Of course a correctly installed plunger tube is best and should last basically forever. This post is not about that. It's about a fail safe measure for a worst case scenario.
The worst case scenario is one in which you are in the middle of a shoot out when suddenly the plunger tube chooses that moment to dismount. The easiest solution is to use grips that make contact with the side of the plunger tube thus preventing it from being pushed away from
the frame if the one or both rivets fail.
Here's a VZ grip that is contacting the plunger tube. If the plunger tube comes loose it will not be able to move away from the frame and cause problems. No need to modify this grip (other than putting the grip screws in).
For those of us who don't anticipate ever having to use our 1911s in a life or death situation there's little reason to do this modification. If the plunger tube fails at the range, it's no big deal. Just bring the pistol home and stake a new plunger tube onto the frame.
However, if your left grip doesn't make contact with the side of the plunger tube and you don't want to replace your grips but you do want the plunger tube to remain in place, here's a DIY modification that you can do to the left grip panel. Obviously, this only applies to 1911s that do not have an integral plunger tube cast into the frame.
The original design of the 1911 specified that the left grip was to support the plunger tube to prevent it from dismounting due to a poor staking job. Manufacturers have long been known for not always doing a good job of staking plunger tubes securely to frames. Some are known to not even countersink (chamfer) the holes through which the tube rivets pass.
If a plunger tube comes loose and is not retained by the left grip panel, this is what happens. When this happens the thumb safety cannot be swiped down into the fire position which is generally considered to be bad thing when you're on a two way range.
Below is a Hogue grip that doesn't make contact anywhere on the plunger tube. If the tube should come loose, it will be forced outboard by the thumb safety which may result in disabling it.
The objective is to fill in the gap between the grip and the plunger tube. The only thing the bedding is supposed to do is eliminate any gaps between the grip and the plunger tube so that if the plunger tube legs weaken or fail, the thumb safety and slide stop will continue to function correctly.
Epoxy bedding will eliminate this gap. JB Weld
works fine for this application and is available at any hardware store. No need to spend the big bucks on Devcon or Marine Tex.
Make sure you apply a thin coat of release agent such as neutral shoe polish or paste wax to any surface that you don't want the epoxy to stick to. Before applying the release agent thoroughly clean all surfaces to remove all oil so that the release agent can form an unbroken film layer.
When applying the epoxy don't let it ooze over the top of the plunger tube or you'll have a terrible time trying to remove the grip. Don't let it get into the grip bushing holes in the grip either.
Here's a 5 second How-To lesson on bedding.
First up is a pic of a left side grip showing where the plunger tube fits.
Prep the grip by roughing up the surfaces of the yellow shaded area shown below. This is where the epoxy will be applied.
If you have the tools to do it, carefully drill some small holes at different angles into the yellow area to enhance the gripping action of the epoxy and to create a physical lock when the epoxy cures. The holes were drilled at different angles which would act as a physical lock for the epoxy when it dried.
Then coat the red areas with the release agent so the glue doesn't stick to it. This is the absolute minimum area I'd coat. When in doubt coat everything. You can use masking tape or painters tape on the front of the grips. I used paste wax at the top of these grips because tape won't get down into the checkering. Tape is too thick to be used on the back of the grips or on the frame behind the grips.
Don't forget to coat the frame as well. If you don't coat the frame (every nook and cranny), the grip will become a permanent feature of the frame which you do not want to have happen. Coat the grip screw bushings, the plunger tube, and the area around the plunger tube very, very well. Block both open ends of the plunger tube with a gob of wax. Use a toothbrush to get the neutral shoe polish or paste wax into the areas where there's a right angle like between the frame and the plunger tube.
As seen below, I detail stripped the frame and applied two or three coats of Butcher's Bowling Alley Wax (any paste wax is fine) on the frame and the top portion of the grip both front and back. After each coat of wax dried, I buffed it with a rag before applying the next coat. This kept it from building up unevenly. I also stuck a piece of painters tape on the front of the grip in case my fingers got into the epoxy. Rubbing alcohol and Q-tips are standing by to be used after the epoxy is applied to the grip and the grip is secured to the frame
Have some rubbing alcohol, paper towels, Q-tips, and a small tool (popsicle sticks) handy to remove any epoxy that goes where you don't want it to go. Q-tips soaked in alcohol work well to smooth out the wet epoxy.
The release agent will save you from making a terrible mistake.
After you spend as much time as needed to fully coat the areas that will not
receive the glue, you can mix up some epoxy and apply it to the yellow shaded areas. Then press the grip onto the frame. Make sure it is firmly seated. As long as you don't see any epoxy oozing up around the grip screw bushings, you can secure the grip to the frame with the grip screws.
Let everything sit overnight and remove the grip the next day (24 hours for full drying).
Things tend to get a little hectic after mixing up a batch of the JB Weld epoxy so no pics of that. This is what things looked like while the epoxy was still wet. You can see the wax has filled in the grip checkering.
After letting the epoxy dry overnight I removed the grip and did a little clean up around the edges of the now hard epoxy. I got most of the wax out from the checkering but I missed a couple of spots that I'll attend to later. Note the pin hole in the epoxy towards the rear of the grip. That indicates the presence of a small bubble caused by me just glopping the epoxy there instead of slowly rolling it along.
This is what the finished product looks like. Not too bad. I was in a bit of a hurry and this isn't a beauty contest. If I'd really wanted to, I could have mixed in some dye to change the color.
Time to show my goof. You can see the voids along the inside edge of the grip. I didn't use enough epoxy to do a picture perfect job. I could have gone through the process again to fill in the voids but it would have made no functional difference in supporting the plunger tube.
You can see smooth surfaces where the epoxy was squished into tight contact with the plunger tube. I guaranty the plunger tube is not going to move even if the flared ends of the legs fail.
Ignore the strand of rag I was using to wipe things down. You can see there's still some left over paste wax inside the tube. Time to break out the Hoppes and a pipe cleaner. Compare this pic to the earlier one where the plunger tube was hanging out in the wind. The plunger tube is being pressed against the frame. Mission accomplished.