I tabbed in a divider in the wardrobe closet. The aft side will be a hanging closet and the forward side will be converted into shelving and a counter top for a small round sink as part of the head "system." With a sitz tub on the port side and a head there was just not enough room for the sink. We discussed installing a folding sink but decided it was not the right answer for us. We needed a permanent sink to support four people. This seemed the best way to meet the requirements. We don't think we need a 30" wide closet. The divider/bulkhead is 1/2" BS 1088 plywood. There is a single layer of 1708 biaxial on each side both top and bottom. I power planed the ends down 1/16" so the biaxial would lay flat with the surface of the plywood to make it easier to apply the staving. I left a space between the back side of the bulkhead and the hull so there would be room to remove the chain-plate which you can just see glassed into the hull and under the edge of the hull-deck joint.
12 Apr 12 (Updated 14 April with additional text and photos). Below are some pictures from the recent work on the sitz shower tub. I have been thinking about how to build the tub for a long time. The difficulty is that if the tub is built small enough to be built outside the boat and passed through the companionway, it would be too small to use. Thus, it has to be built in place. However, because the space is so tight and restricted if I use the stitch-and-glue method I won’t be able to get to the back side of the tub to tape the joints. The tub, though only used for sit down showers and not filled with water like a tub at home, still needs to be stout and water tight. In a perfect world I would be able to remove the tub in-tact if it needed to be repaired or if I need to get to the inside of the hull behind it. But, I don’t see how that’s possible. So, if for any reason I need to get behind the tub, it will need to be cut out with a “saws-all.” The 1”x1” horizontal and vertical Douglass Fir cleats provide a little stand off so air can circulate around the tub and so the bulkheads will be protected if I need cut the tub out.
The tub will be about 33” across the aft end and about 27” across the forward end. It will be about 33 ½” long and about 27” deep from floor to top edge. The inboard side will be vertical while the outboard side will have “chines” and generally conform to the shape of the hull. The tub will be made with 1/2” marine grade mahogany plywood. It will be coated with numerous coats of epoxy inside and out to include the end-grain. The inside corners will have thickened epoxy fillets. There will be a removable teak seat in one end set about 10” above the bottom. There will about 40” of vertical clearance between the top of the tub seat and the overhead. The side of the tub towards the boats centerline, the side you step over to get into it, will be faced with vertical v-groove staving just like the rest of the boat. The top edge will be trimmed in raw teak all the way around. The tub will drain into a grey water tank which will be pumped overboard by my manual bilge pump that will be connected to the tank via a diverter valve. The head and pump up spray bottle will be located in a seat locker in separated compartments each with a hinged teak lid that won't be visible when they are not in use. The “user” will sit perpendicular to the centerline with back to the shower tub and feet oriented towards the centerline. This will provide lots of elbow room. The seat will be nearly 35” long (fore and aft) and about 19" deep (less with the hinged lid up) so it will make a good place to sit when getting dressed when using the forward, in-port, cabin. In a perfect world I would have the head oriented fore-and-aft and I spent several days trying to make that work but there simply was not enough room. The best solution was to piggy-back on open floor space already there – the passage way between the saloon and the forward cabin -- for the “users” feet. That gave us the solution for tub and head size we were looking for.
Updated 13 Apr 12: The first thing to do was to install the horizontal and vertical cleats that will support the tub sides. I used 1" x 1" Doug Fir. I cut them to length and temporarily installed them. Satisfied, I removed them and applied two coats of shellac sanding in between each coat. Shellac is pretty good stuff. It is a great sealer and though not as waterproof as epoxy it is a lot easier to work with. It dries in about 20 minutes and can be sanded in an hour. They will never see standing water and in fact will see very little water if any at all. The nice thing about V-groove staving is it provides drainage for water and allows air to circulate. After installing the cleats I called it a day.
