Tape I use (except when I forget) to keep my Dexcom sensor on. Comes in a roll. You can order online, sorry, I’ve forgotten what it’s called or who makes it.
Restarting a sensor is easy. When you start your sensor session keep the code of that sensor written down somewhere because you will need it do this easy restart.
(This is the more complicated way if you’ve not kept your code. It’s the second method offered, the first one is what I describe below.)
Easy restart in 5 steps
Let sensor expire
Restart it choosing “no code.” Let it run 15 minutes
Stop the sensor session (It will tell you you can’t restart but it’s not true)
Restart the sensor with the code option
Sensor will begin its 2 hour warm up and you’re good to go
What to watch out for? Twice it’s happened to me. While my sensor is on its second round, it falls off. Usually I’m changing my shirt and that knocks it off or some such thing. The point is that the tape has loosened to the degree that the slightest movement will knock it off your body. I don’t usually find I need to use additional tape on my first 10 days but I stupidly forget I absolutely need to do so entering the second 10 day period.
If you call Dexcom they’ll give you 10 clear, tape covers cut to cover over the sensor’s adhesive. I bought the medical tape I use a long time ago on the internet, but I’m sure you can google it and find out what many of us use. If you’re reading this and you use a tape you like, please share.
As for sharing I want to thank my fellow T1D bloggers for putting this information out there, (up there in this blog) because this is how I first discovered a 10 day G6 Dexcom session can become 20.
I’ve only restarted my sensor twice, since discovering this, and not tried restarting it for a third round so I can’t tell you whether or not you’ll be successful. But, hey, if you get that far, you can always give it a try.
Diabetes Stories 
I have trouble with my second session of my Dexcom. how to put sensor code in to start
Is this method still working for you? Do you have a 81 transmitter? The later model transmitters seem to be very picky. Also, are you restarting using the dexcom receiver or are you using a 3rd party phone app?
I have found luck by stopping the session before it expires. Teasing the transmitter out of the sensor while leaving the senor on my body. Leaving the transmitter out for a half hour. Then starting a new sensor pretending that everything is normal and using the same sensor code as you did before. Everything works fine IFF I use the receiver. My Xdrip is not reliable for restarts anymore (and the Dexcom app won’t work on my phone).
Also, Skin – Tac works fabulously for tacking down the fraying edges of the sensor so that it stays in place. I use the skin-tac with the dauber, and just daub down the edges when they need it. I had terrible trouble with them flying off, but now they are staying in place quite nicely.
I don’t know what an 81 transmitter is…I haven’t been able to restart my G6 on my phone and that’s all I use, I don’t use the receiver. I do use Skin-tac and it works great.
I was not able to do the restart. I tried on my phone.
Make sure you wait an hour before doing the restart and when you put in the code don’t do it manually, take a photo of the code on the piece of paper it originally comes on. those were two mistakes I made early on. Now it works for me.