I purchased a 1985 MacGregor 25 about a year ago and have stored it in a fresh water marina (Whiskeytown Lake, Redding, CA) for the past year. I just pulled the boat out today so I could do maintenance over the next 3 months and I plan to put it back in the water on April 15. The first thing I noticed is that the portion of the hull that is normally submerged is covered with a brownish green material that is very hard to remove. I first tried normal household cleaners (Windex, Simple Green, 409, TSP, etc) combined with a 1500 psi pressure washer but had no success. I then tried Soft Scub cleanser width a soft bristled scrub brush and it did remove the material but only after very hard scrubbing and lots of Soft Scrub) .... it took three applications per area and it took about an hour to do 3 feet of hull. Is there an easier or better way to clean the hull or am I destined to be a scrub person for a few days each year <grin>!
How to clean the hull
- Thread starter Bruce20841
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clenz all
I've had good luck with a product called Clenz All http://www.clenz-all.ca/en/clenz-all.html
I've had good luck with a product called Clenz All http://www.clenz-all.ca/en/clenz-all.html
The first thing they do at a boatyard
when a boat is hauled is they hit the hull with the pressure washer as you suggested. This knocks all of the growth and slime off while it is alive and wet. Give this organic mess a chance to dry out and it can form some very impressive, hard to get off coating. I am not sure that is what happened to your hull or not. It sounds like you eventually got to it with the pressure washer, not right after haulout. I dont know if there will be a chemical magic bullet for your situation but I would try out various thinners/cleaners that you may have around the house or garage before buying every product that promises a miracle cure. Lacquer thinner comes to mind, it takes the paint off of almost anything with a little elbow grease. There may be some marine hull cleaner products that you should try that will no doubt be mentioned by the denizens of this forum. In terms of elbow grease, I would resort to using a tool with an abrasive attachment such as the Scotch brite wheel drill attachment for example. It sounds as though you should plan on repainting the hull after you get whatever organic gunk is on there now. Ablative paints are a good choice as upon each haulout and power washing it will come quite clean, quite quickly. Then re-coat. I am sure you will get many more suggestions. There is a live surface coating inspector (TonyB) who regularly contributes here. I have looked at a lot of paint and various finishes too.
when a boat is hauled is they hit the hull with the pressure washer as you suggested. This knocks all of the growth and slime off while it is alive and wet. Give this organic mess a chance to dry out and it can form some very impressive, hard to get off coating. I am not sure that is what happened to your hull or not. It sounds like you eventually got to it with the pressure washer, not right after haulout. I dont know if there will be a chemical magic bullet for your situation but I would try out various thinners/cleaners that you may have around the house or garage before buying every product that promises a miracle cure. Lacquer thinner comes to mind, it takes the paint off of almost anything with a little elbow grease. There may be some marine hull cleaner products that you should try that will no doubt be mentioned by the denizens of this forum. In terms of elbow grease, I would resort to using a tool with an abrasive attachment such as the Scotch brite wheel drill attachment for example. It sounds as though you should plan on repainting the hull after you get whatever organic gunk is on there now. Ablative paints are a good choice as upon each haulout and power washing it will come quite clean, quite quickly. Then re-coat. I am sure you will get many more suggestions. There is a live surface coating inspector (TonyB) who regularly contributes here. I have looked at a lot of paint and various finishes too.
The magic cure…
“On & Off” It’s an acid. Be careful using it. Will not hurt gelcoat. It will hurt the galvanizing on your trailer, so cover that. It will take the stain off the gelcoat.
“On & Off” It’s an acid. Be careful using it. Will not hurt gelcoat. It will hurt the galvanizing on your trailer, so cover that. It will take the stain off the gelcoat.
Hydrochloric Acid
also called miuriatic acid.. Some algea deposit calcium and the HCl will dissolve these calcium deposits. It's used in construction to clean bricks. Try it diluted 1:10. It will make holes in your clothes so be carefull. "Lime away" will work but is more toxic as will phosphoric or even acetic acids. But HCl is cheap and readily available at Lowe's or Home Depot or about any construction supplier. I applied mine with a garden sprayer and then rinsed with a water hose which should always be available. Eye protection is a good ideal. When the hull stops fizzing like an alka zeltser you know tha tyou have dissolved all of the calcium Carbonate. The HCl concerts the calcium carbonate into calcium chloride and carbon dioxide which is the Fizz. Be sure to rinse well and don't leave the acid on metal for a long time. But at this weak concentration it wont hurt plastic or metal unless it's left for a long time. It will irritate your skin if not rinsed off quickly. Use old clothes and shoes as they may be ruined.