The next day it was time to work on the plywood sides of the tub. After considerable measuring and too much contemplation I was ready. I picked up another 4x8 sheet of type I Mahogany marine grade plywood from my supplier and also some more door skin ply which I use for making templates. I ripped the door skin into my standard 1 ½” wide strips. I used my hot glue gun and tin snips to cut the doorskin to the proper lengths and glued them together creating the shape I needed for a proper fit. I removed the pattern and traced them on the plywood. For jig saws and skills saws it is best to make the cuts with the good side of the plywood down since most of the blades for these tools cut on the up stroke and it will leave a cleaner cut on the good side of the wood. It’s not very noticeable when you are cutting with the grain but it makes a big difference when cutting across the grain. Then, I temporarily screwed the plywood in place. Satisfied with the work I moved on to the next step.I wanted to use a good rot resistant wood for the cleats that will support the bottom of the tub. So, I milled some 8/4 Iroko. I had to determine the slope of the bottom of the tub. I decided on four degrees, sloping from the bow to the stern. With that decision made I ripped some Iroko into 1 ¼” x 1 ¼” cleats with a four degree bevel. This will ensure the floor of the tub lays flat against the cleats. With that done, I checked the fit by temporarily securing the Iroko cleats in place with some two sided tape. Satisfied, I drilled holes for quarter inch bolts and temporarily installed them. With the end cleats installed I laid a couple of straight pieces of wood across them and used doorskin and the hot glue gun to build a template for the tub center support. I needed it in place to support the template for the bottom of the tub. I cut the center support from a piece of scrap BS 1088 ½” plywood. I hot glued it into place. Later it will get sealed with many coats of epoxy and glassed in place.
Next, I built another doorskin template for the floor of the tub. I placed some ½” blocks on the Iroko cleats to ensure the template measures the widest part of the floor (which in this case is the top). This is essential when the piece to be cut will require a beveled edge. I cut the mahogany ply and then test fit it. I spent a little time shaping it for a better fit with a small low angle block plane and a spoke shave. Later, I will trim the floor back even more but not till I am sure where the outboard vertical sides of the tub will join the floor. With this done I called it a day.
Updated 14 Apr 12: We fiddled around and wasted a lot of time today sorting out how to build the sitz tub outboard side panel. To be honest the sitz tub is kind of small though we can't really be sure till we have the seat mounted in it . . . or build a full size functional mock up and bolt it in place and that is not going to happen. I built two different side mockup panels today. The first one did not have a chine. Just a straight angled panel at about a 50 degree slant. We set up buckets to sit on in the tub and different platforms to vary the height. It was OK. Not great. Then, I built another mock up using only doorskin templates (see latest photo in gallery below) and we liked it better as we gained another 3 inches in width at seat height level. The challenge is the vertical inboard face of the tub which can't be changed if there is to be enough room for the head. The vertical panel has an adverse impact on the usable room in the tub. It cramps up your ability to move around. Well, after staring at the thing for too long, making more sketches, and looking around the boat for any other viable option--there were none--we will start building the chined two-panel option tomorrow.
Image:
The next day I started off by rechecking the temporary cleats I taped in place yesterday. Satisfied that every thing still fit, I took some measurements with a bevel gauge to determine what kind of angle I would need on the permanent Iroko cleats. The angle is necessary to match the tub that isn't square--it gets wider from forward to aft due to the widening of the hull. The angle is 11 degrees. I then all the panels out of the boat and ripped 1"x1" Iroko cleats and then ran them back through the table saw to get the correct bevel. I installed them with 1/4" bolts. It's way over kill given that they will also be epoxied in place but "nothing to strong ever broke" and I can't easily remove the tub if there is a problem . . . so let's not have a problem with it. "P" for plenty as we say when using demolitions in the Marines. Next, I added some additional Douglass Fir cleats to add to the rigidity of the foward and aft panels. Then, I reinstalled the forward and aft panels. I then built templates one at a time to the new cleat system and used them to trace the patterns on what was left of the 1/2" mahogany plywood. When looking for a close fit you get better results if you build each template next to the panel just installed. That way you reduce the chance of a compound error. I used my circle saw to cut the panels from 1/2" mahogany plywood. I cleaned up the edges with a block plane.
The panels were a snug fit as I had not cut the bevels to match the 11 degree bevel on the cleats. I cleaned up the edges with my block plane and then used the plane to add the correct bevel checking it with a combination square. I was very satisfied with the final fit.
After that is was time to clean up the boat and the shop and call it a day. This week I will start applying epoxy to the panels and cleats and begin the process of "stitch and glue" to connect the panels.
Image:
Yesterday, I wet the edges of the two joints between the horizontal panels and the floor of the tub. I secured them in place with small screws and two spring clamps. Then, I mixed up some epoxy thickened with cabosil and reached underneath to fill the gap between the corners of the outside corner (the inside corners being on the inside of the tub faces toward the center of the boat). I let it sit overnight and then spent time researching a suitable drain. By bonding the panels together using the cleats as a jig, so went my thinking, I could remove them from the boat and they would remain correctly aligned. Then, I could apply biaxial tape to the back of the two seams I can't get to when they are mounte in the boat.
