| SJ23 Tech Tip A01, (Updated 2017-09-05) Bob Schimmel, Betsy Schultz & Randy Cook | |
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SJ23 Trailer, Desirable Features, Maintenance & Launch Tips. INDEX - FRAME TYPE, COUPLER
& BALL,
AXLES, TIRES,
RIMS, SPARE TIRE, |
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can't recommend any particular trailer manufacturer over another, as
there are good and bad designs all over this planet. But you
definitely get what you pay for. The majority are
good, most are adequate, some are downright slick and others are just
plain lousy. The latter are pretty easy to spot. I
wouldn't touch them with a 10' pole. It many cases a good design depends on which
boat it has to support. There are designs specifically suited for power boats,
others for sail. Don't interchange these because each have their
unique requirements. Some trailers intended for a deep keel
boat can be converted
to handle a shoal draft boat but this takes a lot of cutting,
grinding and welding. Most designs work well on a
gently sloped ramp but few designs work well on a
steep ramp. With some ingenuity a trailer can be modified to operate
better on a steep ramp but there is a limit. It all depends on the combination of
frame and the hull shape. If you want worry free trailering for your SJ23, read
on. The following ideas are the culmination of many knowledgeable, experienced
SJ23 owners. |
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FRAME AND COMPONENTS
________________________ TOP ________________________ COUPLER and TRAILER BALL - Ensure the coupler is bolted to the frame with the correct size and grade of bolts. Lock the nuts. If you also weld the coupler to the frame, well all the better. A friend of mine had a very narrow escape due to a welded only coupler that cracked. Because of this narrow escape, most of us now inspect our trailers annually, cross our chains and use heavy cargo straps to secure the hull to the trailer. But people forget so heed this advice. Lock the coupler before traveling down the road. Use a 2" solid
ball with lock washer and torque the nut to specification.
Solid balls are the strongest and the metal is not prone to crystallizing
(becoming brittle), resulting in breakage. A split ball doesn't have as
much shear strength as does a solid ball. It should be understood that
the coupler MUST MATCH the ball size and that the latching adjustment on
the coupler MUST
be set to have no more than 1/16" play! ________________________ TOP ________________________ AXLES - Choose tandem axles
with a minimum 3500 lb load rating, each. This way, if you have a flat,
the remaining axle can still support the boat till you come to a stop.
Tandem axles contribute greatly to equal load distribution, cool running
tires & bearings, directional stability at highway speed and smooth riding, as
Betsy will tell you in her
modification. Equip all four wheels with brakes for safety and to be
legal, regardless of where you travel. Equip the wheel bearings with
BEARING BUDDIES to easily grease the bearings
and keep the water out. Use
a bearing bra over the buddy to keep the dirt out. Don't
cover the vent/drain hole of the Bearing Buddy with the sleeve of the
vinyl bra since it traps damaging water on the outside of the Bearing Buddy.
I cut a small V notch in the bra to leave the vent hole open. Use a grey bra to
minimize hot cold cycling from the sun. A bearing exposed to the
sun will always run warmer than a bearing in the shade. ________________________ TOP ________________________ TIRES - Many trailer have old tires with lots of tread. The problem with these tires is they age out before they wear out. Typically they are more than 10 years old with only about 1000 miles. Read this and consider new tires before hauling your boat. "Test data performed by the National Highway Traffic Safety Administration (“NHTSA”) proves that after a tire reaches six years of age, the chances of catastrophic tread separation increase substantially. A tire’s biggest foes are heat and oxygen. Over time they break down a tire’s adhesive bond between the various layers of the laminate structure. This phenomenon is known as thermo-oxidative degradation. Thus, tires older than 6 years that have been exposed to prolonged heat and oxygen, cause the tire to become a safety risk. Consequently, any such tire should be removed from service and destroyed. To determine the age of your tires, read the D.O.T. code adjacent to the bead of the tire. The last four digits of the D.O.T. code show the week and year of manufacture. For example, the last 4 digits of a D.O.T. code end in “0806." This tells you this tire was manufactured in the 8th week of 2006. When purchasing new tires for your vehicle, you should always check the D.O.T. code. If the tire was manufactured more than six months ago, consider asking for newer tires. Even though a tire has never been used, thermo oxidative degradation affects it." Betsy Schultz The other obvious thing you can do is to cover the tires to protect them from UV damage. Its important even in winter. ________________________ TOP ________________________ RIM STYLE - A HUB MOUNTED