also called miuriatic acid.. Some algea deposit calcium and the HCl will dissolve these calcium deposits. It's used in construction to clean bricks. Try it diluted 1:10. It will make holes in your clothes so be carefull. "Lime away" will work but is more toxic as will phosphoric or even acetic acids. But HCl is cheap and readily available at Lowe's or Home Depot or about any construction supplier. I applied mine with a garden sprayer and then rinsed with a water hose which should always be available. Eye protection is a good ideal. When the hull stops fizzing like an alka zeltser you know tha tyou have dissolved all of the calcium Carbonate. The HCl concerts the calcium carbonate into calcium chloride and carbon dioxide which is the Fizz. Be sure to rinse well and don't leave the acid on metal for a long time. But at this weak concentration it wont hurt plastic or metal unless it's left for a long time. It will irritate your skin if not rinsed off quickly. Use old clothes and shoes as they may be ruined.
Use toilet bowl cleaner
and a scrub brush. Be sure to use one that contains HCl (hydrochloric acid or muriatic acid). It is a little more expensive than the previous recommendation to use diluted HCl, but it comes already diluted, in a squirt bottle, and in addition, it contains a surfactant (soap) that helps to wet the surface and remove dirt etc better than straight HCl. I use "The Works" Since this stuff is a VERY strong acid, use proper protection, especially for your eyes. BTW, there was a comment about phosphoric acid and acetic acid. These two items are both in fairly high concentration in many foods (colas contain lots of phosphoric acid and vinegar is at least 3% acetic acid). Neither is particularly good at cleaning boat bottoms, but the phosphoric acid is probably better than vinegar. You used to be able (and perhaps still can) buy a hull / water line cleaner that contains oxalic acid. Oxalic acid is a powder that you dissloves in water. It is a stronger acid than vinegar, and won't attack your trailer too badly. It's used in wood working to bleach out dark woods. Steve Alchemist
and a scrub brush. Be sure to use one that contains HCl (hydrochloric acid or muriatic acid). It is a little more expensive than the previous recommendation to use diluted HCl, but it comes already diluted, in a squirt bottle, and in addition, it contains a surfactant (soap) that helps to wet the surface and remove dirt etc better than straight HCl. I use "The Works" Since this stuff is a VERY strong acid, use proper protection, especially for your eyes. BTW, there was a comment about phosphoric acid and acetic acid. These two items are both in fairly high concentration in many foods (colas contain lots of phosphoric acid and vinegar is at least 3% acetic acid). Neither is particularly good at cleaning boat bottoms, but the phosphoric acid is probably better than vinegar. You used to be able (and perhaps still can) buy a hull / water line cleaner that contains oxalic acid. Oxalic acid is a powder that you dissloves in water. It is a stronger acid than vinegar, and won't attack your trailer too badly. It's used in wood working to bleach out dark woods. Steve Alchemist
Toilet bowl cleaner is usually potassium hydroxide
I haven't done a survey but the ones that I have looked at are strong alkalis. They are good for dissolving organic types of material and might work if your stuff is mostly organic. But if the deposits are mostly calcium salts the acid will work better. Acetic acid is in vinegar and will dissolve calcium carbonate but not really well. Phosphoric acid is excelent but I haven't seen any readily available. Oxalic acid is excellent but it is more toxic. Oxalic acid is a chelator and chemically binds the calcium. Oxalic acid is the active ingredient in "lime Away" .The thing that I like best about hydrochloric acid is that once it is neutralized it is harmless becoming essentially salt water. HCl is produced in our stomachs to help us digest food. TUMS are basically calcium carbonate and dissolve and react with this HCl to relieve acid stomach. I work in a laboratory for a living if anyone wonders why I think that I know this stuff.
I haven't done a survey but the ones that I have looked at are strong alkalis. They are good for dissolving organic types of material and might work if your stuff is mostly organic. But if the deposits are mostly calcium salts the acid will work better. Acetic acid is in vinegar and will dissolve calcium carbonate but not really well. Phosphoric acid is excelent but I haven't seen any readily available. Oxalic acid is excellent but it is more toxic. Oxalic acid is a chelator and chemically binds the calcium. Oxalic acid is the active ingredient in "lime Away" .The thing that I like best about hydrochloric acid is that once it is neutralized it is harmless becoming essentially salt water. HCl is produced in our stomachs to help us digest food. TUMS are basically calcium carbonate and dissolve and react with this HCl to relieve acid stomach. I work in a laboratory for a living if anyone wonders why I think that I know this stuff.
