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Cockpit Sole Repair by Rex Miller

The construction of the Renegade cockpit sole lends itself towards being a problem, as shown in the Rudder Log diagram, because the joint between the Rudder Log and the upper laminate of the cockpit sole is not a tabbed in joint, relying on a sealant compound to keep water out of the balsa core. Over time the sealant fails and the core fills with water ultimately causing rot and delamination. This is not a minor project and consumes about 9, non-linear, days of hard work. The initial removal and placement of the core material and laminate takes about three days intensive work. Re-glassing, fairing and sanding another two days with the final painting and anti-skid application yet another two days, all of which would otherwise be good sailing days.

The first step is to remove the top laminate. Mark a grid of 6" to 8" squares and number each square of the area to be removed, in my case virtually the entire sole. The numbering is so that the pieces can be reused when reforming the upper laminate and the numbering makes it quick and easy to correctly relocate each piece. I found the Rotozip with a fiberglass bit the best tool for cutting the laminate sections. Set the bit depth to just below the upper laminate. Do not cut all the way through the core and lower laminate. Where delamination occurred removal of the balsa core is easy, however, even when saturated with water, most will still be epoxyed to both laminates. A great deal of care needs to be exercised not to go through or rip out the glass roving lower laminate too often. When the lower laminate is breached repairs will be needed which adds to the repair work and time. I used knives, screwdrivers, chisels, broad ended pinch bars, and a vacuum cleaner etc to pry out and clean up the removed end grain balsa core. The choice of weapons is user defined and whatever gets the job done and suites the individual is ok. If a belt/disk sander is available the belt is great for removing the balsa from the underside of the removed upper laminate sections.

The selection of replacement core materials is up to the individual. End grain Balsa sheets are the cheapest but other materials are available from chandlery outlets such as Defender Industries and West Marine. Due to material availability and time constraints I went with end grain balsa but would have preferred one of the closed cell, water impervious, polymer based products. Lay out and number the new core material sections. I recommend leaving approximately half-inch gaps between sections of the core to later be filled with epoxy, creating water barriers, which will isolate sections when upper laminate damage occurs. Remove the new core material and set it aside. Repair any damage to the lower laminate. Wet out the entire lower laminate repair area with a standard epoxy mix. Depending on time available to do the job and temperature a fast curing hardener may be a better selection that the slower hardener. Note that the epoxy will want to pool towards the cabin end. Be careful with the volume used at one time because thick sections of epoxy will go exothermic. Once the surface of the lower laminate is tacky place the new coring in position. With a highly filled epoxy resin fill section gaps and build up to as close as practical to original level but not above the original level. Place the saved original upper laminate sections in the filled epoxy. Once dry but not fully cured over level with 3M Above/Below Water Line Fairing Compound. There is a green and a red style but I have been unable to find what the difference is between them. Once cured sand down to original level.

Sand the rudder log so good adhesion can be made for the tabbing of the new cloth. With the surface faired and sanded cut 5 or 6 pieces of heavy glass cloth to cover the repaired area with sufficient material to tab to the rudder log. Wet the repaired area with a standard epoxy resin mix. Lay cloth, add epoxy resin and work into cloth making sure the air is removed from under the cloth. Allow to cure to a tacky surface and repeat cloth and resin application. Repeat until all layers have been applied. Because of the reuse of the original laminate 5 or 6 layers of heavy cloth provides sufficient strength for the sole to carry the loads it is exposed to.

New upper laminate in place made up of 5 or 6 layers of roving followed by cloth.

I allowed the repaired area to cure for a week but made sure it did not get UV exposure, as UV is very destructive to epoxy resin. I re-sanded the surface to remove glass spikes and provide adhesion for the paint. I did not attempt to recreate the anti-skid pattern. Using a one-part deck paint I applied a coat, letting it dry without a full cure, then applied the second coat immediately followed by a liberally application of anti-skid grit to the wet second coat. Once dry, but again not fully cured out, I applied the third and final coat.

