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Can I Use Repelin On My Fiberglass Hull? Will Repelin Ruin My Fiberglass Boat?


Doug Martin asked:
I own a fiberglass 18′ power boat that I will be mooring from March to September on the Columbia River here in Washington State. I moored it in the river last year and had a hard time getting the river algae off the boat in the fall. I did get it off but since have talked with people who told me your product Repelin, is great on fiberglass hulls. I noticed on your web site you say this product is for rubber rafts and ribs. Will this product ruin my gel coat or cause damage to the finish if left on for 4 or 5 months?

For your convenience, I’ve highlighted the hyperlinks. Click on the hyperlink to get more information about the selected product.

Repelin will work and will not harm your fiberglass, however it was invented primarily for use on Hypalon and PVC. VS721 Bottom Coat will work better since it was invented especially for fiberglass and aluminum. It has stronger bonding properties. It’s important to get your hull back to pristine before you use it.

If you have any remaining growth, use Algae Strip to get it off (no hard work, roll on, rinse clean) If the growth is all off, you don’t need this. If you have any stain, use Waterline Stain Remover (no hard work, roll on, rinse clean). If there are no stains, you don’t need this. If there is any growth remaining on your stern drive or lower leg of you OB, use to get it off (no hard work, roll on, rinse clean) If the growth is all off, you don’t need this. If you have any stain, use Algex to get this off. Again, if it’s perfectly clean, you don’t need this. You can find more information on these products and how to use them at .

Use Boat Scrub to clean and prep the hull, even if the bottom is clean. Use a Marine Power Mitt if you want to save some labor/effort. This will also get scuff marks and oxidation off, if present. Rinse clean and let dry. Apply VS721 Bottom Coat with a damp sponge or cloth and wipe off the haze with a dry cloth. After 24 hours, repeat. Wait 48 hours before launching your boat. You’re good to go.

If your boat is on a trailer go to Ask The Skipper > Bottom Cleaning > How to raise your boat off the trailer, to get information about getting under the bunks or rollers. There is more information here about cleaning, restoring and protecting your boat.

Thanks for your question,

Captain Aurora
Richard Kittar

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