Mold "Skinned" - What To Do About a Loose Flap?

I guess the actual answer is that I should call my audiologist and see what she says.

However, thought with the many person-years experience of folks on this forum, it would be good to get a “second opinion” - (and a third, fourth, fifth, etc., ! :slightly_smiling_face:).

My left external mics were defective, turned the whole HA with receiver, mold and all into the audi and she said, “We’re going to send the whole thing off to ReSound and see what they can make of it.” I got a replacement HA back but I would have presumed that she would have kept the receiver, wire, and mold herself while ReSound inspected the body.

Just about the first day I cleaned the mold on the returned HA with my Jodi-Vac, I noticed that there was a small semi-circular flap flush with the rest of the surface of the mold and as the tip of the syringe vacuum needle runs over the area, the flap can be popped away from the rest of the surface of the mold, exposing a “rawer” area underneath. The flap is about as wide as a small power dome, 6 mm or less in the center of one of the lateral sides of the mold. The two “gestalt” things are the flap that comes loose almost looks like a different material from what’s underneath, a “skin” (??) formed by curing the silicone mold when it was made? - and the other amazing this is how perfectly circular most of the flap is.

Normally the flap is glued flush against the rest of the mold body and only disturbed by the Jodi-Vac needle or by wiping the mold with a Q-tip or alcohol wipe. I’m wondering if the fix is to just cut the flap off or to try to glue it back in place? My main concern is that as time goes by the gunk that accumulates under the flap and is difficult to thoroughly clean away is going to be a source of problems.

Any suggestion as to what to do would be welcome. I’ll see what my audi has to say. I’d hate to pay another $100 for a new mold if the current left one, other than my “gunk” concern, is perfectly functional. The mold passes the feedback test with flying colors and lets very little if any sound leak out between the mold surface and my ear canal, as the flap is normally flush against the rest of the mold surface when I am wearing the HA.

The very regular shape of the flap makes me think that it must have something to do with the manufacture of the mold. It’s hard to imagine post manufacture what could have loosened such a regular geometrical bit of mold “skin.”

Gave my audi a call. She said that, Yes, she has seen a “skin” flap come loose on molds sometimes and she’s not sure what causes the occasional defect to appear, possibly something that didn’t go right in the final buffing process of finishing up the mold when it was first made. She said that what she usually does, if the defect doesn’t go too deep into the mold, is just to cut such a flap off and recommended that I do the same. I asked if my use of a UV device to “sterilize” my molds could have anything to do with the defect finally manifesting itself and she thought not. I decided to just let the flap stay in place, which usually firmly adheres to the rest of the mold. In terms of my worry about accumulating gunk, there are several other crevices in my molds where the receivers and Select-A-Vent plugs go in that I can’t thoroughly clean on a daily basis either but I do clean once a month by removing the molds from my receivers and soaking them in dilute dish detergent before thoroughly rinsing and drying. I should imagine in cleaning my molds on a daily basis that some of the benzalkonium cleaning solution and some of the alcohol wipe isopropanol gets under the flap, too, to help disinfect that area.

Think that I finally understand what might be going on with the loose flap on my left silicone mold. I finally accidentally vacuumed the flap off the mold while cleaning the mold with my Jodi-Vac. The flap was very thin, flexible, and diaphanous, and also seemed circular over much of its shape. What remains underneath in the mold is a somewhat irregular elongated hole in the mold through which I can see part of the bare side of the receiver metal. Here’s what I think is going on/went on. Anyone with better knowledge about such things is free to set me straight.

I think that the basic problem arose in casting or 3D printing my left mold. My left ear canal is very small. Besides having to fit the receiver into the mold, I requested Select-a-Vent, which means the venting hole has to be much larger than just a small hole for the vent bore of a few mm or less. The Select-a-Vent insert has to be large enough in a cylinder of plastic to contain the vent hole within it. Both the receiver opening and the vent insert hole should be made in the mold a sufficient distance away not to weaken the walls of the mold. But that appears to be the problem. The receiver opening was placed too close to one of the lateral walls on the mold during one of its inward bends needed to fit to the shape of my ear canal, I think. So perhaps as my audi suggested, in buffing any roughness off the cast/printed mold, I bet whatever tool was used broke through the wall of the mold. Here’s the pure supposition on my part. I presume the diaphanous very regular circular-shaped flap that came loose and got vacuumed away was just a patch glued by ReSound over the defective spot. Presumably, they could have chucked the whole mold and started again. But they’d be faced with the very same problem, how to fit both Select-A-Vent and the receiver bores into a very small mold. And if the defect has been there for the last 1.5 years, just covered over with a “tire patch,” I doubt that the mold is going to further disintegrate in any moderate amount of time. Now that the opening is exposed, I can more easily clean and disinfect it than when there was a loose flap still adhering to the broken mold wall.

The long-range view, if my suppositions are correct, is that every time I request a new left earmold be made for whatever reasons and want Select-A-Vent, I’m probably going to have to worry about the same sort of defect being made into the mold for reasons of very limited real estate to work with. So I’m going to be much more careful literally microscopically inspecting whatever comes back from the mold maker to start with.