center rim is superior to a lug mounted rim because the weight is
supported by the
hub. This style of rim slips over the axle hub with only a few
thousands of an inch for clearance. The trailer weight is transferred to
the rim via the hub to hole contact and the tapered studs simply hold the
rim against the brake drum. Since there is little shear force on the studs
this is a very safe design for a trailer and one loose stud should not
result in the loss of a wheel. WHEEL STUDS -
Studs and lug nuts on a trailer require more maintenance than an
automobile since they receive a "thorough" dousing of water during a launch and are
usually dried with road speed. Rust
is the end result with slow but sure failure if allowed to drip dry in the parking lot. You can use your
imagination as to what happens to the boat when the studs fall
off, one at a time. If you launch in salt water, rinse the lugs nuts off with fresh water. While you are at it, rise the drums as well. Spray across the trailer and you are apt to rinse the inside of the drum. This goes a long way towards preventing corrosion. ________________________ TOP ________________________
________________________ TOP ________________________ KEEL SUPPORT BEAM - Panache's trailer is equipped with an adjustable (up/down) keel support. Most trailers have a fixed keel support. But the advantage of an adjustable support is that the load can be proportioned between the keel support and the hull support pads to distribute the strain equally throughout the hull, preventing stress. The height of the beam determines how much it supports the keel. The (2x3)" steel beam is mounted across the trailer under the middle of the keel. The fixed end of the beam (curb side) is loosely bolted to a 1/2" bolt to create a hinge and the adjustable end (driver side) is mounted on a screw jack. A 1/4" thick flat steel support plate is welded on the top of the beam where it contacts the keel to full width. The support plate is covered with soft wood to protect the bottom of the keel. It could also be covered with slippery UHMW so the keel could slide but I think that most people would opt for the sticky surface to minimize movement while towing. Click here for a photo of the support beam (white). The photo also shows the keel guides to center the hull on the trailer. The screw jack is made from a 5/8" threaded rod (1.5' long) with a crank welded to the top. The rod goes through a plate welded to the inside of the trailer frame. Two sets of nuts are tightened against each other (cotter pin could also work) above and below the plate. Together they act like a thrust bearing to lock the height of the rod. The hole through the plate is slightly larger than the rod. Below this plate the end of the rod is threaded through a large nut imbedded inside the support beam. Finally two nuts at the bottom of the rod are tightened against each other to prevent the beam from dropping off. Leave about 3" of free thread to raise or lower the beam along the rod. Determine the final proportions with the boat positioned on the trailer. The height of the handle must be positioned so it does not touch the hull or bunk board while being accessible by the operator. Voila, the beam goes up or down, depending on which direction you turn the screw jack. Simple and slick if you keep everything greased. It is amazing how easy it is to lift the hull with this simple lever, so I don't overdo it. If you do, the boat will develop a nervous rocking motion when traveling down the highway. I support the keel only enough to take some strain off the hull. Also, the keel settles on the support as it floats on the trailer and lifts off the support as it floats off the trailer. So you shouldn't have to adjust the support for launch or retrieval. ________________________ TOP ________________________ BUNK BOARDS - The wood bunk boards or support pads should be wide and covered with rug to protect the gel coat on the hull. The more surface area the better. After all, they support the entire weight of the boat while stored on the trailer. Panache is supported by eight 36" long 2x4s with a total area of 1008 in2. This equates to 2.98 lbs/in2 loading on the pads. Most of the keel weight is supported by the keel bar and the bow is supported by the front roller. With the keel support holding 950 lbs the pads now hold 1.8 lbs/in2 while traveling down the road. If a trailer has two long bunk boards they are generally shaped to match the curvature of the hull. I have seen them with 2 and 3 support posts under each bunk board. 