Friday, June 15, 2012

Bulkheads almost there:) ------ 222 hrs

The bulkheads are very nearly completed. I expect that this set of bulkhead took only half as much time to build as the first set. It would have been quicker but of course we changed something:) Some of the savings comes from experience but I think most comes from building all the bearers at one time. Then attaching as many bearers at once that can be installed. I say “as many” instead of “all” since some flipping to put on opposite side bearers is required naturally and we have to wait for the epoxy fillets to “kick” (start to harden) which in our 60degF basement sometimes takes several hours. 

Tables of drying epoxy

The other part that really sped things up that I forgot to mention was using a couple to as many as five #6x3/4inch bronze wood screws to initially attach the bearers. First clamp the bearer in place then drill the pilot holes then drilling the countersink on each. Next I screw the bronze screws filly in to make sure the alignment remains constant when the final glueing without clamps is done. Then we butter the bearer with epoxy and install using the screws. We only tighten enough to get an even light squeeze. Many times the screws are not fully seated. Now since no clamps, weights, holders are being used we can immediately install the epoxy fillet on the lower side. I used bronze so that they can just remain in place. After a day the screws are driven home and covered with epoxy fairing(just same stuff used for fillets) 
Fast and more sure attachment method.
Slower bearer attachment method.  I do this when there is a bearer directly opposite. 
Now the “something” adding to our build time. We decided that all under bunk/floor storage areas are going to get covered in 6oz fiberglass in addition to the specified two coats of clear epoxy. The rationale is that items stored there can shift and easily damage a clear epoxy coat. By adding 6oz cloth the surface become much more abrasion resistant as well as water proof. My guess is this will add no more than a few pounds overall. 

Here is another Wharram plans hard read. Is it 23mm or maybe 28mm? I decide to just go with 25mm, guess I’ll see if it really makes a difference later:) 

Wednesday, June 13, 2012

Still in the 2D world --- 211 hours

We still haven’t progressed much in to the 3D world. After getting BH4 and BH6 all shipshape in their slots I had to really start thinking about the gallery layout. The reason I hadn’t given it much thought so far is that for the longest time I had it in my head we were building the Port hull. For some reason had been thinking the cabin tops sloped inwards. They don’t !! They slope outwards:O No where on the bulkhead drawings does it say “Starboard reverse for Port”. Just have to keep in mind that slope. No harm really because at this stage only BH3 and BH6 are different and only once the floor/bunk/deck bearers are installed. So after a posting some questions on Wharram Builders and Friends I decided to punt and just build the real Port bulkheads since I’ve given that hull much more thought.

Speaking of misreading the plans. I’ll fully admit I’ve made a few goofs of my own making, but I’ll also show that these plans need to be view with a magnifying glass. In the first picture showing BH2, the hull max curve point shows 19mm, but if you don’t look closely it appear 9mm. OK step closer and all is good. The next picture is of the cross beams. I studied this page and I, and a few other Tiki 30 builders, came to the conclusion that the aft and central beams are the same length. 
To tired eyes that small line next to the circle in the nine begins to look like dust:)

I've already written the explaining note, but imagine if it were not written.  Is it obvious  the aft and center are different?

There is the key! One beam is 50mm shorter, next question is which?

But back to bulkheads. Yesterday I had an insight, “production line”! Once the Port side bulkheads are cut out of the 6mm plywood the next step is to make and install about 20 floor/bunk/deck bearers. So instead of working each bulkhead I decided to mill all the bearers then center and make all notches. This saved repeated setup of the table saw and other tools used. I’ll bet it took half the time to make them this way saving several hours. By the end of today we had epoxied about half of them on to bulkheads and it worked great! Port bulkheads should be complete tomorrow. 

All port side BH floor/bunk bearers cut to  approximate length and notched.  I built the four deck bearers after the picture. 

Friday, June 8, 2012

Going 3D!!!! ----180hrs

Today there was a small thrill. The boat build went 3D! We set the keel up in the hull cradles then test fit bulkheads 3 and 4 that slot into the keel. Glad that we did since it took some tweaking(sanding) to get the bulkheads to slot all the way down. All it took was seeing bulkhead 3 in place to put the idea of building both hulls simultaneously is out of the question. 

On the bulkhead front, we got the Beckson 8inch inspection plates via the Brown truck so I cut the holes in BH1,BH6, and BH7. Next I did that little extra not in the plans, over drilled the mounting holes, filled with epoxy, and drilled the final holes. Now the plates are set aside for few months. 

Wednesday, June 6, 2012

How long should it take to build?

