Headlight restoration 50/50.

[mikeCL]

The stuff I get comes in 30oz bottles at Home Depot or Walmart for like 8 bucks......does 30oz last you 3 years or don't they carry the 30oz bottle where you are?

I just came from Home depot this morning and I went to check and the can 1 qt. was like $6 something I saw no other sizes.

[Part-timer]

I just came from Home depot this morning and I went to check and the can 1 qt. was like $6 something I saw no other sizes.

Yeah, it seems that they package things differently in different parts of the country. Here in Daytona Beach, Florida they sell a 30oz plastic bottle of Kleen Strip Odorless Mineral Spirits. I can't remember the price. I was thinking it was like seven something...?

[mikeCL]

Good thing the helsman is on sale at home depot I think It was $12.98 instead of $15

Forgot to get a mixing cup however I skipped the 180 grit sandpaper because the headlights are not in that bad of a shape.

[roswell630]

Good to see this thread still going. Checked back in to get some final pointers. I just picked up some supplies to do mine this weekend... Hope it turns out! You all have some great info. Thanks!

[jbsilver]

So i decided to restore this headlight i found in the trash can. someone decided to buy a new headlight and decided to throw this one out thinking it had no hope. since ive had a few new ideas on how to restore headlights i thought this would be the perfect candidate for the job. now here is the thing that is going to surprise most of you all. I did absolutely NO POLISHING on this headlight at all. Yes you read that right, NO POLISHING. i didnt whip out no compound, no pads, no buffer. All i used was Sandpaper and helmans spar urethane and mineral spirits. that is all i used.

process:
wet sand with 800 grit.
wet sand with 1000 grit.
wet sand with 1500 grit.
wet sand with 2000 grit.
wet sand with 3000 grit.
wipe the lense with mineral spirts to clean the sanding residue.
wipe the urethane at 1:1 with mineral spirits.

i wasent expecting it to look all that great since i was just testing to see how this looked but the results left me far more than amazed. ill let the pictures do the speaking now:











My thoughts:
Personally i think this is a very good alternative of doing this. In the thread where hotrod introduced this idea he updated everyone with the headlights he did. BUT he did compound and polish out the headlights first....THEN applied the urethane mixture. If i correctly remember he updated up to two years and it still looked awesome. Now here is my take on why i think this is a whole lot better idea than polishing and then wiping the urethane mixture. Take this for an example, when a painter is going to paint your car he doesn't buff out the car first to a perfect shine AND then sprays over it right? no. he first sands the paint and then paints and clears on top of it. That same method applies here. Having sanded the headlight up to 3000 grit there were still sanding scratches. super fine microscopic left from 3000 grit. SO when i wiped the urethane mixture, its laying on top of these scratches and "biting" or "holding on". see how this is similar to the example of painting a car? Its the same when i just need to clear a hood for instance. i dont spray clear over a nice shiny buffed hood. I first sand it with 1000 grit and then spray the clear, this way the clear has something to "hold on" to. This is why i think this method is better. its just like prepping a car for paint or clear, you sand it in order for the paint or clear to grab on well. same here, i applied the urethane mixture on top of the sanded headlight so i believe it will hold on alot better. now most of you are probably thinking that if there are any scratches visible. the answer is no. i spent quite a good time on 1000grit removing all the 800 grit scratches. i spent a good amount of time on each finishing grit to achieve a perfect finish.

any thoughts and comments are more than welcome!

[ray6]

Nice job. You're absolutely right. Polyurethane easily fills in 3000 grit scratches. I believe any refining past this point is counter productive because you want a rough surface for the poly to stick.

ray6

[ray6]

one other thing can I use acetone instead of mineral spirits? I hate to buy extra of something when I have like a full can of acetone

Acetone will dissolve the polycarbonate. Wouldn't recommend it.

I use pure alcohol because it dries quickly and adsorbs any water.
ray6

[ray6]

Does anyone feel like maybe the different car makes/models may have different variations of hardness/softness to their headlamp lens composite materials? It sure seems like some are harder or easier than others to remove sanding marks/swirls. Anyone?

There's not too much difference in the polycarbonate itself, except for extreme curves or thickness the mix might be slightly different.

The main differences you will see are due to:

The protective coating formulas, primer vs. no primer, how it's applied (dipped, sprayed, electrostatic etc.,) how it's cured (heat vs. UV), number of coats, etc. All manufacturers apply at least the minimum to pass ANSI tests, but some apply additional material for wearability and abrasion resistance (like Jeep, so bushes don't scratch the headlight).

UV protection is limited because you can only add so much UV absorption material to the carrier. Additional material will not cross-link. This is why some headlights have tough coatings but they are still yellow or cloudy.

The last variable is UV exposure: where you live, where you park, and the shape of the headlight. PT cruisers will always fail sooner than others because the lamp surface is almost horizontal so it gets maximum exposure during the day. Another car parked right next to it (like an older Chevy pickup) with vertical headlights will last much longer because UV exposure is far less.

ray6

[ray6]

Hi to all!
Wonder if using a hair dryer speeds up the drying time of the urethane application.

Jb silver

It will but you must be careful to use low heat. Air flow will do most of the work by evaporating the slovents. Turning on the headlights will also help.

ray6

[ray6]

The stuff I get comes in 30oz bottles at Home Depot or Walmart for like 8 bucks......does 30oz last you 3 years or don't they carry the 30oz bottle where you are?

If you're going to use mineral spirits, be aware that there are 2 flavors; mineral spirits (paint thinner) and oderless mineral spirits. The difference between the 2 is that odorles mineral spirits are distilled multiple times to remove odor causing solvents so it is much purer than regular MS or paint thinner. It may not matter, but when you're restoring headlights for profit and giving a 2 year guarantee, you don't want to take any chances since the difference in cost would be pennies per headlight. We no longer use MS for cleaning, we use alcohol which attracts moisture and dries in seconds.

ray6