Tuesday, January 27, 2015

111 keel

J-111 Keel
Sometimes when a boat comes from the factory, it has issues.  In this J111, we had water seeping out of the leading edge of he keel where the lead bell interfaces with the hollow stainless skeg.

That junction between lead and stainless is supposed to be wrapped in Z-glass all the way around the keel.  In the interest of staying within tight tolerances of the builders keel specification, only a thin layer of fairing was used on the leading edge-no glass.  As soon as the keel flexed, the fairing failed and water began making its way into the void tank in the aft of the keel skeg.  Due to the sequence of lightweight fairing compound and glass (a thick layer of filler was put down first, then glass on top of that) there was delamination at the seam.   That became a resting place for water.

The new keels have glass all the way around the leading edge.

Ready to start taper.

What we did was grind away the glass on top of the fairing compound and then pop the fairing compound off the stainless. It came right off.  Next we roughed up the stainless and tapered the glass.

In the middle photo , you will notice we tapered the fairing/glass layer to accept new glass but we also filled the fissure between the lead and stainless with West System high density filler and 105 resin with fast hardener (it is cold in Chicago).  As that was setting up, we laid in the wetted out 1708 biaxial fiberglass cloth, before we put on the peel ply and applied heat.

Notice that we layered in graduated pieces of glass - big piece down first.

Plenty of overlap.

High density, biax, 407, peel ply in 105 resin.

Now comes the rough shaping and barrier coat
Getting the shape with 3M  Milled fiber filler.

Applying Interprotect 2000 with a super smooth foam roller - they last long enough for 1 coat.

Next we sand the IP 2000 with 80 grit to prepare for the Blato Plate (Interlux Regatta)

Finally we will hit the keel with 320, 400 and 600 grit wet dry sand paper for a baby buut smooth finish!

You may have to hit the zoom switch.

Finish product on its way to Key West!

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