3 seem best because it is possible to force the curve to match the hull. If the trailer has separate support pads they must articulate to align to the hull. A limit to the articulation movement is desirable when retrieving the boat on the ramp. The height of each support post must be adjustable to distribute the weight proportionally. If the posts are made of metal tubing, each post must have a large drain hole at the bottom to prevent water or dirt from accumulating so the post can't rust or split with freezing temperature. Even if you use a crane or travel lift to launch your boat, there is always rain water, wash water or dew to contend with. All the water must run off so the metal drains drip dry. Dry metal can't rust and wet salty metal or dirt coated metal has an affinity for water causing it to corrode all too quickly. IMPORTANT - Most bunk boards or support pads are made of wood that can suffer from dry rot. Dry rot has a way of sneaking up on you at the most inopportune time, like just before a road trip. The pads may look perfectly fine until just at the point of failure. The wood is likely damp and may be soft or slightly flexible (punky). If you fail to recognize this symptom in time, you may discover that a support post has punched a hole through the hull with the collapse of a pad! Ouch. So much for the hull and the road trip. Pads are usually covered in rug or Astro Turf (artificial grass) by the dealer to protect the gel coat. Rug rots and wears out quite quickly but it breathes moisture. Astro turf, on the other hand, doesn't rot, but can't breathe moisture and is almost water tight. It is usually wrapped tight around the pad to look pretty in the showroom which is about the dumbest thing to do for something that is backed into the water. And I haven't even mentioned an empty trailer exposed to the rain. Problem is, by encapsulating the wood pad it traps moisture so the bunk boards are guaranteed to rot. So, if this is the situation on your trailer, at least remove the Astro Turf from the bottom of the pad so the wood can dry. An angle grinder with a thin disk cuts through Astro turf very easily, making a very quick and neat removal job. Leave about 1/2" material wrapped around the bottom for the staples. This way there is less chance of them scratching you as you rub against a pad. If you find any wood with the least sign of rot replace it with pressure treated wood. If the boards are all the same age and you find one rotten board, you may as well replace all of them while the boat is off the trailer. Panache's trailer is just fine now, thank you very much Phil! ROLLERS - Rollers are adequate for power runabouts or ski boats because these hulls are built stiff to take the wave pounding. As such they can be supported by the small surface area of the rollers. Rollers are not good for a displacement sailboat as they cannot adequately support a fiberglass form shaped hull that doesn't have internal stiffeners. If the hull is stored on the rollers for a few years it will develop a dimple at each roller. You cannot alleviate this by transferring most of the stored weight to the keel support but this will only result in the keel being pushed up and developing a cracked hull liner. A sheet of UHMW at the bottom of the keel support helps to minimize the friction. Avoid rollers for a sailboat trailer like the plague. ________________________ TOP ________________________ STRAP BOAT TO TRAILER - "When towing an SJ23 it should go without saying that it must be secured to the trailer with cargo straps wrapped over the hull. It is the best way to ensure it does not roll off the trailer. However, the strap must not crush the toe rails inward when tightened. Doing so can crack the seal, creating a nasty deck leak. In this solution I used
a 91" long (2x4)" across the deck to spread the compression load to the toe rail without touching
the gel coat. A 1/2" deep angled recess is cut into the
bottom of the wood spacer so it fits over the toe rail. The angle keeps the (2x4)" from
sliding as the recess is held captive by the curvature of the toe rail.
