THE CASE FOR REPAIRING A DAMAGED PROPELLER

 When it comes to damaged propellers, the first question most boaters ask is: “Is my prop worth repairing?” The answer is always the same, “It depends on the level of damage.” When considering whether to repair a propeller or to purchase a new one, boaters need to consider several factors.

One of the first and primary considerations is cost. If the repair costs start to approach the price of a new prop, then no, it’s not worth repairing. The second factor to consider is a critical one: What’s the degree of damage? There are some cases where a propeller is not repairable even though the damage doesn’t look like it’s too severe. For example, if the blade is bent in the root, where it attaches to the hub, it is typically not repairable because it’s almost impossible to straighten the blade in this area. Another reason that a propeller may be beyond repair is the amount of material that is missing from the blades. The amount of welding time can increase the cost of the repair to the point where it may be more cost effective to just purchase a new one. In the case where the hub has been shifted, or “spun” from its original factory position, and there is significant damage to the blades, then it may be advantageous to purchase a new propeller.

Other factors include this frequently seen scenario: Boaters bring in a damaged prop that was the incorrect one for their particular boat/motor combination and application. In this instance, it would definitely be unwise to repair this prop. Remember, because a prop came on the boat doesn’t mean it’s the correct one. Another consideration is a practical one. “Will my repaired propeller be as good as the original?” Yes, if it is done properly. When repairing any propeller, care must be taken to bring that propeller back to its original factory design, diameter, pitch, rake, cup, and blade geometry. A certified repair professional will consider these factors in addition to the profile of each blade, its thickness, and the balance of the prop. That’s why it’s important to select a repair specialist that has been certified by the National Marine Propeller Association to perform the repair. When it comes to repairing or replacing that damaged propeller, there is no one size fits all answer.

by Stew Foster, NMPA Certified Member

Prop Masters Inc.