Archive for the ‘Mechanical “How-To”’ Category

Weld the washer to the stub before you weld the nut!

Weld the washer to the stub before you weld the nut!

1. Removing Broken steel engine exhaust bolts or studs that are broken off in a blind hole: If possible, start the engine and get it up to operating temperature, then turn it off immediately and disassemble as necessary to the point where penetrating oil or even candle wax can be dripped on the exposed threads of the exhaust bolt or on the bolt stub. The oil/wax will find its way along the bolt threads. If there is a stub sticking out, an effort must be made to grab it with Vise-Grip locking pliers. If it can’t be gripped, try to carefully turn it out of the hole with a hammer and chisel. A bolt remnant that has broken off flush or below the surface of the work piece will usually be loose in the threads. In such a case, it often works to carefully use a punch or chisel and drive on the outer perimeter of the bolt to turn it counterclockwise.

If these efforts fail then it is a good idea to first weld a washer onto the stub, and then weld a nut to the washer. Next, attempt to turn the stub out by the nut that was just welded.

If this won’t move it, use a left-handed drill bit to drill a hole in the bolt so that an Easy-Out may be driven into the freshly drilled hole to remove the bolt. Just starting to drill a broken stud with a left-handed bit will typically be enough to turn the bolt out of the threads.

A six-point wrench will grip a worn bolt head.

A six-point wrench will grip a worn bolt head.

2. …. a rounded-off bolt head or a head that has rusted away: First, try an undersized 6-point box-end wrench as shown. If this does not work, dress off the rounded head and press or drive a larger nut over the head of the bolt, then weld the larger nut to the bolt head.

 

 

Removing a through-bolted stub

Removing a through-bolted stub

3. …. a bolt used for through-bolting is broken-off: If the back of the bolt can be accessed, it can sometimes be turned by gripping with pliers after treating it with candle wax or penetrating oil.

Removing a below-flush stub.

Removing a below-flush stub.

4. …. a threaded bolt used for through-bolting is broken off, but not in a blind hole: A broken threaded bolt in this state can, with practice and skill, be blown out with a cutting torch, leaving the threads undamaged. After the bolt is blown out, use a thread tap to clean the holes.

5. …. a threaded bolt or stud is broken off above-flush (i.e., standing proud) in a blind hole: To drill out the broken bolt, first grind a center in it, and then proceed as in the accompanying illustration above.

6. …. a threaded bolt or stud is broken off below-flush in a blind hole: Probe gently with an ice pick to determine if the broken piece is locked in place or if it appears to wiggle. If it moves easily, this is a good sign. Grind a center in the broken bolt if it is to be drilled out, and begin drilling with a left-handed drill bit; it may spin right out of the hole.
Drive in a piece of wood to prevent nipple collapse.

Drive in a piece of wood to prevent nipple collapse.

7. …. a threaded brass (yellow metal) fitting is broken off in a blind hole: An internal pipe wrench or large extractor will usually remove this kind of fitting. The internal pipe wrench fits inside the piece to be removed. As the wrench is turned, it expands. This action saves collapsing and damaging the fitting during removal. When no internal pipe wrench is available, drive-in a piece of wood and then use a pipe wrench or vise-grip plier on the outside.

8. …. a pipe nipple is to be removed: The nipple will sometimes collapse under the jaw pressure of a conventional external pipe wrench, especially if it is thin-walled. To prevent this, insert a solid, snug-fitting object into the nipple before using the pipe wrench. Even a piece of wood can be driven inside the pipe.

Use a fitting extractor to remove broken fittings.

Use a fitting extractor to remove broken fittings.

9. …. a threaded steel (gray or bright metal) or aluminum fitting is broken off in a blind hole: Use an internal pipe wrench to remove a larger broken fitting, and an Easy-Out style extractor to remove a smaller one. In the accompanying photo an aluminum coolant pipe was broken off in an aluminum intake manifold. A large diameter extractor was first driven into the broken-off stub of threaded aluminum tubing. Then the threaded boss in the manifold was heated to expand the metal around the broken fitting, and finally the broken remnant was turned counterclockwise and removed. (Excerpt from “PRACTICAL BOAT MECHANICS” to be published this fall.)