I 2nd On & Off
Go to any West Marine, MaryKate, On & Off, it has HCL in it. It should remove most of the scum line. A lot of this kind of stain gets right into the gelcoat. A lot of people don't realize how wax actually attracts and bonds with oil floating in the water. That's why I use NewGlass on my C30's white hull. Nothing sticks to it, NOTHING! Wax and oil are made of the same stuff, they attract and bond. I use to spend hours compounding & waxing only to stain the hull within the first 5 minutes of spring commissioning in a oiling slip at the marina. You'll probably have to do some serious compunding to get all that stuff off the hull but I would start with On & Off first.
Go to any West Marine, MaryKate, On & Off, it has HCL in it. It should remove most of the scum line. A lot of this kind of stain gets right into the gelcoat. A lot of people don't realize how wax actually attracts and bonds with oil floating in the water. That's why I use NewGlass on my C30's white hull. Nothing sticks to it, NOTHING! Wax and oil are made of the same stuff, they attract and bond. I use to spend hours compounding & waxing only to stain the hull within the first 5 minutes of spring commissioning in a oiling slip at the marina. You'll probably have to do some serious compunding to get all that stuff off the hull but I would start with On & Off first.
I am surprized that no one has mentioned citric
acid yet. It is cheap, effective, relatively safe, and comes as a crystline powder. Make a gel with corn starch add the citric acid and brush it on let it sit for an hour and rince it off.
acid yet. It is cheap, effective, relatively safe, and comes as a crystline powder. Make a gel with corn starch add the citric acid and brush it on let it sit for an hour and rince it off.
Phosphoric acid
is sold at Home Depot and other hardware stores as Naval Jelly. It is sold as a rust remover as it eats the metal oxides in rust. You apply the jelly with a brush and let it "dwell" for a period of time. Then spray off with water and other agitation. Muriatic acide (Hydrocloric acid) is also sold in hardware stores for cleaning brick and masonary surfaces and is by far the lowest Ph (strongest acid) available. I was not sure how inert gelcoat and fiberglass would be with this stuff but if you do not leave it on too long the group here assures you it is ok to use as long as you protect yourself and any metal surfaces.
is sold at Home Depot and other hardware stores as Naval Jelly. It is sold as a rust remover as it eats the metal oxides in rust. You apply the jelly with a brush and let it "dwell" for a period of time. Then spray off with water and other agitation. Muriatic acide (Hydrocloric acid) is also sold in hardware stores for cleaning brick and masonary surfaces and is by far the lowest Ph (strongest acid) available. I was not sure how inert gelcoat and fiberglass would be with this stuff but if you do not leave it on too long the group here assures you it is ok to use as long as you protect yourself and any metal surfaces.
barkeepers friend
I have had great luck with barkeepers friend also dilute myratic acid (sp) works well on dried marina scum. Allow both a few minutes of soak time. Mike
I have had great luck with barkeepers friend also dilute myratic acid (sp) works well on dried marina scum. Allow both a few minutes of soak time. Mike
dilute fence post cleaner and black streak remover
for algae (brownish) stain removal....dilute deck/fence post cleaner to 50% solution, spray on with hand held bottle (avoid eye contact with mist). buy the cleaner at Lowe's/Home Depot/etc. it needs to have oxalic acid as the active ingredient for black stains use black streak remover (BoatUS/West Marine), follow directions
for algae (brownish) stain removal....dilute deck/fence post cleaner to 50% solution, spray on with hand held bottle (avoid eye contact with mist). buy the cleaner at Lowe's/Home Depot/etc. it needs to have oxalic acid as the active ingredient for black stains use black streak remover (BoatUS/West Marine), follow directions
On/Off
Works great but you pay for it big time. Try looking around the other marine or marineish stores and look for somthing called aluminum brightner and hull cleaner. I have found two different ones most recently at ACE Hardware smells and works just like the Mary Kate stuff but I paid less for a gallon than what WM gets for a quart of the other stuff.
Works great but you pay for it big time. Try looking around the other marine or marineish stores and look for somthing called aluminum brightner and hull cleaner. I have found two different ones most recently at ACE Hardware smells and works just like the Mary Kate stuff but I paid less for a gallon than what WM gets for a quart of the other stuff.
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