Cleaning boat deck - recommended products and process

[flyingwaspsailing]

Ahoy there sailors - I'm looking for some advice in cleaning my boat deck. With so much advice and so many products I wanted to share photos of it before moving forward. Mine is the dirty one. The other one is my dock mate, which is the same boat, newer and better cared for.

LMK what you think!

- Flying Wasp
Precision 23, 1987

 

[dLj]

Fiberglass deck - Id start with a pressure washer and see from there.

dj

 

[dlochner]

Start with a small power washer and Dawn detergent.

If the discoloration is still there. Try a Non-Skid cleaner on every thing, use a soft brush.

Next up is a polishing compound like Totalboat TotalBuff or one of the 3m product with a buffer.

Clean again with Collinite Fiberglass cleaner and then wax with Collinite Boat wax.

 

[Foswick]

The good news is I think your boat can get there. You'll find a lot of advice, some of it conflicting, but most of it good in its own way. I'll give you my version.

You have 5 jobs, each has its own set of solutions.

1. Surface dirt and grime: Just about any boat soap will do here. I haven't found any to be any better or worse than any other. I think the most important consideration is environmental impact (toxicity). So, pick a product you feel good about. The key is just that you scrub with a medium-soft bristle brush, rinse thoroughly, and don't let the soap dry. When done, you will probably have a more-or-less uniformly off-white surface with a few stains here and there that are not uniform.
2. General uniform discoloration: My "plan A" for this is to use oxalic acid and get down on hands and knees with a handled scrubber. This will probably work really well in some locations, pretty well in some, and seemingly have no effect in others. But, it will cover a lot of area and shrink your job down to just the areas that need special attention. You might try a second round to go over some areas again, but I don't find a second pass with the same cleaner to usually do much unless the initial problem was just inadequate scrubbing.
   1. If this is my initial cleanup, I might break out a Magic Eraser, at this point. This allows you to cover a wide area with a mild abrasive that can perform miracles. But, it does remove the top surface of gel coat, so it shouldn't be part of routine cleaning.
3. Local stains and problem areas: Now, the deck is basically white, but with some areas and local stains that have resisted. This can be the frustrating part. Different stains will respond to different solvents/cleaners and some will only be removed mechanically (using an abrasive).
   1. I might start with Goo-Gone. Occasionally, you get lucky and this works.
   2. After that, I might try acetone for isolated areas. (I have heard that leaving acetone on can damage the gel coat, so I am careful to wipe on and wipe off pretty quickly. And, I would not use this over a large area, for related reasons.) Acetone only occasionally works.
   3. Next, I might make a paste with Bar Keepers Friend. This is really just oxalic acid with a fairly mild abrasive. Working some of this paste with fingertips and a cloth into localized stains can be all you need. In fact, if you keep at it, you can get rid of almost any stain this way because you are removing gel goat and will eventually get to either clean gel coat or raw fiberglass. Just try to be aware of how thick the remaining gel coat is - something that is hard to know until you work through it. Gel coat can be repaired, and it's not the hardest job, but try to preserve what you've got and be as conservative with abrasives as you can be.
   4. Finally, I might resort to wet sanding with fine-grit sandpaper. This is a last resort and should be done with a very measured approach, but can be just what you need. This is just a more agressive version of using Bar Keepers Friend. Before considering this approach, think about which is worse - the stain or the risk of eroding your gel coat down to raw fiberglass. On my boat, the gel coat was applied knee-deep in many locations, so I can remove quite a bit. But, this should be thought of as a one-time deal. The key is to keep things well-maintained so you never have to repeat such an aggressive measure. (My impression from your photos is that nothing there will require this level of aggression.)

Jobs #4 and #5 are polishing and waxing. But, on-deck you need to decide what you want to do. We like to wax any surface that will not be stepped on. Polishing other surfaces, particularly non-skid surfaces, is kind of a special thing. I actually found a product that I used on my previous boat's non-skid that corrected the oxidation but did not leave the surface slippery. (I think it was a 3M product - don't recall what it was - it is in the dock locker and I'll try to remember to check.) I think it would work well for your deck, but it won't work on my new boat, which has a different sort of non-skid.

 

[Foswick]

Oh! Yes, as others have said, start with a pressure wash. I forgot that step. I suspect that will go a long way for you, but it looks like you'll still have some dingy oxidation to remove. Probably nothing too persistent, though.

 

[fred1diver]

Just be careful with the pressure washer, try to avoid the deck fittings, you don’t want water to go in

 

[dlochner]

Just be careful with the pressure washer, try to avoid the deck fittings, you don’t want water to go in

Presure washers can erode the sealant between a deck fitting and the deck causing leaks. Use a low powered pressure washer. In this case more power is not necessarily better.

 

[Tally Ho]

I like Bar Keepers Friend (the powder) to scrub my deck. It contains some oxalic acid, and brightens things pretty well. Wet a section of the deck, sprinkle on the scouring powder, scrub it with a brush, and rinse off.

Greg

 

[flyingwaspsailing]

Wow, you sailors are fabulous. Thank you all for these responses. Time to get to work!!

 

[Foswick]

I forgot to mention: There is a product called "FSR" (Fiberglass Stain Remover). It is a blue gel.

I had never used it before, but actually bought some last week to see if it could help me with some problem areas.

