Minimal Viable Boat

May 20th, 2016

2016-05-13 12.45.56 (Medium) In engineering we talk a lot about the Minimum Viable Product, MVP.  The MVP is the smallest set of features that will allow a product to sell in the market place with the shortest development time.  We often list the features and give them a thumbs up or thumbs down on whether the feature is needed.  When we are done marketing or sales throws out our list and gives up theirs.  Sometimes they are right; sometimes they are wrong.  In either case it is a valuable exercise.

So the time has come to define the Minimal Viable Boat, MVB, so I can do what is important to get the boat in the water and wait on less important items.  The bulkheads have been installed and I am working on the interior sheer clamp, knees, thwarts, bridge deck and anchor deck.  So what do I need to finish to launch Fish Taco?

  1. Cut the Transom.  I need to cut a notch in the transom for mounting the motor.
  2. Purchase and install the battery.  Can’t start the motor without the battery.
  3. Paint the bottom.  The bottom has been primed so I will need at least one coat, preferably three coats of paint.
  4. Knees.  The stern knees and forward knees need to be install to stiffen the boat.
  5. Breasthook.  Like the knees, the breasthook is needed to stiffen the board.
  6. Thwarts.  The two stern thwarts need to be made and installed.  I could build temporary thwarts and replace them later.
  7. Bow Eye.  I will need a way to retrieve Fish Taco onto the trailer so I will need to install the bow eye.  I don’t need to install the transom tie downs since I can put a strap over the entire stern.
  8. Trailer.  Fish Taco is too big to fit in the back of the truck so I need a trailer.  Two friends have offered the use of their trailers so I can borrow one until I get Fish Taco a trailer of her very own.

Now I get to the list of items that would be nice to finish but are not part of the MVB.

  1. Drain tube for mid storage.  I have cut a piece of 1 inch PVC pipe in half lengthwise and it is epoxied into place and covered with fiberglass.  This won’t take a lot of time so I may do it while I am doing other tasks.
  2. Anchorwell Deck.  A piece of 12mm plywood that covers the forward storage area.  Not hard to make but a lot of fitting to match the shape of the hull.
  3. Bridge Deck.  The plans call for 9mm plywood but I am thinking of epoxying two layers of 4 or 6 mm plywood to set the curve of the bridge deck.  Again not hard to do but a lot of fitting and cutting out the hatch can be tricky.
  4. Interior sheer clamp.  Not part of the plans but I want them because they give you a place to grab if needed.  I have scarfed the two interior sheer clamps and are ready to be planned down to size.  A whole lot of work is involved so this task may fall off the list for now.

Here is the list of items that I dreading because it includes the sanding.  I have to fair, prime and top coat the mid storage and forward storage before I put the decks on so I will do this in sections.

  1. Sand the inside of hull.  Ugh.
  2. Put QuikFair on inside of hull.
  3. Sand the QuikFair.
  4. Prime the inside of the hull.
  5. Sand the primer
  6. Top coat the inside of the hull.

There is the Minimal Viable Boat which does not include lights, electronics, down rigger mounts and much more.


Installed the Bulkheads

May 10th, 2016

Another milestone today, I installed the bulkheads. 2016-05-10 19.46.24 (Medium) I used hot glue to attach braces to the hull to keep the bulkheads aligned when I epoxy them in place .  For bulkheads #2 and #3 I added a lip which will become a hand hold when someone is sitting on the bridge deck and it will help hold the bridge deck in place when I am epoxying it.  Bulkhead #1 has the cut out for access to the anchor storage and you can see the support for the anchor deck.  I have not decided if I am going to put a door on the opening.  Bulkhead #4 has been replaced with a frame and two seat supports.  The frame is 1-1/2 inches tall and should be less of a trip hazard compared to the original design.  Next I need to finish the filleting of the bulkhead and start making the frames.

Too Hot for Boat Building

April 18th, 2016

2016-04-18 18.05.28 (Medium)Lake Oswego has been having a heat wave; we had a high of 82°F yesterday, 80°F today and an expected 85°F tomorrow.  For most of the boat build the temperature in the boat shop has been in the 50’s.  At those temperatures I use a fast hardener designed to cure between 40°F and 60°F.  As the temperature started to climb I switched to a slow hardener designed to cure at 60°F and above.  Yesterday I used all of my extra slow hardener designed to cure above 70°F.  I have very little need for the extra slow hardener since I don’t do much boat building during the summer so I had just enough to primed the inside of the hull.  I was able to finish fiber-glassing the inside of the hull by saturating the fiberglass cloth using the slow hardener.

So far on the build I have used about 3 gallons of epoxy and hardener; I expect to use at most 1 more gallon.  I have gone through 22 yards of 6oz, 50 inch wide fiberglass cloth and I should use a another yard to a yard and a half.  For peel ply I have gone through 16 yard and I might go through 1 more but I have 4 spare yards just in case.  I purchased different epoxy fillers per the designers recommendation and I will have enough left over for two more boats.  It is better to have a little left over than to run out and waste time and money getting a little more to finish the job; actually the time cost from running out exceeds any savings by buying just what is needed.

