Monthly Archives: March 2013

Tech terms

Pitch – the theoretical distance in inches that a propeller moves forward in one revolution. Think of a screw in wood. If you increase the angle of the threads, it will move further into the wood in one turn. Diameter – the diameter in inches of the circle that the blade tips will cut. Or, the distance […]

Should I go from a three blade to a four blade prop?

If you look at a propeller from behind, and visualize a circle that the blade tips would draw, you will see that the blade of a 3 blade prop covers about 50 -55% of the circle. (This is called diameter area ratio, or DAR). You can add thrust within this drive circle by increasing that […]

Do composite and aluminum props flex?

Of course! All propellers flex. What is often missed is that flex is a good characteristic. For example, if a prop flexed under the load of acceleration, it would actually be reducing its pitch, which in turn would produce a faster acceleration. A problem would occur only if the prop failed to return to its […]

What about composite props?

When propellers made of composite, or plastic, first came on the market over 14 years ago, I was very skeptical that they could match an aluminum prop in strength and performance. Today, while not all composites are created equal, a couple of manufacturers use space age composites to exceed the strength of the old traditional […]

Should I spend the extra money for a stainless propeller?

In most cases, by simply making a direct conversion to stainless in the same size as your aluminum prop, you will notice an improvement in both acceleration and top speed. The reason for this is very simple, but frequently misunderstood. Stainless is seven times stronger than aluminum. Propellers don’t have to be that much stronger […]

How can I make my boat come on plane faster?

There are many factors that can cause a boat to have difficulty coming onto plane. Consider for example, your total boat weight, weight distribution, engine trim, hydrofoil, and transom tabs before investing in a new propeller. To assist in the correction of on plane problems, you may also need a different propeller. Your first choice […]

Should I repair my prop, or buy a new one?

Most small dings or bends in an aluminum prop can be repaired for a reasonable price. If you do repair, make sure the shop does not file down the blade edges thereby reducing diameter. If your damage includes bites or chunks out of the blade, you should consider a new prop. Keep in mind that […]

How much should I spend on a propeller for my boat?

I advise boaters to spend as much as it takes to get the right propeller for their boating application. Don’t be too concerned with prop costs because the biggest bang that you can get for the buck, when it comes to boat performance, is with the propeller. Remember that a slightly incorrect type or size […]