Tech Net B

Ballistol is a product that works on corrosion, rust, and so much more. Inexpensive. (Destiny)

We have successfully used Ballistol for wound care on humans and animals. (Geru)

(also self-care)


Query: How to keep alkaline batteries from corroding before use?
Use BoeShield T-9. (C_Language)
Use plastic boxes that were designed to store them. These can be found at the Container Store. They each hold 12. (Blackfoot)
Wipe battery before use to remove any residue. (Solitaire)

Issue: Coin battery connections are corroding on contacts.
Clean them with WD 40.
Use Flitz metal polish on connections.
A pencil eraser will also work to clean them.
Use a grease like Lanocote after cleaning.

Do not dispose of batteries in fire. During a trash burn, forgotten AAA batteries went off like fireworks.

Store 9 volt batteries with electrical tape on their terminals. 9 volt batteries are most likely to be shorted by storing them in a box with others. Sometimes house fires have been started by this shorting. (Salty Paws)

Online cross reference charts for battery replacements:
Batteries in a Flash
Watch Battery
List of Battery Sizes - Wiki

(also tech net library)


For the treatment of sulfuric acid burns use water; just water. Do NOT use an alkaline solution... just water. (Salty Paws)

Issue: Corrosion on positive lead.
Use Lanocote to block leakage.
It may be seeping or leakage of acid vapor around the post. Use a felt washer on the post before putting the terminal on. Be generous with Lanocote. (Dyad)
Can use Captain Tolley's then Goop after cleaning the area first. (Salty Paws)
Use liquid silicone rubber as a sealant. It can be found in hardware and automotive stores. (Rejoice)
Increase ventilation in the engine compartment to help prevent corrosion. (Cookie Monster)

Issue: 6 volt lead acid batteries have gray corrosion around negative terminals. Have cleaned them, just to have it return.
There may be a fault in the seal.
Check to see if they've got enough ventilation.
Move the batteries around.
Use some Captain Tolley's to help seal it.
Use greased O ring over the post to help seal a small leak.
Delicately melt the plastic around the post to seal it... however, this may make the plastic brittle.

Issue: Start battery went dry; I refilled it. Now it's flooded.
Give it a slow charge on shore power.
Fully charge it, then let it sit two days, then take a reading.
Check the charge voltage.

Issue: Voltage on gel cells drops fast.
Set regulators to 14.1.
Charge them up, disconnect, then let them sit overnight. Then check the voltage.
You can also run a 20 hour test.
Measure voltage right on the battery, rather than at the panel.

Query: A Battery Life Saver is supposed to prevent sulfation while docked. Is this product any good?
Marketing guys say yea.
Battery guys say nay.

Query: How long do house batteries last?
About eight years.

Query: Five cells had clear liquid, one had black fluid.
Was this from a defective battery or overcharging? It's been replaced.
That's evidence of manufacturer's contamination.

Issue: Switched from lead-acid cells to AGM batteries. They charge too high on the generator.
AC is programmed for 14.35 but when running the generator, it's supposed to get to 14.55.
May have to override the settings.
Generator may be maxed out.
14.55 may be okay as long as it's got ventilation and doesn't get hot.

Query: There's differing amounts of corrosion on terminals. Why the variation?
Some acid comes up as particles and air flow may affect each terminal differently.
There's higher resistance in some terminals.
May want to change the clamp on the problem terminals.
Use copper washers instead of stainless.

Query: Batteries are 5 years old. Should they be replaced now?
Measure the amp hours during discharge.
Visually inspect the plates.
Put a 10% draw on them and let them sit for a few hours to 30-40% test.
Moderate the load at 12 hours.
Measure voltage (DMM).
After testing they should be 12 volts.
If you're dockside long-term, unplug for 30 days and allow solar panels to do the work.
Use a battery monitor such as Link 10.
If you decide to replace, golf cart batteries work well.

Issue: Lead acid batteries. Cells near positive terminals use lots of water while the cells near negative terminals use almost none.
They may be charging at too high a rate.
Check trickle charge rate.
Check the voltage rate at the battery.
Check the battery temperature compensator as the battery gets warm.
With hydrometer, check gravities between cells.
At a heavy charge, physically touch the terminals for warmth.
Clean the terminals.

