I am reluctant to admit what kinds of stuff I’ve used in the past for motor hook retention — when not using the supplied retainer sleeve, if any, on kit rockets. Let’s just say I haven’t been entirely happy about using… what I’ve used.
So thanks, then, to Gary Minton and Chris Michielssen. Chris quotes Gary:
I’m a retired electro-mechanical engineer. I’ve used all kinds of tapes, adhesives and insulating materials.
You might want to reconsider your use of (plastic) electrical tape on engine holders. It’s [sic] adhesive allows creep and softens up under high heat. The tape also stretches. It’s designed this way to allow it to conform to irregular surfaces and allow for future removal when changing electrical connections – not a good match for engine holders.
As you know, masking tape ages badly, gets brittle, loosens and tears. Not a good match either.
Earlier, I used masking tape but I sealed the edges with white glue. This helped a little.
Instead, give Kapton tape a try. It’s what I use. It is high heat, has no creep and doesn’t stretch. It’s expensive, but at just a few inches per rocket, it doesn’t cost much in that sense. Just goggle [sic] Kapton tape for sources. Let me know what you think.
Well, that looked to me like a good idea. And I found some not so expensive Kapton tape on eBay. Even checking North America only — the really cheap stuff labeled “KOPTAN” from China may be perfectly good, but who knows — I found for instance 20 mm x 100 ft (love the mixed units) at $5.49 shipped. That’s what I ordered. I think the stuff is 1 mil thick, but the listing doesn’t make it very clear and I haven’t measured it yet. Haven’t done anything at all with it yet, in fact, other than I looked at it and said, “okay, got tape”. And took a picture. It probably won’t be needed for the next two rockets I plan to start, but maybe the one after those.