Polishing perspex

[KAM]

Does polishing perspex delay crazing.

 

[Bouba]

...or cause it ?

 

[Bobc]

In theory, by making it more reflective, it should be less susceptible to crazing.

 

[KAM]

I was thinking more in terms of polishing out incipient micro cracks before they get too bad.

 

[bluerm166]

Hadlow Marine Services sell a polish for perspex - reputedly used since WW2 to polish the hoods of aircraft and limit deterioration before the event.
My experiment with polishing paste (Farecla G10) on scarred perspex simply produced a very fine matt surface .

 

[KAM]

I have a sliding perspex hatch which looked badly crazed. Surprisingly the crazing was only 0.5 mm deep as the perspex was 22mm thick I tackled it with a coarse belt sander finishing down the grades. Finishing as you say with Farecla I also got the slightly Matt finish which was rather pleasing and much better than the crazing. One year I will finish polishing I'm sure it will come up OK.

 

[johnalison]

Waste of time, money and effort.

 

[KAM]

Why.

 

[PabloPicasso]

Plastics will only have a certain lifespan. UV is often the enemy here. I replaced my aged crazed perspex hatch after an edge broke off. I'd have been fed up if I'd spent a lot of time and effort polishing it only to have it snap completly.

There, you've been warned...

 

[Bobc]

I was thinking more in terms of polishing out incipient micro cracks before they get too bad.

Wasting your time

 

[KAM]

Did my hatch several years ago. It wasn't difficult and doesn't seem to have been a waste of time. It's moulded with a fair bit of machining. Quotes to get one made were very expensive.

 

[johnalison]

Why.

Because I've tried it. The crazing was internal and no amount of polishing would affect it. Polishing will help surface scratching, no doubt.

 

[KAM]

I think it's quote a complex issue. Slightly different compositions and different methods of manufacture. Internal stresses, frost damage and other external factors. I'll do some experiments and report back in a few years but appreciate other comments.

 

[Bouba]

If you start with new Perspex that you can see through and then polish it...it’s harder to look through...swirls and glinting...so unless you are talking about grinding a new surface (using finer and finer pastes until you are using toothpaste)...I think polishing makes it worse

 

[sparkie]

Does polishing perspex delay crazing.

Use Makrolon instead.....much better. Had washboards on my old boat 30+ years old and good as new.