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Monday, April 26, 2021

Installing New Hardware on a Boat

There are many times you may want to add hardware to your boat.  You may need additional cleats for dock lines or spring lines.  On sailboats you may want extra fair leads or cam cleats for convenience in controlling various lines.  You may want to add teak handrails, tie down points, or other accessories.   In each case you will probably be drilling through the deck or cabin wall in order to install the items.  

Sometimes you may have to replace existing hardware.  Damaged components can usually be removed and replaced without much special effort.  However, if the mounting holes or surface has been damaged, you will need to repair the underlying structure before mounting new hardware.  In many cases you will probably want to add or install larger backing plates to prevent future problems.

The primary key to successfully installing or replacing hardware on your boat is careful planning.  You will need to do research to find the right hardware at the right price, inspect where you want to install things to make sure it will be safe to do so, and make sure your installation is secure and properly waterproofed.

Your first step is to decide what you want to install.  You may want to add a mid-ship cleat for spring lines or and extra fair lead and cam cleat for routing control lines on a sailboat.  Or you may just have some neat new accessory you need to mount on the cabin wall.  Make sure it is really something you want and will use.  You don't want to drill unnecessary holes in your boat!

The next step is to determine where the new hardware will go.  Will it be mounted inside or outside the cabin?   Make sure there is room to install it.  Take care mounting things inside the cabin so any mounting bolts don't create safety hazards or cosmetic offense outside.   Then look behind or underneath to make sure there isn't anything that will be in the way of the screws or bolts that secure it to the deck.  Be especially sure it won't impact any wiring, tubing, or plumbing lines.  You will need to determine how long the bolts need to be.  Some light weight accessories might be anchored with screws if the deck material will support it.  Screws might work on wooden boats or fiberglass boats with sturdy wooden cores between the layers of fiberglass and metal screws might even work on metal structures.   Lightweight items can sometimes be secured with metal screws on fiberglass if the fiberglass is thick enough and strong enough,  When in doubt, using backing plates to make sure your fasteners won't pull through.  Unless the area of installation has built-in backing plates, you will need enough room to install them beneath the new hardware.  Backing plates should be a bit larger (1/2"to 1"in each direction) than the base of the item being installed.  When installing items inside the cabin be extra careful if they are going on an outside wall where bolts might protrude outside the hull, possibly creating a safety hazard.  Don't attempt to install items below the waterline unless the boat is out of the water.

Can it be installed without drilling?  Some accessories can be mounted using heavy duty double-sticky tape or adhesive.  Probably a good idea whenever you can do this so you don't have to drill any new holes in your boat.  Every hole you drill is a potential source of a leak but some things, like cleats or other hardware that takes heavy loads, will need to be securely bolted on. 

Backing plates are usually needed when mounting hardware to boats.   Some boats have backing plates built in where cleats and other accessories are likely to be mounted.  Unless you KNOW you have built-in backing plates you should plan on adding them.  Having extra backing plates will only make things more secure.  The only downside might be appearance or perhaps an extra obstacle to deal with inside the cabin.  The only time you don't need backing plates are when you are mounting light weight accessories that will never have an significant load place on them.  Since just about anything you can grab onto could stressed if someone needs extra support, even little things like cup holders and winch handle pockets should be securely anchored.

If you are attaching hardware to a single layer of fiberglass, such as a cabin wall, you will for sure need a backing plate to spread the load.  The use of backing plates is generally a good idea in all cases.  Large washers might be sufficient for lightly loaded items but full backing plates are required for things like cleats that handle large loads.  Check to make sure there is room to install a backing plate before you start drilling holes to install new items.  If there is not enough room for an adequate backing plate you will need to rethink the whole installation!  I had to forgo installing an bow anchor roller on my sailboat because there was no place for a proper backing plate.  Even if I removed and re-bedded all the existing hardware, there still wasn't enough room under the deck for an adequate backing plate.

You never want to drill extra holes in your boat if you can avoid it!   Consider using adhesives where possible.  Accessories that may need to be removed from time to time might be mounted with heavy duty Velcro.   Be certain of where you want each installation to be and "measure twice, cut (drill) once".  If you do happen to drill extra holes, be sure to fill them right away with epoxy or a good marine grade sealer.  I have seen a recommendation that you drill a shallow countersink to prevent cracking of fiberglass.  It also provides a depression for extra sealant to protect against leaks.  Use an over-sized bit (about twice the diameter of the hole) and run the drill in reverse to make the countersink so you don't accidentally drill through!  That works pretty well on wood and fiberglass, but you may need a little extra force when drilling metal hulls but don't push hard enough to push the bit through the metal and make the hole too big!  Some metal hulls are surprisingly thin!

