Building the Koholo 12-6 Stand Up Paddle Board

Posted by twsg2009 on June 2, 2012

The family decided it was time to add a few Stand Up Paddle boards to the ever-expanding list of water toys we have. Along with Alice Gale and the Duck Punt, we also have a “Holy Cow” 15 ft canoe, two plastic kayaks, a Tige Ski boat, and two SeaDoo PWC’s. After building Alice Gale and a Duck Punt I wanted to try my luck out on building a wooded paddle board. I picked the 12.6 CLC Koholo as my base for the design and purchased a plans set. They arrived in good order and I am happy with the instructions and full size printed plans.

Like all blogs the most recent post will be at the top, except for this ‘sticky’ first post. As the SUP’s are being built you will be following the progress towards completion. If you are visiting for the first time you will want to start from the beginning and follow the build sequence from the bottom up. This will take you to the first post.

Finished

Posted by twsg2009 on December 27, 2012

My apology to my faithful followers and here are the latest photo’s of the completed Koholo SUP’s. It is now winter and I will have to wait until warmer weather to launch.

Fin detail

Cloth overlay detail

Installed storage locker

Bow cloth work and storage locker

Foot pads and carry handle

Rear deck cloth detail.

This is my SUP

This is Gail’s SUP

Wood details on my SUP

Wood details on Gail’s SUP

Side by side. Both SUP’s are same size

Shiny details

Fin détails

Fin construction

Posted by twsg2009 on October 1, 2012

You can buy finished fins from CLC or other local sources but I choose to build my own laminated fins.

Alternate colors and width for a nice design

Glued and trimmed, ready for fiberglass

Epoxy edge build up

Ready for serious sanding

First layer of fiberglass

Use alignment blocks to attach, (not shown)

Seams are faired in with more epoxy and fiberglass cloth. Lots of sanding to come.

Cloth underlayment

Posted by twsg2009 on September 15, 2012

Following detailed instructions included in the plans I picked cloth patterns for both SUP’s and installed.

Deck Work

Posted by twsg2009 on August 27, 2012

The decks have been attached and sanding completed.

Used paint cans and weights to hold down deck during epoxy cure

Fiberglass on hull number 1

Posted by twsg2009 on August 23, 2012

I have progressed enough with the build to have sheathed the first boat hull with 4 0z fiberglass cloth and three coats of epoxy.

The second boat has progressed to the deck stage. I should be able to epoxy the deck after sanding the hull of boat number 1.

Support for the center deck handle installed

Bow piece made from pine

Start of 2nd Koholo using easy to bend wire

Laminated tail with contrasting wood

Tail lamination installation

Both boats shown, one on right ready for deck installation

Deck installation, use plenty of weights to hold deck flush to gunwale and stringers

Sanding and patching hull

After hours of sanding the hull got a 4 oz fiberglass cloth covering

Three coats of epoxy and ready for sanding

Made lamination and attached to 2nd boat

I really don’t like Stitch and Glue…yet

Posted by twsg2009 on August 14, 2012

I have been in a war zone considering all the blood I have lost today. Taking stock of my injuries I have about 10 puncture wounds from being stabbed by wire during the stitching process. I spent a full day with the stitching and found it an unpleasant task. I believe the cause to be my choice of wire. The local Home Depot did not have the copper wire needed but I did have a roll of 18 gauge baling wire that I used. This wire turned out to be tough, sharp and not as compliant as copper wire of the same size would be. I suffered through the day of use until finished and after licking my wounds decided to try a different wire option in the future. I tell you this so that you do not make the same mistake I did. If you are building a stitch and glue boat, don’t choose a hard stiff wire for your stitching. I did a few stitches near the end with some 24 gauge galvanized wire that Home Depot did have and this was extremely easy to use in comparison. The only problem with the thinner 24 gauge wire is the ease in which the thinner wire can cut into your wood when tightened. So my second SUP will be stitched with the proper copper wire.

I also struggled with fitting the bow, but finally had good success after removing all the bow stitching twice and planning off more of the wood. I was probably a few millimeters wide on my side panels after scarfing and it made a huge difference in the fit. Once I got the wood closer to plan dimension it was easier. Boat number two will be a cinch.

All seams received an epoxy fillet . A second coat of epoxy was applied to the bulkheads

The stringers have been added along with fiberglassing the underside of the deck.

Assembly

Posted by twsg2009 on August 10, 2012

This was a fun day as I was able to start stitching the SUP together. First I had to finish my patches to the bulkheads and give them an initial sealing of epoxy.

Cleaned up and ready to install

I have just enough space under the table to store all the finished components.

The sides and bottom panels ready to go

The work table cleared and cleaned for the next step

My new DeWalt circular saw is working well. I built Alice Gale with only a jig saw and the DeWalt does make quicker and straighter cuts on the plywood. Watch your lines though as the width of the blade can take off two much wood if you drift in to the wrong side.

Cutting the deck panel

My batten is short and does not bend as well as I desired so I made a new one with the left over pine stock used for the sheer clamps. I now have a nice 16 ft batten that bends perfectly and is easy to hold in place with by 2 and 5 lb weights.

I made a new batten from left over shear clamp material

My 25 lb. scale weights work perfectly for holding panels down for scarfing.

Deck scarf

I am building two boats at the same time so two deck panels are glued at the same time. Plastic sheeting separates the panels from the table top and each other.

