new project

[Howard_Spira]

here are the hatch spacers and sills now sanded to mate with the deck opening. based on a lot of experience, i sculpted the forward spacers and sills to the curvature of the deck in advance so the would install easier and avoid bending the hull out of of position…which happens when you wrench a flat sill and spacer to a curved deck. its one thing if you are installing these after joining the hull/deck or if installing before hand - which is my preference… to ensure everything is sealed up properly with minimum epoxy.

now that i have these shaped, the outward facing will get white stained and then a layer of s-glass on the top of the sill…then installed. once installed, a layer of s-glass will bond go on the bottom of the sill and overlap the surrounding under deck…pictures to come

[Howard_Spira]

here are the sills now stained white and the tops glassed with s-glass.

if anybody has information they would like to share on flush hatch with bungee pulling down internally…i would be interested in your experience…my question is:

• how much down pressure do you need to have theflush hatch mate/become water-tight…and
• what approach do you take on a flush hatch that allows you to pull the hatch up against the bungee force …are you putting some kind of handle or rope or just a finger cut into the hatch?
  i am looking for the ‘cleanest’ approach but not sure how you have a clean hatchless approach and then actually get the hatch off?

[Laszlo_Morocz]

Howard,

The pressure depends on the gasket material. If you use the open cell weatherstripping that CLC sells, it’s never going to be watertight. You need some kind of closed cell stuff. I got some self-adhesive hatch gasket material at Bacon Sails and that works really well. I can provide the name later today.

I used the finger notch method and been very happy with it.

One thing that made it work well is the tension adjustment mechanism that makes it easy to fiddle with the tension until it’s just right.

The other thing is the shape of the hooks.

Full details at my Wood Duck build pages for the hold-downs and the final hatch.

Laszlo

[Aaron_Meade]

I’m really glad I’m not building a kayak. As I ham-fist my way through a Southwester build, the mantra I keep having to repeat is “Im building a sailboat, not a Stradivarious”. The kayaks I have seen from CLC builders have been even more stunning than some of the sail and oar boats.

[Howard_Spira]

Thanks Laszlo, yes, i would like to know the name of the hatch gasket material from bacon sails you referred to above. like the tensioner…very clever.

[Howard_Spira]

stopped at clc yesterday to get some finishing supplies and now working on finishing. todays work was to get the hatch spaces and sills installed.
while a bit hard to see, strapping tape is installed under the deck adjacent to the hatch sills that are holding the shape of the deck (pulling the sides together) so that the installation of the sills don’t flatten out the deck.

the lights when done with the session and turning off the lights in the shop is meditative

[Laszlo_Morocz]

It’s Hatch Cover Tape from MDR (Marine Development & Research) Corp out of Merrick, NY. While I found it at Bacon Sails, it also seems to be available from Fawcett as well as the usual mail-order suspects (Jamestown Distributors, Amazon, etc.) MDR’s product number is MDR-420.

The stuff is closed cell, 1/4" thick and 3/4" wide. It compresses and takes the imprint of the rim to form a watertight seal.

[Howard_Spira]

thanks Laszlo…i will give it a try. i really appreciate the advice.

on the build, tonight i finished up the bottom side of the hatches.

in addition to ensuring i have a way into the fore and aft section of the boat for a lunch, the hatches more importantly, ensures dryness when put away.

also, the hatch, particularly in the rear, adds a bit of structure to the aft deck which is relatively flat on this modified bootlegger sport…and prevents it from oil-canning.

the trick is how to do it without adding a lot of weight…

so i take the basic approach of a flush hatch but execute all the pieces in paulownia, glass the sill on the outisde, agressively shape the underside to be no more material than is necessary and then a layer of glass on top of the entire structure on the inside.

building the hatches, before mating the hull to deck, makes for a very clean inside of the boat ensuring no open wood or cracks or crevasses where water or dirt can find a home.

the other thing you will note is i use strapping tape to hold the deck in its proper shape during this process. both hulls and decks will naturally spread out/widen. so you need to ensure if you are adding the structure of the hatch, you do not ‘lock in’ this relaxed shape with the additional structure of the hatch…

here are the pictures showing the buildup, the shaping and the final glass that i just cut…note i am fulling wetting out, but not filling the weave to save weight.

