Bow tube

[Don Wylie]

Hello all especially Stan.  Long time sailor back into the Seaspray fold. Have a question about the bow tube and I know what I am after is not class legal. Has anyone significantly raised the bow tube or did not use it at all? I remember from when I had a Seaspray years ago that it annoyed me when a wave hit the tube and slowed the boat down or tripped over the tube. Can the hulls or the extrusion in the bow resist the inward/upward pull of the forestay? Has any one installed a bow tube with an arc or straight sections that are welded? I have installed 2   3/8" bolts through the beams in each doghouse and thickened the sleeves but I didn't strengthen the structure under the bow tube extrusion. 

[Don]

Hi Don,

I inserted a couple of pictures to show what has been done that has been acceptable if you want to retain a boat for racing.  This raises the bow tube slightly.  The pipe is two inch irrigation aluminum pipe double sleeved near the ends.  The bridle wires will have to be shortened a bit and the ends are attached to an inner bolt that is not visible in these pictures.  The aluminum castings remain in place but have been cut down to a flat surface to accept the pipe.  The newer boats have the aluminum castings bolted to the top of the deck and can be removed entirely.  You may want to add a few layers of fiberglass to enhance the strength if that is the case.  

If you do not intend on racing the boat then anything can be tried.  Raising the tube by whatever means may give you what you want.   Moving it back and raising it by some means may give you what you want while still retaining the strength of the original design.

Don

T

[Don Wylie]

Thanks Don for the pics. The inner bolt is attached to the pipe? and what did you sleeve the 2" aluminum with? I have epoxied the deck back down so will not be strengthening the bow but the casting is bolted from underneath and has 3 rivets in the front. Do you know of anyone that has sailed without the bow tube and what were the consequences? Sez somewhere in the website that there is a registry of boats. Are the original owners there and any subsequent owners?

Don 

[Don]

The inner bolt is in the same position as the outer bolt but bolted through on the inner hull deck joint and through the aluminum casting depending on which casting you have.  You can attach the outer bolt first on both sides then drill from the underside of the inner hull deck joint and insert the bolt from the bottom.  It takes a bit of tricky work to get the thimble from the bridle wire, washer and nut on the inner bolt.  The outer foot or so is sleeved with the same 2" aluminum irrigation pipe with a 1/2" piece of material removed along the length of the one foot inner sleeve .  This will allow it to be compressed and then inserted.  It gives more strength to the bow tube.  If you like you can get a heavier aluminum pipe that you would not have to sleeve.    If you have a picture of how the aluminum casting on the front that would be helpful. 

If you want to do away with the bow tube altogether you may have to take the decks off around the doghouses in order to reinforced the main and rear beam sleeves.  We have added two 6" bolts through these sleeves in order to stiffen the boat.  You could also do it with more deck screws from the top of the deck on each dog house.  You will be experimenting and it may  or may not work.  

You could also try to sail your boat a bit differently through the waves with a bit of heeling so that only a part of the bow tube hits the waves or move a little bit back.  Steering through the waves may also minimize the bow slap. 

Don   

[Don Wylie]

Thanks Don

I've done the upgrades to the doghouses but am nervous about blowing up a bow or hull so I think I will continue to use a bow tube. - possibly one bent in an arc with a amplitude of about 9 inches. Will post pictures if I do that mod.

Don