Deck scarf

Here’s my first photo of the stitching. I got so excited about assembly that I didn’t even take a photo of the frame installation. I will have more photo’s from this stage on the next boat.

stitching started

To be continued …….

Back to the beginning, mostly…sort of..

Posted by twsg2009 on August 4, 2012

I decided to return to the proper design for the Koholo and chalk up another lesson learned from experience and failure! AFTER I made my decision to return to the true design I read a “ping back” from several days ago that I had not read until this morning. This message came in even before I updated the blog with my design error, so the author was right on target with his/her assessment before I was aware that I had a problem.

[…] you will want to start from the beginning and follow the build sequence from the bottom up. This will take you to the first post. Share this:TwitterFacebookLike this:LikeBe the first to like this. This entry was posted in […]

I am not sure how the ‘Ping Back’ is supposed to work, don’t understand the […], but will learn more about this before the day is over.

So back to the design issues. The day I started the building of the Koholo 12-6 I was on line looking at Google Images of finished Koholo SUPs. One board in particular looked very plain and I didn’t like the look at all. Without considering that every other Koholo build looks fabulous I was determined not to have that board, so I made a rather quick decision to modify my board for a better look. I had a good idea of how the board would look when finished and the new look would have turned out well. But as I have already discovered, I did make a serious design flaw in my attempt to change the original design. If I had discovered my error before committing to cutting wood I might have made the necessary design changes for it to still work. The harder path would have been to redesign the entire transom of the Koholo to allow for water flow out of the recessed platform well. I couldn’t commit to this rather radical change. Adding a drain was another thought process I went through but in the end it would not have been a good solution. The change would be complicated by heavy fittings, through hull ports, or complicated channels added to the board top for drainage. Not a path I intended or desired.

So getting back to the original design. Buy new wood and cut new bulkheads? Well sort of, I just fixed my ‘bad’ bulkheads by rebuilding them.

Here is my design changes that created a swimming pool board top without drainage.

The bulkhead design changes was not necessarily the problem, but the upswept curve I put into the tail was.

If the stringers where flat it would fix the problem but then create a radical change to the tail end of the board.

I decided to just fix my existing bulkheads.

Here is my fix, rebuilding back to original outside shape

First pass at rebuilding

I will be working on each bulkhead until they are true to the original design, but suffice to say I am now back on track with the original design plans for the Koholo SUP. The bulkheads need cleaning up and expansion of the interior open spaces. I also will need to recut the stringers.

Did I mention how much fun this has been.

I also made my sheer clamps and added to the side panels. I made two sets for each boat.

Ripping the sheer clamps from knot free pine

I recommend a roller system when cutting long pieces of lumber, but I don’t have one so I just used the table top to support the long end.

Using a 2 by 4 as a fence I was able to get good clean 1/2 widths from the 16 ft board.

My entire clamp collection? No, I have dozen in waiting.

The blue clamps are my favorite but the yellow ends disappear easily. The green ones have too much pressure for my liking, really good at clamping but a little to0 much squeeze out.

Plane the inside edge of the sheer clamp to reduce weight.

Next step will be building the deck.

Maybe my modification idea was not so good!

Posted by twsg2009 on August 4, 2012

Enjoyed a morning of cutting bulkheads and doing a mock-up of the SUP. The Festool vacuum is really good. It turns on when you cycle the tool on, and turns off about 2 seconds after you turn the tool off. You really never hear the vacuum over the tool noise, and best of all, no sawdust.

Lightening the bulkheads

Nicely modified and ready for a mock-up of the paddle board

I set the board up with bulkheads in the approximate locations on the hull and installed the stringers . While admiring my new design lines I had a sudden realization with the new shape. As much as I like the look, I basically have built a swimming pool into the top of my board. Hard to see this from the photo below, but if you visualize a deck running on all the horizontal surfaces of the bulkheads and stringers you will see a nice shallow pool with a deep end in the middle of the board.

Mock up with bulkheads and stringers in place

Top edge of bulkheads is original height design. Lowest horizontal and stringers show modification low points of design.

My modifications did not take into account that water needs to flow out of the well if your going to lower your deck below the gunnel. Duh! Looking at other finished boards with recessed wells it became more obvious that all of them have an open transom of less hight and are either built with a flat deck, or have a slope towards the stern or tail of the board. My plan was to retain the existing stern hight and feather in my recess. In other words I made my well slope from the stern end to the middle of the well. A two-inch swimming pool!

Not good! So I spent the rest of the day exploring my options. I really want to keep the design concept of a recessed well, so I am looking at other paddle board designs that work, and even an option for putting in a drain.

I considered these options:

Start over, buy another sheet of plywood and recut 2/3 of the bulkheads again, (follow the plan)
Put in a drain( add a simple or complicated mechanism for draining water out of the pool.)
Redesign the transom so the well recess is continuous and open to allow water to flow towards the stern. (The most complex solution now that I have already cut my bulkheads out. Also this design change will have a lot of unknowns about how it would ultimately affect paddleboard balance.
Redo the existing bulkheads, (epoxy patch method, who’s going to know anyway)

Tomorrow’s blog will let you know which method I selected.

Day 4, Happy Birthday

Posted by twsg2009 on August 2, 2012

I had my 60th birthday on July 25th. I was able to cash in on my wish list when my circular saw failed. With permission from Gail, I picked up a few more items while I was out.