Hello all, and thanks for checking out my instructable!

I work in construction and remodeling, and try as I might, I can only keep my safety glasses scratch-free for about two weeks; a construction site is no place to expect to keep things clean and undamaged.

For basic protection, you can buy safety glasses in bulk for less than a dollar each. But I've got two qualms with this: first, it doesn't sit well with me to skimp on eye protection, and second, I prefer not to purchase items that aren't meant to last.

A sturdy pair that can protect against a flying, broken grinding wheel, or errant powder-actuated nails usually cost around $10. That may not sound like much, but if I replaced them somewhat regularly, that would cost over $200 a year - which I would much rather spend on new toys, coffee, and doughnuts.

To remedy this, I've come up with a way to refinish a pair of scratched safety glasses. This technique might even make it more feasible to buy a very nice pair, since I know I'll be able to restore them.

As a side note, this doesn't return the glasses to pristine condition, but it makes them usable again which is what I'm looking for. I'm sure that if you used a power tool to sand and buff, you would get even better results!

Supplies

I used a headlight restoration kit that I had lying around (Rain-X brand), a clean cloth, and a handful of sandpaper strips.

What you'll need:

A polishing lubricant (you could use water, if you needed to)

A headlight restorer (an abrasive paste of any kind)

A sealant (a sealant for resins or plastics, I imagine you could use epoxy if you were confident with it, and used a heat gun to eliminate bubbles)

Polishing pads (I used the three that came with the kit, all finer than 1500 grit)

Additional sandpaper, 180, 400, 600, and 1500 grit

Step 1: Initial Polishing

The pair I used for this instructable were very scratched - and far beyond the repair capability of the restoration kit. That's why I needed the rougher sandpaper grits.

If you only have superficial scratches on your lenses, you shouldn't need to use the extra sandpaper grits that I did.

Start the process by sanding the lens in a diagonal pattern with the roughest grit (pad number one, or a rougher grit). You can see in the second picture that pad number one wasn't rough enough to remove the gouges in the lens. For these lenses, I needed to go down to 180 grit to remove the gouges.

I did all of this sanding by hand, but if you've got a power tool that you can use to sand a buff, your results will be even better.

Step 2: Rougher Grits to Eliminate Deeper Gouges

Use the lubricant freely with all of the sanding you do, for all of the various grits (see the first picture), and whenever you feel like the surface is drying out or becoming sticky.

With transparent sanding, it's important to step up to the finer grits progressively. Patience and consistency is important here.

I moved from the 180, to 400, 600, 1500, and then pad number one once more. I used this progression because it's what I had lying around. If you have more grits, use 'em!

Try to offset the sanding direction with each grit:

with the 180 (or first) grit, use a diagonal direction

with 400 (or next) grit, use an up-and-down (vertical) and side-to-side (horizontal) direction

with 600 grit use a diagonal direction, etc.

Once you finish sanding with the rougher grits (if you needed to), move on to pad number one, followed by pad number two, and then pad number three. Remember to alternate the direction of sanding for each pad number.

Step 3: Polishing

Next, apply the abrasive agent (the restorer) in a circular motion. Work this abrasive in very well, and apply more if you feel it will help. This is the step that really clarifies the material.

You can see the foggy appearance this will have in the first picture. You'll want to wash (with water, and soap if needed) the remaining abrasive off before applying the sealant.

Step 4: Applying the Sealant

In the first picture, you can see the lens after a it's been polished with a spray of the sealant applied. I used the clean cloth to spread the sealant in a circular motion, keeping in mind that I want the sealant to be on the thick side to fill in any remaining inconsistencies.

In the second and third pictures, the full process has been done on both lenses. You can still see some lines on the lenses, which would be reduced with more polishing, but they're usable again!

I didn't spend too much time on the polishing process simply because I know they'll only be in this condition for a couple of weeks on the job.

I hope this helps out some fellow restorers, and thanks again for checking out my instructable!