[Howard_Spira]

Happy Saturday everybody,

i thought i would give a short update on progress.

the other night i reached the milestone of joining the hull to the deck. i wanted to share some pictures and techniques. there were some challenges that i had, that others have from time-to-time, talked about and so i thought i could share the approach.

the main issue was that i had was some major time gaps in the project and the deck and hull no longer lined up. i built and glassed parts the hull and deck pieces and then the project sat for over six months not joined.

during this time, parts of the hull and deck had substantially “relaxed” (widened) relative to their original build positions and simply taping them together could not provide enough force for alignment.

the approach was to use scotch filament tape (which has almost no stretch, does not leave residue and attaches well and can be released and repositioned from an epoxy surface) to pull the hull and decks into shape.

the pictures below show this and the tapes were positioned to perfectly align on top of one another:

the hull and deck was then carefully test fitted and minor adjustments were made (hence the importance of a good quality tape that can be released/reattached - do not use cheap amazon chinese product…tried that…will not work) to pull the hull and deck into perfect alignment.

after the test fitting, a thickened mix of epoxy and cell-o-fill was carefully placed between the tape on the hull/deck edges to be joined (stay about 1/2 away from the tape to keep the tape from getting glued into place) and then the pieces were carefully rejoined with new filament tape pieces just pulling the hull and deck together. similar to the test fitting, even during this final gluing, i ended up making a couple minor adjustments on the tape controlling the width of the hull and deck to ensure alignment.

this is what it looked like, as i was waiting for the epoxy to cure and the process of joining the hull and deck took about 90 minutes as i was really focusing on a perfect alignment.

once the tack welds cured, i removed the pieces of tape that crossed hull to deck and then carefully (and i emphasize the word carefully) pulled out the tapes that were controlling the width of the boat.

this was the most challenging piece. so let me discuss ‘carefully’.

in this technique, if you have a tight seam, the tape has basically only its thickness as the size of the hole to be released…(please remember the note above to keep the glue 1/2 or more from the tape). If you try to pull a piece of tape out that is not perfectly flat (like a piece of crinkled tape that was stuck to itself), it can act like a stopper knot and cannot be pulled through.

anyway, notwithstanding my care, which is more of something i realized after the process then before, there were a couple pieces that were darn challenging to get out. i was ultimately successful but have four cut knuckles and some blood on the boat from my efforts around one particularly recalcitrant piece of tape. there was one moment i was afraid i had gotten my head and one arm stuck in the rear hatch reaching for that piece (had to pull it from the inside out) . i’m writing this, so i was inevitably able to extract myself.

the final result is here:

once the tape is out, if you inspect carefully, you can see the knife like (tape width) gaps in the glued surface. a bit of lightly thickened epoxy was applied with a spatula to fill these little gaps…and i have a perfectly aligned hull and deck - joined

will now move on to internal seaming and outside sanding and seaming as well to ensure the hull/deck seam has all the structural integrity it needs.

hope this was helpful to everybody

H

[William_Seward]

Howard,
This update is timely in that i am at the hatch stage in my Petrel Play build. I used a circle cutting router jig to make a template then cut openings using the template and router guide bushing and 1/16 bit. Worked well and made clean opening and crisp hatch cover from deck cutout. Now i’m a little hazy on detail for finishing the raw wood edge of the hatch covers and topside of the sill. The Nick Schade videos I’ve found show detail on gluing and glassing the underside of the spacer and sill (as you show here as well) but can’t find detail on treating the topside of the sill and hatch cover itself.
You do mention glassing the topside of the sill before installing so that makes sense but how do you treat the hatch itself ? I come back to this post on your build progress often and appreciate you sharing the details.

