Originally Posted by seashine
Thanks for all the advice people, I'm taking the tank to my stainless welder tomorrow and will specifically ask him if he thinks it's a repair or replace job. Also thanks Mark for pointing out the issue of wall thinness after sanding: the reason we were thinking of Dynel/epoxy is that we'd seen a photo
in CH of a tank that had been bandaged and lasted another 8 years. Hence the question about flexing.
BTW: I found JB Weld at Jaycar... a place often frequented by cruisers in search of busbars, tinned wire, heatshrink, solar panels
etc etc Will get some in case the tinnie springs a leak when we're out on the reef: J-B Weld Epoxy - Jaycar Electronics
Sounds like a good plan... BTW, If you ever DO decide to epoxy bond fabric
to SS or for that matter, SS hardware
to the boat, (= bedded in epoxy & fastened mechanically), here is how you prep the SS:
Solvent wash, (Acetone or MEK) the SS, then mask what you don't want scratched up on the SS. Now, fold a piece of new "wet/dry" 80 grit sandpaper and sand the hell out of the SS to be bonded to, but use CATALIZED EPOXY rather than water as the lubricant. I use a HARD epoxy like WEST brand for this.
Next, you immediately apply the fabric
to the SS, wet it out, and squeegee lean, then clean the excess. (let cure & apply several top coats, 45 min apart). The bond is perhaps half as good as if applied to fiberglass
For epoxy bedding SMALL padeyes & such (2"-3" is fine), that will never break, wear out, or need replacement, you do the above treatment to the SS base and bed
in epoxy, thickened in silica & High D fillers. Screw down fasteners and let cure.
I normally bed
through bolted stuff in caulk, if it is possible & on a flat surface. The epoxy bedding is particularly usefull if you need to put a pad eye over a THICK solid wood or solid glass spot, where you can't put a nut & washer. (I have a few of these on my boat)
To fasten these, (1/4 or 5/16)... you use flat head
machine screws 3"-4" long. You drill the holes in the boat (1/16" too small), tap threads with the correct tap, and epoxy saturate the inside threads in the hole. (make a dry run first and screw it down to be sure the threads are deep enough)
NOW, push all excess resin out of the hole with the butt of a drill bit or something, quickly do the above prep to the base of the hardware
, put thickened resin on the machine screws and under the heads, and screw it down snug but not OVERLY tight. Solvent wash the excess...
Mounted this way, a good beefy pad eye will be stronger that the tensile strength of the screw's heads, and last the life of the boat! My last boat had 1/2" U bolts with their 6" threaded legs epoxy bonded into into large holes in the glassed wooden crossbeams. (= no nuts or washers, just filled with resin).
These were my aft chainplates, and I could easily lift
the boat by them!
Good luck on the repair, M.