Dome Light Repair

[Captain Obvious]

3 hours ago, heyitsrama said:

@Captain ObviousIt looks like the LED you went with is back in stock

Thread:

Similar part # but described as 38mm.

https://www.superbrightleds.com/moreinfo/festoon/3710-led-bulb-6-smd-led-festoon-38mm-car/2160/5267/

Any chance we can get those pictures that rotted off photobucket?

Yeah, it was a little bit of work to get the larger 6-LED bulb in there, but I really like the way it turned out. Great brightness, and warm white, so no blueish harsh stuff going on. If you didn't know better, you would assume it's an incandescent.

As for the old dead photobucket sucks pics... I think I can post them here.

Here's some pics showing what I had to do to the mounting clips to get the bulb to fit. I used a carbide burr on a dremel. Don't get tiny brass slivers stuck in your fingers (or eyes):

And even though you can't tell much because there's nothing else to compare it to, here's the obligatory "ON" pic:

And again, if you don't want to deal with grinding off a little of the brass fingers to fit the 6 LED festoon in there, you can get a 4 emitter version instead. And since they keep making LEDs brighter and brighter, I wouldn't be surprised to learn that todays 4 LED bulbs are as bright as the 6 LED bulbs from 7 years ago when I did this mod.

[Captain Obvious]

3 hours ago, heyitsrama said:

Did you change the map light as well? figure might as well fix it all once.

I did the map light as well. I think I posted some details about that somewhere... But if I did, the pics are probably dead on that too.

Here's what I used and I think it's fantastic!

I'm not sure all years used the wedge base though.

Edited March 3, 2021 by Captain Obvious

[heyitsrama]

14 minutes ago, Captain Obvious said:

I did the map light as well. I think I posted some details about that somewhere... But if I did, the pics are probably dead on that too.

Here's what I used and I think it's fantastic!

I'm not sure all years used the wedge base though.

My 74 has the same style IIRC. I should double check, is this also a "warm" LED? Have a part #? 😬

[Captain Obvious]

Yes, it's warm white, and I love it.

As for a P/N, give me a little bit and let me see what I can dig up...

[Captain Obvious]

I dug out my order info for the map light. I got that map light from superbright as well.

The part I ordered (five years ago) was WLED-WWHP15-TAC

But it appears they have changed the numbers and that part is now listed as 921-WWHP15-TAC

https://www.superbrightleds.com/moreinfo/miniature-and-subminiature-bulbs/921-led-landscape-light-bulb-15-smd-led-tower-miniature-wedge-retrofit-100-lumens/2508/

There are different tabs for the different "colors" I like warm white (because I'm old).

[heyitsrama]

@Captain Obvious thx for that I’ll order them, I prefer the dirty JDM yellow lights. I switched all the exterior lights to LED except the license plates because the cool white looks out of place.

Trying to de-yellow the plastic, I cleaned it off with some purple power and a toothbrush to remove the grime. The solution is hydrogen peroxide, and the UV light is one that I used to locate AC leaks. I threw on a rechargeable lithium battery so I can leave it on for several hours. Shall see in the morning. Hopefully it’s still there. 

[Captain Obvious]

I sent out a batch of parts to be plated late last year. As part of the prep of those parts, I did a citric acid soak to dissolve (chelate) rust and strip off the original chromate and zinc. Some of the parts I soaked (like throttle linkage and ash-tray slidey bracket) had plastic bits on them that had yellowed. After the citric acid soak, they looked great.

So if your peroxide doesn't do what you wanted, you might want to try citric acid. Do be aware, however, that the citric acid will eat the yellow chromate and zinc plate off the metal stuff (which is why I was using it). But the point is, if you want to preserve the original zinc/yellow, you can't do the citric.

[heyitsrama]

So far it looks pretty good, I let it sit all day in the sun to use the free UV radiation.

Put it back outside for the rest of the day, I’m pretty happy with the results.

Edited March 5, 2021 by heyitsrama

[Captain Obvious]

Yeah, that looks good. I would probably stop there.

So this peroxide and UV combination thing... Is this internets science? Most times UV makes plastic worse, not better. Not arguing with the results, but wondering if the UV was really adding any value?

[heyitsrama]

4 hours ago, Captain Obvious said:

Yeah, that looks good. I would probably stop there.

So this peroxide and UV combination thing... Is this internets science? Most times UV makes plastic worse, not better. Not arguing with the results, but wondering if the UV was really adding any value?

To be honest @Captain Obvious i have no idea how it works, some people say its the UV that is catalyzing the peroxide.

https://www.quora.com/What-is-happening-in-terms-of-a-chemical-process-when-hydrogen-peroxide-is-used-to-restore-discoloured-Lego

Others say its the bromine in the plastic that is being broken out of the plastic. https://hackaday.com/2017/11/03/yellowing-the-plastic-equivalent-of-a-sunburn/

 

I would agree that UV light is damaging for prolonged exposure (paints, truckers arms, etc.) in fact the reason why I only have one white lens is that the other one disintegrated from exposure to the elements, my car was in the California sun for ~15 years before I started working on it, the paints messed up on the drivers side from the exposure.

Last night i turned off the flashlight because i did not want to over-discharge the lithium cell by leaving it on the whole night. I noticed that in the morning the plastic was a bit de-yellowed, but not like it was out in the sun. I also noticed that after leaving it in the sun, there would be loads of bubbles around the lens while it was in the peroxide.

 

I think the UV might just be expediting the process, it looks like UV-A light can be used as a catalyst for to breakdown H2O4 -> 2[H20] + O2, and the O2 is what provides the cleaning power for us.http://newfrontchem.iqstorm.ro/upload/10-NFC-23-2_Cataldo.pdf

I'm not sure how/why oxygen cleans so effectively.

[Captain Obvious]

So internets science for the win! Whatever the underlying process, that lens looks good. Just hope there isn't any unwanted long-term effects.

On a related note since I know you like to mess with things like this... Have you ever played with taking silicone molds from parts and copying them? That light lens might be an interesting candidate.

[heyitsrama]

Actually I have not, mold making looks like an interesting process, do you have any recommendations for reading material?

I wanted to start poking around working with fiberglass after I shattered half my BRE air dam hitting a pipe on the highway. 

there’s a load of stuff that I need to do this year, I need to get this damn cb500 running and possibly sold, start working on the white Z that I have (might be a can of worms). So much time, these little repairs I’m doing on the Z because I can’t get the damn bike to hold idle, the carbs are being super finicky. 
I’ll have to add learn composite materials and molds to that list.

Edited March 5, 2021 by heyitsrama