[OT] Remove scratches from plastic helmet

[vinicius.jlantunes]

As I remember seeing a few threads on equipment repair where people removed scratches from test equipment panels I thought it wouldn't hurt to ask around here.

I have this helmet which is a memento from a visit I made to one of manufacturing plants of my current employer. I dropped it in a parking lot though and it gained a few scratches... 

Can I do anything to repair / reduce the scratches? Maybe use a hot air gun after sanding it with a very fine sand paper?
See picture.

The helmet is a normal safety helmet made by MSA in HDPE.
(similar to this: http://us.msasafety.com/Head-Protection/Industrial/Helmets/Vanguard%26trade%3B-Lateral-Protective-Cap---Type-II/p/000060001000001000).

[b_force]

Sanding and polishing would do the trick fine.

Why do you want to remove the scratches actually??

[vinicius.jlantunes]

Thanks! Any tips on how to do the polishing?

The helmet is a souvenir from the visit, I would like it to look "as new" if possible.

[rdl]

HDPE does not respond well to sanding and polishing. It's kind of "rubbery" but not very thermoplastic. You can try though.

[vinicius.jlantunes]

hum... ok, thanks for the tip rdl. I will maybe try sanding it a little bit to see how it reacts - if not very well then I will just leave it as is.

[noidea]

Those scratches are more than just superficial, even if you could sand and polish them out the surface will be flattened where they were and you will always notice it as it will reflect light at a different angle to the surrounding surface.
PS that doesn't look like dropped, more like played football with around the car park 

[dexters_lab]

you'll need to sand it down with a coarse paper to get the deep scratches out. Then progress onto finer and finer sandpapers.

Once you have a nice smooth but matt surface, switch to toothpaste with a cloth and it should bring the gloss back after a lot of polishing

[vinicius.jlantunes]

I took the picture with light in an angle that maybe makes the scratches seem deeper than they really are.

But I'm starting to get a feeling I should just let it be... I may make it worst than it is!