The thwarts, bridge deck and anchor deck don’t have any anti-skid coating so I am thinking of using Dynel fabric which has a texture similar to coarse cotton duck.   By not filling the weave all the way I will be left with a very abrasive resistant non-skid surface.

Turnover Day

April 11th, 2016

upside_rightIn the last two weeks I have almost finished sanding and priming the outside of the hull and the boat was turned over.  Turnover day is always a milestone in boat building; it marks the day the boat goes from a project to a real boat.  I modified the plans so the hull would be 13′ 10″ long.  I measured the hull and it came out to be 14′ 1″; oh well that’s bodybuilding.  Now it is time for sanding, taping, sanding, glassing, sanding, filling, sanding and priming the inside of the hull which means I am still 2 months away from launch.

The Candlefish 13 has a bridge deck in the center of the boat which is great for storage but can be in the way.  I decided that I am going to move the bridge deck forward by about 6 inches to make more room just behind it.  Lots of fun work ahead and it is now a real boat.

Two Down, Six to Go

March 27th, 2016

2016-03-27 14.29.41 (Medium)I though that I had put the final coat of Quik Fair on the boat but I did not.  I have been sanding and I found I need to fill the transom more and one spot on the starboard bow.  I estimate that I have 8 hours of sanding before I can prime the hull and I have done 2.  I have finished the first pass on the starboard side and started the first pass on the port.  I also need to sand the chimes and keel which I am saving for last.  With a little luck I will start priming the hull later this week and this next weekend I will start attaching the exterior trim pieces.  I have scarfed the outwales and I need to trim them to length, put a round over on one edge, cut a bevel on the other and then steam so that I can fit it to the hull.  The bilge runners and splash rail mainly just need to be cut to length.  I still need to scarf the keel and cut it to length.  I am going to cut kerfs in the keel so that it can take the bend of the bow.

System Three Quik Fair — First Impressions

March 23rd, 2016

Quik_Fair_A_and_B (Medium)I am trying to have the bottom of the boat painted by the middle of April but I don’t think I will make it.  Boat building is a journey not a destination and I have been learning how to use System Three Quik Fair, a two-part epoxy fairing putty.  Quik Fair comes in two tubs, A which is tan and B which is white.  They are mixed at 100 parts of A to 44 part of B by weight. The A and B are somewhere between mayonnaise and peanut butter but stickier.

Rule Number 1.  Don’t get any A or B in the wrong tub. 

I took some old spoons and marked then A and B and I only have one tub open at a time.  I measure out 100 grams of A on to the plywood palette and then put the A spoon in a tin of vinegar.  I then measure out 44 grams on B, making sure that I don’t get any A on the B spoon.  The B spoon goes in to the vinegar which should neutralize the epoxy until I get a chance to clean the spoons.  I then mix the A and B well using tongue depressors with one end cut off.  My 6 x 6 inch palettes are too small; I should have made them 8 x 8 inches.

quik_fair_on_hull (Medium)I put two batches of 144 gram of Quik Fair on about 1/4 of the hull and I ended up sanding most of it off.  I also found that I had high spots that took a lot of sanding and low spots that didn’t have any Quik Fair.

Rule Number 2.  Put a thin skim coat hull to help find the high and low spots when sanding.

I  made a longboard which is not that long; 4 x 10 1/2 inches which is a little smaller than a 1/2 sheet of sand paper.  I spray a thin coat of adhesive on to the sand paper and wait a minute so it gets tacky and that allows me to peel of the sand paper when it is used up.  I sand in an X pattern; down the hull at 45 degrees to the left and then back the other direction at 45 degrees to the right. I found that if I was not creating dust or I could not feel the sand paper cutting I was wasting my time.

Rule Number 3.  Use good sand paper and replace often.

Some of my sand paper would clog up in a minute and I spent more time changing the paper than sanding.  I found that 80 grit 3M SandBlasterPro “Only at Lowe’s” sand paper worked the best with a good balance of being aggressive without making deep scratches.  I could sand an entire panel with 2 half sheets if I brushed the sanding dust off the sand paper regularly.  On the high spot I went through the Quik Fair into the epoxy and on the low spots there was either no Quik Fair or the Quik Fair was rough.  Any place that I sanded the Quik Fair was almost glass smooth and any place I missed for rough or shiny.

Rule Number 4.  Make sure the Quik Fair has cured before sanding.

System Three says that Quik Fair will cure in 3 hours at 70°F; my garage is at 55°F and the Quik fair was not cured at 3 hours, 6 hours and still soft at 12 hours.  I could tell the Quik Fair was not cured because the sand paper would get clogged in a few strokes.  Once cured Quik Fair was easy to sand as long as I did not put too much on.

