Leaky Window Repair on C&C 35 Yacht

Leaky Window Repair on C&C 35 Yacht

Leaky Window Repair on C&C 35 Yacht

Leaky windows is something we get asked a lot about at South Shore Yachts. Recently, we had a customer ask about repairing a leaky windows on their C&C 35. The customer stated the windows appeared to be glued in and wondered if they would have to use screws to re-seal them.

The short answer is, no! We strongly recommend screws never be used as the acrylic is not designed to have small holes with fasteners holding the window in place. It will crack.

But lets dig deeper into the issue. When a customer comes to us with this problem, it helps for us to know how bad the leak is. If you go below and press on the window, does the window separate from the deck around the entire perimiter? If so, the windows will have to be replaced. If not, then an easy sealing repair can be done.

Below are 2 repair explained in detail. At any time, don’t hesitate to contact us with any questions or concerns via email or phone at 905 468 4340.

Easy Sealing

MATERIALS REQUIRED: “Sudbury” Liquid Elastometric Penetrating Sealant (3oz Tube – Available at South Shore Yachts for $11.50 plus shipping and tax), 2″ good quality masking tape, rags and cleaner for clean-up.

    1. 1. Clean window and deck. While doing this, try and locate the area of the leak.
    1. 2. Once you have located the leaking areas, cover the window around area or the whole window. (we prefer to use 2″ tape covering the whole window and the deck above the window leaving a space between the taped surfaces of 1/16″ to 1/8″
    1. 3. Once area is dry, apply the sealant in a fine bead at the leaking area or along the entire length of the window from the bottom of the forward edge up along to top of the window and down the aft edge. Let this dry and reapply for a second time.
    1. 4. Clean area and allow sealant to cure. Then water test and repeat Step 3 if the window is still leaking.

Please note: This is not a long term repair. Your windows will require replacement in the future.


If your windows are separating from the deck, they will have to be removed and re-installed or replaced. We recommend starting with the realisation that new Acrylic windows should be installed as the old windows are scratched and crazed and the amount of work to do this repair justifies spending the extra to have new windows.

MATERIALS REQUIRED: 2 small scraper/pry bar, 4″ grinder with 40 grit sanding disc, 80 grit sand paper, hand saw, a number of 5-10 pound weights, 1″ wide putty knife, 2x4s to make braces, protective gloves, 2″ tape, acetone, rags, Plexus MA590 (2 tubes if you have 1 window per side or 3 tubes if you have 2 windows per side), Plexus applicator gun, new windows and water for clean-up.

      1. 1. From the inside of the boat push the window out and take one of the small scraper pry bars and wedge it into the space between the window and the deck. Using the pry bar with small force start to pry the window away from the deck and then put the second pry bar beside the first between the window and deck. Then using the second pry bar apply pressure to the window and move the first pry bar to the other side of the second pry bar and continue doing this till the window is free.

It may work that the window will be able to be totally removed using this method but I have only been luck once. You may find that the window will crack and break and you will have to try and start the process over. You may need to use a chisel to get the window out. Everyone is a different experience so remove the hard bits by whatever way you can. Just try not to damage the gel around the window too badly.

      1. 2. Once the window has been removed tape off the ledge of the deck opening inside the window all the way around and then tape off the opening from the inside to stop dust from getting into the boat.
      1. 3. Using the 4” grinder with the 40 grit disc remove and glue and any acrylic from the deck flange where the window was glued. Please remove only the glue try and leave the gelcoat intact if possible. Use the chisel and some 80 grit paper to clean the areas the grinder couldn’t get out.
      1. 4. Repair any areas where the glue has removed the gelcoat with an epoxy putty. Sand the window flange with 80 grit sandpaper.
      1. 5. Repair any gelcoat cracks or chips in the deck around the window.
      1. 6. Take the new window with the paper still on both sides and set the window into place. Trim new window if necessary so there is a 1/8” gap between the window and the edge of the recess.
      1. 7. From the interior, scribe the window opening on the paper.
      1. 8. Remove the paper where the adhesive is going to be applied. Sand this surface with 80 grit sandpaper.
      1. 9. Put window into place and make 3 to 4 2X4 braces, for each window, that will go from the center of the window to the toe rail.
      1. 10. Remove the window and then protect the deck area inside and out 4” – 6” all around the window opening with masking tape.
      1. 11. Insert Plexus glue and static mixer into gun (making opening of static mixer as large as possible) and make two ¼” beads of plexus on the flange of the window opening. Using a putty knife smooth the two beads of plexus together while maintaining as much thickness as possible.
        12. Put window in place and press firmly into position with the outside edge of the window level or slightly proud of the deck opening.

Please note: Working time is approximately 90 minutes.

    1. 13. Install the braces with 5 pound weights on each.
    1. 14. Use putty knife to clean up excess glue from the window edges inside and out. With your wet or gloved finger, smooth out the glue in the space around the window. With a damp rag wipe the areas clean.
    1. 15. Remove masking tape from the interior window opening.
    1. 16. Leave braces on for 24 hours.
    1. 17. Remove braces and paper from the window.

We hope this helps you with your leaky window issues. There are slight differences in the replacement of the surface mounted glued in windows, which makes it a more difficult repair. If you feel uncomfortable to execuite this repair, please contact South Shore Yachts at 905 468 4340 or via email here.

The windows, Plexus MA590 and Plexus Applicator are all available at South Shore Yachts. For the windows, we will require a paper tracing of your present windows so we can choose the correct pattern as each model of C&C has 2-3 different patterns for windows.