Polly Carbonate GLass Care

+ Common Mistakes to Avoid

Clear polycarbonate (often branded as Lexan® or Makrolon® Marine) is a rigid, shatter-resistant plastic used for hatches, windshields, portholes, and instrument covers on boats. It's 250x stronger than glass, UV-resistant, and lightweight, but it's prone to scratching and hazing if not cared for correctly. Proper maintenance preserves its optical clarity and impact strength for 10–20+ years. Always test cleaners on a small area first. Guidelines based on marine experts (Practical Sailor, BoatUS, and polycarbonate manufacturers like SABIC).

1. Rinse Immediately: Use fresh water with low pressure (<40 PSI) to remove salt, bird droppings, pollen, or sand. Avoid high-pressure washers, which can scratch or warp edges.
2. Wipe Gently: Use a soft microfiber cloth dampened with water or mild soap (e.g., 303 Marine Cleaner or Dawn® diluted 1:10). Wipe in straight lines (not circles) to prevent swirls. Dry with a clean microfiber or chamois.
3. UV & Scratch Protection: Apply a dedicated plastic protectant like 303 Aerospace Protectant® or Star brite Plastic Polish monthly. Buff lightly to restore shine and repel contaminants. This prevents yellowing and minor scratches.
4. Inspect Regularly: Check for scratches or cracks; buff out light ones immediately to avoid deepening.

1. Prepare Solution: Mix mild soap (e.g., 303 Marine Cleaner) with lukewarm water (1 oz per gallon).
2. Apply & Scrub: Spray on, let sit 1–2 minutes, then gently scrub with a soft microfiber or non-abrasive pad in one direction.
3. Rinse Thoroughly: Flush with fresh water until no residue remains.
4. Polish & Protect: Use a plastic polish (e.g., Meguiar's PlastX or 3M Marine Restorer) for haze removal, then apply UV protectant.
5. Dry: Air-dry in shade or buff dry—never use heat.

For mildew: Diluted bleach (1:10) sparingly, rinse immediately, and retreat. For scratches: Light buffing with PlastX; deep ones require professional refinishing.

• Clean & Dry First: Always rinse and dry fully to prevent contaminant trapping.
• Protect from Elements: Cover with breathable, non-abrasive tarps (e.g., Sunbrella) to shield from sun, rain, or dust. Avoid tight plastic covers that trap moisture.
• On-Boat Storage: If left installed, loosen fittings slightly to allow air circulation. Use a dehumidifier in the cabin during humid seasons.
• Removal for Long-Term (Off-Season >30 Days): Remove panels if possible; store flat or vertically in a cool (50–80°F), dry (<60% RH) indoor space. Stack with soft padding (e.g., foam or microfiber) between layers to prevent scratches. Never fold or stack without protection.
• Pro Tip: Label storage areas "POLYCARBONATE – NO ABRASIVES – UV PROTECTED."

Polycarbonate's surface is soft and easily damaged by abrasives or chemicals that strip its UV coating. 

Avoid these:

Product to Avoid: Why It Harms PolycarbonateSafer Alternative 

Abrasive Pads (e.g., Scotch-Brite) Creates permanent scratches and haze. Soft microfiber cloth only. 

Harsh Solvents (e.g., acetone, Windex®)Etches the surface, causing clouding.Mild soap + water or 303 Marine Cleaner.

 Bleach/AmmoniaYellows and weakens UV protection.

High-Pressure Washers (>40 PSI)Scratches or cracks edges.Low-pressure hose. 

Automotive Waxes (e.g., carnauba)Leaves residue that attracts dirt. Marine plastic polish like PlastX.

Bug Sprays with DEET/SunscreenEts pits quickly. Wipe off immediately.  

MistakeConsequenceHow to Fix/Prevent

1. Testing hardness with keys/tools Deep gouges that haze the view. Handle with clean hands; use dedicated cleaners.

2. Circular wiping motionSwirl marks from trapped grit. Straight lines only with microfiber. 

3. Storing without UV protectant Yellowing and brittleness in 1–2 years. Reapply monthly; cover when moored. 

4. Leaving exposed in winter: Cracking from freeze-thaw cycles. Remove or insulate; store indoors. 

5. Using glass cleaners Streaky residue reduces clarity. Plastic-specific products only. 

6. Stacking without padding Scratches from pressure points. Foam separators between panels. 

7. Ignoring small scratches They deepen with UV exposure. Buff immediately with polish.  

Pro Tip: Annual professional inspection for deep scratches or coating wear can save replacement costs (panels run $200–$1,000+). For brands like Lexan, and Marine 5.