Drilling A 5/8" Hole In The Hull?

[SEMIJim]

I'm going to be installing a Blue Sea CableClam 1001 in Abracadabra's stern this weekend. The model 1001 has a 0.63" (16mm) opening, which is approximately 5/8". That's smaller than my smallest hole saw, but way too big for a twist bit. What do y'all suggest? I was wondering if a Forstner bit would work well on fiberglass?

Thanks,
Jim

 

[Lost Parent]

Go to Home Depot they have them

 

[jviss]

I'm going to be installing a Blue Sea CableClam 1001 in Abracadabra's stern this weekend. The model 1001 has a 0.63" (16mm) opening, which is approximately 5/8". That's smaller than my smallest hole saw, but way too big for a twist bit. What do y'all suggest? I was wondering if a Forstner bit would work well on fiberglass?

Thanks,
Jim

5/8" hole saws are available.

 

[Charlie Jones s/v Tehani]

Buy a hole saw- you'll F*** up a forstner, which is more expensive than a hole saw.

 

[Rob2435]

Or you can use a smaller bit to drill a pilot hole and work your way up with progressively larger bits until you get to 5/8". I've always done it while working with metal and I am sure it will work on fiberglass.

 

[Ross]

Buy a step drill. http://www.mcmaster.com/#step-drill-bits/=idrnhg

 

[Slow Mo^cean]

I wouldn't use a drill bit. You run a chance of flaking off the gel coat and fiberglass around the hole and not have a very clean cut.

 

[Florida sail]

Step drills can be purchased at Harbor Freight very reasonably. If you are concerned about chipping the gelcoat you can place masking tape first and drill through the tape.

 

[Maine Sail]

Jim,

Buy the right hole saw. Lenox makes them in 5/8" but you may need the smaller arbor. Clamp the arbor in your bench vise and use pump pliers to get the hole saw onto the arbor nice and TIGHT.

Then drill a 1/4" pilot hole and start the hole saw in REVERSE and use very light pressure until you are well through the gelcoat. Once through the gelcoat you can switch to forward and finish the hole.


Lenox Hole Saws

Reverse Trick Results

The pilot hole was done with a BRAD POINT 1/4" bit started in REVERSE...

 

[SEMIJim]

Okay, I'll stop by the local big box stores and look for a 5/8" hole saw. I assumed nobody made them, as I already have two sets and neither has a bit that small.

MS, thanks for the hints. I think I've seen you describe the process before, and I've already used it to good effect when adding a drain for the port storage cuddy in the cockpit. Cut two holes that way, clean as a whistle

Thanks for your feedback, everybody!

Jim

 

[SEMIJim]

It turned out my local Home Depot did not have a 5/8" hole saw, but they did have a 6/8" one, and that's close enough I.D. of the CableClam is 0.63". Hole in the fiberglass will be approx. 0.75". A whoppin' 0.12" difference.

Jim

 

[Slow Mo^cean]

DO you have a Fastenal or Grainger near you? They should have a 5/8" for sure.

 

[Lost Parent]

Its funny you said 6/8 because that is 3/4

 

[Bill Roosa]

You do know that you do not need a hole saw for a hole that small right?
You can use that old 5/8 drill and a layer of masking tape. For the outlandishly annal you could drill it 1/2" and then take a rat tail file and chamfer the edges then drill 9/16" and chamfer again then drill the 5/8" with the tape "mushed down" against the chamfer.

 

[SEMIJim]

DO you have a Fastenal or Grainger near you? They should have a 5/8" for sure.

In fact there is a Grainger just minutes away from work. Hadn't thought of that. Oh well, I've got the 3/4" saw now, and that's easily close enough. (The inside diameter of the CableClam is spec'd at 0.63", which is a skosh more than 5/8", anyway.

Its funny you said 6/8 because that is 3/4

You don't say

You do know that you do not need a hole saw for a hole that small right?

"Need?" No, not necessarily need, so much as I've found that having the right tool for the job yields higher probabilities of a more enjoyable experience and satisfactory results.

And, yes, I've no doubt that, by the lights of some people, I'm anal. Perhaps even outlandishly so.

Jim

 

[Ross]

You do know that you do not need a hole saw for a hole that small right?
You can use that old 5/8 drill and a layer of masking tape. For the outlandishly annal you could drill it 1/2" and then take a rat tail file and chamfer the edges then drill 9/16" and chamfer again then drill the 5/8" with the tape "mushed down" against the chamfer.

Anyone that can have and chuck a 5/8 inch drill should also have a proper countersink. Rat tail file! Indeed!!!