The corners under the turn of the strap were rounded off to prevent
wearing the strap. There are four
eye bolts welded to the frame to attach the straps to; 3/4" eyes in the
rear to handle the greater weight back there and 1/2" eyes in the
front since the bow is also held by the winch
cable." Coat the wood with your favourite stuff to protect it from the elements. Randy Cook. NOTE 1 - In a pinch I've used 1/2" Dacron yacht braid when I forgot my cargo straps at
home since it is better than nothing. Polyester line
is difficult to keep tight over any
time on the road, even with a truckers rolling hitch. Once these straps are in place you should also tie the bow down to the winch tree. Slip a line through both mooring cleats on deck and pull them down so you can tie them to the tree. This simple effort prevents the hull from bouncing up with undulations of the road. With the three in place the hull will ride very steady. B. Schimmel TOP |
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ELECTRIC BRAKES & BRAKE CONTROLLER - My preference is electric brakes because you then have a manual override switch conveniently located on the brake controller to "stabilize the train" when things get out of hand (swaying) back there. Surge brakes have no such manual override inside the vehicle as the braking action is initiated by an inertia sensor mounted on the trailer tongue. It is the deceleration of the tow vehicle that operates the brakes. When a surge brake equipped trailer starts swaying it helps to have nerves of steel to push the gas pedal because acceleration is the action that stretches the train to stabilize it. Not that I drive like "Ronald Racer" when towing a trailer but I've had two experiences that required me to manually operate the electric trailer brakes to stabilize the "train". Each time I was so thankful to have electric brakes. Both Tekonsha & Reese (there are others) manufacture an electronic brake controller that is equipped with an inertia activated proportional braking system. These models have an adjustment to compensate for the ANGLE the controller is installed and a GAIN adjustment to adjust the braking force. If adjusted correctly they create buttery smooth breaking down to almost crawl speed. A proportional controller is direction and angle sensitive so follow the installation instructions exactly. This is likely the preferred controller if you do a lot of towing. Both manufacturers make another controller that actuates the brakes by a time delay relative to the application of the tow vehicle brakes. They operate a bit rougher but can be installed in any angle that is convenient. I have no experience with this system but it sounds like a good system for occasional towing. NOTE: Most vehicles (since 2005) equipped with a trailer towing package have a connector under the dash where the brake controller plugs in. In many cases the vehicle manufacturer supplies a short cable with a mating connector for the controller. Check your manual to locate this connector and check the glove compartment for the cable. If you can't find the cable go to your favourite trailer shop. This will save you oodles of wiring time. The emergency breakaway control system is a last ditch system to stop your
trailer when the coupler detaches from the tow vehicle. In the case
of electric brakes it consists of a trailer mounted battery and a breakaway
wire connected between the tow vehicle and the breakaway switch on the
trailer. When the trailer separates from the tow vehicle the tight breakaway
wire operates the
self latching breakaway switch which in turn applies power to the brakes, locking up the
wheels. Not elegant but it works. Surge brakes also have a breakaway cable that operates the master
cylinder to apply braking force, locking up the
wheels. I'm not sure of the mechanism for maintaining the braking
force but it makes sense that it is held on. The US
Department of Transportation
Federal Motor Carrier Safety Administration
rule 393.43 section (d) states that all trailers with brakes must have a
breakaway system in place.
In Canada a trailer must be equipped with a breakaway system if
it exceeds 2000 lbs. ________________________ TOP ________________________ LIGHT BULB & ELECTRICAL CONNECTIONS - Smear the light bulb sockets with lithium or white grease to prevent corrosion and ensure continued operation after a launching or driving in the rain. The grease keeps oxygen & water away from the electrical contacts, preventing corrosion. DO NOT spread grease on the glass bulb so keep your greasy fingers off them. Electrical brakes are usually connected to the wiring harness with Marrettes. Fill the Marrettes with water proof grease to prevent corrosion. Wrap electrical tape around the open end of a Marrette to seal it and apply a tie wrap around the tape to prevent the tape from unwrapping. This goes a long to preventing corrosion and the prevent connection from coming loose. ________________________ ________________________ TRAILER ELECTRICAL PLUG - Outboard Marine Corp (OMC) retails a spray foaming oil
called, "6 in 1". Other manufacturers sell a similar product.
WD40 works much the same way. Any of these oils are excellent at repelling water and preventing
corrosion on metal. 6 in 1 is used to protect a Sea-Doo engine so it can restart out
on the water. When applied, it foams on the surface and then creeps into cracks.
When dry
the dust does not stick to it, yet it continues to repel water. The
trailer connector on my vehicle had corrosion on it, so I sprayed
it with 6 in 1. After half an hour, the copper oxide corrosion (green grunge)
floated off with the foam, leaving the terminals shiny and conductive.
No more
intermittent electrical connections! The
trailer electrical connector should be checked annually, if not more often.
