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Author Topic: Hole Saw for Thru Hull  (Read 213 times)

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Bill Shreeves

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Hole Saw for Thru Hull
« on: March 12, 2021, 11:50:55 AM »

Any suggestions on what type to buy that might survive well enough to cut through the hull?

Thanks
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The only thing that always works on an old boat is the owner...

Bill Shreeves
s/v "Begnnings" 1987 Shoal Draft #333
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KWKloeber

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Re: Hole Saw for Thru Hull
« Reply #1 on: March 12, 2021, 12:17:42 PM »

Carbide tipped.
I bought a Morse open box set but also found them individually (eBay I think, or Azon) to fill the spot of the missing size.
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Noah

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Re: Hole Saw for Thru Hull
« Reply #2 on: March 12, 2021, 12:30:19 PM »

Milwaukee brand has always worked for me.
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waughoo

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Re: Hole Saw for Thru Hull
« Reply #3 on: March 12, 2021, 05:24:45 PM »

Fiberglass isnt partucularly hard to cut through.  I use a lennox (sp?) Brand most of the time.  I will say that in some cases they are a one shot consumable depending on the material I am going through.  The brand I use isnt anything fancy other than being a bimetal blade.  I wouldnt hesitate to use it for a new through hull fitting.
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Bill Shreeves

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Re: Hole Saw for Thru Hull
« Reply #4 on: March 12, 2021, 08:15:19 PM »

Thanks for the suggestions. Yeah, its not particularly hard but, I know the glass fibers can do a fine job of making short work of a sharp tooth.  Since I never sawed through an inch of fiberglass before I wasn't sure if it might take more than one saw to cut a nice clean hole.
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The only thing that always works on an old boat is the owner...

Bill Shreeves
s/v "Begnnings" 1987 Shoal Draft #333
M25XPB, Worton Creek, MD

Jim Hardesty

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Re: Hole Saw for Thru Hull
« Reply #5 on: March 13, 2021, 04:42:03 AM »

Quote
what type to buy that might survive well enough to cut through the hull?

IMHO if you are only planning to cut a single hole or two a quality steel hole saw from Lowes or Home Depot will work fine.  Did for me.  If you are going into business, doing a few a year the carbide will last longer.
If I remember correctly I cut almost through from the inside then using the pilot hole finished the last 1/4 inch from the outside.  Was concerned about a rough break-through.
I've never got comfortable cutting holes in Shamrock.
Jim
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Jim Hardesty
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scgunner

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Re: Hole Saw for Thru Hull
« Reply #6 on: March 13, 2021, 07:23:21 AM »

Bill,

I'll second Jim, a hole saw will work nicely and you'll get a clean, round hole. I cut similar to Jim except in reverse, I start on the inside with the shallow cut, then from the outside drill through. It's basically the same procedure as Jim's except by doing the deep cut outside it minimizes dust inside the boat.

Jim,

Especially when those holes are below the waterline.
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Kevin Quistberg                                                 Top Gun 1987 Mk 1 Hull #273

mark_53

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Re: Hole Saw for Thru Hull
« Reply #7 on: March 17, 2021, 12:00:56 PM »

Any suggestions on what type to buy that might survive well enough to cut through the hull?

Thanks

Will you cut at the angle of the transom or level with the boat?  That is you were to put a thru hull through the transom.
« Last Edit: March 17, 2021, 12:02:11 PM by mark_53 »
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Bill Shreeves

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Re: Hole Saw for Thru Hull
« Reply #8 on: March 17, 2021, 03:10:58 PM »

I used a reasonably priced Milwaukee hole saw from HD to cut through the hull and it worked very well.  Thanks for the suggestions guys!

Regarding the angle of a hole cut through the transom:
A threaded thru-hull has to clamp to a surface that is perpendicular to the thru-hull.  So, unless your going to add a means to compensate for the angle between the transom and the water level, you must cut the hole perpendicular to the transom.
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The only thing that always works on an old boat is the owner...

Bill Shreeves
s/v "Begnnings" 1987 Shoal Draft #333
M25XPB, Worton Creek, MD
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