The panels slid right out and did not break.
I could not tape to the edge as that part of the panel sits on the Iroko cleats.
I was a little concerned I would not be able to remove the panels the joint breaking but I had no problem. They slid right out. I took them into the shop set up a little jig and sanded the outside of the panels. I fully expected to know the panels off the work bench and but the joints at some point. But, luck was with me. No disasters. If filled the remainder of the seams with thickened epoxy. I remove the forward and aft panels from the boat and sanded the outside of them as well. Next, I applied two layers of 17.08 biaxial tape (5" and 4" wide) to the back of the horizontal panels and the floor panel. The rest of the day I spent brushing on three coats of epoxy. Tomorrow, I will work on the cleats in the boat and drill the holes in the bulkhead so air can move around the tub.
Yesterday, I worked on the cleating system and replaced the lower horizontal douglas fir cleats with some 1”x1” teak I had on hand. I also angled it down instead of positioned horizontally as I had with the Douglas Fir. I rationalized that if any water got on those lower cleats (and it will eventually) the water would run down and drip off to the fiberglass hull vice sit there on the wood and cause problems. I test fit everything to make sure it was still lined up.
Today, I gave a good acetone wipe down to the Iroko and glued them to the edges of the forward and aft panels with thickened epoxy. The tub sits on those cleats. Then, I applied two coats of epoxy to the Iroko, thinning the first coat with a little acetone which helps it penetrate a little better. Adding even five percent acetone by volume weakens the epoxy but since I am using it as a coating the strength is not so important.
Next, I used a 1 ¼” hole saw to cut a series of holes in the two bulkheads on the forward and aft sides of the head compartment so air can move around the tub. It is stale air and moisture that causes mildew and rots wood. The air holes are important. I spent some time trying to make them nice and lined up but there was no good way because of the numerous obstacles to content with such as wood plugs (with ss screws buried up them), cleats, dividers on the other side of the bulkheads, etc. So, I did the best I could and cut a total of 12 holes in the two bulkheads. The holes will not be visible as they are all contained within lockers, settees, and under berths. Then, I took my rotozip with a ¼” collet ¼” round over bit and smoothed out the edges of the holes. The round over is not for looks, though it does give the hole a more finished appearance. It keeps the epoxy from “pulling back” from the edge like it will with a 90 degree turn. The same thing happens to paint and varnish. A gentle bend allow the surface of the coating to follow the turn and to remain thicker and provide better protection to the wood underneath.
I have mixed feelings about coating wood other than plywood with epoxy. As my mentor has pointed out, wooden boats have been around a long time without epoxy. There are often other ways. Epoxy is not a be all solution. It is a tool and needs to be used correctly. And, sometimes epoxy and cause problems. If water gets to the wood under the epoxy and the wood can’t breath and dry out it can be worse than if you had just left it uncoated. But there are times when it makes sense. In this case, I can’t get to the area behind the tub. So, I will protect it best as I can. I did, after much thought, decide to leave the teak cleats uncoated. Since they are not attached to the tub, but really serve to wedge it in place I thought any coating might get scraped off over time as the tub moves around a little with the working of the hull and the crew crawling in and out of it. If so, the protective layer could be broken could seep in under the coating. Better to rely on teak’s great resistance to rot aided by the air holes through the bulkheads. Such is my rationalization for the day.
Image:
I was not satisfied with using the teak as supports behind the forward and aft panels of the tub. Teak is great wood sure, but I knew eventually it would be a problem. It would get musty and it would aggravate me. So, Friday it occurred to me that McMaster Car might have some fiberglass stock I could use. Sure enough, they had hollow, box, 1"x1" fiberglass stock. I ordered two sections of 5' each and it arrived first thing Monday morning. After I ordered the fiberglass I installed a 3/4" Iroko cleat on the outside of the middle panel where the seat cleats will be secured. I needed something thicker than 1/2" ply to secure the cleats to. The teak seat that the occupant will sit on will be supported by the cleat so there will be a fair amount of weight on it.
Monday, I cut the 1"x1" fiberglass stock and installed it where the teak was. Problem solved. Next, I glassed in a support under the center of the tub.
