RUDDER ASSEMBLY TEST

All MATILDAS should have a rudder pull-up and hold-down system in operation- if such an arrangement is not functional, you are asking for trouble.
A. if a rudder hold down plan is not implemented, the rudder could hit the outboard motor propeller.
B. if a rudder pull-up system is not effective and secure, the rudder could be damaged [hitting the ground] when boat is launched or retrieved. Also, if you are being blown into skinny (shallow) water, and there is the risk of the rudder blade being twisted sideways, pull it up to prevent it from breaking.
C. if the rudder does not have a hold-down arrangement that works well in heavy weather and the rudder is allowed to trail straight out behind the craft, a VERY heavy tiller results, as well as the more serious problem of possibly breaking the tiller or the rudder because of the EXTREME leverage exerted by the rudder being straight out behind the pivot point.

Objectives - Rudder Assembly Test # 1
#1 Improve method of rudder hold down and pull up - rope and cleat concept has problems- if rudder has run aground, rope tension increases dramatically and sometimes the only way to free rudder is to cut hold-down rope
#2 Reduce pintle and gudgeon play- existing top pintle was loose in the aluminum rudder head- the lower gudgeon was badly worn resulting in excessive play in the tiller system
#3 Durability of aluminum rudder paint- the 1/4 in. aluminum plate had been painted with TREMCLAD paint which did not adhere well to the rudder
#4 Any difference to handling of boat with rudder at 90 degrees to water surface or does balanced rudder concept [following transom line] offer any advantage

Details -Rudder Assembly Test #1
A. Original 1/4" thick aluminum rudder which had been sandblasted and painted [2 coats epoxy primer + 2 coats FOREST GREEN AWLGRIP paint.]
B. Rudder pullup and transport clips [shown in full down position] which results in a balanced rudder. Clip #1 is used for holding rudder at 90 degrees to water surface. Clip #2 is used for launching and retrieving boat, with the rudder installed.
C. Rudder hold down and pull up spring + 1/8" wire strop [pivots from rudder head bolt to stand/off on rudder]. Spring is 9" closed length and expands to 13" when moved thru full arc [full down to full up].

RESULTS
#1. The spring concept has performed beautifully. MATILDA owners who do not have the spring installed, have sailed our boat and can't believe the difference in tiller pressure. Even in heavy winds, our rudder remains very light to the touch and we can be confident that if the rudder ever needs to go up if it encounters an object, it can.
#2. The upper pintle has been modified using a 3" long 1/2" diameter stainless bolt.The lower portion was turned down to .390" diameter for 1.600" leaving .500" O.D. shoulder for .125". Above the shoulder, the upper portion was turned to .4375" diameter [because that is what it took to clean up I.D. of original gudgeon hole] for .900" and the balance of the bolt was threaded 3/8" -16T.P.I. The stud was pulled into the boss [was a nice press fit] after red loctite was applied. After 2 years of hard sailing, pin is still nice solid fit in boss. The expense of making up the new pin could have been avoided if, red loctite had been applied to the pin when it was discovered working loose in it's mounting.
#2. continued, The lower gudgeon was also badly worn. A bronze bushing 1.000" O.D. was turned up, 1.300" in length. The upper portion of the bushing was turned to .508" diameter leaving .125" collar at the bottom. The .508" diameter was a press fit in lower rudder assembly boss. [It took reaming out to .506" to clean up I.D. of lower boss.] The I.D. of the bushing was reamed to .375" which was the diameter of the lower pintle. Stainless pins don't wear but the aluminum bosses certainly do.

#3. The 2-part paint has stood up well for 2 seasons now. It only requires a wash with MURIATIC ACID to remove the mineral deposits that adhere to all underwater surfaces at WILDWOOD LAKE and looks almost as good as the day it was painted.
#4. The photo on the left shows the rudder in the full down position. The photo on the right shows the rudder in a position [clip #1] that is at 90degrees to the water's surface. I have been unable to detect any difference in the boat's handling between the two positions.

RUDDER BREAKAGE

Because MATILDA rudder blades were made from 1/4" thick aluminum plate, they are quite susceptible to breakage right at the bottom of the rudder cheeks.

Several years ago,a friend of ours broke his MATILDA rudder blade at that exact spot when he was pushing the envelope with his craft. He was out in very strong winds, with his genoa installed and flying along rather well when suddenly the rudder blade broke. Luckily, he had a rudder blade pullup installed and did not lose the blade. He simply started his outboard, lowered sails and proceeded back to the club a little wiser.

After making a template of the original rudder, we proceeded to profile the remaining top of the rudder to the part that had broken off and he was back on the water again. The boat is still performing well to this day with the sawed off rudder blade.