Notices
Marine Electronics Forum

rotozip for fiberglass hole

Old 04-26-2010, 03:46 PM
  #1  
Junior Member
Thread Starter
 
Join Date: Mar 2010
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
Default rotozip for fiberglass hole

I need to cut a 3 3/4" hole in my fiberglass hull to install my new transducer. I can't get my hands on that size hole saw. It's an odd size. My buddy said to use a rotozip with the circle cutter. Which I have and have never used. I'm thinking I might try it on some thin plywood first and give it a try. I also thought about drilling a 3 1/2 in hole and then just making it bigger with a dremmel grinding wheel. Any thoughts.

Thanks Tony
Old 04-26-2010, 03:54 PM
  #2  
Admirals Club Admiral's Club Member
 
Join Date: Oct 2009
Location: Fenwick Island, Delaware
Posts: 920
Likes: 0
Received 9 Likes on 6 Posts
Default

I would not use a rotozip in any fiberglass more than 1/4 inch or so. Is this a cored hull? What is the hull thickness?

Last edited by LoveTheSea; 04-26-2010 at 06:13 PM.
Old 04-26-2010, 04:07 PM
  #3  
Senior MemberCaptains Club Member
 
Join Date: Sep 2006
Location: Palm City ,Fl.
Posts: 1,850
Received 23 Likes on 14 Posts
Default

Originally Posted by sportcraft View Post
I need to cut a 3 3/4" hole in my fiberglass hull to install my new transducer. I can't get my hands on that size hole saw. It's an odd size. My buddy said to use a rotozip with the circle cutter. Which I have and have never used. I'm thinking I might try it on some thin plywood first and give it a try. I also thought about drilling a 3 1/2 in hole and then just making it bigger with a dremmel grinding wheel. Any thoughts.

Thanks Tony
Tony , I just needed the same size hole saw went to Home depot they didnt have it , went to Lowes no good , I found it at the local Rockys Ace hardware store a little expensive but I think when you are cutting something like a transducer hole or thru hull fitting you want it as tight as you can get it. Hold out for the right tool.
Old 04-26-2010, 06:06 PM
  #4  
Member
 
Join Date: Nov 2003
Location: F-burg Va
Posts: 82
Likes: 0
Received 0 Likes on 0 Posts
Default

I would order the hole saw online and get the right size tool for the job. Round holes are a PIA with the wrong tool.

Jay
Old 04-26-2010, 06:12 PM
  #5  
Senior MemberCaptains Club Member
 
Join Date: Nov 2006
Location: New Smyrna Beach
Posts: 8,456
Received 267 Likes on 191 Posts
Default

Thats a huge hole for your transducer. I have a 2kw thru hull transducer and the hole is no where near that large.
Old 04-26-2010, 06:13 PM
  #6  
Admirals Club Admiral's Club Member
 
Join Date: Oct 2009
Location: Fenwick Island, Delaware
Posts: 920
Likes: 0
Received 9 Likes on 6 Posts
Default

Do you understand your hull construction and are you sure you don't have fiberglass/epoxy work to do if you cut a hole?
Old 04-27-2010, 04:49 AM
  #7  
Senior MemberCaptains Club Member
 
Join Date: Nov 2007
Location: Hobe Sound, Fl
Posts: 4,348
Likes: 0
Received 449 Likes on 216 Posts
Default

I would only use a hole saw for this work. We are talking surgery here so why chance it.

As mentioned before, Ace Hardware seems to have just about every hole saw size known to man. Even if they didn't, I would order it and wait rather than any other alternative.
Old 04-27-2010, 06:45 AM
  #8  
Senior Member
 
Join Date: Jan 2007
Location: Lower Florida Keys
Posts: 3,130
Likes: 0
Received 7 Likes on 7 Posts
Default

I have a 3 3/4 hole saw that I used to cut the hole for my airmar b164 transducer.
I obviously do not need it anymore, shoot me a pm if you are interested.
Old 04-27-2010, 06:49 AM
  #9  
Senior Member
 
Join Date: Apr 2009
Location: Florida
Posts: 17,576
Received 2,706 Likes on 1,454 Posts
Default

Hole saw is the best way to go here!
Old 04-27-2010, 07:04 AM
  #10  
Senior MemberCaptains Club Member
 
Join Date: Feb 2002
Location: North Charleston, SC USA
Posts: 22,073
Likes: 0
Received 17 Likes on 17 Posts
Default

If you can't find the correct size hole saw to buy, try a tool rental store.

Ace and True Value often have things that the home centers do not. Also, try an electrical or plumbing supply store. The ones the pros use.