Physically feel the wires and terminals for heat. This will help determine the state of the connections. (Salty Paws)

Lithium Phosphate Batteries (LiFePo). Advantageous for all anchoring full-time liveaboards. They're lightweight, have long cycle life, steady voltage, and a fast charge. They're more expensive at time of purchase but cost less over a lifetime. (Alchemy)

Lithium batteries are a hard on alternators. Run alternator at half power.(Dyad)

Laser thermometers are very accurate and useful for checking battery temperature without burning your hands. (Valkyrie)

Issue: Trace inverter battery charger goes from bulk mode to float mode when there's a heavy DC load.
The fan may not be working.
Adjust the settings on the charger.

Query: My Xantrex battery charger draws too much current from my Honda generator. How can I reduce the power consumption of my Xantrex battery charger?
Adjust the power share in the control panel setup menu. (Windswept 4, Discovery)

I talked to the Deka reps at the Annapolis Boat Show about gel cell batteries. They now advise the highest voltage for charging 14.6 volts, instead of the everlasting 14.1 volts, which is what I have been charging our gel cells for the past 15 years. The reps stated, that there has been extensive testing over a wide time frame to support the new/higher charging voltage. The higher voltage will allow quicker charging and somewhat diminish the plate sulfate issues, which the reps promoted. (Five and Dime)

Query: Would like any input about solid state battery combiners.
Reliable, no voltage drop, low maintenance. West Marine carries them. (Salty Paws)
Rated for 50 amps.
Recommend using more amp rating than you think you need. (Bayou)
It's fast. Responds in micro-seconds. (Zephyr)
They work well and take care of themselves. Have long lifespans.

Query: Can AGM batteries be partially equalized?
No, it should be done all at once.
If you can hold them at 15 volts for 12 hours that will equalize them.

Issue: Equalizing created a variable rate of water usage.
Shuffle the cells around, if possible.

Low voltage during heavy load and/or high voltage during charge probably means a dying battery. (C_Language)

When equalizing doesn't work due to one low cell, try "reverse equalization." Bring all the good cells down to the level of the bad cell then equalize all from that point. (Dyad)

Equalizing less often at a higher voltage is better than more often at a lower voltage.

Perform a draw-down test once a year.
How to Check Your Battery State of Charge
Guidelines and a Useful Reference Table. Article
by Larry Shick s/v "Moira"
Make sure your battery compartment is well ventilated during equalization. (Amazing Grace)

Bogart Engineering carries TriMetric Battery System; battery monitor. TM2025 was actually manufactured for RVs, but it's more than perfect for our needs. (Trumpeter)

Works well, easily installed; extremely satisfied. Here's a link at the same site that shows the different kits for different batteries. (Discovery)

Affordable Golf Carts (Valkyrie)
Crown Battery is a good source for batteries. Free shipping too. (Dyad)
Tee Time Golf Cars in Ormond Beach, FL has good prices. (Discovery)

A Users Guide for Trojan Batteries; wet cell and agm. This pdf file provides much information discussed on the Tech Net relative to the two types of batteries and can answer many questions. Granted this info is provided for Trojan Batteries, but it should be close for other makes as well. (Discovery)

Deka Batteries website has useful pdf files to download, such as spec sheets, 'What's the Difference', and selector guide. (Five and Dime)

The 12 Volt Doctor's Practical Handbook for the Boat's Electric System by Edgar J. Beyn; 1983 Maintenance, troubleshooting, and repair. See Tech Net Library


Issue: Portable battery chargers give poor performance on an inverter.
Use old transformer as inductor.
Use $20 plug-in model 300 watt.
Make sure sine wave is pure.
Use lithium ion batteries.

Query: Are lithium ion batteries better than standard ones?
They're much more forgiving than standard NiCad or NiMh.
They last longer.
They're lighter in weight.

Query: How to repair rechargeable drill batteries?
Find the metal strip, cut it with a dremel then solder to that.
Find a higher voltage new one, then don't use all the cells.

Successful repair with a new 18 v cell. About $15 at Harbor Freight.

Store your recharged batteries in the fridge. (Soul Mates)


Query: What's good for cleaning bilges?
Super Orange Citrus Bilge Cleaner
Totally Awesome, a dollar store item.
Super Clean is biodegradable and dissolves grease on contact.


Query: Inaccessible pump is running slow and hot. It may be a brush issue. How can I fix it?
Thump the unit.
Replace with a larger pump.

Issue: The float switch disintegrated in the bilge.
Float switches won't last forever.
Use the type of float that has a cylindrical tube with a cork slider on the inside.
Float Mate Ultimate Junior has a 2" diameter and is only 6" tall. Use in places that are hard to access. Costs more, but lasts longer.
Buy floats from West Marine. They'll replace them if necessary.

