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Polishing Plastic - Face mask

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Eric The Viking

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It's the same as polishing/sharpening, etc - going "down the grits". You might try this, but beware that shininess doesn't mean good optical performance, so you might find, for example, that it lets you down in strong sunlight.

1. Clean thoroughly with soft materials. I've used my similar mask to shield my face and glasses when jet-washing and when spraying water based paint. This comes off remarkably well with bio washing powder (contains enzymes) Hat-tip to Rafezetter for that one! Put a fairly strong solution on, then clean off with a clean paintbrush and lots of flowing, warm but not boiling hot water. Make absolutely sure you lift any grit or metal particles as soon in the process as possible, as they will add scratches later.

2. Coarse polish with T-cut (for car bodywork), applied with a J-cloth or similar. Make absolutely sure all cloths used are clean, as the shield's surface is such soft plastic. Wash off with baby shampoo or "sensitive skin" bubble bath/shower soap, as neither has many additives. Washing up liquid contains glycerine which is a really bad idea as it leaves a sticky residue. It's worth trying a small area, to see if it's working: do it; wash off and dry; then take a critical look.

3. Fine polish with Dura-Glit wadding (rebranded Brasso recently). Similar caveats - if it's dried up in the tin don't use it. You can use a little water lubrication with this too. You can also use liquid Brasso but it's a bit coarser and prone to drying out in scratchy lumps.

3a. Jeweller's rouge is the next step down, used as a thin-ish paste in water.

4. Finally (LAST RESORT) I would be tempted to try this:
https://www.everbuild.co.uk/product/pvc ... t-cleaner/
BUT it is a seriously nasty chemical (you need barrier gloves - e.g. PPE ones, which it will probably perish), and it works by slightly melting the surface, so might actually destroy the transparency - TEST a small area in a top corner of the shield. Use some old well-washed cotton sheet as a cloth to do this.

Bear in mind it's all about working the surfaces down around scratches. You're not actually "removing" scratches at all. It's a big task with a big area, and you are in essence thinning and weakening it. Only you can decide when it's good enough for practical use.

I also had success with car headlights last year using water-lubricated fine wet+dry followed by T-cut and Brasso/Dura-Glit (beware - uPVC cleaner clouds them!), but it's tougher than those face shields, thicker, and rigid material, and you aren't looking through it.

When all is said and done, how much is your time worth? Doing this right takes a while - you may decide buying three or four more ready-cut-out replacement polycarbonate sheets is much more cost-effective. But if you want to go ahead, that's how I would approach it, personally.

E.
 

Lons

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It depends on the type of plastic Alex, if acrylic ( Perspex ) it can be polished as Droogs said with toothpaste or Brasso and deeper scratches can be rubbed out with micromesh in fine grades.
If it's polycarbonate then it's a waste of time as it's too soft and you'll make it worse. I've had a quick look on the Axi site and can't see what it is.

Personally I wouldn't bother as imo it's not worth the effort, I don't know about this model but the plastic is classed as disposable and replacements are usually pretty cheap, it's only about 1mm thick and if you can't get one you might look at buying sheet and cutting your own or get one from a different make and adapt it.

The only issue you might have is that masks and the materials to make them have been in short supply due to PPE demand for the pandemic.

Without searching properly a very quick google shows you can get a full polycarb visor from Screwfix for £5.83 and here is an example of replacement shields https://www.zoro.co.uk/shop/personal-pr ... rs/f/58178 there should be many more choices.

cheers
Bob
 

Lons

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Eric beat me to it with a much more comprehensive reply. I'll have to learn to type with more than 2 fingers. :lol:

Just to add though you can still buy acrylic polish, even original Perspex branded stage 1 & 2 polish is available if you search hard. I have some that's probably 40 years old now and still good. You can get turners plastic polish often bought for acrylic pens but I wouldn't bother, it's cheaper to buy replacement shields.

EDIT
Better than T cut for fine scratches is G3 liquid or Farecla paste.
 

Rorschach

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Polishing plastics is easy. Polishing plastics to optical quality is darn near impossible. By sanding out the scratches you will create hollows and these will distort the view through it. If it's a light hazing then something like Greygates polish will do a reasonable job of bringing back some clarity but if you actually need to sand out the scratches then I wouldn't bother and would source a new visor.
 

Alex H

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Tried Colgate Total for about 5 minutes - it did clean the mask, but showed up all the scratches that i couldn't see.

Took the sensible option and bought a new one from Screwfix.

Thanks to all for the suggestions.
 

TheTiddles

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You can get special plastic polishes.

Brasso can also be used, depends how deep the scratches are obviously

Aidan
 

Sideways

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Use a vernier caliper to check how thick the visor is, then check out the price of polycarbonate sheet on ebay.
1.0mm, 1.2mm, 1.5, 2.0 etc is all readily available.
There's no reason why you can'r cut yourself another from sheet using the original visor as a template.
I'm considering a similar trick in due course as I bought a visor I like but then realised replacement shields are a bit hard to obtain and overpriced for what they are.
 
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