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I expect to start my Spring Spruce up next week. I'd like to add a 12V 'cigarette style" receptacle in the cabin. Any hints on drilling technique, drill bits etc.

Thanks

If you use a saw tooth style hole saw cover the surface to be cut with mask and engage the surface slowly with the drill at high rpm's. Or use a holesaw with a flat diamond cutting edge and you wont have to worry about chipping.

I've had good luck with my forstner set, but perhaps it's because they're new? Like Scott said "mask it" with some tape first.

I used my Roto Zip....

It's nearly impossible to get a small, precision round hole with a Roto-zip or Dremel, even with the hole cutting attachment. Freehand, forget it. Spade bits are a disaster.

Don't have Forstners but tooth type hole saws are failrly easy; I keep a comlplete set on the boat including the common small sizes for stuff like lighter type electrical outlets and all the standard hull plug sizes. Skip the masking; I've found it not to prevent chipping. Instead, run the hole saw at low speed in reverse to score through the gelcoat. Then run it forward as normal. Keep the speeds fairly low or you'll end up burning through instead of cutting.

I still stand by the diamond tipped flat edge holesaw for cutting brittle anything. No wobble or wander. Super clean holes, just dont apply too much pressure when it breaks throgh or you wind up with a ragged backside/ exit hole. Seems like a forstner bit would make a mess but I could be wrong?

Yea! I'd go with hole saws. Scott, My trouble is that I have one of those hole saw sets where you open it up, and the size hole saw you need is always missing. that's why I used the forstners, and also why it's new. I have a wrench set to match the hole saw set that is always missing the 1/2" and 9/16" but has a bunch of 3/8" wrenches.

Wear a dusk mask and keep your shop vac handy. Fiberglass dust is nasty. And don't be surprised when your hands start itching. A bimetal holesaw works well, but the inside of the hole will be splintery with the glass fabric. I use coarse ( 60) sandpaper to knock this down. I ran a line out to the steering console and put a weatherproof 12v socket below the wheel. It's great for spotlight, cockpit light , fan , etc. You can route the wire out of the battery box, to the rear in the bilge, then up through the the starboard aft berth access hatch and out. Then cable tie to the teleflex steering cable and stuff going up into the console.

Rich I have that same set of wrenches

Chip Hindes wrote:Spade bits are a disaster.

After drilling a pilot hole with a twist bit, I've used spade bits for every lighter plug and switch I've installed on both the Whaler and the Mac and they've worked very well for me. I turn them slowly until they've scribed a groove through the gelcoat, then speed up to cut through. Nice clean holes every time. For larger holes, I use a hole saw.

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Moe

Moe wrote:I've used spade bits for every lighter plug and switch I've installed...I turn them slowly until they've scribed a groove through the gelcoat

Could be the key is to use the higher priced spade bits with a small dropped point on the end of the cutting edge. I've tried the cheaper ones with the straight flat cutting edge, and they work fine until they brak through, at which point they catch and tear up the nice hole you've just drilled, not to mention trying to break your wrist and (on at least one occasion) twisitng the drill bit into a pretzel shape. I know, that was a really cheap one.

Scott wrote:I still stand by the diamond tipped flat edge holesaw for cutting brittle anything.

Can't argue against the quality of the holes they make, but at (for instance) $8 for bimetal, $16 for carbide, and $71 for diamond for an American made 1" diameter saw, minus arbor, you've got to be kidding me. You may have lost sight of the fact you're talking to guys who like to buy boat tools at Harbor Freight.

Brian Russell wrote:And don't be surprised when your hands start itching.

I've worked with f'glass for years and I've found a pretty good method for reducing itching...

First, coat your skin - exposed and not exposed - with talcum powder before you ever get near the fiberglass. This both reduces surface moisture which would attract glass dust as well as blocking the pores where the dust can penetrate and later irritate your skin.

Then, when you're done working with the stuff, use a shop vacuum to draw off all the material, dust, etc. that got on your clothes and skin - don't use a blow-gun as this will drive the fibers into your skin.

Finally, take a *cool* shower - a hot one will open up your pores and let the glass in... a cool one will keep them closed while rinsing off the dust.

This method nearly always works for me... and it's also appropriate for when you're putting up pink insulation in your home!

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Oh, and BTW... a small bottle of talcum/baby powder is an excellent thing to keep on the boat, back in the cockpit. When folks board with sandy or dirty feet it's *excellent* at removing the debris - just dust their feet with talc and you'll see all the sand and rubbish just slough right off. MUCH better than rinsing, and feels better too.

We always carry a bottle to the beach with us as well - it's superb at de-sanding yourself, and leaves you feeling nice and cool, and not damp and sticky!

Wow chip the local hardware store must have not upped prices since '34. I got mine (cig lighter size, I believe 1") for like $9. The diamonds are just grains likely ind grade not the hope diamond.

On edit: I also use diamond blades on my hacksaw. They come in a 4 pack and cut anything better than any hacksaw blade I ever had. The 4 pack was around $6 3 years ago and I still have 3 left. (They dont seem to wear out)