(Some of this material excerpted from “PRACTICAL BOAT MECHANICS”, by Ben L. Evridge, to be published this fall.)

 

Access The \

Remember, some marine transmissions have a come-home feature you can engage if the forward clutch fails. Check the operator’s manual to see if yours is so equipped.

The come-home screws are accessed from the rear of the transmission, as shown above. With the engine off, remove the access plugs and turn the inner screws as directed in your manual, until they bottom. Re-install the plugs.

Caution: With the come-home screws engaged, there is no neutral position or reverse gear. Until your tranny is repaired, the boat will be moving forward anytime the engine is running! (Excerpt from PRACTICAL BOAT MECHANICS, to be published this fall.)

(Some of this material excerpted from “PRACTICAL BOAT MECHANICS”, by Ben L. Evridge, to be published this fall.)

Raw Water Impeller Fragments Recovered From An Oil Cooler

When the raw water pump fails, which is usually due to running dry, the impeller must be replaced. But wait! You must find and remove the pieces of the failed impeller that flowed down stream from the raw water pump. Until you retrieve these pieces, you can consider the water flow from the raw water pump to be plugged.

This plugging will cause overheating of the transmission, the engine and also the wet exhaust system hoses and related plumbing.

As the above photo shows, this transmission oil-cooler, the first heat exchanger in this system, was eighty percent plugged. Transmission overheating and failure was the result.

After clearing the blockage, the next step is to lubricate the new impeller with mild liquid soap before installation of the impeller. Finally, run the engine for a few minutes to wash the soap from the system.

The DE-!0 Fuel System

To identify your Deere diesel fuel system, compare it with this photo and those below.

The VP-44 Fuel System

This photo identifies the VP-44 fuel system used by some Deere engines.

Common Rail Fuel System

This photo will help you identify the Common Rail fuel system that feeds your Deere engine.

An Emergency Frequency (Cycle) Meter Check

When the Frequency Meter on your gen-set goes out, or is in question, try this: Check the accuracy of the frequency meter with a 120-volt clock (with a second hand), and a good wristwatch.

1-Just plug the 120-volt clock into the circuit powered by the generator and coordinate its second hand with the seconds on your wrist-watch.

2-Next, watch for three minutes to see if the generator-powered second hand runs faster or slower than the second hand on your wrist-watch.

3-Adjust the generator engine-speed until the second hand of the 120-volt clock matches the one on your wrist-watch.

(Some of this material excerpted from PRACTICAL BOAT MECHANICS, Ben L. Evridge, to be published this fall)

 

Turn Your Engine Into a Bilge Pump

If your bilge pumps get knocked out and the boat is filling up, remember this: By re-plumbing your engine’s raw-water pump, it is possible to take water from the bilge and pump it overboard.

Simply detach the raw-water intake hose from its sea cock (after closing the sea cock) and plunge it into the bilge. Start your engine and monitor the water level, to be sure your engine has plenty of cooling water.

Be Sure to put some kind of screen or strainer over the raw water pump suction hose, to avoid plugging.

Welcome to our MER Technical Blog. We’ll be sharing the best, most practical boating stories we’ve heard about getting home safely. We hope you’ll share your best boating and survival tips!

Many years ago Kodiak logger, Paul Hansen, was crab fishing with his dad twenty miles east of Old Harbor, Alaska, off Kodiak Island. All was well until something gave way in the steering system, and suddenly control of the boat was lost. Looking in the lazarette, they found a vital piece of the steering mechanism had broken and required welding. With no welding machine on board, they knew they had to get to Old Harbor to make the repairs.

With the broken steering, the boat would only go in big circles, always turning the same direction. To compensate, Mr. Hansen had the crew tie a line to a six-by-six crab pot and ease it over the stern. Next he directed them to secure the line to the capstan in the middle of the deck. They adjusted the line so that the crab pot was barely under water.

When the boat was put in gear and the crew slid the line from the port side of the stern to starboard and back, as needed, to keep the boat headed for Old Harbor. They soon arrived safely, having steered for twenty miles with a crab pot!

The Hansen technique will work with many variations.

(Some of this material excerpted from PRACTICAL BOAT MECHANICS, by Ben L. Evridge, to be published this fall.)