Headlight sealant: spar urethane vs. opti coat 2.0

Kris R said:
I've also used various methods of restoration on headlights. But have you ever noticed, especially when one headlight is NEW and one is yellow, that if you look very closely to the restored headlight, even though it looks PERFECT, it still isn't as clear as the factory?


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Yeah, I don't think you can ever make a restored light loo exactly like a brand new one......but we can get em' dang close to it....lol
 
Part-timer said:
Yeah, I don't think you can ever make a restored light loo exactly like a brand new one......but we can get em' dang close to it....lol
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True. It like a factory light is a glass of bottled water where as a restored light is the same thing with a teaspoon of milk added. Lol



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Kris R said:
True. It like a factory light is a glass of bottled water where as a restored light is the same thing with a teaspoon of milk added. Lol



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I wonder if it's because the factory UV coating fails on the entire lens, meaning behind the edges. When we restore lights, we usually sand down the outer main lens, but you can't really get the sides behind the edges without taking the light out. So if the inner sides are yellow, that might reflect off the housing and make the light still seem a bit more yellow than a brand new one. Sounds confusing, but does that make any sense.
 
AND, on many Chrysler vehicles, the INSIDE of the lens deteriorates, too, though normally slower than the outside. Maybe other vehicles, too. Sad part: I've got a 1995 older Dodge Intrepid where this is happening FASTER on the inside. The outside has not needed ANY treatment yet and the car is 17 years old. It's been garaged almost all its life, that's why the outside of the headlights is still so good.
 
GP49 said:
AND, on many Chrysler vehicles, the INSIDE of the lens deteriorates, too, though normally slower than the outside. Maybe other vehicles, too. Sad part: I've got a 1995 older Dodge Intrepid where this is happening FASTER on the inside. The outside has not needed ANY treatment yet and the car is 17 years old. It's been garaged almost all its life, that's why the outside of the headlights is still so good.
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I've run across several makes and models that develop small cracks which can't be removed......but normally you can highly improve the clarity of the lens. This visually looks better, plus allows more light to shine through onto the road. Thats really what its all about. It is what it is.....and thats all you can do sometimes.
 
Kaban said:
I wonder if it's because the factory UV coating fails on the entire lens, meaning behind the edges. When we restore lights, we usually sand down the outer main lens, but you can't really get the sides behind the edges without taking the light out. So if the inner sides are yellow, that might reflect off the housing and make the light still seem a bit more yellow than a brand new one. Sounds confusing, but does that make any sense.
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How about the UV light penetrated deep into the plastic, while being absorbed more and more as it goes deeper and deeper. That makes the outside of the lens the yellowest, while getting less and less yellow the deeper you go. The lens may be yellowed to some degree all the way through, you are just sanding off the outer worst part.
 
Can someone comment on the drying time of the spar mixture. I've seen 45mins mentioned just recently, but that was in regard to applying a second coat. I'd also like to know if may of you are going to 3000grit as a final wetsand? I'm finding that 2000 grit is not fine enough unless I polish afterward.
 
Why don't you use a small paint sprayer and just spray it on?
 
How about comparing with diamondite liquid armor? Any one tried it?
 
Kris R said:
Why don't you use a small paint sprayer and just spray it on?
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This method was discussed in one of these threads and most people agreed that the extra time involved to prevent overspray exceeded the advantage of using that method.....especially when you can just wipe on the spar with a few quick swipes and your done.
 
bigdriver4u said:
Can someone comment on the drying time of the spar mixture. I've seen 45mins mentioned just recently, but that was in regard to applying a second coat. I'd also like to know if may of you are going to 3000grit as a final wetsand? I'm finding that 2000 grit is not fine enough unless I polish afterward.
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I think the drying time can vary depending on the atmosphere......temp, humidity...ect. I try to get my customers to let it dry out in the sun for at least a few hours......if they can leave it overnight in their garage or not drive it till the next day is best. Many though will pick the car up within an hour of being done. I make certain to show them the result and explain to them not to touch them or get them wet in any way till the next day....just to make them see the importance of drying/curing. Plus, if they know it will cost them for me to "redo" them...they listen. I ALWAYS take before and after pics too.....for those potential disgruntled ones.
 
bigdriver4u said:
Can someone comment on the drying time of the spar mixture. I've seen 45mins mentioned just recently, but that was in regard to applying a second coat. I'd also like to know if may of you are going to 3000grit as a final wetsand? I'm finding that 2000 grit is not fine enough unless I polish afterward.
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I, for one, do use a 3M Trizact foam 3" disc 3000 grit for my final sand before spar.
 