They must not have corrosion on the pins. I also sprayed the lower leg of my
outboard and after an hour it lifted off twenty years of accumulated alkali deposits,
leaving the paint shiny as new. After one season of use, it still repels
water. (I sure wish I had the rights for this
product). TOP |
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LAUNCH AND RETRIEVE The SJ23 manual has a segment on rigging and launching. You can augment the manual with the following hardware additions to make this job easier.  GUIDE POSTS on a SINGLE AXLE TRAILER (1996) - Having a pair of
guide posts on your
trailer is a real asset on the launching ramp, especially when you have a side wind
or current pushing the boat or
when the water is so murky you can't see the trailer to center the boat
over it. (I have never experienced dead
calm weather retrieving Panache. That would be a pleasure because
the boat wouldn't move as I drive up the ramp). Guide
posts for a SJ23 tandem axle trailer should be at least 4' or longer
for a deep ramp.
I know of at least one SJ23
sailor who built a taller version of the posts in this sketch and said it works very well.
When the trailer is submerged on the ramp, the equal lengths of the exposed posts indicate the trailer is level (side to side) and it is at the correct depth to float the hull over. With the boat centered over the trailer there will be equal gaps (hull to post) on both sides, thereby ensuring the keel will drop in the keel slot with the hull resting squarely on the support pads. NO MORE GUESS WORK. All of this to ensure the gel coat is protected, there is equal load on the tires and the hitch weight is correct. Just knowing that the hull is centered over the trailer speeds boat retrieval. Etiquette on the ramp is directly proportional to a speedy retrieval. When Panache's trailer had a single axle, I made rigid guide posts similar to the sketch (not drawn to scale) and a keel guide (Tech Tip A05) to launch on a weather exposed ramp. I needed every bit of assistance to center the hull over the trailer. I couldn't afford the risk of overloading one tire due to an off center hull. With the boat off center by as little as 2", one tire had to support several hundred extra pounds, easily overloading it. My guide posts worked quite well, installed aft of the single axle. But after I converted the trailer to tandem axles the same guide posts were not long enough to be extended so I discarded them. In lieu of guide posts I installed (2010) two yellow fiberglass bicycle whips aft of the tandem axle, at a slight outward angle to create a 1" air gap at the toe rail. The yellow whips (or feelers as I called them) were very visible as the trailer was backed down the ramp. I left them full length and tucked the tops under the life line so they didn't beat against the hull on the highway. I used this temporary system for about 5 years. It was better than nothing and continued my search for posts that could control the hull. Read on. GUIDE POSTS on a TANDEM AXLE TRAILER (2016) - On an SJ23 tandem axle trailer the guide posts have to be installed just aft of the fender. The effectiveness of the posts can be improved by adjusting them as close to the hull as you dare, keeping in mind that the maximum girth of the hull will end up forward of where the posts are installed. But if you strike the correct balance between the length, angle and spacing of the guide posts, you should be able to use the flex of the PVC to gently squeeze and hold the hull over the center of the trailer as it is floated over. You would have to drive slowly up the ramp so the flexible posts can keep the boat centered. In 2016 a local marine dealer had a really good sale on a pair of heavy duty 4' long guide posts. Each guide post consists of a galvanized rail clamp, a steel elbow and an orange capped PVC extension tube. I clamped these to the (3x4)" rails on my trailer where they fit very snug to the frame. The vertical angle of the elbow was adjusted to be parallel to the SJ23 hull (about 100 outward). It was a bit of a challenge to bend them to the correct angle until;... see those trees? Two of them are the correct diameter and spacing to make a nifty pipe bender using a 6' snipe for leverage! I opted to mount the clamps on top of the rails since I block up the trailer with the wood cribs for winter storage.
The unequal length elbows can be installed for maximum reach sideways or upwards, depending on your requirement. I installed mine for upward reach and adjusted them sideways till the posts fit the width of the hull. More later. I thought the upward reach was not tall enough so inserted a thick wall aluminum tube inside each elbow to extend the post up from 4' to 6.5'. This proved to be the right thing to do since there was about 1.5' sticking above the water to center the hull. Then to protect the hull, the white PVC tube was slipped over the aluminum tube. Each PVC tube has an orange cap for visibility and to protect the gel coat. While a PVC tube has a vent hole at the top to prevent it from floating off, it is also through bolted to the steel elbows to keep it there on the highway.
