Hull and Bottom Cleaning
Boat Performance and Efficiency
Have you ever noticed that a good boat dealer or broker will always have the bottom of a boat cleaned the day before a sea trial? It’s a fact; even the slightest amount of bottom growth will cause inefficiencies at running speeds. Even moderate growth can cause loss of speed and RPM. This equates to higher fuel consumption and loading of the Engines. In other words, your engines are working harder and using more fuel to deliver less speed. In some extreme cases, it’s not uncommon for hard growth on the running gear to actually “snuff out” a very powerful diesel engine when it’s shifted into gear. So it just makes sense and saves operating dollars to maintain that bottom and running gear in as clean a condition as possible.
Hull & Bottom Cleaning and Maintenance
Whether you do it yourself or have a diver or a contracted service do it, you’re saving money and protecting your investment by maintaining a clean hull bottom and running gear (props, struts, rudders and trim tabs). The intake and discharge through hulls and all sea cocks need periodic inspection and cleaning. Zincs need to be observed and replaced when required. Bonding plates and trim tabs need to be free of hard growth. All of this needs to be part of the boats normal maintenance program.
Changing the Mind Set
We’ve spoken to a lot of Boat owners and it seems that if they have a Diver or a Contracted service clean the hull, they don’t put a lot of thought into the ongoing maintenance below the waterline. Here’s the question to ask. Is your Diver or Contracted Service paying for your haul outs and Bottom job? Of course not. But if you’re not vigilant they could be removing more paint than they should during each cleaning and that results in a shorter life cycle of your bottom job. We’re suggesting that you ask them to use the least aggressive mitt or brush for the job and try and preserve the paint as much as possible. In addition our rounded corner New Wave Scraper and an Ultimate Scraper with your boats specific shaft diameter notch, should be kept on board as part of the “ship’s equipment”. We haven’t run into a Diver that didn’t eagerly accept better and more efficient tools for the job.
On the way home from the yard, after that new bottom job, your boat is running as good as it’s ever going to. After that and with time at the dock, marine growth starts to attach itself to the bottom paint. Usually it starts as slime, then soft growth, then assorted barnacles and other hard growth. If you keep your boat in the water year round, your challenges are even greater in trying to maintain that “just left the yard” feeling. The more you use the boat, the less static time marine growth has to set up. Regardless of your usage, you should keep an eye on the waterline. It’s a good indicator of what’s going on below the waterline. If you’re noticing growth at the waterline, it’s time to call your diver or get out your SCUBA gear and our Purpose Built Tools.
If you haul your boat in the winter, your bottom paint is most likely different than what is used in the warmer climates. Refer to your Bottom Paint Manufacturers instructions for cleaning tips. There is a Top Shelf Marine Products Scrubber or Scraper for all situations.
Generally speaking hard Bottom Paint can be brushed. The Top Shelf Marine Products “Hull Mitts” and “Lil Stubby Brush ” are great tools for this. You can cover the hull quickly and knock off the occasional barnacle with the “New Wave Scraper“.
Modern Ablative paint is another story. By nature, the “leaching by design” process is what keeps the slime and soft growth from establishing itself. In other words, the boats movement through the water creates friction that “rubs” the slime and soft growth off. This is accomplished by allowing small amounts of the paints top layer to “leach off”. So again, if you use the boat regularly your bottom may require very little attention until the paint is “leached out” and it’s time to reapply.
If you don’t use your boat regularly, like most recreational boaters and the slime doesn’t diminish after some use, it’s best to address it before it turns into soft growth and starts affecting performance.
With Modern Ablative paint, this is somewhat challenging in that you want to remove the slime or soft growth, but you’d like to leave as much paint protection as possible. It is difficult to have it both ways. We recommend a staged approach, in an effort to remove the maximum growth while preserving as much paint as possible.
