Drilling top tube venting holes post-build

[CMiller]

I had some frame modifications done on my bike, including cable stops on the top tube. Maybe it was there before, or maybe it's a side effect of the modification, but I can hear something like sand floating around the top tube.

Would it be safe to drill a hole at the headtube/seattube junction, as seen on a ton of vented steel frames, to allow me to spray framesaver in it and hopefully capture some of that debris? It is a butted Reynolds 531 1" top tube.

https://www.velocipedesalon.com/forum/attachments/f10/100072d1486586990-drainage-holes-head-tube-holes-jpg

Along the lines of this pic from across the hall.

If it is possible, is this something a framebuilder or just a good shop can handle? I imagine it would be easy if you could fit a very small right-angle drill in there.

Thanks!

[Peter P.]

It might work if you centerpunch the spot first to prevent the bit from drifting.

I'd sooner try drilling from the seat tube slot stress relief hole, assuming your frame has one. It would be more of a straight shot.

Framesaver isn't going to capture what's inside. A pump of silicone caulk or Great Stuff would work if the tube is tilted for the debris to get captured.

What you have is some braze or brazing flux floating around in there. It happens.

[8aaron8]

It might work if you centerpunch the spot first to prevent the bit from drifting.

I'd sooner try drilling from the seat tube slot stress relief hole, assuming your frame has one. It would be more of a straight shot.

Framesaver isn't going to capture what's inside. A pump of silicone caulk or Great Stuff would work if the tube is tilted for the debris to get captured.

What you have is some braze or brazing flux floating around in there. It happens.

I agree with the above, coming in from the seat tube lug slot through to the top tube will be your best route.

[Louis]

Framesaver isn't going to capture what's inside.

Although I haven't had to do it personally, I know that Framesaver has been used to silence flux balls. Once it's dry it can hold small stuff in place.

[CMiller]

Thanks all! I'll deal with the noise at first, then try the drill from the slot later down the line