Today, I took some additional fiberglass 1"x1" stock and epoxied it to the outside of the outboard edge of the top panel as a stiffener. Then, I coated the Iroko I installed yesterday on the outside of the tub and the support that will provide additional support under the tub with two coats of epoxy. I thinned the first coat with acetone to help it better penetrate into the wood. After is was tacky to the touch I applied another coat that was just straight epoxy. I let them cure and this evening I set the panels in place back in the boat.
Image:
I used a standard 1 1/4" bar sink drain I bought from Ace Hardware. It is chrome plated brass. I have not used any bedding compound. I will have to pull it out before I glass in the tub with fillets, cloth tape, and several coats of epoxy. After drilling the hole and fitting it for the drain I began to develop the plan for the inboard vertical panel. A/B grade Marine Mahogany only has one good face. You'll be able to see both side of the inboard vertical panel--from outside the tub and inside. We plan to finish it bright so we need to "A" sides. The solution is to make our own A/A panel. I purchased some additional A. Mahogany and while milling the staving to 3/8" (I resawed 4/4 A. Mahogany to get two pieces of 3/8" I also milled some rough planks to 3/4". Then I set the 3/4" aside to work on the quarter berth. Once the quarter berth is finished I'll resaw the 3/4" planks to get two 1/4" pieces from each plank. The plan is to glue them to 1/2" okume to get a very stiff A/A sided panel that will be epoxied and tabbed to the parts already built and installed. If it sounds confusing it will be made clear when we get the pictures of the execution.
Image:
Image:
The next step for the sitz tub was to cut a piece of 1/2" okume ply serve as the core for the vertical panel. Next, I ripped the 3/4" mahogany into narrower planks--less than 6". Next, I stood them on edge and "resawed" them on the table saw. Next, I ran them through the planer and took them down to an even 1/4" thick. I jointed the edges and then back beveled them slightly with a hand plane to the top edges would fit together flush. Then, glued one layer to the okume ply with System Three T88 epoxy, clamped it to a strong back, and let it sit over night. The next day, I unclamped it and applied the mahogany to the other side and reclamped it. Today, I unclamped it, smoothed it with a cabinet scrapper, and sanded it with 120 grit. I checked it for fit. Satisfied, I applied one coat of West Epoxy with 207 clear hardener to what will be the inside surface of the sitz tub and set it aside.
Image:
I had a very helpful phone conversation with Tom Pollock in the technical office at West Systems today. He is a wealth of knowledge and took the time to look at the pictures of my sitz tub while we discussed the best way to glue it up. He agreed that I should epoxy it to the cleats that are installed on the end panels. We discussed the inside fillets and he suggested I should use G-Flex epoxy instead of 105/205. I have used G-Flex before and written a post about it. Though it is a little less strong than 105/205 it is not as brittle. In fact it will elongate 30 percent before it breaks. We discussed the advantages of the fillets being able to flex a little no knowing if there will be any panel deflection due to being tightly fastened between two major bulkheads. He also thought I could eliminate the tape to the inside fillet and also told me that because G Flex gives more than 105/205 it makes up for the strength and in fact "break tests" show it to be just as strong. He advised me to apply a one coat of 105/207 (207 is the clear UV stabilized hardener which I have on hand just for this project) and let it cure. Then install the panels and apply the fillets to the cured coat of epoxy (sanding it first of course). By applying a coat of epoxy to the panels first the thickened G Flex will actually have better adhesion for this kind of application. So, after completing the varnish work on the quarterberth I applied the first coat of epoxy to the panels. I waited for the temperature to start dropping so the condensing air would pull the epoxy into the wood and also eliminate bubbles forming on the surface.
First coat of 105/207 applied to the end panels.
Finally, today I epoxied the sitz tub middle panels to the end pieces. I sanded the single epoxy coat I applied yesterday to the end pieces and the center panels with 120 grit abrasive. I used 80 grit along the edge where the inside fillet will eventually be located. I wet out the cleats and the under side of the center panels with unthickend epoxy. Next, I mixed up 105 and 206 slow hardener with colloidal silica and trowled it onto the cleats on the end pieces. I used a plastic stir stick to create a little bit of a bevel to the thickened epoxy laying on the cleat so that it was neatly beveled to the outside edge. Then, I placed the center panels into position. I had just the right amount of squeeze out and the panel sat perfectly in position. I installed three # 8 screws that I had previously drilled to keep the panels in position and apply a little pressure to the cleats. I clamped the bottom inboard edge of the panel with two spring clamps. Next, I mixed up a little System Three T88 (the same epoxy I use on the staving) and epoxied two more cleats to the bottom inboard edge of the lower panel. This will give me cleats on the bottom of the tub to screw the inboard vertical panel into when it is time for it to be installed (tomorrow?). I wiped up excess epoxy with a stir stick and cleaned everything up with an acetone dampened paper towel. Then, I installed three mahogany wood plugs over the screws heads.
