If you’ve ever been bilge-diving in your boat, then you’ve likely been face-to-face with a water strainer at one point or another. Designed to filter out everything from seaweed to Styrofoam, these devices keep debris from clogging all sorts of boat pumps, including engine, bilge, air conditioning, and freshwater pumps—and beyond.
Like all boat parts, they have a tendency to wear and fail, with the primary culprits being seals, sight glass bowls, and baskets. Luckily, many of the strainers installed on boats over the last few decades have changed very little, and that means means finding repair parts and kits can be relatively easy.
The most common type of strainer found on inboard powerboats or sailboats with auxiliary engines is a raw-water strainer. These are used to keep jellyfish, plastic bags, and other debris from clogging your engine’s cooling pump, and are generally made out of bronze, with a plastic sight glass and a stainless, plastic, or Monel strainer basket. Plastic ones are becoming more and more popular, especially on European-built boats. You might also find raw-water strainers on air-conditioning or wash-down pumps.
The strainers used for bilge pumps, shower sumps, and freshwater pumps are common on all types of boats, and generally are made entirely of plastic, except for the strainers, which are mostly stainless-steel. That means their overall low replacement cost can make finding individual parts difficult; sometimes simply buying a new one is more realistic than tracking down individual parts.
All of these strainers share some common replaceable parts. These include, as mentioned, the sight glass, strainer basket, and sealing gaskets. Some of them, especially raw water strainers, have an access lid sealed by a gasket that allows the strainer basket to be removed for cleaning. Yours may also have a drain plug and seal. Others, like bilge and freshwater strainers, have sight glasses that simply spin off, and are often sealed by a simple O-ring.
Depending on what ails your strainer, first snap a photo of it with your camera or smartphone; most strainers have lots of identifying marks or labels. Next, take the offending part(s) and your snapshot to your local marine supply outfit. Gaskets and O-ring seals are usually available in an off-the-shelf repair kit, while baskets and sight glasses are less common and often must be ordered.
There’s not much substituting to do with most of these parts, but you can often find generic O-ring seals at an auto supply house or hardware store. Just make sure they are exactly the same size and shape as the old ones; more than a few boats have sunk from faulty seals on raw-water strainers. Also ask for nitrile rubber O-rings, as they are solvent-resistant. Some strainers use cork seals, which are harder to find substitutions for.
If you strike out on finding repair kits or individual parts, the first thing you need to do is decide whether you have the time and patience required to track these bits down, versus simply buying a whole new unit. No time or patience? Have your marine supply shop pro spec out a new one for you. But if time and patience are on your side a bit of research can make you more knowledgable, and maybe save you money.
If you know the manufacturer, try sleuthing around their website to find your particular strainer model (refer to those snapshots you took with your smartphone or camera), and then contact them to see if you can order the parts you need. You may also want to look in marine retailer catalogs to find a match. Here are some popular strainer manufacturers, with links to their websites.
If you don’t have any luck, don’t worry; there are still some options. Try looking online for owners’ associations for your particular make and/or model boat. Those associations or groups typically have a discussion board where you can post pictures and ask questions about your own boat. Also give general boating enthusiast sites a try. And consider perusing one of the big box marine store catalogs—you may just come across your particular strainer model and be able to order parts for it.
For more used-boat part sourcing ideas, see the following:
- Used Boat Part Sources: Latches and Locks
- Used Boat Part Sources: Gas Struts
- Used Boat Part Sources: Port Gaskets
- Used Boat Part Sources: Hatch Gaskets
- Depthsounder Transducer Cables: Airmar-Gemeco Retrofits
General tips for locating hard-to-find replacement parts for your used boat:
Take digital photos of the item you need to replace and compare them with photos you find in Google Search –> Images. When you find a match, click “Visit page” in the image dialogue box. That will often get you to the source – or at least a step closer.
Google the part numbers
Look for a part number on the item you need to replace. Even if you don’t know the manufacturer you can enter the information you do have in Google Search, e.g. “SPT 10-437A, 12-volt cabin light” and you’ll often get good results.
These days a tremendous number of manufacturers and distributors of marine parts have storefronts on Amazon, and Amazon has really superior search, reference, and logical abilities.
Boat Trader has plenty of Buying and Selling advice, but also check out the hundreds of articles in the Boating section, with tips on everything from seamanship to maintenance, how-to, where to find replacement parts, and much more.