You should understand that the ramp I haul out on is not the most ideal for a keel sailboat. I usually haul out in late Fall when the temperature is between 5C and 10C. There is usually no ramp traffic then, which is very nice! Going in the water to solve a problem at that temperature is not an option so the system has to work. I don't have antifreeze flowing through my veins despite what some cartoonists will have you believe about Canadians!
From this point on I pulled the trailer up to the top of the ramp where I let the water drain out the frame members. Its a good way to wash the inside of the frame and drip dry it to flush any critters, zebra mussels, weeds, etc, trying to hitch a ride. (In the photo at right the hull is supported by the bow roller and the aft pads. When the trailer is pulled up the ramp the hull settles on the bow roller and all four support pads). All went very well this time.
UPDATES ____ TOP ___
SLICK LAUNCH/RETRIEVE SYSTEM - In 2002 I was told about the slickest launch/retrieval system of a sailboat I have ever heard. This sailor totally rid himself of the boat to trailer alignment problem and the strain of pulling the boat up the ramp by rethinking the whole process. What made his technique so remarkable is that he regularly retrieved a 32' deep keel boat on his own, with absolutely no problem, regardless of the condition of the ramp. The launch is pretty simple since all he did was back the works into the water till the boat floated off. The retrieval is slightly harder and went something like this:
The whole launch, including stepping the mast, took a little over an hour which tells me that his system is well thought out and he was very well organized. One of these days I will see if this technique works on an SJ23. The hull has sufficient buoyancy to support a 1000 pound (approx, but less in water) trailer and the gunwales are strong enough. I confirmed this with a fellow SJ23 owner who accidentally launched his boat in 2011 while still strapped to the trailer. (Many of us have come close to this). "The combo floated quite nicely," he said. If you want the trailer to have more buoyancy it wouldn't be difficult to add some floats along the end of the frame by using fenders or such. This would take some strain off the gunwale. The four wheels of a tandem axle add a considerable amount of buoyancy. Probably 200lbs each. Hmmmm, (1000-800=200). This is now sounding more workable than ever. Slick idea huh? This system would make the lousiest ramp useable. ________________________ TOP ________________________
NOTE - The V-block on Panache's trailer was changed to a roller to receive the bow because of the difficulty I had retrieving when we ran out of ramp depth due to the really low lake level. 3 more feet of ramp would have created more depth to float her on. A guy loaned me a roller at the time to protect the gel coat and he didn't want it back. He thought it worked better on my trailer than in his spares bucket. Such a nice guy. That's when I discovered that a roller protects the gel coat on the stem better than to skid the stem along a sticky V-block. The roller also cups the stem perfectly which makes for a secure load while driving. Installed as such, the position of the roller now stops the trailer eye for correct fore aft weight distribution and position on the support bunks. Without this you are just guessing. Just winch the hull up till the trailer eye meets the bottom of the roller and the hull is perfectly positioned. The height of the winch must be such that the 3/8" line pulls the hull up slightly to prevent the hull from binding against the bunk boards. In addition, with the trailer eye and winch line under the roller it allows the boat to float onto or off the trailer unimpeded. No more snagging the trailer eye on top of the roller from which it is impossible to lift. If you look closely at the photo, there is a safety break away chain clipped to the trailer eye. Since this chain is not tight it can't prevent movement. Therefore, it is a good idea to tie the bow down and slightly forward around the tree for secure hauling. NOTE: The boat must be floated on/off the trailer as the trailer eye and winch are not strong enough to pull ~3000+ pounds over the bunk boards! That 3/8" line on the winch is original when I bought Panache in the early 1990s. It gets stretched really tight as it pulls the hull up to the roller. It has broken only once, at a weak spot, which is OK. I would rather see the line break than the trailer eye get ripped out of the stem. See Tech Tip B26.
