Install boat prop

Note: A vise can be used to hold key and then filed, but care must be taken not to tighten too much, causing burrs and irregularities on key. When propeller hub moves to the correct position, install propeller nut on shaft and torque to seat the propeller. Install the torque jam nut also, if your shaft is so equipped. If you have any questions, please email us or call Remove propeller. Put propeller back onto shaft taper. It it does not, perform the following: a.

Remove propeller from shaft. Place a file on a flat surface area or work bench. Install cotter pin at the end of the shaft.

Each winter, and during often clearly predicted equinoctial gales, mariners who exercise very poor judgment are snatched from vessels nearly all of which are conspicuously floating on their lines along the US East Coast.

Last January a catamaran was abandoned in much the same manner, off North Carolina, it was a new boat on a veritable shake down with a professional skipper. Lucky for these folks, the region has what is likely the most complete rescue safety net in the world, which includes Coast Guard, Navy and Air National Guard assets among others.

I have a theory as to why the incidence of such rescues seems to have increased. This was a training ground of sorts. These folks gained experience, and if they opted to go off shore, they invested the time and effort to learn how to use a sextant and sight reduction tables. For better or worse, this is no longer the case, anyone who can push a button can venture off shore. Still, I believe there is a connection between its proliferation and those being rescued.

Before setting off on any voyage, know the limitations of your vessel and her crew, and make sound decisions regarding the season and weather. For those genuinely in peril through no fault of their own, of course none of this applies. Look for an upcoming in-depth analysis of this event by Marine Systems Excellence contributor, author and circumnavigator Ralph Naranjo.

I hope you find it both useful and interesting. Please visit www. Top Shelf provides unique, specialized products for in the water hull and bottom cleaning,engine room and deck care and maintenance. A few years ago I delivered a seminar in which I discussed the procedure for propeller installation. The number of steps involved in executing this process came as a surprise to many of the attendees.

In my experience, in roughly three out of four propeller installations the necessary steps are not followed. During the years that I worked as a marine mechanic and then boat yard manager I established a protocol that I believe leads to secure, reliable propeller installation. While you may not undertake this work yourself, you certainly can insist and ensure that others follow these important steps.

Inspect shaft tapers for any signs of corrosion, pitting, scoring or any irregularity. Pitting, shown here, would require repair or replacement of the shaft. Inspect both the prop shaft taper and the propeller bore, the cone shaped hole in the center, for dents, scoring, corrosion or defects of any kind.

Be sure to inspect the keyways the rectangular troughs on both the shaft and prop as well, along with the key for similar issues. Keys should fit snugly into keyways, not too loose and not too tight. If the key is too loose, the propeller can move independently of the shaft, which in turn will lead to keyway damage. Keyways should be clean and free of debris or scale, to ensure the key fits properly, and avoids binding of the propeller during installation.

Lapping compound, shown here having been applied to a shaft taper, has the consistency of we sand. It removes material from the prop bore, allowing a custom fit between bore and shat taper.

The first time a propeller is mated up with a shaft, whether both or either are new, they should be lapped to ensure a proper fit. Doing so grinds away some of the material in the prop bore, establishing a custom fit. The prop is then removed and the lapping compound washed off. Machinists dye, typically blue or purple, acts as an indicator, determining where the shaft and prop are making contact.

The propeller should then be placed onto the shaft as far as it will go, without the key installed. Using a sharp awl, scribe a line in the shaft at the point where the forward section of the propeller hub ends. Remove the prop, install the key and then apply a light coating of liquid lubricant such as CRC or WD 40 to the shaft taper and key.