Observer Seat Base Repairs

Another project I’m still working on is a reverse observer seat. My boat originally came with a bucket seat up front. So I always wanted the reverse observer seat from day one.

After a very long time locating one, this one I purchase will need a lot of TLC to the plastic base and the seats plywood rebuilt/replace. So I started doing some research on what type of black plastics are wieldable and how to repair since I never done this before. The seat base is a type of polypropylene. A thermoplastic that I should be able to weld back together.

The seat base I brought has really damage and abused. It had 3 major breaks and 13 stress cracks

The break along the back where you can see the foam, I cut some of that foam out in order to pull it back together. Was not a whole lot but enough so when I start clamping, there won’t be any resistance. I clamp the base up and heated up the seat base with a heat gun to formed back in shape again. I reheated the base every other day for 2 weeks.

 After forming back into the original shape, I used some Gorilla Glue that is compliable with the foam inside the base to glue the foam back together that I cut out. And then re-clamped all back up.

Went to Harbor Freight and purchase a plastic welder kit. Kit comes with everything you need for the repairs. I did a small practice spot on the bottom of the base to see if it’s wieldable. And yes it is.

Removed one clamp to have access to the back support of the base where you could see the foam and the long crack. Welded the crack all away across. Just enough plastic rod to weld back together. The kit also came the wire screen. Cut to size and I reheated the area while I push the screen into the plastic on both side of the crack for re-enforcement. Added more welder plastic rod on top of the screen for more strength. Made sure I heated the original plastic along with the new welding rod plastic to blend together.

As I continue welding the base back together I got better welding and went quicker. The trick is to blend /weld the plastic back together to have a good connection again. All of this was slow work.

This is the back side of the base where I screened in after I welded the crack. Also the front of the base needed screen. After the screen was tack in place, I went back over to push it in deeper into the plastic so that it’s below the surface level.

After all the breaks and cracks where all welded back together, Only 3 areas where screened in for reinforcement. The other cracks were just welded back together. All areas were sanded smooth. Many steps in the sanding process. By all means this base is not perfect but I was able to salvage a part from ’88 and repaired it for my Nautique when I get the seats rebuilt and recovered. Looking forward when all is completed and installed.