I’m currently building a Chesapeake 16 and have a question about attaching the deck at the scarf joint. Has anyone used wooden dowels set in epoxy in place of the traditional brass or copper nails?
I’m considering temporarily installing screws to pull everything tight, then removing them and drilling for dowels once the epoxy has cured. Structurally, does this approach make sense?
I also like the idea of the exposed dowel ends as a visual detail along the deck. Any thoughts on strength, longevity, or best practices would be appreciated.
Hi RFulcher,
i have built many of the chesapeake series. so i have a lot of experience with this.
the construction approach as laid out in the instructions involve copper nails and thickened epoxy glue between the bottom of the deck and the shearclamp.
in this technique, the copper nails are really acting as a ‘holder’ for the deck while the epoxy sets. and in this construction the ‘holders’ are left in place…and become part of the boat and either a decorative element or an element that some folks paint over.
however, if you have an alternate approach to ‘holding’ the deck in place while the epoxy sets, you can dispense with them. so if you don’t like the nailheads, you can use an alternate technique for ‘holding’ the deck…or if you want to do what you described - use screws as an alternate holder and then ‘dowels’ you can do that too…but neither dowels or nails are required from a structural perspective if you have properly epoxied the deck to the shear clamp.
the most common technique for those who want to build a chespeake without nails is to use fibre reinforced strapping tape to hold the deck temporarily in shape while the glue sets. it is critical to use a high quality tape like 3m and you need to use tape with fiber in it to prevent it from stetching. i would highly recommend rehearsing it. it will cost you a bit of extra money but the nice thing is at least you can rehearse it…you can’t do that with nails. this is the brand i use (Scotch Reinforced Strength Strapping Packaging Tape 1 1516 x 30 Yd Clear - Office Depot)
when i say rehearsed, i did one ‘reheasal’ taping to just get the hang of it and ensure that i could bend the deck and not have any significant gaps and that the tape would stay in place for at least 72 hours…one thing i learned in reheasal was to use shorter pieces of tape to pull the deck into shape but then a wrapping piece of tape around the hull/deck and short tape pieces to ensure it did not come loose after a couple hours.
screws are another possibility for a temporary ‘holder’…but depending on what look you are looking for, now you will have holes you need to address…
in the picture below, just showing some ideas: the boat without paint had its deck strapped on with strapping tape…and then when the glue cured, the tape was removed - no nails. the blue hulled boat was done the same way as the unpainted boat, but i painted the hull and extended the paint over the the deck becuase i thought it looked nice that way. my main goal on the blue boat was to save the weight of all the nails. the yellow and red boats used nails but i chose a paint scheme that painted over the nails becuase these were some of the first boats i built and my nail work was pretty sloppy.
i hope this helps.
h
Hi Howard,
Thank you very much for the thorough reply. You helped answer my question and gave me several additional ideas to consider.
My initial thought was to use screws as temporary anchors, then back them out and drill the holes to the appropriate size for dowels, assuming they would need to be there (much like nails) for a secure, long-term fit. I wasn’t sure whether epoxy alone would be sufficient, but it sounds like it is.
I may still use dowels as a decorative accent, but I think I’ll try your approach using tape (thank you for the link as well). Your finished kayaks look great, and I’m really enjoying the process and the time spent on this build. I can already see more kayaks in my future too.
When I built my wife’s CH16LT I used ratchet straps to hold the deck in place while the glue cured. I was worried about the alignment slipping so during the “rehearsal”, while the deck was in place, I drilled 4 holes, one one each side of the deck joint by the coaming. When I put the deck on for real, I put dowels into the holes. The deck aligned exactly as it had been during the rehearsal.
Once the glue cured, a razor saw and some sandpaper made the dowels flush with the deck. Visually it ended up looking like trunnels and was a nice effect.
The takeaways are:
- As Howard says, the copper nails are only needed for holding the deck in place until the glue cures and you can substitute other methods for the nails.
- While dowels won’t work to hold the deck down for gluing (they only provide tension and shear, not compression) they work very well for maintaining alignment.
- The dowels can also make a nice visual effect, looking like old-timey pegged construction. They’d make a decorative way to fill screw holes.
Laszlo
1 Like
happy to help.
just to build the knowledge a bit. in addition to the epoxy glueing the deck to the shear clamp, you also glass the outside of the hull with the fibreglass cloth overlapping the joint. so between the epoxy and the glass, its pretty much bullet-proof. the wood will typically break or crack before the epoxy and glass joint itself would fail.
also, by the time you get to glueing the deck to the hull, you have some practice with epoxy and have built up some confidence with various epoxy mixtures and set times.
the only real structural risk to the deck is if you had a bad batch of epoxy that never properly cured - in the case of strapping, the deck would simply pop off. which is actually a good thing i suppose becuase nails could mask a bad glue batch.
the ‘rehearsal’ as i mentioned and laszlo also commented on is important…and your rehearsal should also include the notion of how fast you need to work. the key thing after the batch is mixed is to get the epoxy on the shear clamp quickly and out of the mixing cup. once it is spread out on the shear clamp, you will have generous working time.
h
1 Like
Thank you for the additional ideas and tips. I hadn’t really considered doing a rehearsal or using a couple of dowels as presets for alignment. With the process already feeling like a rush to get everything right, that approach would definitely take the stress down a notch.
