Headlight Restoration-new UV sealant idea

[Cougarstang]

Looks fantastic. I did a set about 6 months ago too, and they're holding up as well as your sister's

[emaxxman]

The diluted spar-urethane mixture is basically a diy version of a wipe-on poly. Furniture makers, instead of buying expensive pre-made wipe on polyurethanes, will make their own by diluting it.

Polyurethanes (a type of varnish) are extremely strong but not very flexible. Flexibility is something you need for any outdoor finish product since wood (the intended use for spar-urethanes) will absorb/release moisture and swell and shrink as well.

Spar-urethanes were created to provide the protective ability of polyurethanes/varnishes and the flexibility needed. I'm willing to bet the urethane sealant will last at least a year ... they've protected wood on boats year round.

What I would concerned with is the urethane yellowing. While they have some UV inhibitors, varnishes in general are very susceptible to yellowing from the sun.

[sparkie]

Longevity test- On going, 6 months after restoration

Here are some more recent pics of the headlight restoration I did about 6 months ago. Anyhow, the lighting sucks, so the pics are not the best. But, the headlights are still holding up with the spar urethane sealer. I live in Kansas, so we have a lot of temperature/weather changes, so in different climates the urethane may react differently. I will continue to update every three months if there is any interest.

Don't forget to keep us updated......

[HotRod]

What I would concerned with is the urethane yellowing. While they have some UV inhibitors, varnishes in general are very susceptible to yellowing from the sun.

I have no doubt that the urethane will fail. The question is, when will it fail? Every type of coating, whether it be wax, paint sealer, clear coat or the spar urethane will fail and the plastic light turn yellow and cloudy. Then it will have to be restored again or replaced.

On other forums, there have been discussions on this exact method. And many say it will never work because it was not made for plastic. Or that it will turn yellow or streak. Also they have said it cannot be removed from the light once its been cured.

My responses are:
Well, for a product that was not made for wood, it works pretty darn good so far. Maybe the Helmanns company needs to make a product for plastic lights. Then there would be no "controversey".

All lights, with any UV clear coat or sealer will fail, nothing lasts forever. If you got the money, buy new lights and maintain them regularly, and you may never have the "headlight failure" problems.

Also, this spar urethane can be removed after fully cured. I have tried it my self, it wet sands off fairly easily, then reapply the urethane and its as good as new.

This uv sealer has already outlasted the Klasse method I was using before.

Will the urethane last forever? NO

Will the urethane fail? YES

Will the urethane turn yellow? Probably, just as clear coat or any other coating you apply to the lights will fail and turn yellow.

As far as I know, I am one of the few doing this longevity test for the spar urethane, but I was informed that it has lasted as much as 2 years in the South. I would be happy with a year atleast.
Also, there is only one coat of the urethane when doing lights. When you apply it to wood, its layered and sanded in between coats.(according to the directions on the can) Also, its not mixed with mineral spirits when applied to wood like when you apply it to lights.(maybe I am wrong) So I dont know if the mineral spirits will take away any of the UV strength capability.
But, what I do know is it lasts for 6 months. I will continue with the longevity tests every 3 months.

[A4 1.8tqm]

Thanks for keeping us updated. I've been following this thread and may try this method on my headlights soon.

[02nissanISR]

Hey HotRod still starting trouble with this uv sealant i see. Well i for one am a believer. why you may ask.... simple because i tried it. i did my wife's 94 corolla august 31 and i did my 2002 maxima on october 21 and they both still look great. i can post pics another day to dark out now.

I think what we need to remember is that this is not the end all cure all of uv headlight protection. the factory protection doesn't last forever if it did we wouldn't be having this discussion.

The point is in my limited experience this outlasts a lot of other stuff out there. And the whole idea behind it was to find something that lasts longer than a few months. By now, without this uv sealant, i would have to restore my headlights again.

Look at this way a lot of people swear by the boars hair brush, then there are those who tried it and don't like them, then there are those who say ill never touch my paint with a brush they have what is called a preconceived idea. the idea that brushes are not made for paint. without having tried it they dismiss it and at times convince others to do the same. so i would say this, before you dismiss it, before you convince someone else not to try it........ Try It. Let the results speak for themselves. Obviously others have tried it and had success.

happy detailing everyone

[emaxxman]

I have no doubt that the urethane will fail. The question is, when will it fail? Every type of coating, whether it be wax, paint sealer, clear coat or the spar urethane will fail and the plastic light turn yellow and cloudy. Then it will have to be restored again or replaced.

