CD 330 water tank

[dr2owen]

Just figured out where the damage on the cabin sole came from - tiny crack in the starboard water tank on my CD330. Any ideas where to get a replacement Kracor water tank.

[John Ring]

I found cracks in my Kracor water tank last year, where a plug was threaded in too tight causing a split in the tank. We were half way to Bermuda when we noticed the 40g of water we thought we had, was now 40g of air. The bilge pump quietly tossed all 40g of fresh water into the Gulf Stream without any of the six crew hearing a thing. All I can say is, thank God is wasn't there beer or they'd have been a mutiny.

I tried to get a new tank from Kracor, but they wouldn't work with me at all. I called Robinhood Marine, and Robinhood called Kracor. Kracor gave Robinhood the same response, saying they only work with active boat building clients & don't even have the old molds anymore.

I priced a new fabricated plastic tank from a local plastic tank maker & received a quote for around $1,500, without fittings. I bought a hot air plastic welder on Amazon for $150.

As the crack was in the upper aft outboard corner, I cut the whole corner off with a hand saw, taking the old unused fitting off along with the two cracks. I bought a small square of 3/8" of HDPE from McMaster, & turned my new plastic welder loose. After a little practice it came out pretty good, and I only lost about a quart of water capacity. I figured, "why spend $1,500 when 99% of that old tank is perfectly fine?" I replaced all the tank hardware with 1/2" Sched 80 PVC NPT fittings from McMaster too, cost very little.

It all worked out great.

John Ring
CD36 TIARA

Tank Sawed.JPG

Tank Cracks.jpg

IMG_6913.JPG

[John Ring]

A little follow up here, the rest of the water tank photo story.

John Ring

welded.JPG

12in NPT fittings (2).jpg

[John Stone]

Outstanding John Ring. You did a better job than any boat yard would have done.

[dr2owen]

John - Thank you so much for the help. I would have gone crazy trying to figure out what to do and replacing the rotted cabin sole is making me crazy enough. Is there a particular plastic welder that I should get? My wife is ecstatic that I am going to buy another new tool

[John Ring]

Thanks John, much appreciated.

Amazon has a few listed. I'd go with something like the Ridgeyard 1600w air plastic welder (green body) & some PE sticks. (PE = Polyethelene)

Get a few pieces of 3/8" thick HDPE (high density polyethylene) and a few LDPE (low density PE) from McMaster. Watch some YouTube videos on plastic welding & practice first. Don't stress too much - if you don't like your weld you can always cut it off & start again.

Don't forget to stand the tank up on end with your weld on the bottom, and put some water in the tank to check for leaks at the weld. Try to get the water over the weld more than one foot deep to apply about 1/2psi pressure on the weld. Let the tank sit/stand overnight & check for leaks in the morning.

Be sure to mount the new tank thru-hull hardware a little low from the very top, to avoid landing on the curved inside corner between the side & top of the tank. Landing the flat thru hull gasket on the curve would stop the it from sealing. Note mine isn't right a the top, worked out great.

Good luck,
John Ring

[Steve Laume]

Plastic welding used to be the only way to fix, plastic, white water kayaks. It is a bit of an art.

When West Systems came out with g-flex, I had to get some to play with. The only thing I have repaired with it is a plastic garden tractor hood. The things always crack in the same place. I sanded, flame treated and epoxied it with some glass tape for reinforcement. It has held up for years now. No sign of additional cracking or any delamination.

The plastic welding of the water tank seems like a great first step in the repair. I would then back it up with some glass cloth and g-flex. Those tanks take some pounding from the water sloshing around. If the plastic weld were to blow out, it would be empty in seconds. For something as critical as your fresh water supply, I would feel more comfy with an epoxied repair, Steve.

[Steve Laume]

I forgot the link.
https://westsysteminternational.com/en ... flex-epoxy

[John Stone]

I should have mentioned gflex too. Steve is quite right. You can’t reuse plastic mixing cups after you mix gflex in them...they become one. There is a great video about a couple of guys that saw a kayak in half and epoxy it back together with gflex. Then, they proceed to try and break it. They ride it down a gavel mountain. Throw it off a hiway overpass onto a concrete road etc. They can’t break it. Pretty good testimonial in G flex’s value in repairing plastic.

[Jim Walsh]

I had a similar experience as John Ring in 2015. When I arrived in Bermuda I discovered most of the water in my starboard tank had escaped custody. Since I could easily get along on my bow and port side tanks, and the culprit was not readily apparent, I just isolated it at the manifold and got on with the cruise.
Upon my return I removed the starboard settee plywood to expose the tank in its entirety. It was a semicircular crack at the base of the boss the tanks vent threaded into. I looked for an appropriate epoxy and decided to go with g-flex. I was aware West does not reccommend its use where food products are concerned but decided the repair would have no appreciable contact with the tank contents.
I cleaned and dried the mating and surrounding surfaces, I also scored them to increase adhesion. I did three light fillets just because the tank was in place and it tended to creep until it set up.
Here's a picture of the crack and the finished repair. I know it's not much to look at but it has certainly performed as intended.

[bottomscraper]

If the plastic welding doesn't work out you can try Ronco. I'm not sure if they have anything to replace the starboard tank on the CD330 but they have a wide variety of tank shapes and you can specify where fittings get installed. We used a Ronco to replace our bow tank on Mahalo a few years ago. I believe they are made to order so it may take a few weeks. You may not be able to find an exact replacement but you can probably find something that would work.



https://ronco-plastics.com/

[dr2owen]

Thank you for all the help and feedback. What a great group!!!!!