Query: Is Water Witch bilge pump switch recommended?
Yes. It's good for fiberglass, but bad for aluminum or steel bilges.
Water Smart by SeeWater is also a good product. Uses no float or other moving parts. (Salty Paws)

A diaphragm pump and air pressure switch last a decade. (Shining Star)
A filter is necessary with this setup. (Amazing Grace, C_Language)
Using a screen filter will be most useful if the bilge access is difficult on your boat.

I purchased a water alarm, 9v battery powered sensor on a 6' cord. It has the ability to splice in additional length. Home Depot, around $10. (Blackfoot)

PAR [short for Peters and Russell, now ITT Jabsco] diaphragm pump; Hypalon can be used to fabricate a replacement diaphragm. (C_Language)

Check vented loop on bilge pumps to prevent siphoning. (Fiscal Stray)

Atwood pumps. Available at Wally World (Discovery)


Issue: Recently, saltwater accumulates in the bilge and it only happens while underway.
It may be due to heavy provisioning, thereby lowering the water line. The rudder stock interface may be the source.
Also, while underway, the stern wake is higher.

Issue: There's a mystery source of fresh water in the bilge.
Sacrifice a roll of toilet paper or newspaper and lay it around to search for the source and follow it to the top.
Use food coloring in the fresh water tank. Bleach will clean up any residual stains on leak points.
Use a different color in each tank if you have more than one.
Don't discount the possibility of rain water intrusion.
Aluminum tanks may have eroded leaving tiny weep holes.

Query: How to test whether the water in the bilge is fresh or salty without tasting it?
Use your ohm meter. Compare bilge water against known resistance of fresh water. Set probes about 1" apart.
Test with a bit of antifreeze. Antifreeze in fresh water will remain clear; in saltwater, it turns cloudy.


Query: The soft eye cups have deteriorated over the years. Can they be replaced?
Best bet is to repair them with Sugru.

Fujinon binoculars that have no built in compass are much lighter in weight than those that do. (Dyad)


Query: Would a Cetane booster in the diesel hold up during longterm storage?
It's good for about a year.
It holds up well even during winter storage.

Query: If the boat is hauled out for an extended period, how is the bottom paint affected?
It depends on the paint type and the local environment. Both hard and soft types will need cleaning first, and then checked again before splashing. Look for possible cracking, crazing, peeling, blisters, etc.

Query: Do I need to empty my 35 gal. gas tank?
Don't store any ethanol fuel in the tank.
Leave it filled with non-ethanol.
Run a few gallons of non-ethanol through, then store with an empty tank.
Query: How to decommission solar panels for lay ups?
No need to do anything.
If you have a high float voltage on the controller, then disconnect.
They can be covered to prevent them from producing energy.

When laying up long term, disconnect all electronic devices. This will leave a smaller footprint. Turn off all power and unplug everything to prevent electrolysis and lessen the chances for damage if struck by lightening.

Place a gallon bottle of bleach onboard with the cap off. This will keep the boat free of mold when closed up for a season. Also use a fan, remove nylon fabrics, and leave all enclosed cabinets and lockers open. (Amazing Grace)
Kanberra is a product made from tea-tree oil. Open the inner seal of the can and leave in the boat to prevent mold, mildew, bacteria, fungus, and to control odor. (Five and Dime)

Use WD-40 on connectors or dialectic grease. Do not use any product that contains wax. (C_Language)

Leave fresh water in head when leaving the boat for an extended period.
Use about a half gallon of vinegar in the head. (Trumpeter)
Acidity goes down as vinegar eats salts. That's why no harm comes from long term use. (Kismet)

Change oil right before a layup to reduce acid from sitting on the bearings. (Alcid)

Test for electric conductivity. Check for electric isolation on sail drives. (Salty Paws)

Prevent growth on props. Cover them with a black plastic bag. I had no growth at all while sitting on a dock for four months. (Valkyrie)
Sandbags work as well. The woven material is easy to work with and is durable. (Cat Tales)
A friend used socks on each prop blade and it worked. (Passages)
Agricultural feed bags would work. (Kismet)

Run an empty plastic shopping bag up the halyard to prevent birds from landing when layed up. It creates noise and motion. (Mon Amie, Cat Tales)

(also tech net library, corrosion)


Query: Are there any reputable boat yards in the northern Bahamas or east coast of Florida capable of handling heavy work?
Bahamas: Spanish Wells or Green Turtle Cay.
Florida: Cracker Boy Boat Works. Located in Ft Pierce and West Palm. (Hot Lattetudes)

Cracker Boy Boat Works has a very good reputation. But, they require you to buy all materials from them at a hefty mark-up. That would include bottom paint at about $300/gal. (Hot Lattetudes, Salty Paws, Shamal)
Call or e-mail them in advance so there will be no misunderstanding about costs later.

