attaching turn signal lens

[Previologist]

I found a good turn signal housing in my pile of parts, but the lens fell off. Whats the best thing to use to adhere it again? I have plastic epoxy but I wonder if something more flexible would be better. The internet has all sorts of sketchy sounding answers

[man_btc]

The internet has all sorts of sketchy sounding answers

Here's yet another one! Did you see references to 'butyl tape?" my understanding is that there are "channels" (like those for some gaskets) into which fits the gummy-ish tape, then the entire assembly is heated to soften and really gummify it, after which the lens is firmly seated to the housing. When the whole thing cools you have a firm but flexible seal. I would imagine that's the "proper" way to do it which involves a lot of time, patience and a heated enclosure that is not-your-oven. In any case I would definitely not use anything that dries "hard."

[Previologist]

No I didn't see any reference to butyl tape, not since I used butyl-backed tape on the joists of my balcony last year. But it looks like a winner, they actually make "butyl headlight tape." Who knew? I mean other than you and probably a million other people who never told me.

[man_btc]

Maybe everybody else knew about it but I didn't until I started web-searching; it wasn't that I wanted to look like I knew something, more like I always wondered myself what exactly that black sticky crap was. Unfortunately, like a lot of things, it looks like a PITA to do correctly as a DIY'er one-off.

[Previologist]

Having one apart, it looks like they used a hard glue (its hard 27 years later anyway, but also clear-yellow like most hard adhesives), and there's a rubbery weather strip around the edges.

I decided to see what I could do with the several I have with broken tabs, since they are kind useless if I don't use them. I drilled a hole at the base of the broken tabs on 2 of them, and used the hole to wire tie it where the screw would go. That's all hidden under the hood. We'll see how long they stay put. For now anyway, I have full lighting. All that's missing now is the soft bumper and cheesy styrofoam shock absorber.

I started wondering why signal lenses don't yellow. I thought the consensus reason the headlights yellow was the sun, but now I wonder if its the headlights themselves that turn the lenses yellow.

[man_btc]

Looking for an excuse not to have to start working on replacing the rusted-out rear cross-member on my '98 Camry, I did a little more research (I have a Master's degree in procrastication). If it was me, and I had to make a decision now, I would use a urethane adhesive, which appears to be the modern-day successor to butyl and the same as what gets used on windshields.

For instance

3M Auto Glass Urethane Windshield Adhesive, 08693, Medium Viscosity, High-Strength, Fast-Curing, 310 mL/10.5 fl oz Cartridge , Black

[man_btc]

Also, if you at one point want to make/reconstruct the tabs for those parts, I love JBWeld Plastic Bonder. Following front-corner "episode," I had to make new tabs for much of my front bumper cover with #50133 (tan) before I discovered the black #50139. I roughed up the existing plastic, taped on a backing" of aluminum foil, then applied a "sandwich filling" of the adhesive to cover the tab area, sandwiched by another piece of aluminum foil (and maybe some cardboard backing - don't remember). After it dried, resurfaced/reshaped the "tabs" with a grinder and drilled new holes.

Helpful hints
- make a paper or cardboard template as to where those tab holes need to be beforehand (learned the hard way).
- Only grind off what you need to make things fit - it's all hidden anyway as you noted.
- Use a backing when you drill so you don't stress the plastic.

Some pics from my years' old repair...

Bumpercoverground.jpguseabacking.jpgfoil grinds off.jpg

[Previologist]

I thought about that, I have some plastic epoxies but figured it would just break off. I'm also considering it to repair my old cover if I can't use the bumper cover from my 93, but so far I see no reason that i can't.

[13ozLatte]

In the past, I've installed headlight rings on cars for people. I actually would heat the whole headlight assembly in my oven, at super low temp, to soften all the plastic and adhesives. Then I could seperate the lens to put in the rings.

Afterward, I heat up the assembly again, put a windshield adhesive in the channel of the housing, and pressed the lens cover back on. Heating it up allows the tabs to flex without breaking. You could probably also use a heat gun, but I found the oven worked very well without overheating any part.

On the Previa corner lights, I don't think there's any tabs, which is probably why the lenses fall off. So I'd probably try just using urethane windshield adhesive, since it's flexible and strong. But no need to head it up.

Actually I have two corner lights with lenses off in my parts, maybe I'll try it out on one of mine and see how it turns out!

[man_btc]

Just to be clear, My last post was about the tabs that mount the entire assembly to the van, not what attaches the acrylic lens to the ABS housing with the bulb in it. As far as epoxies go, you want to make sure the one you use says it's appropriate for ABS - many are not, even though they will adhere to other types of plastics. And to get further detailed - if you do use the JB weld stuff I mentioned, let it sit and dry for a long time; I found only waiting as long as the package directs means you have something that's still kind of gummy and not hard enough.

[Previologist]

The tabs are so flimsy I'm not confident they can be repaired or reproduced unless a person made them much more robust, and then they might not fit. On the left is a somewhat "good" tab, on the right is a typically broken one. The ones i drilled and installed were broken off even more, I drilled very near the base of the tab and partway through (but not entering) the housing.

Anyway, so far so good. I went over some RR tracks today and I didn't hear anything fall off.



KIMG0651.jpg

[Previologist]

In the past, I've installed headlight rings on cars for people. I actually would heat the whole headlight assembly in my oven, at super low temp, to soften all the plastic and adhesives. Then I could seperate the lens to put in the rings.

Afterward, I heat up the assembly again, put a windshield adhesive in the channel of the housing, and pressed the lens cover back on. Heating it up allows the tabs to flex without breaking. You could probably also use a heat gun, but I found the oven worked very well without overheating any part.

On the Previa corner lights, I don't think there's any tabs, which is probably why the lenses fall off. So I'd probably try just using urethane windshield adhesive, since it's flexible and strong. But no need to head it up.

Actually I have two corner lights with lenses off in my parts, maybe I'll try it out on one of mine and see how it turns out!

Did you? I ended up fabricating a tab on my intact one and installing it. But ironically, the day after I installed my strut, it vanished. It was the least sturdy part of my front end repair, so it wasn't entirely surprising. It never quite fit perfectly. I almost wonder if it was stolen though, because the short subharness went with it.

Anyway I drove 2 hours to get a used one today, and the lens popped off when it was being removed, but I made certain the screw tab was intact. So I will be finding out shortly how the windshield urethane works.

[Previologist]

The day after I bought the new used housing, I ran into a pair of people replacing a windshield for someone. They had the urethane gun out and were going at it! But I had taken my housing out of the van the night before. Dohhh! I probably could have had it done for free. Next day I went to an autoglass place but they didn't have any open tubes around, and the cheapest I could find was nearly 25 bucks. So I said screw it and just used the cheapest plastic bonding epoxy I could find. And I discovered why I had such a hard time fitting the one I lost, and went about fixing them. I just had to bend the fender a bit and the piece that screw screws into. I think its pretty solid now.

I also noticed that my fabricated tab from the old housing was still attached by the screw. On close examination I could tell that the stub of old tab that it was attached to is what broke off, not the fabricated part. So thumbs up for JB Plastic Weld, I guess.