Hi all,
I've started my Kaholo, a 14' plywood SUP from Chesapeake Light Craft. So I thought I'd do a "build log" as I go along over the next few weeks. Hopefully it will be of interest to others here.
CLC mainly make kayak kits (see www.clcboats.com) using plywood and "stitch and glue" construction - basically, you "stitch" panels together with wire, then glue it with epoxy. I've built 2 kayaks using this method in the past, and just finishing off a third.
The 14' (4.26m) board is 29" / 74cm wide and 11cm deep. Seems bulky, but ply boats generally are as they don't have the curves of other build methods. And I've never heard a bad report about it's on-water performance. It shouldn't be too heavy, and I'm aiming to save weight where I can.
So, to the build... I'll break it up over a few posts. Feel free to ask any questions (or offer suggesitons ).
Regards,
Darren
First step is to cut out panels from 1200 x 2100mm 3mm thick marine ply (don't be tempted to use cheaper ply, it has voids, knots, etc that will weaken the structural integrity). I get mine from Plyco, they make it locally (Yay!).
Here's a pic of panels. They aren't cut to the exact panel shapes, as these (especially the sides) would be too flimsy. Panels from two sheets are joined together end-to-end to give blanks 4.2m long. A bit tricky to manoeuver in the garage.
CLC provide full-size templates for the parts - just amatter of transfering the outlines to the panels, then cutting out with a jigsaw - fairly easy!
Stringers are added to the side panels. I used strips of Paulownia, a locally-grown lightweight timber that has the strength of Western Red Cedar but at a lot less weight.
These were scarfed also to get full length pieces. You can see cut pieces on the left of the first photo in the second post (on almost-complete kayak).
All glueing is done with Bote Cote epoxy - again, Aussie-made and less nasty and easier to mix than other brands.
You can never have too many clamps ...(and don't forget plastic underneath so you don't epoxy it to the table!
Now the fun begins and it starts to take shape.
The sides are stitched together with wire, and held into shape by 'bulkheads' that run across the hull. In the plans they are solid, but I've cut holes out to reduce weight. I did the same with the deck support which slot into these (you can see them to the right).
Although drilling out a few bits of ply may not save tons of weight, it should shave off a kg or two. Everything gets covered in epoxy to waterproof it, so if it isn't there it won't get epoxied! It's important to clean up eny epoxy drips too, as they add nothing to the strength and just add weight.
At this stage it's upside down.
And just a close-up of one bulkhead wired to the sides.
Finally for tonight, the hull bottom is laid on top, ready to be wired up.
The rear half is one piece, whilst the front is two pieces which will form the V shape of the hull when joined.
Wiring this on will pull in the bottom of the sides and start to show the proper shape.
More to come once the bottom is wired, then the inside gets finished off. I also need to laminate the bamboo veneer to the deck before attaching it.
I'm awaiting a handle (recessed into the deck like 'normal' boards instead of grab handles CLC suggests), goretex vents (to allow it to 'breathe') and a leg rope anchor from Shapers. I'll also probably add a small hatch and compartment for car keys, snacks, etc.
Hi TK1,
This is a really interesting project. I once rebuilt a Hartley 18ft TS and enjoyed every bit of it.
Keep up the progress pics, I'm looking forward to seeing how it looks completed.
DM
Hi,
Build update. Sorry for the delays. Now the pressure is on to finish it by 30th December!
Hull panels are stitched together, so I can see the final shape now. Hull is constructed upside down, with wire twisted tightly to pull the panels into shape. Blue masking tape was used to ensure all edge joints were aligned and held tightly, as well as to catch any epoxy that drips through gaps.
Once stitched, hull is flipped - see second and third pics. I mounted the hull on two sawhorses, then clamped straight bits of wood to them and shimmed until level. The forward one has a wedge cut out so it only supports the sides of the hull, allowing the bottom V to sit naturally. Longitudinal deck supports aren't glued in yet, but I put them in to check alignment. I also added a ply stern piece.
The hull curves in a bit at the back, so I used a couple of ties to hold the shape whilst epoxying, and some tape at the bow to ensure it sits fair.
