On to the tops

OK so now I have to cut all the access holes in the tank tops, so we can get in to them to clean when needed. The tops had been cut and fitted to the tanks earlier so I thought I was almost done. Wrong again, it is turning out to be more work than I had hoped for. Some things never change...

Here is one of the access holes as seen from the inside of the tank. The tops are cored with plywood, cutting a hole straight through the top would have exposed the core which is really not a great idea. So I have cut the hole larger on the underside and beveled the core down to the upper fiberglass skin. I plan to cut 1/4 thick aluminum bars and thread 1/4-20 stainless steel bolts into them. Then drill clearance holes in the upper skin for the bolts and glass the bars in from the underside. This would seal the bars, core and bolts on the inside of the tank. The access covers will just have clearance holes for the bolts and be held in place by nuts with fender washers. The aluminum bars are there to keep the 1/4-20 bolts from coming loose in the top. I figure that if I thread the bolts into the aluminum with locktite they will not work loose. Encasing in fiberglass is just an added precaution to avoid leaks.

Here is the view of the entire port side cover with the 4 holes cut. Had a little problem in that the builder only put a single layer of mat and roving on the underside of the core, not even close to the required amount. So I cut through the top skin in a couple of places which will have to be fixed. Oh boy more work....

Here is top side of the top at the same hole location as the first picture. I have added one layer of 24 oz combo mat over the remaining core as well as 2 layers of 24 oz. Biax tape around all 4 sides of the hole. Next step will be to trim the new glass work and install the aluminum bars and bolts. Then it will be ready to seal up with a layer of 24 oz. Biax tape wrapped from the underside up over the bars, though the hole and onto the tops side.  That should be easy... I am really looking forward to that mess.

Got smarter on the Starboard side top. I marked where the holes are on the top side and added the glass reinforcement before cutting the holes. Also added glass reinforcing to the rest of the areas where there was not enough thickness over the core. Port side top is now ready to cut the holes and bevel the core in preparation for the anchor bars.

One last shot showing the lower center tank top in place. I still have to finish it before it can be installed. But I wanted to see it in place. Looks like the access will be fine. Only catch is that the shower pan sits over the forward end of this tank. So I had the move the access port aft of the deepest part of the tank. I am planning to mount the suction tube and tank gauge in the cover. So I guess I shall have to plumb them with a 45 degree elbow so they will reach the bottom of the tank. But not today, gotta leave some work for tomorrow, and next week and next.....