Backing plates could be made of wood, metal, or fiberglass.   Plastic isn't recommended as it can compress under stress.  What we think of as solid plastic is actually a very thick, viscous liquid!  By the way, so is glass!   Over time, window glass will eventually be thicker at the bottom than it is at the top!  Whatever you use for backing plats should be able to stand up to the rigors of a marine environment.  Aluminum and stainless steel are good choices.  Ordinary steel is not as it will rust possibly compromising its strength as well as making an unsightly mess. Marine grade plywood also works pretty well.   Backing plates should be larger than the base of the hardware being installed and should extend about an inch outside the bolt holes in all directions and be thick enough or sturdy enough so they are not distorted by tightening the bolts.    Another guideline for backing plate size is to make them slightly larger than the footprint of the object you are installing on the other side.  Use fender washers for added safety and load distribution on the backing plate.  I also like to use nylon lock nuts to make sure the nuts won't come loose due to vibration or flexing.  Lock washers or Loctite might also be used to keep nuts from coming loose.  Or double-nut the bolts,  Avoid using Loctite on anything you might want to remove from time to time.  Always use backing plates unless you are certain there will never be a heavy load placed on the hardware.  However, since you never know when someone will abuse an accessory so better to be safe than sorry.  Without proper backing, the fasteners holding hardware on will pull through the deck when a heavy load is applied causing serious damage as well as failing to perform their intended function.  NEVER install life support hardware without a backing plate.  You may need to consider the aesthetics if a backing plate will be visible from inside the cabin.  In that case you will usually want to paint or varnish backing plates to ensure they are moisture resistant and, if they are visible, you will want to make sure they look good

You will need to determine how long the bolts or screws need to be.  If you are using screws they need to be short enough so that they don't come out the back side of the installation.  If you are using bolts they have be long enough to reach through the accessory, the deck, the backing plate, plus washers and nuts.  You can get plastic thread protectors to cover the exposed ends of the bolts to make them less apt to cause damage or injury if something brushes against them so you might want to include the length of the thread protectors.  One way to determine the length is to drill one of the holes for the installation and push some small item like a cable tie through it so you can mark the length you need.  Then get bolts that are at least as long as you measured.  Longer bolts can usually be cut off but shorter bolts won't work at all!  Longer bolts might intrude into the interior space and that is particularly dangerous for things mounted to the cabin roof where you might hit your head.  Trim protruding bolts as short as practical.  Plastic thread protectors over the end of any protruding bolts will help cushion the impact and lessen abrasions.  If you plan to use thread protectors use or cut the bolts long enough to install them, usually about 1/4" past the nut.

For any marine installation you will want to use corrosion resistant fasteners, such as stainless steel.  Brass was used on boats for many years and still works well, but it does tarnish and you should avoid using dissimilar metals as different metals often react with each other to promote corrosion.  Using stainless steel fasteners with stainless steel hardware and a stainless steel backing plate would be a good pattern to shoot for.

Anything installed on the exterior will need to be "bedded".  That means placing a material between the hardware and the mounting surface to seal the joint so no water gets in.  Even a tiny leak into a bolt hole can eventually allow enough water to soak into the wooden core between layers of fiberglass on fiberglass boats to cause dry rot.  You never want leaks around any kind of hardware.  Butyl tape, sometimes called dum-dum tape, is one of the most common ways to bed hardware but sometimes rubber or vinyl gaskets might also be used.  Sometimes you may want to add some additional sealer (like silicone) along the line where the hardware meets the mounting surface.  Holes drilled through the wooden core on fiberglass boats should be sealed so that if any moisture gets into the hole it can't get into the wooden core.  Leaks into the wooden core quickly lead to rot and serious failure.

I have seen two good ways to seal the bolt holes for deck installation.  The easiest way is to use butlyl tape.  Drill a shallow countersink into the top of the hole in the deck.  The butyl tape will squeeze into the dip.   Wrap a little bit of butyl tape around the bolt (enough to more than fill the countersink hole).  When you install the bolt, hold the head steady and turn the nut so the threads on the bolt don't strip the butyl where it contacts the bolt.  A little butyl tape might squeeze out between the item and the deck.  Anything the protrudes beyond the item isn't necessary, but its presence is a good indicator that it the fastener is tight and the butyl tape is doing its job.  Simply cut or scrape away any extra for a clean look.   For fiberglass decks with wooden cores there is a second, more complicated technique, that ensures the wooden core is protected from moisture even if some leaks in around the bolt.  Drill the hole about twice the size you need for the bolt, then fill the hole with epoxy and let it set up.  Then drill the right size hole for the bolt through the center of the epoxy.  That way the epoxy completely seals the wooden core against water getting in and causing dry rot and the epoxy "sleeve" provides a solid point of little compression where the bolt will be tightened.  For a little extra protection for wooden cores when using the simple butyl tape method, spray a little paint into the hole before installation so it can coat the exposed core and help seal out moisture if you don't have any epoxy to coat the inside of the hole.  If you do use have epoxy, tape over the bottom of the hole, fill it with epoxy, then poke a hole in the tape to let the excess epoxy drip out, leaving a coating on the inside of the hole.  Be sure to follow the manufacturer's instructions regarding the use of an activator to be sure the epoxy will cure properly.