Amazingly, it did brighten up a few random areas but had no effect on some other areas. But, now I need to find FSRSR (Fiberglass Stain Remover Stain Remover) because it left blue stains in a few places. I thought they might fade on their own overnight, but they did not.

I would say to avoid that product. But, it is probably good if you know the secrets of when to use and not use it.

 

[BigEasy]

Power wash to remove the mildew & crud. Fiberglass stain remover if any persistent stain remains in isolated spots. I have used Woody's spray on deck sealer / wax with fairly good results. (Not slippery when wet after initial application dries). Follow up with Starbrite non skid deck cleaner with PTEF every couple of weeks.

 

[Davidasailor26]

1. Local stains and problem areas: Now, the deck is basically white, but with some areas and local stains that have resisted. This can be the frustrating part. Different stains will respond to different solvents/cleaners and some will only be removed mechanically (using an abrasive).
   1. I might start with Goo-Gone. Occasionally, you get lucky and this works.
   2. After that, I might try acetone for isolated areas. (I have heard that leaving acetone on can damage the gel coat, so I am careful to wipe on and wipe off pretty quickly. And, I would not use this over a large area, for related reasons.) Acetone only occasionally works.
   3. Next, I might make a paste with Bar Keepers Friend. This is really just oxalic acid with a fairly mild abrasive. Working some of this paste with fingertips and a cloth into localized stains can be all you need. In fact, if you keep at it, you can get rid of almost any stain this way because you are removing gel goat and will eventually get to either clean gel coat or raw fiberglass. Just try to be aware of how thick the remaining gel coat is - something that is hard to know until you work through it. Gel coat can be repaired, and it's not the hardest job, but try to preserve what you've got and be as conservative with abrasives as you can be.
   4. Finally, I might resort to wet sanding with fine-grit sandpaper. This is a last resort and should be done with a very measured approach, but can be just what you need. This is just a more agressive version of using Bar Keepers Friend. Before considering this approach, think about which is worse - the stain or the risk of eroding your gel coat down to raw fiberglass. On my boat, the gel coat was applied knee-deep in many locations, so I can remove quite a bit. But, this should be thought of as a one-time deal. The key is to keep things well-maintained so you never have to repeat such an aggressive measure. (My impression from your photos is that nothing there will require this level of aggression.)

To this list I would just add LA’s Totally Awesome, available from places like dollar stores. Sounds goofy but it works remarkably well on grime and spots like spider stains.

Polishing other surfaces, particularly non-skid surfaces, is kind of a special thing. I actually found a product that I used on my previous boat's non-skid that corrected the oxidation but did not leave the surface slippery. (I think it was a 3M product - don't recall what it was - it is in the dock locker and I'll try to remember to check.) I think it would work well for your deck, but it won't work on my new boat, which has a different sort of non-skid.

Could’ve been Woody Wax. That does a pretty good job of sealing the non-skid gel coat without leaving it slippery.

 

[jssailem]

I’ve had success on surface stains with the “Soft scrub Bar Keepers” product

 

[jssailem]

If the gelcoat is old like mine, as you pressure wash the oxidized gel coat will leave a milky white slurry in the water.

For me it is about time to paint as the 51 year old gelcoat has aged.

 

[Ralph Johnstone]

I'll try to apply the KISS procedure here.

Remove the loose surface dirt with whatever soap and/or pressure washer you find which leaves a smooth surface. If you don't remove the surface dirt, it will scour and scratch the gel coat. It still looks as if you've got some gloss remaining under the dirt.

In order to remove the remaining oxidized and dingy gel coat, you want an extremely fine oxidation remover :

​

.................... which is Meguiar's Color Restorer. This will not affect any existing gloss but will remove any finely oxidized gel coat and grime.

After you do a small area to see how any of the above methods work, please leave a post telling us which method you found to be the easiest and most productive.

 

[Project_Mayhem]

The last yard I was at used brushes on brushes on little Milwaukee drills and Zep cleaner. Brushes seem like they might be a bit harsh on shiny gelcoat but I'm not sure what they were using

If your gelcoat is already dull, you can use magic erase sponges and acetone. For general washing I usually use a heavy amount of boat wash soap and some concentrated pressure washer cleaner additive (i believe it was meant for boats/cars).

Fiberglass deck - Id start with a pressure washer and see from there.

dj

Never use a pressure washer! They blow away sealant which in turn causes leaks!

 

[dLj]

Never use a pressure washer! They blow away sealant which in turn causes leaks!

I believe that statement should be never use a pressure washer on areas with seals.

My previous boat which was all fiberglass deck was pressure washed every year as part of spring prep. Works great - just don't hit your sealed bits

dj

 

[Mark Maulden]

I would bet there is also mold mixed up in all that ”dirt”. The last step I would do is to wash the “clean” boat with a solution that kills/removes mold. Not meaning a bucket of water with bleach though..I think Starbrite or Meguiars or someone has a mold remover.

 

[Ralph Johnstone]

never use a pressure washer on areas with seals.

Truer words were never spoken !

They get mad as hell when disturbed and can give you a nasty bite.

 

[JBP-PA]

I use a scrub brush and plain water. I used to to use various soaps, but I don't want to be the source of soapsuds floating down the river. To be honest, it works nearly as well anyway. Add beer or wine and it works great!