Getting Rid of Smells and Mold on a Boat– Posted by RichH

There’s a very straightforward ‘process’ solution to mildew control.
1. First THOROUGHLY Clean out every dark corner and ‘undersurface’ possible in the boat.
2. Dissolve the mold/mildew with a caustic based detergent … but not on bare or oiled or varnished teak. If you use Tilex or Clorox, you will leave ‘dead cells’ and they will only be used as a nutrient for ‘other species’ of mold/mildew – OK to use clorox on painted varnished surfaces but you have to followup clean to remove the dead cells.
3. So, after a thorough CLEANING, then get some sodium silicate or other ‘highly caustic’ detergent and dilute it 1:1 with water and SPRAY but DONT WIPE it from all the ‘under and hidden’ surfaces. Let the caustic solution DRY and it will become the modern ‘equivalent’ of ‘whitewashing’ … the process that our ancestors used for 1000s of years to control mold/mildew.
Once you have mildew unless you clean out ALL the dark and hidden places where the mold is growing … and is forming SPORES !!!!!!, and THEN chemically ‘whitewash’ those under surfaces, etc. you will have the mildew, etc. under control. You have to kill the ’spore forming areas’ to prevent or retard further outbreaks. No sense in attacking ‘visible’ mildew until you Clean out and ‘whitewash’ the hidden areas and ‘undersurfaces’ where its growing.
Caution: do not spray diluted caustics on varnished, oiled, ‘finely’ painted surfaces … its going to LIFT/’bubble’ the coating; on BARE teak it will extract the tannins from the teak.
Special Caution: Never ever clean ‘dry’ mildew, always ’spritz’ it before scrubbing. Only clean/remove wetted (can be clorox to wet-out) mildew. Wear respirator …. you ‘build-up’ additive toxicity to mildew.
Dark and hidden places:
1. the VENT exit area of your water tank
2. undersides of flooring and ‘pan’ liners
3. behind cabinets and hull liners.
4. behind ceiling panels
In the special case of Ty37’s, etc.:
Under the ‘flooring’ where the batteries are located under the cockpit – unscrew the flooring to check/clean.
The bilge area under the engine
The Cavernous Locker under the cockpit
The void area in the stern behind the steering quadrant
The Anchor chain locker … under the ‘false flooring’.
Inside the Dorade boxes !!!!!
The damn seat locker in the shower stall and under the shower stall floor pan.
Behind the ‘fascia’ for the chainplates … and especially if the chainplates are ‘dribbling’ – UNDER the flooring under the settees.
Anywhere the bulwark is leaking down into the hull.
The area UNDER the fridge where the fridge drain hose exits into the bilge !!!!
‘whitewashing’ …. just thoroughly clean and spray on and let dry any ‘caustic based’ detergent … I prefer Tuff-eNuff by Wallace and Sons (Florida) -used to be carried by WM so they can probably special order it – expensive. Stuff is good for mildew/fungal removal (those teeny black spots) on woven dacron sails. Other ’sprayables’: VERY very diluted lye solution, diluted TSP solution, etc. Mildew spores will not ‘activate’ on a ‘whitewashed’ (caustic) surface.
Special: if the boat is closed up for long periods of time – get some Paraformaldehyde crystals (read instructions/cautions carefully as this stuff is not compatible with human lung tissue) hold your breath and sprinkle onto large plastic containers before you leave and close the boat … when it ‘off gasses’ it attacks mildew cells. When returning to the boat HOLD YOUR BREATH, rush inside and open up any port-lite, hatch, etc. while holding your breath until you are forced to go outside. Open all possible openings and then let the boat air-out for ~30 minutes before you go back in (holding your breath) to put any remaining ParaF crystals into plastic bags. Youll probably have to ’smuggle’ ParaF in to Kalifornia, etc. Commercial form of Paraformaldehyde: “MildewGaz”, etc. — only way to kill the mildew spores during a long term closed-up boat.