Accent lighting adhesive failed

geoB

Just getting trailer ready for a new trip when I saw this:

The adhesive failed. But I don't know what to use to repair. Gorilla Glue works but is nasty. For now I'm holding it in place with egg carton (retrieved from today's recycle pickup.)

But I don't expect this to hold when on the road.

Suggestions? & Thanks!

manyman297

Mine is doing the same thing. I was thinking of just using some 3M VHB tape.

geoB

Looks like the best way. The fixture is wider than 1/2", so the 1/2" tape version should do the trick.

I suspect that hot weather was the primary cause. If the fixture falls again, retaping is feasible (assuming that pulling the old tape does not leave too much behind.)

manyman297

The nice thing about VHB tape is it holds up under high temps and can be removed if needed. If you go the Gorilla glue route get the clear version. It doesn't foam up and make a mess.

geoB

I'm leaning toward the tape. Tricky part will be prepping the surfaces. Have you tried anything yet?

manyman297

I haven't yet. I originally was going to just use tape but as we go back and forth I'm starting to lean towards gorilla glue. The track the lights are in should be a permanent fixture in the cabinets so gluing it in seems to be the most logical...but tape would be a lot faster and easier. The problem with VHB tape is it's thick and that could make that section of track more exposed....that's more a perfectionist thing but something to think about.

geoB

The tape is less than 1/16" thick, which isn't much of an exposure. But wrangling double-sided tape is always a challenge. You may be right about Gorilla glue, though. I'm just not sure about aluminum to wood - mostly for prepping.

How troublesome is it to pull the  microwave and disconnect the fixture? That would surely make prepping easier.

Horigan

Removing the microwave is very easy, just four screws visible on the front.

geoB

Good to know about the microwave. Did you happen to notice whether the lighting fixture was hard-wired or easily disconnected (and then could be reconnected)?

manyman297

The metal-to-wood issue is the exact reason to use Gorilla glue. It's meant for these types of dissimilar material connections. I made some wood caps to put over our existing stair railings in our house. Normally you'd attach them with hardware but the way our railings were created didn't allow for that. So I ended up using Gorilla glue and it worked extremely well....maybe too well. I don't see that wood cap ever coming off unless I physically destroyed the wood cap.

geoB

On prepping the surfaces: at least in my case, it appears that the adhesive used was a clear silicone rubber cement. A 1/2" chisel carefully used can scrape off most of the remnants on the fixture. Not quite so easy at either end. Getting the adhesive off the wood trough is no where near the fun. I've tried using a 1" chisel to scrape at 90 degrees. A lot of the adhesive on the near side is not reachable.

RobS

A thin coating of contact adhesive will work better than polyurethane glue and be a lot less messy.

Marceline

I think the 3M VHB would be preferable to any kind of glue because electrical fixtures do fail sometimes and if you ever need to replace it, it will be a lot easier to remove if taped in. I’m just fundamentally opposed to gluing anything that might need to come back out again someday. 

I don’t know exactly what this light fixture looks like, but there are also clips that are made for aluminum channel LED lighting. You screw the clips into the cabinet and then pop the aluminum channel into the clip. 

RobS

Well, the aluminum channel LED lighting in my 2022 320 appears to be attached by some kind of contact adhesive, perhaps 3M Fastbond.  3M VHB will also add a very visible gap between the light fixture and cabinet.

geoB

@RobS : if your 320S is similar to my 400, then the cross-section of the fixture mounting would be something like this:

If so, the fixture fits into a trough which is much deeper than the 0.045" of VHB tape.

@Marceline : You've made up my mind - tape it will be. Replacement is virtually always an issue.

geoB

Finally got the fixture installed. Hope the tape holds! But for my 400, the fixture and tape remains invisible to the casual observer.

geoB

Turns out that the adhesive on the VHB tape cannot stand up to the heat. The trailer was in storage until the temps got into the high 70s here in Reno. It was surely much hotter than that inside.

I was able to push the lighting fixture back into place and the adhesive held. So now I'm working on a method to hold the fixture in place while it's in storage.

geoB

Here's a photo of what I'm using now to hold the fixture in place while the trailer's in storage. There are three of these - a 3/4" 10-32 coupling nut & 1" 10-32 socket head bolt. Scotch tape is on each end to prevent scratching surfaces. Relatively easy to install.