World Leader in Marine Exhaust

Frequently Asked Questions

Frequently Asked Questions About Marine Exhaust Systems

A salt deposit on a muffler indicates a “weeping” spot where water is escaping. How to fix a leaking boat silencer is a question frequently asked of the exhaust systems experts at Centek Industries.

THOMASVILLE, GEORGIA (USA) – Since 1962, Centek Industries has designed, engineered and built more than 15,000 custom marine exhaust systems for yachts, workboats, military and law enforcement vessels and many of these designs are used continuously to build exhaust systems for thousands of new boats and refits annually.

At Centek headquarters in Thomasville, Georgia (USA), company experts frequently answer questions about the design, engineering and manufacturing of custom marine exhaust systems. Centek’s engineering staff has more than 80 years of marine wet exhaust system design and innovation experience. Centek is the only registered engineering firm to offer fiberglass exhaust components that are Lloyd’s Register Type approved and meet or exceed ABYC-P1 standards. Centek has also earned a Certificate of Conformance for ISO 9001:2015, for the excellence of its quality management system.

Here are some the most frequently asked questions.

1How do I make my boat quieter?
This one is right in our wheelhouse. There are several options available when it comes to sound attenuation for both propulsion and generator engines. Centek assigns a rating to their standard exhaust products with the range going from Good to Better to Best. Generally speaking, and compared to straight exhaust, the Good rated muffler provides 15-18 dB of attenuation, a Better rated muffler gives a 22-28 dB improvement and a Best provides an improvement of 25-30 dB. These are ballpark estimates and should be used as a rule of thumb. Also available are custom systems that can provide even better results depending on your specific engine and space available. For generator mufflers, these same standard mufflers and ratings are used but at the same time there are other considerations to take into account. Is the noise you are hearing actually the engine running or is it the irritating splash you hear as the exhaust cooling water is discharged overboard? If the overboard discharge is the culprit, consider adding a Gen-Sep and separate the cooling water from the exhaust gasses. The exhaust gas is then discharged to the atmosphere and the cooling water is discharged below the water line thus elimination the splash you hear when the gen-set is running.
2I am doing a re-power - can I use the same exhaust?
This is usually one of the first questions asked when it comes to a re-power for both propulsion engines and for generator upgrades / changes. The short answer is maybe. To get the most from your new engine or gen-set, it is important to make sure that the exhaust system is properly sized. A properly sized exhaust system provides the best sound attenuation and stays within the backpressure limits set by the engine manufacturer. When Centek engineers recommend a specific size, they take into account a number of variables which include, but are not limited to, horsepower, raw water flow, exhaust flow and temperatures, the position of components relative to the waterline and the backpressure limits. If you have a question whether or not your current system will work, call and talk with a Centek engineer and let them help guide you through the process. Also, keep in mind that Centek can supply an almost endless variety of elbows and fittings for your new project.
3I have a leaking muffler. How can I fix it?
Often customers call in with questions about boat mufflers or other exhaust components that have developed a leak. In addition to looking for dripping water on the muffler body or water in the area of the muffler, another sign to look for is salt deposits on the muffler. These salt deposits appear as a white chalky substance and indicate a “weeping” spot where water is escaping. Before any consideration of a repair or replacement, first determine why the leak occurred. Almost 100% of the time, this type of leak indicates that the boat silencer experienced overheating due to a loss of cooling water in the exhaust stream. If the cause of overheating is not corrected, any repair is going to be short lived. Centek uses high temperature resins in all our products; however, if cooling water is interrupted, exhaust temperatures can sky rocket quickly. When temperatures reach a certain point, the resin is essentially baked out of the resin/glass matrix causing water droplets to seep from the damaged area. When a muffler or other exhaust component develops a leak, the best course of action is to replace the item. A good fiberglass shop can patch a leak on a temporary basis but replacement is critical. Keep in mind, when cooling water is lost and temperatures spike, damage can occur to the internals of the muffler or component that is often impossible to see.
4I have limited space in my engine room for a genset muffler and none of your catalog mufflers will line up. What can I do?
Rest assured, we can help! While we have a catalog full of standard mufflers and components, our specialty is designing custom parts to fit unique applications. The process is pretty simple – just give us a call at 229-228-7653 and talk with one of our engineers. They will ask a few questions about your genset to make sure they size the muffler correctly and will then work with you to design something that will fit in your available space. It could be something as simple as moving an inlet or outlet a few degrees to designing something from the ground up. Either way, we can design and build whatever you need.
5My boat has an old metal muffler that is rusty and leaking. Can I replace it with a fiberglass muffler?
Assuming that your engine is water cooled and does not have dry exhaust, the answer is yes. In fact, why metal mufflers are ever used in a wet exhaust system is a mystery to us! All we need is a bit of information about your engine and its location relative to the waterline along with some general dimensions. The quickest route is to give us a call or drop us a line at . If you have pictures of the old unit(s), those would help as well. You can even send us the old mufflers and we can measure them up and send you a drawing for your approval. Once everything is approved, we build the new units and send them to you. Easy as that!
6I have an old cruiser with a muffler called a “Naqualift” that I need to replace. I searched for that brand and see that the company is out of business. Do you have something that will work?
Naqualift was a brand name from a company called Marine Muffler which closed their doors back in 2008. The good news is that we can certainly help. We have a cross reference list of their old part numbers and if that doesn’t work, we can build you something from scratch. Either way, give us a call and we will get you back on the water ASAP.