Rule Number 5.  The last step to applying Quik Fair is to smooth out the ridges.

I found that as I apply the Quik Fair with the squeegee I would always have some ridges on the hull.  I would try to smooth them out but sometimes I would make a mess and have to re-apply the Quik Fair.  Sam Devlin talked about using a cloth wetted with denatured alcohol to smooth out the epoxy fillets which got me thinking that might work for the ridges.  When I have put the entire batch of quick fair on the hull I would thoroughly clean my squeegee with a paper towel dipped in denatured alcohol.  I would then go over the ridges with the clean and slightly wet squeegee.   I would clean the squeegee often.  I found that I could knock down most the the ridges without messing up the fairing.


Bits and Pieces

March 14th, 2016

scarfing_jig (Medium)I started to make the gunwale, splash rails, bilge rails and keel out of Philippine mahogany.  The boards are 10 feet long so to get them the length needed, which is 15 feet, I need to scarf the planks and to do that I built a scarfing jig.  The clamps hold the work piece against a guide and to avoid cutting the clamps with the saw which would ruin my day, the clamps and the blade I put a screw in the jig so I could not push the clamps into the blade.  The scarf is about 10:1 which means that for 1 inch of width the scarf is 10 inches long.  I started to build another jig to hold the work pieces while I glue them.

I also cut the blanks for the frames out of Alaska Yellow Cedar which is very rot and insect resistant.  AYC is about 3/5’s the weight of white Oak, another popular boat building wood, and has similar characteristics.  The one downside to AYC is that it is not very hard and easily dented but the workable makes up for it.

Lessons Learned

March 12th, 2016

hull_wetted_out (Medium)I pulled the peel ply off this morning and started to scrape the high spots.  Since the epoxy was not completely cured, the scraping was fairly easy.  I had about 6 to 8 spots were the fiberglass lifted away from the hull; most of them were at the gunwale.  There were other spots that the peel ply was not toughing the epoxy/fiberglass so I got a low spot at showed the fiberglass weave.  I decided that I needed to scrape the lifted fiberglass off and cover bare spots with epoxy.  One thing lead to another and I ended up putting a seal coat on the whole boat.

The boat looks good so I will add the Quik Fair fairing compound once the epoxy starts to cure.  I am still hoping to prime the hull by next weekend.

Fiberglassed The Bottom

March 11th, 2016

2016-03-11 13.51.06 (Medium)Today with help from Mark R. and Mark N., I was able to fiberglass the bottom of the boat.  The bottom received one layer of 6 oz. fiberglass cloth and each side also received one layer of 6 oz. fiberglass cloth.  Since the fiberglass cloth is 50 inches wide, the result is the keel has three layers of glass, the bottom up to about 6 inches passed the bottom chime has two layers and one layer from there to the sheer.  The transom also received one layer of glass and the transom looks so good I just might have to finish it bright; that means the transom will have varnish on it and you can see the wood.  After the fiberglass was set on the boat, the epoxy was poured on the horizontal surfaces, spread out with an epoxy spreader to work the epoxy into the weave of the fiberglass and then I pulled the excess to the dry fiberglass.  For the vertical surfaces the epoxy was either brushed on or rolled on.  Once the fiberglass cloth was saturated and smoothed out, peel ply was placed over the fiberglass and also smoothed out.  You can see from the photo what the boat looks like covered with peel ply.  One of the advantage of using peel ply is when you rub the hull with paper towels you can soak up excess epoxy which results in a finish that needs very little sanding.

Once the epoxy starts to cure I can pull the peel ply off and scrap the rough spots.  The epoxy will not have curred hard so the scrapping is fairly easy.  I will also touch up some of the rough areas with Quick Fair which as the name suggests is a fairing compound which should let me fair the boat out quickly.  With a little luck I will be putting the first coat of paint primer on in a week.

I had previously using denatured alcohol to clean up the uncured epoxy but I have often read that boat builders were using white vinegar instead.  I tried it for the first time and I was impressed with how quickly and easily it cleaned up the scissor and roller frame.  I also tossed the epoxy spreaders in a can with some vinegar and it quickly cleaned them up.  It will definitely save me some time and money when I use vinegar to clean my tools.


Sanding Fair

March 6th, 2016

There are no pictures but I have been sanding the fairing compound that was put over the fiberglass tape to make the hull fair again.  I need to put a second coat of fairing compound on and then sand it off again.  For the first fairing I used West Systems 407 Low-Density Filler which is phenolic microballoons, perlite and amorphous silica.  I don’t know what  amorphous silica is but I suggest you don’t breath it.  For the second fairing I am going to use System Three Quick-Fair which includes chemical compounds that are trade secrets so we don’t know what it is.  I should be finished with the second fairing in a week or two and then I will prepare fiberglass cloth and peel ply for the glassing of the bottom.  May be by the end of March I will turn the board over and start on the inside of the hull.