iíve brought for my transom is just under 26mm OD.

All the hole saws I have, or can find, jump from 25mm to 30mm although I believe a flat wood-boring bit of 28mm is available if I can find one.

Firstly does anyone have/know of a 27/28mm hole saw? Or Imperial equivalent?
Because I only have decent access from the outside, if the reach isnít enough for 2+ inches of Marine ply and Fibreglass Iíll have to stop and break out the plug before continuing.

Or, has anyone used a Flat blade type wood-boring bit for Fibreglass? Does it splinter too badly?
I obviously want to bung a load of Sikaflex around the fitting before fitting, but really only wanted a 27mm hole, so I could shave a bit off either side of the 28mm tool.

Help.

Nasher.
__________________

__________________
RIBBED For extra pleasure.
Member of the ebay Blue RIB cover club.
Member of the Bombard 380 Aerotec club
Nasher is offline   Reply With Quote
Old 02 April 2007, 08:55   #2
Member
 
Country: UK - Scotland
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX
Join Date: Oct 2002
Posts: 4,962
Quote:
Originally Posted by Nasher View Post
Or, has anyone used a Flat blade type wood-boring bit for Fibreglass? Does it splinter too badly?
Nasher I've used them often. They are a bit crude but they work OK. Rock the drill a bit. They tend to get a ring of fibreglass stuck on the point. They do splinter when you burst through. I usually try to go in from the second side once the point is showing through. If you can get one, the type which have a wee ear on the end of the blade make a nice clean cut before the rest of the blade chisels out the centre. These blades are normally soft enough to sharpen them with a file so you can make an ear onto and ordinary flat one.
__________________

__________________
JW.
jwalker is online now   Reply With Quote
Old 02 April 2007, 09:05   #3
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
Do a test cut first - I doubt the 25mm or 30mm will cut exactly on size. MAYBE they will cut slightly under or oversize - worth a try. Wouldn't it be possible to use a small drum type sander or roughing bit to enlarge the hole slightly?

Screwfix do a 29mm if that helps.
__________________
codprawn is offline   Reply With Quote
Old 02 April 2007, 09:08   #4
Member
 
Country: UK - England
Town: Blackpool
Boat name: Magic II
Make: Tohatsu 6.1
Length: 6m +
Engine: Evinrude 115 E-tec
MMSI: 235050189
Join Date: Oct 2006
Posts: 151
Send a message via Skype™ to kwil
Had the same problem, hole borers are not usually deep enough, so I used a Forstener bit they are usually used by kitchen fitters to mount hinges etc in chip board but it worked fine.
Heres a picture of the bit.
Attached Thumbnails
Click image for larger version

Name:	060230216[1].jpg
Views:	98
Size:	13.7 KB
ID:	25959  
__________________
kwil is offline   Reply With Quote
Old 02 April 2007, 09:16   #5
Member
 
Country: UK - England
Town: Poole
Make: Aquaflyte
Length: 6m +
Engine: Merc 90 2Str
Join Date: Feb 2006
Posts: 414
Nasher

Just found this that claims to have a 2" deep 26mm diameter hole saw. Don't know how deep your transom is but if you use JW's suggestion and go from either side you should be able to get through a 4" transom

http://cgi.ebay.co.uk/7-pc-2-HOLE-SA...QQcmdZViewItem

Hope this helps

Andrew
__________________
AndrewH is offline   Reply With Quote
Old 02 April 2007, 10:04   #6
Member
 
Nasher's Avatar
 
Country: Other
Town: Principalite d'Chaos
Boat name: The Nashers Revenge!
Make: Ocean & Bombard
Length: 6m +
Engine: Suzi DT200EFI, DT9.9
MMSI: "Mmmmm SI" she said!
Join Date: Jan 2004
Posts: 4,147
Thanks all.

I'll try a 25mm one I have to see how big it actually cuts, But I think its 25mm

I did see the Forstener bits, but could only find expensive sets available, and only with the usual 25mm and 30mm.

The Flat Wood borers I saw had the ears on the end, but the 28mm ones were out of stock, I'll try to get one and slim it down by a mm or so.
Unfortunately I can't go in from both sides as mentioned because of the small bilge well in front of the transom.

If all else fails I'll try opening up a 25mm hole with a sanding tube, but 2+ inches of fibreglass and marine ply will take a time.

Codprawn - Screw fix have opened a trade counter today just around the corner from work.

Andrew - In my experiance those multiblade hole saws are quite useless for anything more than a few mm thick. Thanks anyway.

Nasher.
__________________
RIBBED For extra pleasure.
Member of the ebay Blue RIB cover club.
Member of the Bombard 380 Aerotec club
Nasher is offline   Reply With Quote
Old 02 April 2007, 12:57   #7
Member
 
Hightower's Avatar
 
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,855
Don't do anything yet mate!

I'll have a look at work tomorrow for something in the 28/27mm range.

I've got a 29mm diameter one here if that's of some help. If not wait till tomorrow evening and I'll check.
__________________
Andy

Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hightower is offline   Reply With Quote
Old 02 April 2007, 13:29   #8
Member
 
Country: UK - Scotland
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX
Join Date: Oct 2002
Posts: 4,962
Quote:
Originally Posted by Nasher View Post
Unfortunately I can't go in from both sides as mentioned because of the small bilge well in front of the transom.
Get someone to watch you and when the bit begins to come through, stop. Take the bit out of the drill, put it into the hole on the inside and turn it with a pair of grips. It's a bit of a guddle but not too difficult. Turn it until the ears cut a groove deep enough to make the connection into the main hole.
__________________
JW.
jwalker is online now   Reply With Quote
Old 02 April 2007, 13:33   #9
Member
 
Country: UK - England
Town: Liverpool
Length: 10m +
Join Date: Feb 2006
Posts: 234
i have a 27 and a 29mm. They are made by starrett who make just about every size...

http://www.lawson-his.co.uk/scripts/...%20Hole%20Saws

these guys are quick on the delivery too
__________________
Endeavour is offline   Reply With Quote
Old 02 April 2007, 13:42   #10
Member
 
Country: UK - England
Town: Liverpool
Length: 10m +
Join Date: Feb 2006
Posts: 234


Just read this article again. These holesaws are only about 30mm deep so u will need to break out the plug before continuing all the way.....

__________________

__________________
Endeavour is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 12:34.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.