This subject always cracks me up…
Listen guys……. crazing in acrylic is caused by either thermal or mechanical stresses imparted during production, transport, manufacture or in use.
Acid rain,Ultra – Violet degradation, Windex or the boat detailer’s magic deck cleaner (to name a few) accelerate the process.
Once something is crazed it is significantly weaker than the same part in factory OEM condition.
How do you stop it? Make Sunbrella covers (not vinyl backed Sunbrella!!). Use cleaners specifically designed for Acrylic.
How do you repair it? You don’t.
We have all seen the lotions and potions sold at boat shows to cure everything from warts to your crazed hatches. You still have the warts don’t you?
You can follow the military specification procedures from the USAF/USN and sand the lens until you are below the crazed line, sand again in successive grits and buff with 4 or 5 different compounds until clear again. Remember annealing? Yea…. you need to get the mechanical and thermal stress you just put in with the sanding and polishing out! Well at 170 degrees F for 12 hours (1/2 inch acrylic) and cool down at the same rate, oh and now you’ve found the seal puddled in the bottom of your wife’s oven and the parakeet is dead from the MMA vapor being out gassed during the process. New seal, new oven, new wife?
By the time you have completed this repair you could have purchased two hatches, thrown one overboard and had the most expensive yard in the States install the second with the gold plated rag-surcharge and be ahead of the game.
I repair thousands of hatches every year. I know replacing the lens is an option but repairing the crazing with potions or flames is not realistic.
Let me know if you want some pictures of really crazed hatches. I have seen every make and model you could imagine.
I would like to help. But even the Hatchmasters can’t make crazing disappear. (yet)