Are people who choose to build a Wharram catamaran, by that very choice, unable to follow plans? This thought came to me as I puzzled out the rudder hinge locations. The plan has a recess cut then 5 holes drilled, and Voila! In 10-15 minutes it done. And in less than two hours all eight are done and time to move on to other projects. Heres the point at which every builder, including me, that I’ve seen “improves” on the hinge. Mill out an oversized slot, fill with epoxy, add extra abrasion resistance, then drill out 5 holes through the epoxy. That series, in my case, gets this hinge up to the 1+ hour range. And this type of “improvement” is done over and over and over during the build. There is no doubt that I, and I’m sure other builders, think these improvements are highly desirable, if not needed. These changes all attempt to improve on the boat’s durability, strength, safety, comfort, or beauty. The key point is that these boats are not built strictly to the plan. 
So I think it’s not really fair to carp at Mr Wharrams build time estimates(900hrs for the Tiki 30) since I don’t know of anyone building a Spec boat. I’m just as guilty, right there on my side bar I say in a somewhat snarky tone “big grain of salt” about the estimate, but hey wait minute, I’m the one deciding not build to Mr Wharram plans. So I’ve changed the sidebar to be more fair to Mr Wharram. 

Sunday, June 3, 2012

When it doesn’t add up, STOP. ----154 hrs

Today progressed from strictly bulkhead work to the sternpost/skeg.(aft most part of the hull where the rudder will attach). Last fall I slotted and epoxy filled the areas where the rudders will be lashed on and added kevlar tape to some of the wear areas. Today I decided to drill out the holes for the rudder lashing. I thought for sometime about using a small drill press I have but thinking about the rigamarole of setup I decided to just use my cordless drill and forstner bits. By laying the sternpost horizontal and using the bubble level in the rear of the drill it was pretty easy to get decently straight holes. The STOP in the title refers the adjacent picture. I need to return to kindergarten and relearn my counting. First person to identify my problem wins a Guinness stout. You’ll need to stop by the house to collect, but be warned I may put you to work:)

Just watch the bubble.

On the bulkhead front, I decided to add 6oz fiberglass to the lower sections that will become the buoyancy compartments. My thought is these areas can get condensation which will settle to the bottom and likely be unnoticed for weeks if not months. My experience with just coating plywood with 2 or 3 layers of just epoxy is it can fail when constantly submerged. But when cloth is added, no problems. So at the weight penalty of literally about 18oz for both hulls, I’d rather be sure the lower bulkheads don’t eventually rot. 

BH1 lower forward buoyancy compartment side getting 6oz fiberglass

Todays favorite tools are the Ryobi Cordless 18V Drill and Forstner bits. I get hours and hours of use out of one charge and I have enough things that need a plug, But what puts this over the top are the Forstner bits. They aren't cheap but they bore flat bottomed holes and have near zero tear out at the edge of the holes. 

Hero tools of the day:) Also the traveller rigging holes are drilled out. 

Saturday, June 2, 2012

Hi ho, hi ho, it’s off to work I go.... --- 146 hrs

…..well that’s said with a little grin. After all who can call building a terrific Tiki catamaran work? Actually we cleaned up the shop area a few days ago and got in about 3 hrs of work on the Tiki. Some of that time was just figuring out were we left off 7 months ago.
Bulkheads 1,2, and 3 with final epoxy coat. 

Our current push is to get the bulkheads for the port hull completed. The plans say to get these complete as possible since they are much easier to work on while laying on a bench then when they are in the hull. So step one the other day was surveying each bulkhead and listing what remaining work is needed. The list has items like, “bunk bearer aft side(BH3)”, “fillet under floor bearer(BH3)”, “finish cutting out (BH7)”. 

Today the last couple 20x32 mm douglas fir floor/bunk bearer  and larger curved deck bearers were installed.  In order of bearer build difficulty its floor easiest then bunk and finally the deck bearers require most work. The floors are just straight pieces with ends angled to the bulkhead. The bunk bearers at same as floor plus notches for stringers. Then the deck adds to bunk by making the top curved. This is so ultimately the deck will have a curve, making it stronger and shed water more easily. 

Building the bulkheads also brings up other issues, such as, access to buoyancy compartments. Plans call for a 6inch access plate in BH1,BH6, and BH7. I had thought of building wood access plates but when I asked on the Wharram Builders forum about this , Scott Williams said he used Beckson and that there will be plenty of wood building. After looking things over I decided to go with the 8inch ID access plates. This will give more reach in room without weakening the bulkheads. But the $24/each price tag was a little hard to swallow. Even the 6inch were $16/each. The forward buoyancy compartment is about 70inchs BH to Stem so even with an 8inch access plate not the entire volume can be reach by hand.

Time for a favorite tool, the table saw! My old Sears POS has been dragged from one house to the next for probably 25 years. It’s deadly, zero safety equipment. I always wear a face shield and watch that blade like a hawk. On the positive side it rips the douglas fir 2x4s pretty nice with a new blade. And it knocks out these recesses in the deck and bunk bearers. The build directions show using a hand held back saw to cut each side then using a chisel to take the meat out. I did a few this way, but I can do 12 on the table saw in the same time as one by hand. Also the 1” belt sander gets a fair workout. It’s great for final shaping but it’s powerful and a light touch is needed.
First set the blade height.

Make repeated careful passes. 

Deck bearer is ready.

Sometimes a touch of the belt sander cleans up the notches then a chisel to clean the corners to finish the job.