Carver Owners Forum

Flex seal is great for plastic. Did a shower sump box last season and still holding.

Midnightsun wrote:Qr Bbpost....If plastic, then I wish you luck with any kind of repair as they are normally polyurethane which is basically resistant to any type of glue and must be heat welded. I went through this a long time ago and after every advertised polyurethane adhesive product in the book was used....

I agree plastic is difficult to repair, pretty well known fact but I've had some success with a few different products. Perhaps the most surprising was a cracked built-in welded outlet fitting (plastic) at the bottom of a water tank. When I got the call to assess, the only thing I had on me to save the weekend was 5200 and figured it was a temporary measure until I can schedule tank removal and replacement. That was about 6 years ago. I still service this vessel regularly so I check it when I remember and am surprised it has held up this long with no leaks. Considering a hose is hooked up to the cracked piece and the crack encounters some stress from vibration, I'd say it's done very well for what was meant to be a temporary fix. Surprised, but I'll take it, and the owner is good with that too 'cause we don't have to tear the boat apart yet to remove the tank.

Welding plastic tanks is absolutely the way to go. Using a nitrogen welder even better, but there are adhesives that will work for temporary fixes or even permanent. Welding plastic using the proper welding rod for the type of plastic is going to get your best result. if you can find a shop that plastic welds, they might be able to weld it right in he boat, as the welders are very portable. I weld plastic on a daily basis on various types of plastics and they all react differently but it is possible to repair!