First day trying

[jayjacque]

Ok so I finally did a couple headlights. Cut a deal with a dealer to do a couple half price so I can get some practice. Here's how it went:

I started out on the worst one. I was a little afraid to sand too much, but in the end that's exactly what I did. Badly oxidized and spotted, yellow and cloudy. Started out with 320, then 600, then 1000, then polisher. After close to an hour, got rid of the spots, got it improved but still too grey or opaque, not very clear is what I'm trying to say. So first question for you guys: Do you avoid ones that are that bad? Or just keep on sanding down? Anyway I made a royal boo boo, I wet sanded with the pads using a Metabo, ruined a few pads before I realized that doesn't work. Then the machine seemed to sand slower, so I had to do more hand sanding than I figured I would. (When I got home the sanding speed seemed to return so I'm keeping my fingers crossed, hoping I didn't screw a new tool up)

Second one went better, but when I got to the final stage of applying shine/UV restorer, there were some lines showing which bothered me, so I used the heatgun to dry and re-applied some. Then on one of the lens I even used a polisher to even out. So another question: Is that common? Do you guys re-apply and/or polish if it doesn't look even enough?

The third one I did had a yellowish grey look around the top and sides. It turned out to be part of the vehicle itself from underneath giving it that look. So I did it anyway for the experience, but if I'm right, it technically didn't need it as badly as first suspected. Again a learning experience. The last 2 vehicles took about half as long as the first did. Sander was still slow, so I did more hand sanding than I wanted to. Do you guys with a Metabo find it slows down? Or do you think it just did that because I started out wetsanding? Oh yeah I reapplied the final coat to this one too. It looked right, then I heatgun dried and some uneveness was there.

Thanks in advance for your answers. Just trying to learn.

[Wade]

Jayjacque,

The forum is a great place to ask questions and learn from fellow techs. I hope more reply to this post.

Did you use the prep and spray the lens before beginning the repair? This will remove most of the bugs/road grime and make the beginning of the process much more effective.

As for the severity of the lens, they should all be able to be refinished. The oxidation and discoloration you see is in the UV layer and not in the lens itself. Since this process strips the UV coating and applies a new one, there is no reason to treat one lens any different than another. If anything, you may have to use the 320 grit more than once.

When sanding with the Metabo I crank it up ion the highest speed and the 320 grit seems to take little effort to strip off the old coating and after 2-3 passes. At this point the lens will look pretty cloudy and you won't be able to see through the plastic. I spray the lens with water and wipe it to look for any places I might have not sanded completely. It's very important to have the lens completely sanded with one grit before moving on to the next (finer) grit of paper.

Proceed with the 600 and then 1000 grit making sure that the entire lens is sanded during each step. Use water to help you inspect the lens between each step but don't use water during the sanding process. I haven't found a need to wet sand. On some vehicles there may be a little hand sanding needed in the corners or along the edges if the sander doesn't reach. Once the lens has been completely sanded with the power tools, use the white Scotchbrite pad included with the kit and go over the entire lens for a final buff before polishing. At this point the lens will still be some what cloudy.

The Polishing process is pretty straight forward. Apply an ample amount of polish and use the polisher until the outer layer of the lens looks nice and bright. On a side note, I like to smear the polish all over the lens with the power off before I hit the on button. This has helped me reduce the amount of splatter.

Clean the lens thoroughly with the prep once polishing is complete be sure to remove any water or other liquid that may be under moldings and edges of the lens. Once everything is dry and free of contaminates I apply the UV coating.

Mix the UV coating 50/50 and swirl it of stir it to get a complete mix. Use the square edge of half a blue shop towel that has been folded 3 times, about 2" by 2" square and apply a quick, even coating and then LEAVE IT ALONE!!! I have put my finger prints and streaks in more than my share of headlights I have refinished. It's really important to just let the coating do its thing. It will even out and lay down by itself. If you would like to use a heat guy I recommend using it on a low fan speed and temperature setting.

I have never had to reapply a coating (unless I put my finger prints in it) or polish a lens once the coating had been applied. Maybe someone else on the forum could say if they have.

We have not had a problem with the Metabo slowing down. Were you applying a lot of pressure? Did you happen to bump the speed setting knob located near where the cord runs into the sander?

[GlassStarz]

Not sure what system you are using never walk away from the bad ones they are the reson you are there.
I would suggest hand sanding until you have done a few you will learn the feel of when one is sanded enough this way.
Like anything the more you do the quicker and easier it is ith the process I use I never stay on a pair more than 15 min start to finish
One of the things i dislike about some of the top coats out there is they leave ridges and you are tempted to polish them to smooth. (paint thinner on a paper towel will do the same just give it a lite wipe)
I cut my top coat about 40% with a mineral spirits based thinner

[t4k]

I have removed the polish step. My last sand grit is 3000 then I clean throughly and top coat.

[t4k]

Another thing to remember now that cool weather is here, is to warm the lens prior to coating. I worked on a set today for an Acura and I was in the shade, so I turned on the headlights on bright for a few minutes to warm the lens. They turned out great with no lines.

[jonnyques]

what system are you using?

As for WET SANDING.... ALWAYS!
WHY?
CANCER!
The lens are polycarbonate, READ the W.H.I.M.S Sheets on it. It is a carcinogenic. In its powered state you can breath it in. When wet sanded it stops the dust.

I would go with the blotches as not having sanded all the original UV protect ant off. I also finish sand with a higher grit than 1000. Ill go up to 2000. 3000 would be even better.
The time, effort and quality of the sanding steps have a direct affect on the finish product.

[DASARO]

I have done several HL's in my shed, today is my first job, or should I say 2 sets. I really wasn't looking for any to do for money, but we were sitting at a steak house talking with some friends, I was telling them about my new venture, when the guy sitting next to us over heard our conversation, when I got ready to leave he handed me his business card, he has a 04 Kia and she has a older Tarus and ask me how much, I told him I was just learning and would do them for 1/2 price. That was last Sunday, I called on Wed to see if he was serious, he said yes and today at 1pm I will do my first set. Exciting! Should be about 45 or 50 degrees.
I will let you all know how it went.

Dan

[Kgobin]

Good Luck on the headlights

Please let us know how it goes.

[DASARO]

The sun is shinning, but it looks gloomy, I'm ready to seal it and rain drops/sleet started to fall. LOL And it hasn't stop! Boy I didn't even think about something like that. Anyway the guy is going to make room in his garage tomorrow, so hopefully tomorrow I will finish my job. When I get this all going I want to be mobile, so many things to learn.

Dan

[GlassStarz]

I have repaired many in sub freezing or wet conditions I have a patio style umbrella to protect the light I turn on the headlights and after a couple minutes use a blow dryer on low to move along the process really hate working in those conditions which is why I moved here