Post by RaisedByWolves on Mar 14, 2012 17:52:55 GMT -5
Every now and then you just plain goof, other times the deck is stacked against you from the beginning. Breaking bolts and stripping threads can be a nightmare if you dont know how to repair or at least limit the damage done to the threaded hole.
Everyone knows about Helicoils and while these work good Im going to discuss a couple other options. These options are handy in light of the fact that to use a standard Helicoil you need to start with a somewhat round hole.
With some of the other options you do not need a good hole to start with and many butchered holes can be repaired to like new with these other options.
Keensert
A Keensert is a threaded insert with the repaired thread on the inside and the mounting thread on the outside.
Their as simple as drilling, or severely buggered holes milling a hole and threading it to accept the new threaded insert.
Here is an animated video of the process.
www.repairengineering.com/keensert.html
Timesert.
A Timesert is similar to a Keensert but is better for low clearance applications and newly manufactured items.
Animated video of a Timesert installation.
www.repairengineering.com/time-sert.html
And lastly there is the old school method of hole plugging or plug and peen.
Hole plugging is usually a last resort now that there are ready made options available for purchase but can still be used in extreme cases.
Hole plugging requires a threaded "Plug" of the same material of which the hole was originally drilled in. An oversize hole is drilled and tapped to accept the threaded plug and then is chamfered or counter sunk on both sides for a through hole or just one side for a blind hole.
The threaded insert is then prepared so that it is longer than the depth or thickness of the hole to be repaired. Once prepared to the proper length (figuring the proper length takes practice for different diameter holes) and it then inserted into the hole with Loctite or another bonding compound, but green loctite is preferred.
Once screwed into the new oversize hole the plug is then "Peened" into the hole with a Ballpeen hammer so that it gets bound by the threads and peened over into the chamfer you created at the top of the hole.
You want to get it peened in as close to flat with the original surface as possible, then grind and file off any excess with a file till flat.
Now that you have filled the hole with the Plug and Peen method you can layout, drill and re-thread the hole to its original location.
Everyone knows about Helicoils and while these work good Im going to discuss a couple other options. These options are handy in light of the fact that to use a standard Helicoil you need to start with a somewhat round hole.
With some of the other options you do not need a good hole to start with and many butchered holes can be repaired to like new with these other options.
Keensert
A Keensert is a threaded insert with the repaired thread on the inside and the mounting thread on the outside.
Their as simple as drilling, or severely buggered holes milling a hole and threading it to accept the new threaded insert.
Here is an animated video of the process.
www.repairengineering.com/keensert.html
Timesert.
A Timesert is similar to a Keensert but is better for low clearance applications and newly manufactured items.
Animated video of a Timesert installation.
www.repairengineering.com/time-sert.html
And lastly there is the old school method of hole plugging or plug and peen.
Hole plugging is usually a last resort now that there are ready made options available for purchase but can still be used in extreme cases.
Hole plugging requires a threaded "Plug" of the same material of which the hole was originally drilled in. An oversize hole is drilled and tapped to accept the threaded plug and then is chamfered or counter sunk on both sides for a through hole or just one side for a blind hole.
The threaded insert is then prepared so that it is longer than the depth or thickness of the hole to be repaired. Once prepared to the proper length (figuring the proper length takes practice for different diameter holes) and it then inserted into the hole with Loctite or another bonding compound, but green loctite is preferred.
Once screwed into the new oversize hole the plug is then "Peened" into the hole with a Ballpeen hammer so that it gets bound by the threads and peened over into the chamfer you created at the top of the hole.
You want to get it peened in as close to flat with the original surface as possible, then grind and file off any excess with a file till flat.
Now that you have filled the hole with the Plug and Peen method you can layout, drill and re-thread the hole to its original location.