Sadler 29 skin fitting

[derekgillard]

I am trying to fit a Nasa clipper log on my Sadler 29 , because of the double skin the paddle wheel and housing are only just not long enough. I can only just tighten the padle wheel to the housing and there is no room to encapsulate the assembly in G.R.P.
Nasa do not do a longer paddle wheel and housing.
Has anyone had this problem or have any suggestions.

Thanks

 

[Strathglass]

In order to ensure that the housing is secure to the hull one way you could do this is to effectively make the skin thinner in this area.

Enlarge the hole in the inner hull to about 4" .
Remove the foam between the hull shell for another 1/2".

Cut three marine ply discs.
The first 18mm thick by 3 1/2" in diameter with a 7mm central hole.
The second 4" in diameter with a 3" concentric hole, The thickness of this is made such that when the two discs are fitted in the 4" hole the top face of the 4" disc is flush with the inner skin of the hull.
The third about 12mm thick and 6" in diameter with a 45 degree taper on the outside edge and a concentric hole 3" in dia.(the taper can easily be cut using a jigsaw)
Cut two perspex discs 6" diameter with a central 7mm diameter hole from at least 6mm thick material.

Fill the 1/2" void between the hulls with an epoxy/microfibres/silica mix and epoxy the 18mm disc to the inside of the outer face of the hull, epoxy the 4" disc in place followed by the 6" disc and finally clamp the whole assembly together using a M6 bolt and nut. <font color=red> do not overtighten or you will push all the epoxy out</font color=red>
When everything is set remove the two perspex discs (epoxy will not stick to the perspex) and the M6 bolt, drill a hole in the 18mm ply plate for the fitting and coat the inner faces of this hole with epoxy. When set fit your skin fitting using the recomended sealant.

A bit long winded but this way you maintain the integrity of your hull and it will produce a strong job. My sizes are only aproximate they will depend on the thickness of your hull and the dimensions of the skin fitting.

Best of luck

Iain

 

[paulplatts]

The earlier 29's had a large hole through the inner hull to take the transducer. This was mostly filled with a thick wooden "washer". The old Shark transducer bolted through this and the hull. Newer transducers, such as the NASA have much shorter fittings. In my case I removed all of the wood and filled the surrounding surfaces with gelcoat filler. The new transducer will now happily fit through the hull.