SailNet Community

SailNet Community (http://www.sailnet.com/forums/)
-   Gear & Maintenance (http://www.sailnet.com/forums/gear-maintenance/)
-   -   Howto drill center of a rail. (http://www.sailnet.com/forums/gear-maintenance/97900-howto-drill-center-rail.html)

xymotic 03-26-2013 03:12 PM

Howto drill center of a rail.
 
I'm installing some lights on the bottom of a 1" SS rail. I need to drill a few holes in a 1" SS rail. Is there a 'trick' to reliably find the center so each light isn't a few degrees off?

Alex W 03-26-2013 03:34 PM

Re: Howto drill center of a rail.
 
Is the rail already on a boat, or is it just tubing in a workshop?

This is easy to do in a workshop by laying down the tube on a flat surface, then drawing an old machinists square along it. You will get a reference line down the highest point on the tube. Use it as the reference for your holes.

If the tube is already on the boat then I'd use a good sturdy and flat piece of plywood to make a temporary surface then do the same trick. That piece of plywood can be mounted to the nearest vertical members of the railing.

Don't forget to center punch the holes before drilling (to keep the bit from wandering) and to use sharp drill bits, lots of coolant, and a slow and steady speed that always keeps the bit cutting fresh metal. If the bit makes a pass without taking a cut it will work harden the stainless and dull the bit.

rhr1956 03-26-2013 03:49 PM

Re: Howto drill center of a rail.
 
Make one of these out of a good piece of 3/4" hardwood. Place it over the rail and when it shows "level" clamp it and drill.http://i1217.photobucket.com/albums/...psa8800ea4.jpg

chef2sail 03-26-2013 05:27 PM

Re: Howto drill center of a rail.
 
I have one of these handy dandy grill guides I got at sears

Wolfcraft Drill Guide For Horizontal Vertical & Angle Postion 1/4" - Tools - Power Tool Accessories - Drill Bits

TejasSailer 03-26-2013 06:02 PM

Re: Howto drill center of a rail.
 
A drill guide specifically make for tubing might be what.

Drill Steady Tubing Tool - Great for Drilling Stainless Steel Tubing

JimMcGee 03-26-2013 06:28 PM

Re: Howto drill center of a rail.
 
Quote:

Originally Posted by xymotic (Post 1008184)
I'm installing some lights on the bottom of a 1" SS rail. I need to drill a few holes in a 1" SS rail. Is there a 'trick' to reliably find the center so each light isn't a few degrees off?

There are quite a few jigs available like this one from Sailrite.

If you only have one or two holes to drill I'd make a jig like rhr1956 diagrammed.

To keep it simple just route out a one inch channel, take it out with a dado set or nibble it out with a table saw.

If you're not set up with woodworking tools you can make it by gluing pieces of plywood together.

Just remember to make the jig long enough that you can use a clamp to hold it in place.

A good tubing cutter will have a de-burring tool you can use to clean up any rough edges on the hole and some heat shrink tubing on the wires where they pass through the hole will prevent shorts.

BELLATRIX1965 03-26-2013 06:40 PM

Re: Howto drill center of a rail.
 
As Tehas said - the "drill steady" is available at Gemini also:

Drill Steady drill guide - Gemini Products

This drilling rig is made from a water pipe grounding clamp, available at any electrical or home supply retailer - if you are handy, you can make your own and save 50 bucks!

PorFin 03-26-2013 07:01 PM

Re: Howto drill center of a rail.
 
Quote:

Originally Posted by Alex W (Post 1008198)
Don't forget to center punch the holes before drilling (to keep the bit from wandering) and to use sharp drill bits, lots of coolant, and a slow and steady speed that always keeps the bit cutting fresh metal. If the bit makes a pass without taking a cut it will work harden the stainless and dull the bit.

Alex's advice is worth reading several times (the better to remember it when the time comes to drill.)

I'd strongly recommend forking out the extra money for a good drill bit (cobalt as a minimum; harder would be better.)

In addition to the slow speed, you need to really bear down on the bit. You want to see those long ribbons of cut metal coming up the flutes of the bit. If all you're getting are little chips, then you aren't applying enough pressure.

If the hole you are drilling is bigger than 1/4", consider doing it in a couple of passes. Use a small bit first, followed by a larger bit to enlarge the hole.

fallard 03-26-2013 07:09 PM

Re: Howto drill center of a rail.
 
In case you missed it in PorFin's post: Use a cobalt drill bit--nothing less will do. If you don't, you'll regret it.

tommays 03-26-2013 07:20 PM

Re: Howto drill center of a rail.
 
1. Black Sharpie marker or pencil

2. GOOD 4R Ruler

3. Make some wee marks with the Sharpie and wipe them off until your happy with there location

4. GOOD CENTER PUNCH and whack ONCE the wee Sharpie marks and check again with ruler

5. small holes like 10/32 ? a 135 degree split point #21 (we buy them in bulk )

The black and decker Bullet® Drill Bit singles at home depot will get you through the deal is HEAT KILLS and you have to use much pressure and slow speed

When i cant get oil all over the boat i do short pulses of 3 seconds

http://i565.photobucket.com/albums/s...228_135607.jpg

http://i565.photobucket.com/albums/s...130_155128.jpg

http://i565.photobucket.com/albums/s...130_153947.jpg

http://i565.photobucket.com/albums/s...130_163228.jpg

All of these holes are 1/4-20 through .187 stainless


IMHP working in a machine shop i am not real big on cobalt in hand drills as it is so HARD IT CHIPS REAL EASY AND BLACK OXIDE does fine if you mind the heat


All times are GMT -4. The time now is 03:21 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012