Basically, yes you do need both. The nut is there to lock the propeller to stop it unscrewing while the washer butts up against the end of the tube to minimise water entry into the boat.

There are some possible solutions or a combination of them.

It might be possible to get hold of a thinner nut and washer.

Trim the the boss of the propeller by taking the point off to increase the clearance.

If it is just the propeller boss that is interfering with the rudder can you make a small cutout in the rudder to accommodate it?

If the rudder is mounted on the back of the boat is it possible to move it backwards slightly?

Use a smaller propeller which doesn't protrude so far, it will run faster so speed will probably not be much affected on a narrow boat.

Good luck,

Colin

I never felt the need for a lock-nut on boats which did not have a reverse – I/C motors or fast one-way electrics. But I always used a teflon washer to take the thrust…

Tony,

What you are suggesting is the best option if you can make it work OK. It's quite normal to find you have to make adjustments like that. On one of my models the original prop didn't give enough thrust but a bigger one wouldn't fit as it fouled the rudder post. The solution was to change the prop from a 3 blade to a 4 blade to get the extra power without a physically larger prop.

Colin

Tony

I had a similar problem on a Revell Snowberry conversion. The plastic prop wouldn't fit so I removed the nicely shaped bit on the front of the prop boss.

If you enlarge the rudder hole use a square of styrene on the inside with tight fitting hole for the rudder shaft, then seal this to the inside of the hull.

On the subject of checking before you have finished the model, it always seems to be different when you try the first time in the pond. I took a small daughter boat for it's first sail this am, to find it won't steer in a straight line and so much rudder throw that it turned almost in it it's own length.

But I did get it back without wet feet or using waders.

Tim

Is that the all-in sailing weight or extra to be added after the rest of the build is considered? In many narrowboat models, SLA batteries do the ballasting job nicely. Just as long as the weight is kept low.

Hi Tony

Fullsize narrow boats commonly have a layer of bricks under the floor to add stability, I've just completed a 30" long narrow boat which required 5lbs of well painted steelplate laid in the base of the hull + the NiCad to achieve the scale waterline. So your suggested 10-12 lbs would sound about right. I would suggest casting some small blocks from fast setting cement with some wire reinforcement in as a cheaper solution ?

Ray