The Skipper's Blog

Ask The Skipper
Views Counter

Will Algae Strip damage the bunks on my trailer?


Rod Bolton asked:

I have been reading about your product “Algae Strip” on the internet. My boat is on a trailer with hardwood runners covered with broadloom supporting the hull. My question is; can this product be used safely without damaging the trailer supports or the paint on the metal parts of the trailer?



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


Algae Strip is an acid based cleaner and if applied or dripped directly onto the bunks or the trailer will cause damage. Besides cleaning the bottom of your boat, you have two other issues; one is protecting the trailer against damage and the second is cleaning the parts of your boat that are resting on the bunks.

The solution is quite simple and is covered at some length in another section of this blog under . Once you have the trailer lifted off the bunks, you can protect your trailer with plastic sheeting or plastic garbage bags. Dollar stores sell inexpensive plastic sheeting used as drop cloths for painting which will work for this purpose.

Algae Strip works very aggressively to remove marine growth from fiberglass but is inhibited so it will not damage the fiberglass. It also biodegrades rapidly when reacting with marine growth or when rinsed with water so although the active cleaner can cause damage to your trailer the effluent will not and will not damage the environment.

Another alternative for cleaning the bottom is Green Genie. It is a new formulation that uses organic salts instead of acids. It is more environment friendly but not so aggressive. It works just as well but takes a bit longer (30 to 60 minutes instead of 15 to 30 minutes for Algae Strip). It has other advantages of being safer to use and can be sprayed on as well as applied with a paint roller. You should still protect your trailer as all heavy duty cleaners can cause damage to the bunks and finish.

If your boat is aluminum or if you have metal parts that you are trying to clean, including the propeller, or painted lower units of stern drives or outboards, I suggest that you use Algex as it is intended for cleaning metal without damage. Algae Strip can darken stainless or bronze and can corrode aluminum. After cleaning the marine growth and stains, it makes sense to protect your boat against reoccurrence of attachment of algae, zebra mussels, barnacles etc. I recommend that you deep clean the bottom with Boat Scrub to remove any residue, scuffing, oxidation etc. and then protecting the bottom with VS721 Bottom Coat. You need 2 coats. You can apply one now and the second in the spring before launch. VS721 will reduce the attachment of marine growth and seal the pores in the fiberglass to protect against osmosis blisters. Other benefits are improved performance and reduced fuel consumption. VS721 is recommended by boat manufacturers to prevent osmosis blisters.

Thanks for your question

Captain Aurora

The Skipper Recommends:
More Info
More Info
More Info
More Info
More Info