Sunday, August 19, 2012

Wrapping up the super structure metal work

Getting all the little odds and ends completed before I can paint the super structure is taking quite a bit more time than I had anticipated. I'm trying to work out a few problems as once I start paint prep, I don't want to stop to do some welding. Once the boat is at the launch site, I have a feeling I'll be doing some welding I forgot on the super structure, but my hope is that I get it all figured out now.

The first thing I did on the super structure was to install a temporary floor in the wheel house to bring  things close to the finish floor level. After I had the wheel house floor back up to grade I installed all of the cleats and tabs I need to bolt the lumber to. Trying to use up what material I have on hand, I cut my longer pieces of flat bars in to tabs, and wherever possible, used the tabs welded in place to bolt lumber to. Once I have the interior painted, I'll bolt lumber to the tabs and cleats, then have the insulator spray foam the interior of the super structure.

 I'm limited to the wall thickness around the windows to 2.25" due to using the clamp rings. The clamp rings will make for a nice neat finish, but I wish I would have been able to get the rings for a 3.5" wall thickness. I'm able to make the wall thickness on the front of the wheel house 2.25", but the rest of the boat is going to be thicker due to the framing, so I'll have to build some custom wood trim rings to tie everything together.

Once I had all the cleats welded in place I turned my  focus to the welding needed to be done on the super structure roof. The roof work has turned out to taking a little more time than I had thought it would. I am planning for using a LP fired stove in the galley, and I needed a place to store propane. I framed a propane locker on the roof that will be large enough to store two bottles. Even though I'm not going to be doing any fairing work on the roof, I used pipe to make the corners of the propane locker. The pipe corners will paint up nicely, and will require little fairing to make them look good and cut down on future maintenance. The locker has two drains to let wasps in and water and any propane that could spring a leak out. I welded a 1/2" stainless nipple in the bottom of the locker to allow me to plumb the propane supply line in to the galley. The lid for the propane locker will be a simple lid with two pins for hinges and a simple latch.

In the center of the super structure sits the exhaust stack funnel. I'm using a keel cooled main engine and a dry exhaust system. The exhaust system is basically like a truck, and uses a pipe to bring the exhaust up and out of the boat. Along with the exhaust from the engine, I'm using the exhaust funnel to vent the hot air out of the engine room. I also am using the exhaust funnel to bring cool air in to the engine room. In order to do this, I partitioned the exhaust funnel in half, with one half dedicated to getting hot air and exhaust out of the engine room, and the other half for bringing cool intake air into the engine room. The largest hole I could cut in to the exhaust funnel at what I would consider an elevation where the hole would actually do something was 12"x16". So I have a 12"x16" hole for the intake, and the same for the hot air exhaust. I purchased a cheap coil stock louver from Lowes to see how it would work out, and I'm going to buy some better quality louvers for the final install. I'll probably use the cheap louvers over the winter just to keep the weather out. Removing the louvers is also how I'll gain access to clamping the exhaust pipe to the 4" stainless pipe I welded in to the exhaust funnel top.

I like the way the exhaust funnel looks and in order to keep things looking good I had the metal formed on a press brake. The fab shop owners is one of my neighbors and it was fun helping him do this small job for me. The exhaust funnel is tapered so there are two different radius's on the piece. In order to get the different radius's Mark set the machine to hit harder on one side than it did on the other. His machine is a Cincinnati 300 ton press brake, and was built in 1942. Cincinnati is a good brand, and this machine was built in a era in this country that has faded fast. We need our manufacturing jobs. Mark laid the pieces out for 20 hits per piece, and in this picture, you can see him lining the die up to hit on his punch marks.