Return to Projects & Refits Home Click on the images to enlarge	Cockpit Sole Repair by Rex Miller The construction of the Renegade cockpit sole lends itself towards being a problem, as shown in the Rudder Log diagram, because the joint between the Rudder Log and the upper laminate of the cockpit sole is not a tabbed in joint, relying on a sealant compound to keep water out of the balsa core. Over time the sealant fails and the core fills with water ultimately causing rot and delamination. This is not a minor project and consumes about 9, non-linear, days of hard work. The initial removal and placement of the core material and laminate takes about three days intensive work. Re-glassing, fairing and sanding another two days with the final painting and anti-skid application yet another two days, all of which would otherwise be good sailing days.
	The first step is to remove the top laminate. Mark a grid of 6" to 8" squares and number each square of the area to be removed, in my case virtually the entire sole. The numbering is so that the pieces can be reused when reforming the upper laminate and the numbering makes it quick and easy to correctly relocate each piece. I found the Rotozip with a fiberglass bit the best tool for cutting the laminate sections. Set the bit depth to just below the upper laminate. Do not cut all the way through the core and lower laminate. Where delamination occurred removal of the balsa core is easy, however, even when saturated with water, most will still be epoxyed to both laminates. A great deal of care needs to be exercised not to go through or rip out the glass roving lower laminate too often. When the lower laminate is breached repairs will be needed which adds to the repair work and time. I used knives, screwdrivers, chisels, broad ended pinch bars, and a vacuum cleaner etc to pry out and clean up the removed end grain balsa core. The choice of weapons is user defined and whatever gets the job done and suites the individual is ok. If a belt/disk sander is available the belt is great for removing the balsa from the underside of the removed upper laminate sections.
	The selection of replacement core materials is up to the individual. End grain Balsa sheets are the cheapest but other materials are available from chandlery outlets such as Defender Industries and West Marine. Due to material availability and time constraints I went with end grain balsa but would have preferred one of the closed cell, water impervious, polymer based products. Lay out and number the new core material sections. I recommend leaving approximately half-inch gaps between sections of the core to later be filled with epoxy, creating water barriers, which will isolate sections when upper laminate damage occurs. Remove the new core material and set it aside. Repair any damage to the lower laminate. Wet out the entire lower laminate repair area with a standard epoxy mix. Depending on time available to do the job and temperature a fast curing hardener may be a better selection that the slower hardener. Note that the epoxy will want to pool towards the cabin end. Be careful with the volume used at one time because thick sections of epoxy will go exothermic. Once the surface of the lower laminate is tacky place the new coring in position. With a highly filled epoxy resin fill section gaps and build up to as close as practical to original level but not above the original level. Place the saved original upper laminate sections in the filled epoxy. Once dry but not fully cured over level with 3M Above/Below Water Line Fairing Compound. There is a green and a red style but I have been unable to find what the difference is between them. Once cured sand down to original level.
	Sand the rudder log so good adhesion can be made for the tabbing of the new cloth. With the surface faired and sanded cut 5 or 6 pieces of heavy glass cloth to cover the repaired area with sufficient material to tab to the rudder log. Wet the repaired area with a standard epoxy resin mix. Lay cloth, add epoxy resin and work into cloth making sure the air is removed from under the cloth. Allow to cure to a tacky surface and repeat cloth and resin application. Repeat until all layers have been applied. Because of the reuse of the original laminate 5 or 6 layers of heavy cloth provides sufficient strength for the sole to carry the loads it is exposed to.
	New upper laminate in place made up of 5 or 6 layers of roving followed by cloth.
	I allowed the repaired area to cure for a week but made sure it did not get UV exposure, as UV is very destructive to epoxy resin. I re-sanded the surface to remove glass spikes and provide adhesion for the paint. I did not attempt to recreate the anti-skid pattern. Using a one-part deck paint I applied a coat, letting it dry without a full cure, then applied the second coat immediately followed by a liberally application of anti-skid grit to the wet second coat. Once dry, but again not fully cured out, I applied the third and final coat.