[Peter_Martin2]

Hi Howard,

Really enjoying following your build, I really like how you used tape straps to pull the hull and deck together before joining, that seems much more certain than relying on friction between the deck and hull after fiddling with a putty knife.

Anyway this is in reply to your questions about securing the hatch using bungees and sealing strips.

For the sealing strip I used some neoprene weather strip from ebay and that seems to work pretty well, though I think I made the recess a little too shallow to get a completely flush hatch. I’m going to change this for some 4mm strip I’ve now found.

6mm Thick - Neoprene Adhesive Backed Foam Sponge Strip Roll Sheet Tape Sticky ...

To lift the hatch I made a small 3d printed maroske type fitting and use a small loop of 4mm rope to lift the hatch. Still not 100% happy with how that looks though.

I use 5mm dyneema covered bungee which I had left over from the deck bungees and fiddled with the tension till it seems tight enough. I like the tensioner that Laszlo posted though.

[Peter_Martin2]

William, to seal the edges of the hatch I warmed the hatch up and then painted on some warmed unthickened epoxy and let it all cool down. That seems to have sealed the edge with a smooth finish which needed very little cleanup. Time will tell if thats enough to sto pwater getting in between the top/bottom glass and the wood though. I think a layer of glass and epoxy would be too thick, but interested to hear what other builders have done.

[William_Seward]

Peter,
That’s what I figured to be the best way to seal up the sill and opening edge without adding thickness with glass. I guess you could adjust for that with thicker spacer but with the layers of glass on the underside of spacer and sill bonding it all to the deck I don’t think glassing the topside would be needed. I did finally find a YouTube vid of hatch build detailing the complete process including treating the sill topside, which he does exactly as you describe. From the Orca Boat channel

Building Skana - A Wooden Kayak EP10 Hatches

[Howard_Spira]

Hi Bill,

on the hatch itself, i lightly sand the exposed wooden edge and then paint that edge with unthickened epoxy so that it gets pulled into the endgrain of the wood a bit and ensure a watertight seal. i then usually make another pass with slightly thickened epoxy (with cellofill), and then sand/repeat until have i have an edge that is completely sealed and smooth/epoxy coated.

i hope i understood the question and answered it.

h

[Howard_Spira]

Hi all.,

i continue to move forward…thanks everybody for hatch ideas…probably will get there in another week or so.

today i did the internal seaming…and was happy with the results.

for the folks who are interested in saving ounces, i have been doing my internal seaming with two inch kevlar tape. the kevlar is bullet proof (litterally), and is a very thin/light weave that easily wets out and does not use a lot of epoxy. to the extent, you can cope with the yellow color its great stuff. i have been going with this for my last several builds.

you do need a special kevlar scissors to work with this material…but only about 15 bucks on amazon…

next steps are to sand the external hull and then seam the outside…which i will do with 2 oz e glass which is very clear. i will do the middle 3rd of the boat with two layers for four ounces and the outer thirds with one layer of the 2 oz. as i have gained experience in light builds, i have been getting a bit more attentive to putting the material/strength in high stress areas…and lightening it up in areas that are under lighter loads. building light is a game of ozs…

h

[Howard_Spira]

a couple more pictures of details that help keep things light.

today was a wrestling match with the closed cell foam bulkheads. (it always is a wrestling match because we want them very tight so that they arent going anywhere and it will just take a little 5200 to make the tiniest of fillets between the hull and the bulkhead) teh 5200 is not needed for watertightness as much as to to keep sand/dirt getting into the corners.

the first picture is the forward bulkhead:

in order not to muck it up as the boat tapers very quickly here , i mark the side facing the cockpit ‘in’ with blue tape…that i pull it off afterards. this helps me not to accidently taper the wrong side of the bulkhead. these foam bulkheads are three inches thick…and while the are compressible…they are pretty rigid…but incredibly light..

