Thanks for the thanks! <blush> As to cloth-vs.-mat: I'm more of a fan of using many light layers squeegeed together. This promotes absolute bonding and conformation to the substrate. Any gaps between layers are weak spots, even if they are filled up with epoxy. You want a bit of flex to your patch, not some crystallized mass that will fracture at the slightest movement. A trick that I've used in the past to repair the sacrificial strip on the sharp keel of my kayak was to roll up 3/4 oz. cloth on a dowel, and carefully slide it off. This leaves me with a 20-ply piece of "tape" that lays down easily on to wet epoxy. The edges are ground off, and the whole affair is given a coat or two to seal it off. Back to your tank. I'm assuming that you can't get the tank out, or at least get to the underside? Maybe wedge in something from the ends on the outside? Also, that the crack is in the corner, not in some easily assessable place in the middle? ^From inside the tank, I'd do the following: 1. Using slow set catalyst, mix up your schmutz, glop, or goop and make sure that it thoroughly penetrates the crack. Leave a smooth, small mound on the surface. 2. Mix up some straight epoxy, and lay down some very light cloth, like 2 oz., or under. Put on a bunch of layers, and squeegee out as much epoxy as you can, without disturbing the still-wet schmutz. 3. Get some cheap plastic drop cloth (always nice to have around when using epoxy), and cut out a big square that more than overlaps the repair area. 4. Apply the drop cloth piece, and then screw on your L-shaped piece. 5. About 6 hours later, when things are fairly well set, but not fully firmed up, remove your L and peel up the drop cloth. 6. Finish up the repair by applying a few more layers of cloth, which are squeegeed onto place. Once these are set, apply a final coat of epoxy with a brush, tied on to a stick, if need be. I'd also look into what initially caused the crack in the first place. Is your tank shifting around? Maybe you should use some building foam and foam that bad boy in place? Good luck! The job sounds like misery any way that you look at it, so be sure to lay in a good stock of libations. The specter of Post-Traumatic Work Syndrome is not one to be taken lightly! <grin> ___________________________ Doug Barnard rebuilding a 20' Skipjack trawler-crawler wannabe > -----Original Message----- > From: owner-trawler-world-list@samurai.com > [mailto:owner-trawler-world-list@samurai.com]On Behalf Of Richard > Tomkinson > Sent: Saturday, February 10, 2001 5:25 PM > To: Trawler-world-list@samurai.com > Subject: TWL: Holding tank woes > > > Doug Barnard and others... > Thanks for the post. Your timing is perfect. > I take it that epoxy is OK on cloth but not on mat? > > I have opened up the toop to a large openiing, now I can see most of the > split with my naked eye rather than a mirror. However, it is still not > possible to see what I am working on, while I am working on it. > > Also, I still cannot reach to the end of the box or even to the end of the > actual split without the aid of a pusher stick, which means that I will > still not be able to do a perfect job of surface prep. > > I am struggling with how to hold up the bottom to its original position > (with the gap closed) after I have pushed in the schmutz. What do > you think > of useing the "L" beams that I have already constructed, with a > pad at each > end, and simply screw them to the bottom which will pull the > bottom up into > alignment and hold it while the schmutz sets. Them I unscrew and > remove the > beam, an fill the screw holes with schmutz. > > I think that 'after schmutz' layering of some reinforced epoxy will be > crucial to a long term fix. > Richard > > > >

Doug Barnard and others... Thanks for the post. Your timing is perfect. I take it that epoxy is OK on cloth but not on mat? I have opened up the toop to a large openiing, now I can see most of the split with my naked eye rather than a mirror. However, it is still not possible to see what I am working on, while I am working on it. Also, I still cannot reach to the end of the box or even to the end of the actual split without the aid of a pusher stick, which means that I will still not be able to do a perfect job of surface prep. I am struggling with how to hold up the bottom to its original position (with the gap closed) after I have pushed in the schmutz. What do you think of useing the "L" beams that I have already constructed, with a pad at each end, and simply screw them to the bottom which will pull the bottom up into alignment and hold it while the schmutz sets. Them I unscrew and remove the beam, an fill the screw holes with schmutz. I think that 'after schmutz' layering of some reinforced epoxy will be crucial to a long term fix. Richard

I went through a repair exercise on my holding tank several years ago. At that time I was told by many members on the list that there is nothing, absolutely nothing that sticks to polyethylene. Most any holding tank I have ever seen is made from polyethylene. If yours is, the way I understand it, it can't be glued. Options for repair are: welding with polyethylene rods or making a gasket/plate for a bolt-on repair. George of Scaramouche, Lake Ontario, Canada P.s: I went for the welding repair.