Monday, May 31, 2010
Here's some pictures of a few odds and ends we've been working on while we wait to start the paint prep. Looks like next week sometime for that. We will be painting the interior first but before that job, we have to get all the framing that is welded to the hull cut free. I found a pretty good deal on ten very heavy used boatyard stands. A few will need to be cut down to fit under the chine midships, but they should support the hull quite well while we paint (and allow me to sleep at night when the wind is blowing). We should have enough support so that we can move the stands in pairs as we paint the hull to get everything coated. Since we will not be putting up the sail rig right away, I am fabricating a temporary mast at the back of the wheelhouse to hold our antennas, radar, etc. Should have that done this week. Also on the list is fabricating some kind of deck shower (hot and cold freshwater) and a salt water wash-down mount on the transom for use on the swim step. A stainless hose bib will be fine for the wash-down, but the shower arrangement will require a bit of engineering. There are some commercial transom shower set-ups made out of plastic but, like most ready made stuff out there, they just don't seem that durable. I will probably end up building some kind of utility box with a cover built into the transom to house this stuff. Also had a visit from our friends and neighbors at Galilee Harbor. Always nice to get some encouragement to keep forging ahead...
Monday, May 17, 2010
If you haven't visited in a while, you may want to go back a few posts... I've added some new ones in the past couple of days. With our new studs in place we were able to install all (fourteen) fuel tank inspection hatches with gaskets, cap off all the fuel plumbing vents, fills, etc. and put some pressure in the tanks to make a final check for leaks. Before bolting down the covers, we thoroughly vacuumed and wiped clean every inch of the tank interiors. I've heard of hardware, wrenches, welding rods, and worse being left in tanks when they are sealed up after construction so we made sure there was nothing in our tanks but air. Then we prepped and painted the seating surfaces of the hatch and tank top with 235 marine epoxy and cleaned and treated all the threads with never-seize, on the off chance that we ever have to deal with opening the tanks up again. The covers were bolted down with 1/4" nitrile (fuel-proof) gaskets. Whoever invented the impact ratchet gun deserves a round of applause... with this we were able to torque all 500 hatch bolts in less than hour. With 2-2.5 PSI in the tanks, we sprayed every weld on the tanks and all the welded fuel plumbing with soapy water and looked carefully for any bubbles that would indicate a pinhole or weld defect. We found a few spots which will need to be fixed, but they are all easily accessible, and we'll be getting to those this week and then re-testing. After that it will be on to paint prep...
Monday, May 10, 2010
Definitely one of the cooler toys we've used to build this boat... it consists of a huge 600 pound battery pack with ac charger that allows you to deliver extremely high amperage for a very short duration, a timer box, and a gun that position and "fires" the threaded stud into the surface that you are working on. With the battery pack, we can reload and shoot a stud about every 45 seconds so there is a huge time savings over hand welding the studs or drilling and using bolts. The result is a very strong, permanent attachment point for anything that you need bolted down. When we folded over our test studs with a 10 pound sledge, the stud broke but the weld stayed intact, so no worries about strength. We are using this machine to install studs for all the fuel tank inspection hatches and zinc anode attachment on the bottom of the boat. We are also shooting studs for the floor supports, interior framing, and ceiling nailers for attaching our wood interior. With this machine, we have been able to shoot studs at the rate of about 100 per hour... which is good since we will end up with well over a thousand threaded studs throughout the boat.
Also got all our zincs together and drilled. The zincs serve as sacrificial anodes to protect the hull and fittings below the waterline from galvanic corrosion, which can erode metal at an alarming rate if you are not properly protected. This is especially of concern in harbors and marinas where there is often quite a bit of stray current from other boats and electrical hookups. The idea is that the zinc is more reactive than the other materials that the boat is built from, and will sacrifice themselves before your underwater metals are affected. Since much of the bottom and keel of the boat is fuel tankage, weld-on zinc anodes are not really an option. So all our zincs will be bolt on with 1/2" studs welded to the hull. This also makes it easy to change the zincs out in the water if needed. Our planned anode arrangement will give us about 200 lbs of zinc below the waterline which should keep us well protected for 2+ years even in relatively "hot" harbors.
We received the tanks last week from plastic-mart (http://www.plastic-mart.com). Great prices and service. While our fuel tanks are integral steel tanks built into the hull and keel, all the rest of our tankage (black water, grey water, and potable water) is heavy duty 3/8"seamless polyethelyne. We used off the shelf rectangular tanks but since they come as blanks, you can specify the location, size, and number of fittings. This required us to map out most of the plumbing on the boat so that we could determine what fittings we needed and where. The steel foundations for these tanks are now installed and it looks like everything will fit up as planned.
Sunday, May 9, 2010
Finished fabricating and installing the anchor roller... It took a little trial and error to get the geometry right. We made a mock-up of the roller frame and the anchor out of plywood and used this to try different angles and roller locations. Had to make sure that the anchor launched ok, cleared the stem and the bow of the boat, and locked into the roller assembly without any free-play when it was pulled all the way in. Once we had the geometry figured out, we made the real thing out of 3/4" 316 Stainless side-plates, with a 1/2" x 4" Stainless flatbar center piece. This forms an I- beam and is very strong. The whole assembly was welded to the foredeck and bow plating. The bail (the part that keeps the chain from jumping out of the roller and side-plates) is bent from a 3/8 x 3" Stainless flatbar. Finally, we used some 3/4" Stainless round-bar to trim the opening in the bow. I don't have the patience or the inclination to polish any of the stainless on the boat to mirror finish, so I went with a bead-blast, brushed finish- similar to the bitts and fair-leads. Finished by hauling the real anchor (Rocna 55, 120lbs) up from the ground to the stowed position in the roller and all seemed to work fine. Next project...
Monday, May 3, 2010
Finished the Dorade boxes for the forward deck. These are basically water traps that allow you to keep ventilation open in all but the most extreme conditions. I made ours out of 3/16" welded steel plate with a 1/4" bolt on cover. They are welded inside and out to the deck and the deck penetration is a 6" steel pipe. They are probably ridiculously overbuilt but we certainly don't have to worry about them being blown off the deck by a wall of green water. I also came up with a pretty cool mechanism for closing them off completely from inside the boat. I'll include some pics of that once I get it put together. Also completed all the bulkhead penetrations for wiring, plumbing and such. Once all the wiring and plumbing is run through these, they will be filled with a fire-stopping watertight sealant that will maintain the integrity of our watertight bulkheads.