Frozen bottle cage screw: suggestions?

[OtayBW]

Hello there - I've got a hex head screw frozen in my ST bottle cage boss and now unfortunately stripped. I cut a slot with a dremel to try to take it out with a screwdriver and that ultimately chipped the head and made it worse. Tried a screw extractor (grabit, or something like that...) which did nothing. It's now nearly flush with the cage and the only way I know to get it out is to drill it out carefully with a small drill bit. However, I don't want to risk the frame, so I may wind up just leaving it in there. :mad:

It's in a carbon frame which I assume has Al threads in the boss. It may be a Ti screw and may have had some sort of galvanic/corrosion thing going on (?).
Any thoughts on this greatly appreciated.

Thanks much.

[peanutgallery]

pretty sure you can carefully drill it out and replace, it is a rivnut if we are talking a carbon frame. if not, you can drill it out and put a rivnut in

if you have a good wrench, might be worth the dough to take it to him/her. there is a special tool to install it and some skill

for future reference, a bit of heat from a hair dryer and some penetrating oil will usually do you in situations like this to get that bolt out. use anti seize on the bolt when you button it all back up. 2 different kinds of metal and a heavy dose of sweat will do this. have a good xmas

[Black Dog]

Drill it out with a ver small bit first then use progressively larger bits. The previous hole acts as a guide.

[OtayBW]

Great info, folks. Thanks. I'll report back with the outcome.

[martinrjensen]

Yes, were talking
"very" small drill bits. if it was me I would start with a bit about .020" diameter or smaller. it's real easy to break these also, which will be obvious once you look at them. Takes a stead hand and usually bracing yourself agains something so you don't wiggle.Drill it out with a ver small bit first then use progressively larger bits. The previous hole acts as a guide.

[11.4]

First confirm that it IS a rivnut. If so, simply drill out the whole rivnut and replace it. If it's a glassed-in threaded stud, you have to proceed more delicately because it's hard to replace the threading.

There are plenty of threads on here about rivnuts.

[Peter P.]

You might find it tough to start a pilot drill bit as the sheared surface of the screw is likely not flat. Be sure to use a center punch before you drill so the bit is less likely to drift.

I'd recommend cutting away the bottle cage so you can grab what's left of the screw with vise grips if possible. Sacrifice the cage and buy another one. Always "work" the screw back and forth until it moves and never in one direction only.

You could notch the remnants of the screw with a Dremel Tool to create a groove that's screwdriver friendly. It may cut into the threaded insert but it likely won't go deep enough to damage the threads. Use 2 hands and protect the surrounding area with duct tape.

First, I'd try spraying an entire can of freeze spray on the screw head. Wear gloves because the can will get cold. If the parts contract at different rates it may break the bond between the screw and the threaded insert.

If cold doesn't work, try applying a soldering iron to the screw to heat it up. It may take 5 minutes to do this effectively but it can break the bond as well.

If all that fails and a local shop won't touch the repair/replacment of the threaded insert, you can always send the frame out to any of the carbon frame repair shops such as Calfee Design as I'm sure they've encountered such problems before.

[biker72]

You might find it tough to start a pilot drill bit as the sheared surface of the screw is likely not flat. Be sure to use a center punch before you drill so the bit is less likely to drift.

I'd recommend cutting away the bottle cage so you can grab what's left of the screw with vise grips if possible. Sacrifice the cage and buy another one. Always "work" the screw back and forth until it moves and never in one direction only.

You could notch the remnants of the screw with a Dremel Tool to create a groove that's screwdriver friendly. It may cut into the threaded insert but it likely won't go deep enough to damage the threads. Use 2 hands and protect the surrounding area with duct tape.

First, I'd try spraying an entire can of freeze spray on the screw head. Wear gloves because the can will get cold. If the parts contract at different rates it may break the bond between the screw and the threaded insert.

If cold doesn't work, try applying a soldering iron to the screw to heat it up. It may take 5 minutes to do this effectively but it can break the bond as well.

If all that fails and a local shop won't touch the repair/replacment of the threaded insert, you can always send the frame out to any of the carbon frame repair shops such as Calfee Design as I'm sure they've encountered such problems before.

Looks like Peter has been down this road before...:)
I've used a few of these methods on non-bicycling applications. Great tips.

[Tony T]

Tried a screw extractor (grabit, or something like that...) which did nothing. It's now nearly flush with the cage and the only way I know to get it out is to drill it out carefully with a small drill bit.

Grabbit tries to grab the screw head.
Try an easy-out type extractor (http://www.amazon.com/Irwin-Industrial-53700-Extractor-Pouched/dp/B00004YOBM/ref=sr_1_16?ie=UTF8&qid=1356526363&sr=8-16&keywords=easy+out+screw+extractor). You first drill a hole in the broker screw (use a punch to center the drill bit), then use the extractor. (.....or is this what you meant by 'drilling it out')

[Tony T]

Tried a screw extractor (grabit, or something like that...) which did nothing.

I snapped the head off of a screw today and removed it with the Grabit Micro (http://www.amazon.com/Alden-4507P-Grabit-Broken-Extractor/dp/B000Q60UOO/ref=sr_1_1?ie=UTF8&qid=1356746165&sr=8-1&keywords=grabbit+micro) (I thought it just worked on stripped heads, but it works on broken screws also)

When you said it "did nothing", did you have the drill in reverse (and slow speed) when you drilled the hole?

[OtayBW]

I snapped the head off of a screw today and removed it with the Grabit Micro (http://www.amazon.com/Alden-4507P-Grabit-Broken-Extractor/dp/B000Q60UOO/ref=sr_1_1?ie=UTF8&qid=1356746165&sr=8-1&keywords=grabbit+micro) (I thought it just worked on stripped heads, but it works on broken screws also)

When you said it "did nothing", did you have the drill in reverse (and slow speed) when you drilled the hole?
Yup - had it in reverse and it wouldn't grab. Wound up drilling the bolt out and made out OK. Saved the (expensive...) bottlecage to boot, so I'm good to go.
Thanks all.