Once the base is level, the hull is levelled using two spirit levels, and sighting along the hull to ensure there is no twist, and the hull adjusted until completely true. This is important so it doesn't lean or sit unevenly when finished. It was only out by a couple of mm's so easy to fix. Anther tip is to run a string line from bow to stern centre, and check measurements at points on each side. Easy build so far
Fiberglass cloth has been purchased - 78gsm for the deck interior (light weight but gives it some extra strength) and 130gsm ("surfboard weight") for the exterior.
I've now 'tack welded' the hull *(pics in next update). I used a syringe to apply a thin bead of epoxy to each join, leaving the wires unglued (mostly!) so they are easy to remove. Once removed the joins get a larger fillet of epoxy.
Probably halfway there, and the the hull assembly was the hard part.
Goretex vents, handle and leash plugon the way from Shapers in Qld, and wood fins on the way from Gray Whale in the US (original designer of the Kaholo). Should both arrive Thursday so then Xmas will be spent glassing and assembling it.
More updates soon
Regards,
Darren
Hi,
More progress. Managed to escape the in-laws and Xmas washing up to do bits over the last few days .
Once hull was spot-glued, all the wires were removed. At this point it's fairly rigid so safe to move, but I kept it on the level stands to avoid twist as it dried. Next all joins had fillets of thickened epoxy added for extra strength and to lock the panels together. Although not specified in the nstructions, I also added some 50mm fiberglass tape I had lying around on the bottom and fore side joins. This is done with kayaks, and it doesn't add a lot of weight but adds more joint strength.
At this point I also fiberglassed the inside of the deck, and coated the interior of the hull with epoxy for waterproofing and extra rigidity. I also managed to epoxy it to the floor but got it unstuck...
Photos below show hull interior taped and epoxied. The dark brown bits are the thickened epoxy fillets. Tape and fillets were added to the deck supports too.
Once the joins had all dried, two bottom stringers are added to the hull bottom to give it some stiffness - basically to just stop the panels flexing. The instructions suggest using wedges, but lacking the time to make them I packed leftover wall tiles between the stringers and the deck supports (see photo below).
The photo also shows an addition I made - the box just behind the second deck support. This will be a waterproof compartment with a 6" screw-in hatch.
It will have two functions - firstly to hold keys, phone and snacks (all in watertight bags, just to be sure) on paddles, and secondly it has a drain plug which can be opened to equalise the pressure inside the board when not on the water.
A wedge of ply was also added to the nose to support the front of the deck.
All going well so far
Regards,
Darren
Hey TK1 looking good.
I built one a couple of yeras ago and use
it all the time.
You'll love it
Cheers Bill
Looks good Bill! I'm hoping to try mine out for fishing sometime too.
Well, I didn't make my self-imposed deadline . Got caught up with other things and wouldn't have had time to get the coats of epoxy and varnish on. So no progress last week. Had to paddle the wife's 11' NSP board instead down at Barwon Heads (when not kayaking). Still good fun.
So, more updates shortly...now that I have time. I've decided to add a veneer of bamboo to the sides to match the top. Pics and details of the deck veneering and final construction steps should take place over the next couple of weeks.
Stay tuned!
Regards,
Darren
OK, I'm finally back on track.
I wanted this finished for New Year's Eve, but that obviously didn't happen. Then work, life and other projects got in the way. But in the last week I've gotten back into it (spurned on by not having it ready for a race this week ).
So, I'd gotten the hull pretty much done. Following on from the last post, I added the deck stringers, which provide support/stiffness where you stand.
The other change I made to the plans was instead of having handles on each side of the deck, I got a recessed deck handle from Shapers in Qld. To hold this, you'll see in the pics I added a foam block in the centre of the board.
Before adding the deck, the critical step is ensuring the deck is flat - so out came the hand planes for stringers, etc. I ran into a problem here as the fore one had somehow dropped a bit, so I added some strips of wood to bring it back into alignment.
