Derick Gates SM2K #400 Brava
My copper tubing at the base of the holding tank failed two years ago, both aft and forward heads within months of each other. The copper tubing was so thin at that point that I could easily peel it out of the fiberglass sleeve with a pair of vice grips.
I replaced the copper tubing in both cases with about 7 inches of 1.5 inch diameter PVC tubing. I needed to use some wet/dry sand paper to remove a small volume of the PVC pipe so that it would snugly penetrate the fiberglass hole to the right depth (about 3 inches) and then I used silicone sealant to afix it. The previous hose to the shut off valve fit on the PVC pipe without modification, using two hose clamps.
This fix has worked well with no evidence of leakage.
Currently in Falmouth Harbour, Antigua