Adhesive between Dexcom sensor layers: Sugru?

Posting here to see if I’m crazy.

I of course like to extend my CGM sensors as long as possible. One thing I feel makes them die sooner is when the adhesvive in the middle (under the transmitter) loosens, and this causes the back of the sensor to lift up really easily. The only way so far I’ve found to secure this, sort of, is putting a bandaid over the back of the transmitter to hold it down. But this often causes the corners to dig into my skin and is uncomfortable, and the sensor still seems to shift around and dies within a week, typically.

So the other day as I was re-taping I wondered if I could put a bit of Sugru between the bottom edge of the sensor and the top of the tape layers to secure that back portion in place.

I have some in my Amazon cart and will probably buy it. I’m pretty sure that using it in this way would not come into contact with the transmitter or my skin. However, I’m a bit nervous that Flexifix may not be totally impenetrable and some chemicals might get through.

Has anyone here used this product and can give feedback? I really do not want to glue my skin by accident, that would not be pleasant.

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I have used Sugru for different purposes :slight_smile: I used it mostly for molding around cables, replacing rubber pieces that had gotten lost etc. It is a useful tool, and remains flexible, but its adhesive capability is comparatively low: I am not sure if it is strong enough for what you want to use it for: it does not seem like it has the oomph. But I could be wrong.

Despite the usual warnings, I think that this material is less dangeorus to use than cyanoacrylics and user superglue materials.

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Thanks! I will buy some (it’s cheap and seems interesting for other projects as well) and maybe test it out with some old sensors and transmitters and Flexifix attached to a surface other than my skin to see how it responds, before I decide if I want to experiment. :slight_smile:

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Yeah I don’t think the sugru is necessarily dangerous, but I am skeptical it will work well for that, vs a tape of some sort. I’ve used it to repair cables, and it’s great for that. Extended the life of my chargers that way.

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@Jen like @Michel I have used Sugru for similar purposes, namely resealing Dexcom Transmitters after a battery change. IMHO it won’t be adhesive enough for your needs. Think of Sugru like playdoh that has been left out in the air a little too long. I might explore one of the liquid adhesives to bolster the sensor adhesive. Unless my research is wrong (and I do make mistakes) all but one of the liquid adhesives use the same main ingredient Acrylate polymer. To my limited knowledge Mastisol is the outlier, using gum mastic as the primary adhesive.

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I’m unfortunately allergic to the “rosin” ingredient in Skin Tac and most of the other liquid adhesives. I have not tried Mastisol, though, so might give this a shot.

I’m not sure I’m being totally clear on the way I’m thinking to use the Sugru. The plastic on the G4/G5 sensor is flush with the sensor adhesive everywhere except at the back where the transmitter snaps into the sensor. Those two “snap” pieces ahve have an area underneath that is not attached to the adhesive. When I re-tape the sensor, often at the front I’ll place my tape up over the edge of the plastic (the slanted part at the front of the sensor) and this holds it in place very securely and is easy to re-tape if it starts coming loose.

The back part is not so easy to tape because it is already “loose” and when I’ve tried to tape up over top, the face that it’s not attached to anything underneath and is able to move around means the tape just comes right off. In my experience, for the liquid adhesives to work, you must put them down and then have whatever they are gluing down not move at all for at least an hour or so until it is completely dry. If there is any movement, it doesn’t end up sticking at all (at least from my experience with Skin Tac). So I was thinking I could use a bit of Sugru to fill in the non-adhesive gap and hold things in place (the Sugru I was looking at said it was “skin safe” and safe to use on things that would be against the skin for extended periods of time, versus the original that caused reactions for many people and surely would for me!). Maybe that will not work from how people are describing it. I wonder if some double-sided tape (do they make that for medical purposes?) plus a band-aid might work? Or maybe the Mastisol instead of double-sided tape in combination with a band-aid?

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I think that now I understand what you are trying to do. We don’t see that problem but it may well.be because we use 3 layers of SkinTac on the skin first.

