How to Rebuild a Rotten Battery Tray

The battery tray on Summer Dance was heavily water damaged. The nails holding the side pieces to the base had rusted away and the pieces pulled away easily by hand, leaving only the base. It was badly stained and rotted and gave off a very funky smell. Fortunately, the previous owner had installed a plastic battery box and screwed the strap anchors into the base, but it had to be replaced completely.

A certain Catalina parts dealership recommends replacing the wood tray with a fiberglass tray. It’s a nice part and a permanent fix, but at nearly $80, it costs more than the battery that it holds. $tingy Sailor says don’t buy what you can easily make, especially when you have most of the materials on hand.

BEFORE - rotted and rusty
BEFORE – rotted and rusty

Just like the original, only better

Using the old pieces as patterns, I built a new tray out of scraps of 3/4″ plywood and 1×2 cedar. The parts are attached to each other with nails and glue. I gave the whole tray two coats of epoxy to waterproof and strengthen it.

A flat pry bar and a rubber mallet removed much of the rotted plywood base. A sharp wood chisel removed even more, and a 4″ angle grinder cleaned up the rest down to the body filler that held the base to the hull. I left the body filler that was solid as a base for the new tray.

After the old tray was removed
After the old tray was removed

I mixed up some leftover body filler, applied layers to both the old base and the new tray and pressed the new tray into place. While the body filler set up, I filleted the bottom of the new tray to the hull with epoxy thickened with colloidal silica. This waterproofs the tray/hull joint.

After the new tray was bedded and filleted
After the new tray was bedded and filleted

After the epoxy fillets had dried, I painted the new work with leftover oil-based primer and alkyd enamel paint. Finally, I screwed the old battery box anchors into the bottom of the new tray and reinstalled the original box and battery.

This fix is a little better than the stock battery tray since it’s sealed and filleted with epoxy. The original tray lasted 30 years and this will probably last at least that long if the bilge is kept dry.

The Bottom Line

Suggested price: $79.80
$tingy Sailor cost: $15.00
Savings: $64.80

Have you replaced your battery tray?


3 Comments Add yours

  1. Hi. What sort of body filler did you use to attach the box to the hull?

    1. Hi, William

      I just had some standard, polyester body filler on hand that I used. I don’t remember what brand it was. It only took a little bit but I wanted it to fill the voids and seal the bottom of the box so that water couldn’t seep back under it.

      Thanks for your question,

      1. w holland says:


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