If your bottom paint is fairly new or fresh, use the Top Shelf Marine Products “#1 Hull Mitt“. The soft Microfiber mitt will work on the slime while preserving the paint. As the paint gets a little older and the slime and soft growth get more easily established use the Top Shelf Marine Products “#2 Medium Coarse Hull Mitt” The scour pad material is more aggressive on more established marine growth. For maximum cleaning of thick slime and marine growth, use the #3 Hull Mitt. This will remove the heavy build up the quickest. It is also the most aggressive on the remaining bottom paint as well. Because of this we recommend using this on the “last 1/3” of the paints anticipated life. If you ever see a “plume” of paint in the water, you’re using a mitt or brush that may be overly aggressive. Use the least abrasive mitt or brush that removes the slime or soft growth but leaves as much paint as possible. Modern Ablative paints are much more Eco-Friendly than they were some years ago, but you should always be prudent and try to remove the growth and preserve the paint. There will be less impact on the environment and you may be able to stretch the period between haul outs. Always check for compliance with State and local regulations.
Barnacles and other hard growth are sharp, always use our mitts with the appropriate gloves. You should also note that our mitts are consumables, so for longer life, you should chip or scrape hard growth prior to the rub down with the mitt.
Propellers are a major investment and effect engine and boat performance tremendously. Once you get them “dialed in” you want to maintain them in pristine condition. This should include scheduled inspections and cleaning when necessary. Boats that are run and used often rarely need to have their props cleaned. There just isn’t enough static time for soft and hard growth to start and establish itself. In these cases little to no treatment or coating of the props are required. However, boats that are used once a week or a few times per month suffer the most from soft and hard growth on the props. Because of this additional coating treatments are sometimes added in an effort to minimize soft and hard growth on the props (and the balance of the running gear). Some of these coatings are quite effective in reducing growth, and where growth is established, most of it is often “ejected” or knocked off as the prop moves through the water.
But even if you use TriluxTM, Mussel BusterTM, PropspeedTM, ViVidTM or other underwater metal coatings on your props, they will need to be inspected and maintained. Usually just a good wipe down with the Top Shelf Marine Products #2 or #3 Hull Mitt is all that is needed. If you’ve got hard growth on your props, the Top Shelf Marine “Ultimate Scraper or New Wave Scraper ” is the right tool. We discourage you or your diver from using a standard hardware or home improvement store paint scrapper or putty knife. The sharp corners of these scrapers score the Nibral or Bronze. If you just Propscanned® or have CNC machined props, can you think of anything worse to use on them?
Struts are what your prop shaft(s) ride in and the struts stabilize and help balance the shafts. While dirty or fouled struts don’t have as much effect on boat or engine performance, they will create drag which will slow the boat and cause the engines to labor. They need to be inspected and cleaned as well. Recently some of the above mentioned underwater metal treatments are added to shafts, rudders and struts, as well as the props with good success. The Top Shelf Marine Products #2 Hull Mitt or #3 Hull Mitt work here as well.
Cutlass bearings keep the shaft(s) turning without overheating in the struts. If you’ve ever looked at a cutlass bearing you’ll know that there are series of peaks and valley’s fabricated out of polymer or rubber. This keeps the shaft(s) centered in the struts with the “peaks” making contact with the shafts. The “valleys” are extremely important because the flow of water through the “valleys” keeps the cutlass bearing and the shaft cool. Hard growth is notorious for forming on the front and rear of cutlass bearings and impeding water flow. The Top Shelf Marine Products “Ultimate Scraper” has a pick end designed for this application and is a great tool to remove hard growth from cutlass bearings. Our “Utility Chase and MacGyver Wire” is a great tool for pushing through the “valleys” of the cutlass bearings to ensure unimpeded water flow.
Shaft(s) and Rudders
Shaft(s) and Rudders have the same demands as props and struts. Soft and hard growth adds drag and effects performance. In extreme cases a large amount of hard growth on the shaft(s) can induce vibrations and cause excessive wear on the cutlass bearings. For soft growth we recommend the Top Shelf Marine Products #2 Hull Mitt or #3 Hull Mitt. For hard growth the Top Shelf Marine Products “Ultimate Scraper” is notched for your specific shaft diameter and does a great job of knocking hard growth off quickly and efficiently. You can scrape an entire shaft in two or three passes as opposed to many with a traditional scraper.
Intake and Raw Water Screens and Scoops
Your main engine(s) and generator depend on an unobstructed flow of raw water to maintain cooling. Dirty or fouled Intakes or Scoops impede water flow and set up downstream strainers and other plumbing for restrictions and blockages. Use the pick end of the Top Shelf Marine Products “Ultimate Scraper” to keep the slots or holes of Intakes and Scoops clean.