Getting The Crud Off The Fiberglass Hull

[MDCHILDS]

I aquired an old 16 ft fiberglass boat - for restoration - has been in a freshwater lake for years and the old owner did nothing to clean the hull - after a few years in storage the stuff is as hard and stone and abrasive (you will scrap the skin off your knuckles on it). I used a pressure washer (just water) on it --- only the really loose stuff (10%) came off.

How do you get this crud off the hull without damaging the gelcoat. Is there a chemical or process I should be using?

[CatBuilder]

Originally Posted by MDCHILDS

I aquired an old 16 ft fiberglass boat - for restoration - has been in a freshwater lake for years and the old owner did nothing to clean the hull - after a few years in storage the stuff is as hard and stone and abrasive (you will scrap the skin off your knuckles on it). I used a pressure washer (just water) on it --- only the really loose stuff (10%) came off.

How do you get this crud off the hull without damaging the gelcoat. Is there a chemical or process I should be using?

I'm a salt water guy, but I assume the principle is the same.

If the pressure washer didn't get it off, you can try muriatic acid (HCl). They sell it in most chandleries. That stuff takes just about everything off and doesn't harm the gel coat. Wear an "AG" (acid gas) mask when you use it because after spreading it out on the hull, a whiff can really burn your respiratory tract.

If all else fails, you can also abrade it away with very fine grit sand paper.

[rasorinc]

Try spraying it with oven cleaner, then wait 30 minutes and wipe off. I use this on the outside of frying pans to get rid of the food and oil that gets baked on hard. it works. Next, I would try CLR.

[PAR]

Put it back in the water for a few days then pressure wash shortly after it comes out again. Muriatic acid it a great way to learn about burned lungs and eyes and wouldn't be recommended. You could make a career out of using oven cleaner and how many bottles of Easy Off does it take to do a small boat anyway. Lastly, it has to be a serious pressure washer, not some pack pack thing with an extension cord. 3,000 PSI at least. Work slowly and methodically with the wand. The big mistake novices do using these things, is sweep the thing back and forth covering 24" per second. You can't clean anything like that. You want to move 1" per second and 6" or closer to the hull shell. This will blast the crust off my ex-wife's butt (okay maybe not).

[tunnels]

Get it wet use house hold cleaners and a green pot scrubbers at the same time .The pot scrubber used without applying to much pressure and the house hold cleaner together i even use on my car now and again to get rid of gung that wont wash off easly . When all else fails ,Sand and buff and re wax with a good quality car wax !!.

[PAR]

Green scrubbers will work (3M pads), but I prefer to use them on a DA or buffer/polisher instead of by hand. These will get the last remnants of goo and growth, but pressure blast it first. With this much growth, you'll never get it back to looking good. It'll be stained and scuffed. You can try rubbing compounds then polishing, but in the end, I'll bet you'll just have to prep for paint.

[CatBuilder]

I missed the point that this boat was out of the water for a long time without any cleaning. I had never seen a boat in my life that wasn't cleaned on the slings as it was first hauled, but then saw this was a trailer boat.

Most boats are pressure washed upon haul out, so re-dunking it for a few days is the way to go for the pressure wash.

Next, go to the chandlery and pick up the acid. I told you what's in the product in case you can get it cheaper. Here it is:


http://www.jamestowndistributors.com...Bottom+Cleaner
(notice it has a nearly perfect 5 star rating because everyone likes it and uses it - read the reviews for how it works)

Pressure washing does not remove stains, period. Things like the "brown smile", which is tannin from fresh water tributaries of the Intracoastal Waterway cannot be pressure washed off. You must use the acid. This is what professionals do.

Later, after all of the pressure washing, if you are in salt water, (which the OP is not), you will often still have barnacle anchor points, looking like flat little white pearls, very firmly attached to the boat. Again, pressure washing isn't going to cut it.

The acid will loosen them, but if some still won't come off, abrade them off. If you make sure you don't use low grit (low number) abrasives on there, you can just sand any gel coat to get these off. This will not mar the finish of the gel coat if you use the highest grit number possible. Use the highest you can find. Wax will fill in any dullness created by this sanding. Do not actually sand the gel coat if possible, but just sand the small barnacle attachment point. Maybe a Dremel would work. I usually just do it by hand.

Again, these are methods professional crew use to clean boats. Follow it up with this stuff:

http://cruising.stuffiminto.com/mari...t-cleaner.html

If you want a yacht-like finish, you have to use professional techniques. They are a lot of work, but they do work.

[michael pierzga]

Yup...acid works.

An all to common clean up job is a tender who has been in the water too long. Normally no marine or hardware store is nearby for cleaner purchase so you must raid the bosuns locker for cleanup materials. Two part teak cleaner is a kick ass cleaner ....wash with part a, bleach with part b., If no teak cleaner is onboard, Duckie style toilet bowl cleaner is the best, cheapest, cleaner for substrates that need both a soapy cleaner for oily marks and an acid to pull out the brown..tannin...stains. works great.

[tunnels]

One of the biggest problems is the old gel coat will have lost the nice luster micro surface it had when it came out of the mould and it will be into the porous gel behind . The bubbles are so so small but they are just right for mold grow and gung to stick to so you need a liquid cleaner to get it out and semi bleach the dirt . Thats why when its completely dry use a really good quality auto wax to fill the pores of the gel coat to help keep the gung from sticking again !! When you wash you boat dont use anything but clean water .any soaps or detergents will remove the wax . Need to re-wax 2 or 3 time a year !!

Note ! I always use automotive car waxes and do everything including the inside and out side of windows and windscreens . Just water takes the salt off and if you get rained on while you out in the sea then thats even better !!.
I have never been a fan of acid wash of any kind !.Gel coat is quite porus and not very thick so just be carefull .

[michael pierzga]

Originally Posted by tunnels

One of the biggest problems is the old gel coat will have lost the nice luster micro surface it had when it came out of the mould and it will be into the porous gel behind . The bubbles are so so small but they are just right for mold grow and gung to stick to so you need a liquid cleaner to get it out and semi bleach the dirt . Thats why when its completely dry use a really good quality auto wax to fill the pores of the gel coat to help keep the gung from sticking again !! When you wash you boat dont use anything but clean water .any soaps or detergents will remove the wax . Need to re-wax 2 or 3 time a year !!

Removing the oxidation and filling the pores is about all you can do. Ive never been happy with wax's...they leave a sticky dirt collecting surface. Has anyone had an experience with this new fancy Nanotechnology surface treatment instead of wax. The stuff costs a hundred euros for a small bottle. Does it work any better than wax ?

[MDCHILDS]

Thank you all for your input on this one --- sounds like putting the boat in the water for a couple of days --- blast it with a high pressure washer (very slowly) to rid the hull of the bulk of the crud, then a cleaner/acid (muriatic acid is not available and risks are high on the health side) with 3M pads on a power buffer should remove the rest of it... buff up smooth - bloodywell keep it clean (not a big chore if I do it each time I take it out - as it will not be docked anywhere - it will get cleaned many times a year)

[tunnels]

Ok this i have seen done and worked a treat but messy and very time comsuming !! After the surfaces is 100%cleaned to get gel the same colour and a rag rolled into a small ball and use catalyzed gel and simply rubbed the gel on the surface and keep rubbing till it shines . then carry on to the next bit ,Saw it done but only on a small area , worked like magic and was better than new .

Or you could simply clear coat it with a urethane 2 pot !!!

[nrg]

Are you using the right sized buffer? You may need a bigger one, or even a variable speed random oscillating sander. If all else fails try the magic eraser those things are freaky.