Fasteners should be appropriately tightened.  If possible determine proper tightening specifications and use a torque wrench to ensure it is correct.  Lacking any technical specs, hand tightening most bolts and screws is usually adequate.  To some extent the length of hand held wrenches allows you to apply the proper torque for the fasteners they fit.  Don't over tighten fasteners as doing so will damage the hardware, the fasteners, or what they are attached to.  Bolts are usually tight enough if when using lock washers, the lock washers are completely compressed.  Torque specs are based on clean (usually new) fasteners.  You may experience extra drag on old, rusted or corroded parts.  It is always preferable to use new fasteners to ensure proper installation,  If you must reuse old fasteners, clean them before reusing them.  A little light lubrication might be appropriate and old fasteners but don't over do it.  Speaking of lubrication, coating the threads on screws being driven into wood can make driving them easier and reduce the chance of stripping the head or twisting off the screw as they get tight.

You will often need a second pair of hands to hold the nut on the underneath or backside of the hardware you are installing.  When installing hardware on the deck you will need someone inside.  If you have to work alone, you might be able to get the nuts started, then secure them with Visegrips so you can tighten the heads.  Many times the handles of the Visegrips will reach far enough to push against a bulkhead or some other obstruction or you might be able to tie them off to keep them in place.  I usually tie a string to the handle in case they come off and fall down into the hull where it might be hard to reach them.

Once everything has been tightened down your new accessory should be ready to use!  Enjoy using it.  Make sure it is tightened appropriately but take care not to over tighten any fasteners.  Come back and check the tightness after the item has been in use for a while to make sure it is still secure.  New hardware often "settles in" a little bit and can benefit from being re-tightened after a little use.

When installing lights or other electrical equipment you will need to take the wiring requirements into consideration.  Since most boats are made of wood or fiberglass you will need to run a ground wire to each fixture in addition to the hot wire.  Metal boats may need ground wires also as metal components might not always have a direct connection to the ground side of the battery.  When you need two wires, use a cable with two conductors instead of running two individual wires.  It will look better and will provide better protection against wear and chafing.  Wires should be run as short a distance as possible and be routed where they will not chafe or present an unsightly nuisance inside the cabin.  Look for places they can be hidden behind cabinets, under shelves, or behind valances, then secure them with nylon clamps or cable ties to keep them from moving around.  Always use marine grade wire and create waterproof connections.  See my post on Boat Wiring for additional details.  Some inexpensive LED light modules create radio frequency (RF) interference so be careful installing them near antennas or electronic equipment.  To avoid RF problems, use the more expensive and higher quality components that are RF rated.

Sometimes you may have to repair existing installations.   Even properly installed hardware can sometimes work its way loose or suffer damage that requires fixing.  You may have to repair bolt holes that have been damaged by excessive loads.  Enlarged holes will need to be carefully filled and sealed.  You may need to put some kind of temporary backing plate on the inside so you can fill the holes with fiberglass resin.  If possible, relocate the item to an area that has not been compromised or repair the damaged area adequately before proceeding.   If that isn't feasible, be sure to use a larger than normal baking plate to spread the load and compensate for any reduced strength in the repaired area.

Plan on inspecting each new installation often in the first few days of use.   You want to make sure things are secure.  It is normal for things to loosen up a little as vibration and use may cause things to "settle in".  If there is any exterior penetration also look for any leaks so you can rebed or re-seal the installation before there is serious collateral damage.

Inspect all the hardware on your boat (both what you have added and what came on it) on a regular basis to make sure it is secure and doesn't leak.  Loose cleats will allow the bolts to elongate and enlarge the bolt holes until there is significant damage and the cleat doesn't even hold anymore.  If there are any signs of leakage, remove and re-bed the hardware before the leak causes a lot of collateral damage.  Even a small leak on a fiberglass boat may allow enough moisture to get into the wood core between the layers of fiberglass to cause it to rot and fail if not corrected in time.

Accessorize!

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