On other forums, there have been discussions on this exact method. And many say it will never work because it was not made for plastic. Or that it will turn yellow or streak. Also they have said it cannot be removed from the light once its been cured.

My responses are:
Well, for a product that was not made for wood, it works pretty darn good so far. Maybe the Helmanns company needs to make a product for plastic lights. Then there would be no "controversey".

All lights, with any UV clear coat or sealer will fail, nothing lasts forever. If you got the money, buy new lights and maintain them regularly, and you may never have the "headlight failure" problems.

Also, this spar urethane can be removed after fully cured. I have tried it my self, it wet sands off fairly easily, then reapply the urethane and its as good as new.

This uv sealer has already outlasted the Klasse method I was using before.

Will the urethane last forever? NO

Will the urethane fail? YES

Will the urethane turn yellow? Probably, just as clear coat or any other coating you apply to the lights will fail and turn yellow.

As far as I know, I am one of the few doing this longevity test for the spar urethane, but I was informed that it has lasted as much as 2 years in the South. I would be happy with a year atleast.
Also, there is only one coat of the urethane when doing lights. When you apply it to wood, its layered and sanded in between coats.(according to the directions on the can) Also, its not mixed with mineral spirits when applied to wood like when you apply it to lights.(maybe I am wrong) So I dont know if the mineral spirits will take away any of the UV strength capability.
But, what I do know is it lasts for 6 months. I will continue with the longevity tests every 3 months.

The mineral spirits shouldn't affect the characteristics of the urethane. The spirits act as a dispersion liquid but the resins are still intact. The mineral spirits and the oil in the urethane will evaporate as it cures. What's left behind is a very strong cross linked molecular structure (the reason for why polyurethanes and other varnishes are so strong).

The cross linked structure is also the reason that the urethane has to be sanded off. Once cured, it can't be dissolved by chemical means (at least any chemical that you would want to use). There are other clear finishes that can be simply applied over previous coats. I want to say shellac is one but I not 100% sure right now. These finishes melt into the previous layer. Urethanes need to lightly sanded to give some "tooth" for the next layer to adhere to (similar to paint primer).

To be honest, I'm surprised that the urethane itself didn't add a yellow tint. It is dispersed in oil and that lends an amber tint to it.

With all of that said, the lights do look good and if it works out, then more power to you.

[mfortier]

Emax,

You raise a good point. I have used spar urethane on many outdoor applications - wood planters, plastic planters, metal yard pieces, etc., and it has always yellowed with UV exposure. Regular polyurethanes (I guess "non-spar") are only intended for indoor use. Anyway, because of the severe yellowing issue I moved to clear, gloss laquers - which hold up only moderately well for outdoor "protection" (but they don't yellow) and this summer I will be trying some spray clearcoat for those "garden" applications.

Anyway, I suspect that the mineral spirits do "something" to the spar urethane that prevents the typical yellowing. Could not do the chemical analysis on this but spar urethane NOT yellowing (over a month or two) is really something in my experience. Most spar urethane products say right on the can "this product will yellow with age" or words to that effect. It must be an auto geek "miracle" for headlights.

Regards,

Martin

[sparkie]

I'm thinking about trying this on a Infiniti G35. I have polishes out these headlight I know 4 or 5 times over the years.

[WindyCity]

As far as I know, I am one of the few doing this longevity test for the spar urethane, but I was informed that it has lasted as much as 2 years in the South. I would be happy with a year atleast.
Also, there is only one coat of the urethane when doing lights. When you apply it to wood, its layered and sanded in between coats.(according to the directions on the can) Also, its not mixed with mineral spirits when applied to wood like when you apply it to lights.(maybe I am wrong) So I dont know if the mineral spirits will take away any of the UV strength capability.
But, what I do know is it lasts for 6 months. I will continue with the longevity tests every 3 months.

Hey hotrod i am doing a test on my beater railroad car as well. I was supposed to post pictures a while back but i never got around to it and i agree with you as well this method had worked much better than all of the other restorations i have used in the past. I like that it will last at least a year because when i sell it to customers i know they are not going to wax their headlights and they will start to yellow in 6 months which looks bad for me since i charge 50 bucks for the service.