Final pic shows the last look inside before the deck is added - I'd already epoxied most of it for waterproofing, but I gave it all a coat of gloss marine varnish to be safe.
Next, the deck goes on...
Regards,
Darren
The pic in my post above showing the final look inside shows the deck sitting to the left in the pic. The underside was epoxied and sanded flat. I didn't make it perfect, just flat.
Before adding the deck, I used masking tape to mark the locations of the centre handle support and where the hatch would go.
Now for the hard part. I had to apply thickened epoxy to all mating surfaces then put the deck on. I forgot that mixing a large batch of epoxy generates a lot of heat and goes off quicker than a small batch. So on a 40 degree day, I mixed a pile of epoxy and about 3/4 of the way through applying it, it started to dry .
But a quick second batch and it was done. The idea is to then weigh the deck down so it glues completely. So with the help of the wife, the deck was placed on (admittedly, complete with lots of swearing and screming form me that i'd wrecked the whole thing and next step was to attack it with the chainsaw!)...
Pic below shows the solution to epoxy starting to dry and not having thought how to weigh the deck down beforehand. Lots of spare tiles, timber, boxes of stuff, a camp stove, clamps and a kayak-building strongback.
Moment of truth is tomorrow night when all this comes off and we see how flat the deck is.
I was going to add bamboo veneer to the sides, but will leave them wood now as I don't want to add weight, and this is the 'practice' one anyway. I did ask about 14' vs 17' boards in another thread so will build a 17' and probably a 12'6" plus a surfboard for my daughter. That will keep me busy over winter
Regards,
Darren
lift your game bud. other things to do in life,pfffft. thanks once again,oh and thankyou for not making it seem like everything goes perfectly all the time. i already know im a bit crap at being handy
Hi,
Finally making more progress...
Good news and bad news at this stage: the good news is that the fiberglassing is almost done and the board looks pretty good.
The bad news is this...remember the delay in a previous post when I had to shim one of the fore deck supports as it had dropped a bit? I thought this was a minor issue, and so didn't think it through. With this being out of alignment, when I glued on the deck, it put tiwst into the hull
So, first thought was to cut it up with a chainsaw but I decided to persevere and finish it off. Deck was trimmed and everything was sanded back to 320 grit. You can kinda see the twist in this pic if you look at the tail.
Glassing began with the lower hull. I had bought some "surfboard" cloth - 130gsm, 700mm wide - but with the board being 700mm wide, I'd need 2 pieces to get it to wrap around the sides. So I found some spare 200gsm that was 1m wide and used that. A bit heavier than I wanted but bulletproof.
Pic shows underside glassing - top has been done now, so tomorrow night the sanding should begin, then it's finishing off and varnishing ...ready for the Cerberus paddle next SUnday!
This was always a practice build, but with the twist I'll have to see how it paddles - probably won't track straight but will be an OK cruiser. So I'm planning a racing board based on this, with some modifications from lessons learnt from this build.
Completion of the build coming up, foolwed by build #2!
Almost there!
All glassed up (mmm, shiny now) and last night the fins were attached.
I didn't have time to sand all the epoxy back (having been distracted by a bottle of red wine and a Dr Who repeat, so I didn't want to be sanding at 10pm ).
So I sanded back the fin area, levelled the board, and epoxied down the two fins send from Grey Whale in the USA (designer of the Kaholo). I was going to go with a larger single fin, but all reports state that these 2 fins are sufficient for straight tracking. And who am I to argue with the designer when I haven't paddled it? (Although I plan to put fin boxes in the next one to give me options).
My professional and complicated jig for fin alignmnet can be seen below. But they're straight and level. A strip of glass down each side, and tonight I hope to sand the rest of the board and start varnishing tomorrow.
I'll also attach the leash plug, 2 goretex air vents and the hatch lid. For now I'm just going to use stick-on 3M grip tape until I can get soem proper pads.
Looking good for a launching this weekend...finally!
Great job Darren.
You are smashing it and it looks great. Those fins look awesome and can't weight to see it finished.
You wll suffer from "carpark syndrome" everytime you unload it.
Cheers