Stiz tub epoxied into position. The rest of the tub is sanded with 120 grit abrasives.
Today we installed the last panel on the sitz tub. The first step was to remove the clamps from yesterdays work. Then I scrubbed the edges down with a little water and a 3M scrub pad to make sure I removed any amine blush from the 105/206 resin/hardener I used yesterday to install the middle section panels. I wiped it dry with plain white paper towels. I also sanded the inside surface of the inboard vertical panel with a finish sander and 120 grit abrasive. I had previously applied one coat of 105/207 clear UV hardener. I made one more round of sanding the edges where the fillets would be applied with 80 grit abrasives. I temporarily installed the panel so all the holes and countersinks would be completed before I epoxy glued the panel in position. Then, I prepared all the supplies I would need in the boat. I vacuumed all the surfaces and performed one last acetone wipe down.
We added mahogany wood flour to the epoxy tfillets o help them blend in better. The tub is sanded so it looks much lighter than it will when it is varnished.
Once we were ready, Gayle mixed the G/Flex epoxy with colloidal silica and a little mahogany wood flour till the color looked about right. I previously sifted the wood dust through several strainers so that it would be flow on smoothly. With out the wood flour the fillets would be a light creamy yellow due to the color of the G/Flex and the silica thickener. We trowled the mixutre into a 75cc syringe and I laid a bead along the joint and then used a rounded plastic stir stick to make the fillets. She continued to mix epoxy and load the syringe while I focused on making the fillets. This saved a great deal of time with the curing clock running . . . tick, tick, tick. After applying the fillets to the back panel vertical and horizontal joints we stopped while I installed the vertical inboard panel. I started the fillets with it removed so I had better access to the tub surfaces. With all the holes predrilled it took less than five minutes to install. We quickly mixed up some 105/206 with colloidal silica and applied it at the bottom of the panel and the Iroko cleats I installed yesterday to ensure there could be no gaps between the two. I screwed the panel on and removed the squeeze out. Then, we applied the final fillets. After that I cleaned up the edges around the fillets as required and policed up the area. That completed the day. I am very happy to have the installation of the sitz tub behind me. Tomorrow I will remove any amine blush, sand the fillets till I am satisfied with them, and then lay on two finishing coats of 105/207. The outside of the vertical panel--the part you can see from the centerline of the boat--will be varnished. The edges will eventually be trimmed with bare teak and ash ceiling will hide the hull.
The next day I applied two more coats of epoxy to the interior surface of the sitz tub. I started off by scrubbing the fillets with some water and a maroon 3M scrub pad to remove any amine blush. I wiped it dry with paper towel and let it sit to further dry while I gathered the supplies I needed to brush on the epoxy. Then, I ran some personal errands and ate lunch. After lunch I sanded the fillets with 120 grit which took about an hour. I vacuumed the dust and performed a final acetone wipe. It was time to epoxy. I mixed up some West Systems 105 resin with 207 clear hardener. This is the same hardener they recommend for use when building kayaks and you are going to finish them bright. It is formulated so it does not produce amine blush. I applied the epoxy with a short bristled 3" "chip" brush that cost about $1.25 at Lowes. I tipped with a 3" Jen Poly foam brush that I bought from Jamestown Distributors--36 brushes for $9.00. I applied two coats over about four hours from start to finish. I am not sure if I will leave it as is or if I will eventually apply two part polyurethane. I'll see how it looks tomorrow. I need to get a couple of coat of varnish on the inboard side of the tub's vertical panel and apply a couple more coats of varnish to the quarter sea-berth vertical panel. I may work on the deck hatches after that or go straight to the ice box. I'll think about it some more tomorrow while I'm varnishing.
The second and third coat of epoxy applied. The fillets are a little darker than the mahogany but not bad. The black marker lines on the doug fir cleats show me where the screws are located. All that will be covered with bare teack trim.