I welded a four inch stainless pipe in to the exhaust funnel. I'm thinking about running the exhaust stack up the mast, and if I do that, I'll probably either do that in chrome or stainless. If I don't run it up the mast, I'll clamp a stainless or chrome 45 on the the nipple and call it done. I have room for a silencer on the exhaust piping, but for right now, I'm not going to install one. If I run the exhaust pipe up the mast, the outlet will be so high and with the wind blowing the sound away from the boat, I doubt you'll hear it. You might hear the whistle from the turbo, but I think that sounds good. I can always add a silencer if I need to, I just would rather not as they get hot and it's just one more thing to buy and maintain.

The inside of the exhaust side of the funnel will be  insulated to help keep the heat headed up and out. I'll post more on this later down the road, but I'll be using some fans in the engine room to help air get in and force warm air out.

The salon roof is where we'll be storing our skiff, bikes, and kayaks. Because of having to work up there, I decide to install a hand rail around the salon roof. I'm not ready to install the hand rail, and really don't want to do that job just yet, so I decided to cut some 1.5" discs to act as a doubler for welding the 1"  handrail stanchions to. By using the doubler discs, all I'll have to do is sand the paint off the disc and weld the stanchion to the disc. The disc will act as a heat sink and not burn the paint from the outside or inside of the roof. I'll be TIG welding ( Norm F. @ Kevin M ) the hand rail together, so splatter will not be an issue. I cut the disc on my mill using a hole saw and cooling the bit with water. The disc will also look decent with the hand rail stanchion, will not look like an afterthought, and allows me to keep things moving as doing this work is a hell of a lot easier with the hand rail not installed.  As per my locating the hand rail stanchions over a frame, I have kept in line with over building everything. The hand rail stanchions ended up being 30" on center.

I also will need a cradle for our yet to be designed skiff ( Kevin M), so instead of figuring out a cradle for a skiff I don't own yet, I just welded some 12" long x 3" wide doubler plates where I plan on building the skiff cradle. A 12' long skiff will fit nicely, but a 13' would also fit albeit tight. I'm going to build the skiff in aluminum, but that won't be for another two years. Getting a little off subject, I sure would like to weld part of the cradle to act as a fuel tank for storing gasoline for the skiff. Again, the doubler plates will allow me to build the cradle later without destroying the paint outside or inside under the finished ceiling. The plans I'm looking at for a skiff is 12' long, 5' beam, powered by 20 hp, and can carry 1000 lbs. It will weight about 300 lbs when completed.

The last roof job I need to complete is welding the tabernacle for the mast along with the pad eyes for the mast fore stay and shrouds, and brackets for flopper stopper poles. Flopper stopper poles are poles that extend away from the boat when at anchor and allow you to hang a device that helps mitigate rolling of the boat. I accepted some advice from an engineer I know and am reinforcing all of these parts to be robust enough to accept a more demanding paravane system to help with rolling while we're under way. Because I'm building a lot of these parts out of 1/2" stainless, I had to develop a cut list and have a local shop cut all the parts for me on a band saw. I just got all the parts back from the shop the other day, and I'll start putting it all together this week.

By the end of the week, I'll be able to move the welder off of the roof and finish a few simpler jobs on the aft wall of the salon. Primarily, the fill and vent points for the fuel tanks, the outdoor shower brackets, cutting the starboard side of the salon  so the boarding door works, and a few other smaller brackets. I feel pretty good that I'll be prepping for paint in a week or ten days, and should be done painting by mid September.. I might sneak away from work a few days to make sure I can get all this done, but early October looks to be about when I'll be moving her out.  


  1. Amazing build. Regarding your skiff, you should look at Stanley boats. They are in Canada and build plate alloy boats of all sizes.

    They have a small camp tiller model that might be about what you are looking for.

    Might be useful for some design thought starters.

    I wish I had 1/2 your skill.


  2. This “super structure” is quite the creation. It definitely needs a lot of welding, seeing as how you need to completely secure each piece with each other to create the whole structure. Great job, man! So, was your some sort of a premonition true that you might have to do some more welding by the time you’re in the site? No matter what, it is important not to lose focus. And never forget all the training you’ve had.