Awesome thread!!! I'm looking forward to a difference in OC vs valspar to see if it mixing this stuff is worth it to me! This is cool! Thanks to Matt for the link :)
 
I found this thread about last fall, and with i made my headlights brand new. Thank you for that.

Unfortunately since then I have applied a second coat of the spar urethane because it was getting cloudy and "spotty". And now it is in need of a 3rd coat. I can't tell if I did something wrong with the mixture I applied for it not to last as long. I use the same "Minwax Indooor/Outdoor Clear Gloss Spar Urethane" called for in this thread, and believe i mixed it at 1:1 urethane/spirits... maybe 1:2 at worst.

Would the slight different in mixture be my problem? I love the results but I was hoping that it would require less maintenance. I live in Baltimore and there was zero snow this winter and no great fluctuations in weather to account for this. That said I do park outside, maybe the sun made it degrade quicker?
 
If you actually applied 1:2, yes it makes a difference. 1:1 is 50% urethane, 1:2 is only 33% urethane.
 
i'm fairly certain it was exactly the ratio that was called for, ie 1:1

Would using more urethane/thicker coat help extend it?
 
IceWilly said:
i'm fairly certain it was exactly the ratio that was called for, ie 1:1

Would using more urethane/thicker coat help extend it?
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I'm guessing that it would. I've gone to a 60/40 mix myself......although I have noticed that some Makes/Models don't seem to last as long as others, no matter what kind of coating you put on. The Chrysler PT Cruiser is one.....seems like you see a ton of those headlights are bad also. The older (squared looking) Ford Focus is another, Chevy trucks go bad quickly. Kia's and Hyuandia's seem to go bad quickly too. Lots of Chrysler products. I feel that the quicker they go bad from the factory new....the more often they will need to be "redone". (just my opinion)

Some just don't last as long as others.
 
kimtt said:
How about comparing with diamondite liquid armor? Any one tried it?
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was wondering that myself.

i'm actually thinking about pulling the lamps and clear coating them the longer lasting way.

chris<pixelmonkey>:D
 
Can anyone give me as many details as possible about Minwax Spar Urethane (what is it made from maybe, some pdf explaining content)?
I am still looking for an equivalent in Europe/product that will give the same results without damaging plastic lens.

Maybe some pictures around the can will do.

Thanks in advance
 
Part-timer said:
I think the drying time can vary depending on the atmosphere......temp, humidity...ect. I try to get my customers to let it dry out in the sun for at least a few hours......if they can leave it overnight in their garage or not drive it till the next day is best. Many though will pick the car up within an hour of being done. I make certain to show them the result and explain to them not to touch them or get them wet in any way till the next day....just to make them see the importance of drying/curing. Plus, if they know it will cost them for me to "redo" them...they listen. I ALWAYS take before and after pics too.....for those potential disgruntled ones.
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Polyurethane dries by evaporation of the mineral spirits solvent and oxygen adsorption of the urethane. It will vary with temperature and humidity. You can speed it up by applying mild heat with a heat gun. Hair dryer may also work, but with either one keep the temp. low.

I don't use the spar varnish material, but regardless of what sealer I'm using, I always finish off the headlight with 3000 grit abrasive to give the coating something to hold onto. Also, regardless of the type of coating you use, always scrub the surface with propanol or other alcohol, but don't use rubbing alcohol because it will contain some water. Wax and water are your enemy when using polyurethane.

ray6
 
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