Have a picture or drawing of your boat to show the boat lift operators for strap placement. (C_Language)


The Cruiseheimers Book Shelf.
Filled with good reads that were recommended here on the Tech Net.

The Tech Net Library for recommended technical books, articles, documents and manuals.

(also media)


A plastic dust pan on a long stick works as a scraper for barnacles. The plastic won't gouge the bottom paint; the width makes for quicker work. (Dyad)

Plastic paint scrapers.
Plastic 8" wide drywall blades.
Use a threaded brush on a threaded extension handle. Place a scraper on the opposite side.
Dough cutters.

Muriatic acid is good for removing calcium/barnacles on inflatable dinghys. (Salty Paws)

Whink Cleanser. It's a laundry product and works well on bottom weeds. (Dragon Seeker)

Marykate brand On and Off. Cleans scum almost instantly, also etches aluminum. Contains oxalic acid. (Dyad)

Scotch Brite pads will remove ablative paint quickly. Use a plastic scraper instead.

(also hull care for above waterline and topside)


Issue: The top six inches are not ablating. The paint is just building up there.
The only solution is not to paint heavily on that area.

Query: Hydrocoat needed too much maintenance; didn't last long. Would Micron 66 work better and is it worth the extra cost?
Yes. Mine lasted three years and only accumulated a small amount of slime. Definitely recommended.

More comments:
Pettit Trinidad is a hard bottom paint that lasts about 3 years. Can be cleaned without paint removal issues. (Island Spirit)
Interlux Trilux 33 is very good for grass growth prevention.
Sea Hawk paint is durable. Their black color lasts longer than the blue. (Wind Rider)
West Marine used to carry the same formula Pettit Trinidad uses for much cheaper. Inquire as to availability.
For best results use three coats each time.
Clean with pressure, not scraping.
For metal parts, use an etch coat primer, a tie coat, then bottom paint.
Pettit and Interlux sites have how-to's.
Defender has better prices on bottom paint.

Interprotect 2000E by Interlux is an excellent 2 part primer. Good cover, tough and rugged, easy to apply. (Minx, Dyad)

Amercoat PPG is the new name for Ameron ABC-3. (Destiny)

According to Practical Sailor, [March 2013, vol 39 #3], two years at best, is what you'll get out of bottom paint no matter what you pay. (Valkyrie)

We painted our sail drive with white E-paint. It's working very well. We used their slow-moving boat formula (for under 30 knot travel). (Salty Paws)

Barnacle Buster paint additive. Hamilton Marine has best prices.

Ameron ABC-3. Used three coats and after one year it has only minimal growth. On the bottom where it was out of the sun, it looks like new. (Dyad, Salty Paws)

Pettit Vivid has been working well for two years with very little hard growth. (Scaramouche, Cat Tales)

RECOMMENDED Great prices on bottom paint with free shipping. (Valkyrie)

Anderson Paint in Portsmouth, VA delivered 5-gallon buckets of bottom paint to Portsmouth Landing. Local deliveries only. Good price. Good service. (Destiny, Dyad, Salty Paws)

Raka in Fort Pierce, FL is a good place to buy name brand paint at good prices. They answer their phones. Good customer service.

(also hull care, paint)


Butyl Tape is partially cured caulk. It stays in a nice soft mount. Lots of adhesion properties. It's used for mounting auto glass too.

It's very easy to use with great results for setting ports and windows. Use the edge of an old credit card to trim the squeezed out excess. RV suppliers carry this.

I used butyl tape successfully on my chain plate. (Serengeti)
This is much less messy than any type of caulk or compound. (Valkyrie)
Use it to seal the holes wires pass through on electronics. If it's too sticky, place it in the fridge for awhile. (C_Language)
The product can ooze out a little over time. Just trim the excess. (Passages)
Mineral spirits will soften it, which means it's easy to finger smooth or tool. (Serengeti)
Butyl Tape is also known as putty tape.

(also caulk, glass and glazing, hatches & ports)



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