Drilling/tapping fiberglass tank

[carlisle]

I'm going to install a clear sight tube so I can keep better track of fuel in my older Model 2. Looking into partially opaque inside wall of tank just doesn't hack it, especially when the fuel is low and the butt rib and some cockpit tubing are in the way.

So, I'll empty the tank and tap in a couple of fittings. How's the best way to keep the drill filings out of the tank?

Chris Carlisle
Model 2, 582, C box, Ivo light
Sioux Falls, SD

[jtpitkin06]

Drill a small starter hole using a vacuum to collect shavings. Follow with a final size drill bit and the vacuum. Use very slow speed on the drill bit to control the shavings. You should be able to drill without any contamination. Tap the hole with the ever present vacuum.

John Pitkin
Greenville, Texas

[carlisle]

Thanks John. Always informed and helpful. I grew up in TX. Met my wife in Dallas, went to college in Denton. Missing the weather there about now.

Thanks,
Chris

[cap01]

i know a different situation . i had to drill and tap for a vent fitting in a new tank that wasnt installed yet . i set the tank up on its side with the area to be drilled off the edge of a bench and drilled up into the tank . had a small amout of shop air pressure in the tank to blow out any chips . seemed to work pretty good .