Water-lift Muffler Advice

Centek offers guidance on DIY muffler project.


I want to build a stainless-steel water-lift muffler for my boat. The muffler will have a 2-inch inlet/outlet for a 15-horsepower OMC saildrive. What should the distance be from the bottom inside floor to the bottom of the outlet exhaust pipe?

Steve Strickland
Icebraker, Buccaneer 27
Milton, Ore.

We consulted the folks at Centek Industries, a company that manufactures custom and production water-lift mufflers, to answer your question, and they explained that it really depends on the diameter of the mufflers body and the engine specs. According to Centek Vice President Bill Arwood, the exact ratio is a trade secret, and he wasnt keen to share it. However, Arwood did say that Centek engineers are available to help guide you through the design process for your do-it-yourself (DIY) muffler.

He also cautioned against using stainless steel as the material for a muffler because of its tendency to corrode, especially in salt water, in muffler applications. When the salt water mixes with the exhaust gases, it creates a very acidic solution and really does a job on the steel, Arwood explained.

Instead, he recommended a muffler made from fiberglass. They are inexpensive and will last the life of the boat, as long as the engine they are connected to doesn’t lose cooling water and overheat, Arwood said.

Centek sells production muffler kits and also builds custom mufflers (inlets/outlets in unusual spots or at unusual angles) for the same price as the production mufflers, according to Arwood.

If any other readers have successfully made a DIY water-lift muffler, wed like to hear about it. Please email your story and photos to practicalsailor@belvoir.com.

Freeing Stuck Masts

Fairly often, we are asked whether there is a proven way to break an anodized aluminum mast away from an aluminum mast step. While the question typically comes from small-boat owners, we were encouraged to print a response by the several complaints we received about corrosion-fused masts and mast steps from Islander 36 owners surveyed for this issues used-boat review.

Assuming that the problem is indeed corrosion at the step-to-heel interface, we recommend starting with the least invasive option-as you should with most boat projects. The first treatment should be dousing the junction with white vinegar and wire brushing the corrosion; squirt the white vinegar into the mast-wire exit hole, near the heel fitting, multiple times. Let this sit for a while, and try to release the mast again.

If the vinegar wasnt successful, rinse the area with fresh water, allow it to dry, and then apply a penetrant such as WD40 in the same area. Use a rubber mallet to coax apart the stuck parts.

If the mast still isn’t budging, carefully heat the mast heel or step (whichever functions as the socket and needs to expand) with a hair dryer, heat gun, or propane torch (if its not painted). (Keep in mind that some of the penetrants are flammable; having a fire extinguisher at the ready makes sense.) Then spray PB Blaster (www.blastercorp.com) or CRC Freeze Off (www.crcindustries.com) onto the heel (or whichever part needs to shrink slightly). If its still a no-go, keep dousing the area with Liquid Wrench for a few days, and then, try again.

For more on penetrants, check out Freeing Seized Hardware in the January 2016 issue and Rust Busters in the April 2009 issue.

Practical Sailor has been independently testing and reporting on sailboats and sailing gear for more than 45 years. Supported entirely by subscribers, Practical Sailor accepts no advertising. Its independent tests are carried out by experienced sailors and marine industry professionals dedicated to providing objective evaluation and reporting about boats, gear, and the skills required to cross oceans. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser who has been director of Belvoir Media Group's marine division since 2005. He holds a U.S. Coast Guard 100-ton Master license, has logged tens of thousands of miles in three oceans, and has skippered everything from pilot boats to day charter cats. His weekly blog Inside Practical Sailor offers an inside look at current research and gear tests at Practical Sailor, while his award-winning column,"Rhumb Lines," tracks boating trends and reflects upon the sailing life. He sails a Sparkman & Stephens-designed Yankee 30 out of St. Petersburg, Florida.


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