Given what you are explaining, it may be that Sugru I will work for you: you are implying in only needs to hold for a few hours. One possible issue is that, if I remember correctly, Sugru requires about an hour to set—but you are writing that you need it in place for that crucial first hour.

Regardless of Sugru, based on what @elver wrote, it seems to me to be a really good idea to try Mastisol. SkinTac makes a world of difference to us: the ability for you to get a good barrier adhesive would, I think, make your life easier (if it can work).

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@Jen i too have issues with Skin-Tac which led me to Mastisol. I purchase the spray top version (at a premium) and the accompanying Detachol for removal off Amazon. The spray version is my favorite because it puts down a light coat that I let air dry for several minutes before applying the Dexcom sensor. As long as I do a light coat, the applied area is sticky to the touch in a minute or two. I am too lazy to block out a specific area for the sensor wire to penetrate the skin and instead just apply the sensor over/through the Mastisol sprayed area willy nilly. I generally get > 28 days per G5 sensor.

IMHO, the Sugru is going to harden like an epoxy and might cause you more grief than expected for the limited securing that you might obtain.

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Are you using sensors for a month? I don’t have a problem for the first one to two weeks…it’s after that when the Dexcom adhesive has lost all its power and my own tape is starting to be the only thing holding it down that I start getting problems.

Though I do think Skin Tac helps a lot. I tried using that and adhesive-wise it was excellent. I used the technique of “painting” it over the Dexcom adhesive. But I’d always react with horrible itching and rash and the sensor dies within 24 hours. I hope I’d be able to use Mastisol the same way. I will buy some and give it a try instead of the Sugru.

I wish… We used to get 2 weeks, but now a week is good. On the other hand, with a 14 year old these sensors go through swimming pools, push and shove sessions, wrestling, soccer games, hour-long steaming showers etc…

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my personal 1 month formula ( as everyone’s skin is different)

apply fine mist of Mastisol over intended insertion site plus a 1.5 -2 inch outer “moat”

wait 1 to 2 minutes until sticky

play acupuncturist’s apprentice with the inserter

press sensor sticky back to skin firmly.

insert transmitter

apply GrifGrif fabric overpatch

Re-apply overpatch as needed every 1.5 to 2 weeks.

(the dexcom white adhesive patch won’t pull off my skin with out using copious amounts of alcohol, Detachol, or making a skin donation)

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Ha ha, it sounds like this is what I need, then! I also hear that the spray version of Cavilon acts a bit like an adhesive, and that’s something I’ve been meaning to try as I find Cavilon is one of the only things that helps me not react. Dexcom sensors have usually been relatively okay (compared to infusion sets), but the last few sensors have gone through periods of crazy itchiness and one had a rash that took about two weeks to go away, so I think I need to start treating them more like infusion sets (though since there is no insulin delivery to be screwed up, I’ll put up with itching and irritation as long as I get readings…my last sensor was the first one that I pulled purely because it was getting too painful, and that’s the one that had the two-week rash…).

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FWIW Dexcom has spoken in the Earnings Calls about the change in adhesives on the G6 which has led to premature failure rates. It would not surprise me if they have tried other adhesives across the board on all the sensor families.

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Yes, it’s been the last two sensors that have been problematic. This one I’m currently wearing seems fine. But since I take sensors from wherever I can get them and don’t necessarily use them in order (I tend to use them in order of expiration, but not always), I don’t necessarily know what I’m using. I did definitely wonder whether there had been an adhesive change…

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I’m going to have to research Cavilon now. Hopefully it will not have an adhesive ingredient that I react to, then I will have an alternative to Mastisol. Thanks for the suggestion @Jen!

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I thought they designed the back of the sensor/transmitter to float because if it is pulled down that will tend to pry up on the sensor wire at the opposite end, which is a pretty direct way to get a sensor to fail. So I’m not thinking that connecting the back end of the sensor to the tape underneath will help. But improving the glue between sensor and skin sounds like a good idea. I’ve had good luck with mastisol for regluing the sensor tape when it starts to peel, but have never used it before insertion (I use skin-tac for that with no issue.) I got a bottle of liquid mastisol because it was cheaper, and apply it with a Q-tip.

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