How to Prevent Growth on Boat Propellers and Running Gear

So you have gone to the expense of applying bottom paint to your boat, and now you have to ask the question “what about propeller paint and running gear paint? Just like the rest of the bottom of the boat, marine growth will cover the props and running gear if left unprotected. This will lead to loss of power and speed. With severe growth, you can even lose the ability to get the boat on plane.

There are a few options for keeping growth off your propellers and running gear and we will explore advantages and disadvantages for applying various coatings to your propellers and running gear. Keep in mind that when you paint props and running gear they are under extreme conditions with speed, cavitation, electrolysis and environmental conditions ( like running through sand or hitting ground or objects). These can cause the same result as sandblasting your running gear – something you will want to avoid after you choose a coating!

1. PropGlide Foul Release Coating | The Best Solution for Preventing Growth on Props and Running Gear

Advantages: Best adhesion, best performance, actual increase in speed, lowest risk of electrolysis issues, non-toxic
Disadvantages: Higher Cost, Environmental Variables (sand, running aground), Detailed application

Foul Release Systems provide the best solution to keeping growth of your props and running gear. While these are not antifouling prop paints, they do keep the growth off buy creating a super slippery surface that the marine growth cannot stick to. Propspeed recommends that their kits by applied by a professional Propspeed applicator. On the other hand, PropGlide is available for any DIY applicator and is less costly and more product for the money. If you want to apply this yourself, be sure to follow the details in the respective application manuals.   You can find these on any of the Propeller Foul Release Kit listed on our website.

PropGlide and Propspeed are foul release systems that are applied to underwater metals including props and running gears. These foul release coatings are sold in kits ranging from 175ML, 200ML, 500ML, and 1000ML Kits. You can view the all of our Foul Release Coatings to determine which kit size if right for you.

2. Paint the Props and Running Gear with Bottom Paint

Advantages: Lower cost option
Disadvantages: Trouble staying on, electrolysis concerns, Environmental Variables (sand, running aground)

Applying bottom paint to your underwater gear is a little tricky because there are additional steps that must be taken before applying the bottom paint. Especially if you have a fiberglass boat. Most bottom paints contain copper that act as a biocide and prevent growth. However, when applying bottom paint (with copper) to metal, you create a battery effect with the metal on metal. This leads to electrolysis and pitting of your props and running gear. Follow these basic steps before going with this option

Basic Steps

  1. Prep: Make sure to remove all prior coatings and contaminants prior to applying any coatings. The should be done by a sandblasting, soda blasting, or a good ole fashioned sanding. The recommended grit and profile should be 80 grit. This will provide a efficient surface for the new coating to adhere.
  2. Tuff Stuff Marine Epoxy PrimerPrimer: Apply a two part high build epoxy primer that id designed to prevent corrosion and enhance adhesion. The best we have found is Sea Hawk Tuff Stuff High Build Epoxy Primer. It is easy to use and works extremely well. Apply two coats!
  3. Bottom Paint: Apply a hard modified epoxy bottom paint with not too high a load of copper. Sea Hawk Sharkskin and Blue Water Copper Shield 35 Hard are among the best choices. The epoxy primer will insulate the copper bottom paint from the metal of the props and Sea Hawk Smart Solution Outdrive Paintrunning gear (remember the battery effect!) If you are concerned about electrolysis or already have some issues, then you should use a copper free bottom paint. The only true metal free bottom paint that we found and that still is effective in preventing growth is Sea Hawk Smart Solution. Either way, be sure to apply the first coat of bottom paint the same day as the 2nd coat of epoxy primer. If you don’t, it will not stick!

3. Aerosol Sprays

Advantages: Lowest cost option
Disadvantages: Trouble staying on, ineffective antifouling performance. electrolysis concerns, Environmental Variables (sand, running aground)

There are a few aerosol spray systems that can be used, but these are generally ineffective for props and running gear, and are reserved for outdrive applications. These include Interlux Trilux 33 and Primocon, Pettit Alumaspray and Prop Coat Barnacle Barrier, and the Sea Hawk Premium Outdrive Kit that contains Smart Solution (brush on Pint) and Barnacle Blocker. Our advise is to save your money before applying these to props and running gear.