________________________ TOP ________________________ BOW ROLLER - If your trailer is not
equipped with a bow roller under the hull, install one. You'll be
amazed at how much easier the hull pulls up on the trailer, right to the
winch post roller or V block. As
the boat is winched on the trailer the roller lifts the bow forcing the hull to be
almost parallel to |
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SAFETY ANNUAL FRAME INSPECTION - If the trailer members are welded together, check all the welds annually for cracks. Do this with the boat off the trailer. The cracks are very tiny and may be difficult to see due to dirt, rust, etc. Use a wire brush to clean the welds and take a REAL GOOD CLOSE look at each. You can increase the strength of the joint by welding a triangular gusset plate at each corner. I think a bolted trailer is better in the long run but then nuts can loosen as well! Nuts have to be checked for movement or torque on an annual basis. SAFETY NOTES - Remember, the wheels get immersed in water and receive a double dose of water on the road while towed in the rain.
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Return to Tech Tip Index. . . . . . . . . . . . . . . Have a Question? |
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The guide posts are positioned behind the fenders, which is just aft of the maximum
girth of the hull. They are set about
1/2" away from the hull (approximately *
94"
apart at gunwale height) which is slightly narrower than the
beam of the hull.
Since each post can bend outward about 2" they can spread as the girth of the hull passes between them
and spring back to hold the hull centered as the narrower section of the hull
stops
between the posts. However, with the trailer underwater and the hull
several feet above it, the posts are not pushed apart. The hull will just settle between the posts as
it floats above the trailer. Looking aft over the trailer you can see
the posts are also angled outward about 100 which is another
feature that helps to center the hull as it goes up
the ramp. It would have to be pulled up slowly for this to happen. 
In the mean time I was cleaning the deck of snow & ice to pull the winter
covers over the boat when I spotted this little pest next to the winch.
Mother Nature was generous with her early delivery of snow in mid October.
We Canadians have quite a celebration after the first killing frost because
it means no more mosquitoes. I was quite surprised to see this one still
flying. That is a chunk of ice in the upper left corner. You can't convince me they won't be the last living
thing on this planet when everything fails! 
LAUNCH
SPRING 2017 - Many people ask just how deep a trailer should be to launch or retrieve an SJ23. It should be noted that a launch is easier than a
retrieve and can be done in slightly less water. In this photo Panache has just slipped off the trailer
with the new guide posts. The trailer is immersed 4'6" at the guide
posts (note the blue tape at the water line). The upper red
band on each guide post is level with the gunwale when the boat is on the trailer. 
HAUL OUT
FALL 2017 - This was the easiest haul out I have ever done due to
the new guide posts.
With the posts marked for retrieve depth I backed the trailer in till the marks were
about 3" above the water. The trailer was level (left/right) as you can see
at right. (The angle of the guide posts are
symmetrical by the
way. Lens distortion is making the right one appear bent further than it
is.) The hull was floated over the trailer and the winch line
pulled the hull till the bow eye was snug under the roller as you can see below. The placing of the bottom marks was a
guestimate that turned out to be right on. Sometimes you get lucky. 
Here you can see the bow pulled up over the roller at the front of the trailer tree till the bow eye kissed the
bottom of the roller on the tree. All during this time the guide posts held the hull
over the keel slot. There was never a doubt the hull was centered
and that the keel wouldn't drop in the slot, which it did. At this stage the hull is almost parallel to the trailer. I love it when
there is nothing to worry about. 
the trailer
frame. At this point the hull may
be resting on the aft bunk boards and bow roller. When the
trailer and boat are pulled up the ramp, the bow should remain 
seated
behind the tree roller with the hull settled on all 4 bunk boards.
Without a bow roller the hull will rock back, pivoting on the front bottom corner of the keel, several inches from the winch tree roller. Once the trailer/boat is on flat ground it is impossible to winch the boat forward or slam on the brakes to skid it forward. The stem/roller gap makes for an unsteady ride down the road. With the bow wedged in the roller and secured to the winch tree, the boat and trailer are a steady load while trailering. No hull moving around to give you the willies while towing. My bow roller is positioned 6' back from the tree roller. I use an 8" wide rubber roller that has a shallow V shape to gently direct the hull to the middle of the roller and keep it there. DO NOT use a flat roller. You DON'T want the hull to slide off the side of this roller so make sure the bow meets it on the center when starting to pull the boat out of the water! This roller also supports the bow to prevent drooping during storage. This is a design idea of mine that I installed on my
previous trailer and it works just as well for a SJ23.