I don't think the Roto Zip is a good choice for this hole.
Old 04-27-2010, 10:16 AM
  #11  
Senior Member
 
Join Date: Apr 2009
Location: Too far from salt.
Posts: 10,110
Likes: 0
Received 1,112 Likes on 574 Posts
Default

Use the biggest hole saw you have, then use one of those barrel sanders that attach to your drill. I recently did this to install new gauges and it worked great. I have used a roto zip saw and finished it with the barrel sander as well. Wear a mask/respirator.
Old 04-27-2010, 10:57 AM
  #12  
Senior MemberCaptains Club Member
 
Join Date: Mar 2007
Location: Annapolis
Posts: 1,929
Likes: 0
Received 0 Likes on 0 Posts
Default

Hey, Sport craft, what kind of transducer needs a hole that big?
Old 04-27-2010, 12:18 PM
  #13  
Senior Member
 
Join Date: Oct 2009
Posts: 482
Likes: 0
Received 7 Likes on 3 Posts
Default

Lennox definetly makes a 3 3/4" hole saw
Old 04-27-2010, 12:45 PM
  #14  
Senior MemberCaptains Club Member
 
Join Date: Jan 2003
Location: Houston,Tx,U.S.A
Posts: 11,746
Received 787 Likes on 440 Posts
Default

When you have the transducer in your hand order the holesaw you need..

*****Do Not Drill any Holes until then***


John
Old 04-27-2010, 01:25 PM
  #15  
Senior Member
 
Join Date: Jan 2007
Location:
Posts: 274
Likes: 0
Received 0 Likes on 0 Posts
Default

Amazon.com has it
MK Morse AV60 Hole Saw, 3-3/4-Inch Bi-Metal Boxed

by MK Morse
No customer reviews yet. Be the first.
List Price:$21.16Price:$12.65
Old 04-27-2010, 02:32 PM
  #16  
Admirals ClubCaptains Club Member Admiral's Club Member
THT sponsor
 
Join Date: May 2002
Location: Brookhaven, LI, NY
Posts: 15,757
Likes: 0
Received 25 Likes on 17 Posts
Default

3 3/4" is not an odball size??? And I'm sure you got it already, but DO NOT use a roto-zip. USE A HOLE SAW. They are online and all over the place.
Old 04-27-2010, 07:27 PM
  #17  
Junior Member
Thread Starter
 
Join Date: Mar 2010
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
Default

To answer some questions. It's a 25' 1997 sportcraft. I don't think it's cored. I will be installing an airmar SS264W transducer. And I used the word "oddball" because I went to Lowes, Home depot, and my local true value, only after checking with 6 friends that are plumbers and in construction. (all of which didn't have it, but did have 3 1/2 inch and 4 inch, along with myself. One friend has an adjustable hole saw that I might use. Or as someone suggested drill the 3.5" hole and use the barrel sander. If I order the amazon saw I will have to wait and it will be 25 bucks by the time I'm done.
Thanks Tony
Old 04-27-2010, 07:37 PM
  #18  
Senior Member
 
Join Date: Jul 2004
Location: S Fla
Posts: 23,400
Likes: 0
Received 19 Likes on 16 Posts
Default

do not use anything on a hull but a hole saw. You do this once and do it right. A 3.75 saw is what's needed for the x64 series airmars....
Old 04-28-2010, 05:25 AM
  #19  
djy
Senior MemberCaptains Club Member
 
Join Date: Dec 2003
Location: Babylon NY
Posts: 1,169
Received 39 Likes on 26 Posts
Default

just installed the same transducer for a customer yesterday.use the the hole saw.If you have to buy it online and you are in a rush you can have it shipped overnight.
Old 04-28-2010, 05:28 AM
  #20  
Senior Member
 
Join Date: Apr 2009
Location: Florida
Posts: 17,576
Received 2,706 Likes on 1,454 Posts
Default

Originally Posted by sportcraft View Post
To answer some questions. It's a 25' 1997 sportcraft. I don't think it's cored. I will be installing an airmar SS264W transducer. And I used the word "oddball" because I went to Lowes, Home depot, and my local true value, only after checking with 6 friends that are plumbers and in construction. (all of which didn't have it, but did have 3 1/2 inch and 4 inch, along with myself. One friend has an adjustable hole saw that I might use. Or as someone suggested drill the 3.5" hole and use the barrel sander. If I order the amazon saw I will have to wait and it will be 25 bucks by the time I'm done.
Thanks Tony
Considering what the boat is worth - heck, the price of the ducer alone, if you're not willing to pay for a hole saw -- I don't know what to say.

I wouldn't drill a hole in the hull of my boat unless I *KNEW* I was using the very best thing I could.

But that's just me... well, and just about every other person in this thread.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.