the next picture iis the rear bulkhead.

the rear bulkhead is very challenging in that the cockpit is recessed and my placement of the bulkhead -1 1/2 inches back fro the rear cockpit opening means the bulkhead needs some carving and has some unqiue geometry which prevents it from being installed in one piece. to install it, the bulkhead is cut horizonally from side to side…the top piece is then inserted up to comform to the recesss…then the bottom side, with a lot of coaxing, can be pushed in flush to the top half’s face. in this pictue you can still see the seam…but with a little more work, it will disapear.

i also started to finish sanding the hulll, prior to seaming the outside…

if you look carefully, you can see that there are some minor sand-throughs foreward of the forward hatch…these are then carefully restained…so we will have perfectly straight seam line…we will grab a picture of that tomorrow.

ok…amazing we. can edit posts now…so here is the touch up stain for the sand-throughs.

the last piece of the hull prior to the outside seams are the external bow and stern stems which i am doing in carbon fibre weave…a bit of extra effort…but as mentioned…i hope it will look cool. here is a progress pic with the carbon initially glassed to the black-stained underlying wood. this will take another two days to complete…then they get epoxied and glassed on…then the outer seams will be applied so that final sanding before varnish can be reasonably efficient. fwiw, this 6 oz crbon weave uses a lot of epoxy to fill the weave without vacume bagging…so it’s important to keep these parts small or else the whole thing would get very heavy.

[William_Seward]

Howard,
I am at nearly the same point in my Petrel play build, and I followed your lead and acquired some Kevlar “tape” and just did the seams. I am now mulling over how to do the final hull and seam glassing after reading your method . I had just revisited Nick Schades Petrel Play video on that subject and wondered if there might be different approach and curious how you came to your method of “thirds”. One thought I had was to do 50/50 graphite/epoxy on the bottom third for abrasion protection and reinforcement and something similar to your method for the seam and middle third. Not sure about adding any more glass to the deck though.

Also curious what is your weight at this point and what do you anticipate the final tally after outfitting?

[Howard_Spira]

Hi Bill,

right now i am at ~ 25 lbs. i expect from this point to add between 2 and 3 lbs before i splash it.. the weighing method is not super precise. i have a bathroom scale…i weigh myself with and without the boat and repeat the process three times and take the average…

the weight today was every component except the outside seam tape, the varnish and the rigging. i have a bill of material worksheet for the boat…so 2 lbs is light varnish and rigging, 3 lbs is more coats of varnish and some extra lines.

here is what it looked like when i weighed it:

and here is a close up of the carbon fibre stems…these have been sanded a bit…but look amazing once clear epoxy is painted over them

i installed the stems this evening…

on the question about seaming…

when i was talking about seam tapes…i just am referring to the hull/deck seaming…which visually, you don;t want to see…so i am a bit confused by your question.

the outside seaming is this step in the picture below: picture one with the 2 oz being applied between the blue tape and second picture is after trimming the 2 oz cloth to the blue tape line and removing the tape.

for clearness i prefer e-glass. and to keep it light, i try not to have any more layup then i need as glass and its wet out and fill coats of epoxy is where weight can quickly add up. so in this case, my outer seam approach that i find is strong enough and easy to work with is making my own strips of 2 oz e glass to use as the seam material vs buying fibreglass tape which is typically based on 6 oz e glass and is relatively thick.

however, based on my engineering background, my sense is 2 oz glass is relatively light construction so when i seam a boat, I want more than 2 oz if there is going to be significant stress…for me, that’s going to be a minimum of 4 oz. but the seam along the entire length of the boat does not experience the same stress…its concentrates around the cockpit area - the middle third of the boat broadly speaking. so to keep it light i seam the boat end to end with 2 oz e-glass…and then do a second layer on the middle third of the seam.

