Our Zodiac is really four years old although we have only had it in service for two years. But it has been two years of tropical sun, so right on schedule, the adhesive is failing. For two months now we have been babying it along, but lately we were even afraid to leave the outboard on it. Something HAD to be done.
We did some research and found that it could be disassembled and reglued, so we bought the two PolyMarine adhesives at West Marine and decided it was now or, or, or buy a new dinghy!
First we tried using a hair dryer to undo the remaining seams, but our inverter wasn't happy about that, so we used a propane torch and kept it far from the surface. You don't want to melt anything, just heat it enough to make the glue let loose.
Then, using this sand empregnated nylon brush, we tried to remove the old glue. It sort of worked, but in the end we also used scrapers, acetone, Scotch Brite pads, and lots of elbow grease. This was the hardest and most time consuming part of the project, but all the old glue must be removed, and the surface abraded, to ensure a good bond. This took us all day.
You can see the shiny glue still on the upper part of this rubber piece. The bottom part is dull and has had all the glue removed and been abraded with a Scotch Brite pad.
This morning we started putting the Zodiac back together. First we "primed" the wood transom and the rubber brackets that hold it onto the pontoons with the Hypalon adhesive. PolyMarine says that the PVC adhesive won't stick to the wood or rubber, so you need to prime it with the Hypalon adhesive first.
First you mix it 25:1, then brush on a coat, wait 30 minutes, and brush on a second coat. Then you mix the PVC adhesive 25:1, brush on a coat, wait 30 minutes, and brush on a second coat.
Now comes the tricky part. These are contact adhesives meaning that they STICK to each other on contact. There is no way to move the parts once they've touched. To keep the flaps from touching while we aligned the bracket, we cut little pieces of BBQ skewers and taped them into position on both sides where the flaps would go.
Then we slid the top edge (on the right in the photo below) into position and proceeded to push the bracket against the edge of the transom. Pressure is key with contact cements, so we also hammered it to position. Because the glue is dry when you assemble your project, we easily removed the skewers and pressed the flaps down, repeating the hammering.
Once we had the flaps pressed down, we drilled extra holes and installed more bolts to hold it all together. Not only will these help to keep everything together, but they hold pressure on the glue while it cures. The glue is dry in 48 hours, but takes a week to fully cure.
So now we have done the first step and hope to finish up tomorrow. And yes, Angie Wilson, we did use the Corona Extra. It held up the transom while the glue dried.