i have never had a boat break or fall apart using this method…i am not very harsh on my boats like nick…but i do weigh about 190 lbs…so things need to be sturdy

if you want to clarify your question bout about carbon i am happy to try to share whatever i have learned.

regards,

h

[William_Seward]

Howard,
Ok I misunderstood your post, as you were referring to outer seam only and not additional glass to the hull, and you are adding second layer of reinforcement to the middle third/cockpit area seam. I had just watched Nick Schades Petrel Play episode in which he does the outer seam and additional layer of 4oz glass on the hull and that was my mindset
Disregard the graphite/carbon/epoxy question as it pertained to additional hull reinforcement and after further reading on that it is mostly for abrasion resistance and appearance only.

Regarding the hull, did you end up using 1/4” Paulownia on bottom section?
I ended up using 3/16” paulownia for the entire hull and am wrestling with whether to add another 4oz layer to the hull or leave it as is. Or another thought is to reinforce the inside cockpit area only

Being my first build, I am treating as learning curve/test case and will figure what works and what doesn’t in real world use. I can always add more reinforcement later when I break things.
Also my weight with the with deck and hull joined and seamed (3” Kevlar tape) is 26lbs.
It would lighter, but I had issues with over beveling strips attempting to get tight fit and had to backfill gaps on the inside.
Really appreciate you taking time to share your methods and experience. The carbon fiber stems look great

[Howard_Spira]

Hi Bill,

on this build i used 1/4 inch strips on the bottom. on the petrel play that i built previously, i did the entire boat in 3/16 paulownia.

on my petrel play that i did with 3/16, i ended up putting another 4 oz layer on the bottom and another 2 oz in the cockpit area on the inside as it just felt too soft/easy to deflect before the reinforcement. it was noticably more flexible than any of my other kayaks i have built…and since composites generally fail catastrophically once you exceed their load limit, i just was not interested in exploring what i perceived as building a boat without appropriate margins strength.

so i picked up another ~ 1 lb plus of epoxy and glass to do the reinforcement.

i went back and forth with several folks i respect about the need for the reinforcement and just decided i wanted to address the ‘concern’ while it was relatively easy (don’t have to remove varnish) and just didn’t want to worry about it. fwiw, there was not a consensus from my expert advisors that i had to reinforce…sort of a split decision. nick schade, fwiw, was a proponent of not reinforcing immediately and trying it out on the water before deciding. i seem to recall he said, paddle it… and if you feel the hull is deflecting (oil canning is the nautical term), then reinforce it. i am assuming, however, that nick was not suggesting to stress test it, but to simply see how it behaved in the water…which is different than the concentrated push of a hand on the hull.

like i said above, when i netted it down, i just wasn’t interested in running the experiment and potentially having a lot more build work to do after i had sort of put away the building materials.

i suppose you could experiment with the boat on the water prior to varnishing the hull and doing all the rigging…take it out for a light paddle…and see what happens…and then decide.

but it was after that experience, that i decided on this build, which has a similar bottom shape (with the flat sections uder the cckpit area) to just go with the 1/4 inch as you can acheive stiffness with a thicker core and same sheathing at less weight then adding additional glass to a thinner core. i can easily attest, at this point, i have a very stiff bottom and no need for anything more than the 4 oz s glass that is on there.

basically, with the same 4 oz glass, 1/4 inch is almost twice as stiff as 3/16.

if you look carefully at this picture, which is the petrel play hull, you can see the extra layer of 4 oz cloth aong the bottom section of the boat.

i think your approach of just doing the reinforcement on the inside with another layer of 4 oz cloth might be the lightest solution if you are focused on keeping things light. adding to the inside is easier to strategically place the cloth without creating challenging faring/sanding with a lot of epoxy to create a fare surface.

regardless…if you are at 26 lbs now…and you continue with care…it sounds like you will end up around 30 lbs…give or take a lb…and thats really excellent performance.

h