DGW Posted November 7, 2017 Report Share Posted November 7, 2017 I am about to start skinning my Shad and have thought ahead to the coaming part of the job. I will be using the plywood coaming where the skin is captured between the upper and lower plywood parts. It seems to me that it will be quite difficult, if not impossible, to insert screws from the bottom at the forward and aft ends of the coaming because the screws holes are on top of the deck stringers or very close to the frames at these points. I plan on using a ratchet brace and socket to hold the Phillips head driver - a technique suggested by Jeff - but will I be able to get this under the coaming at the front and back? I think I will need about 2" of space. Will the polyester let me lift it that far? Or do I need to be satisfied with screws from the top in the areas at the front and rear of the coaming? If I have temporarily lashed the coaming in place it would seem the lashing precludes screwing from underneath. Your advice is eagerly sought. How about I abandon the lower coaming ring and sew the polyester to the upper plywood coaming in the manner suggested for laminated coamings? Are there any shortcomings to sewing onto plywood coamings? Again, your advice would be dearly appreciated. In the meantime, here is my Shad frame on grass photo. For the frames I used a plywood sold here as a marine ply called 'e lite'. I sunk a test piece in a bucket of fresh water for a week and there was no sign of the glue line failing. I was attracted to it because it is very light weight and has very few, very small voids. It is seven ply with very good maple (or meranti?) face veneers. The external and internal edges have a small radius routed on the corners. In the photo, the frames look as though they are painted white but I think that must be a trick of the sun. The stringers are all cedar. The plywood frames received two coats of urethane before I built the frame and the completed frame was finished with two coats of urethane. Cheers, Denis 1 Quote Link to comment Share on other sites More sharing options...
Kudzu Posted November 7, 2017 Report Share Posted November 7, 2017 Putting in the screws from the bottom is not easy! There are always a couple of spots that are very hard to get to and it is just very awkward to do because you are working blind often. It looks great once done though but if it is worth it depends on you paitence level. It is barely worth it for me and if I built me another one I probably wouldn't do it. There is SOME room to move the coaming around but you shouldn't be able to lift it up 2". But sometimes you can shift it forward or backward. Never done this but I have though about countersinking the holes from the top and just plugging the holes. You would have to work out proper depth and screw length ahead of time. You do not want screw point protruding through the lower ring!! Quote Link to comment Share on other sites More sharing options...
benhardt57 Posted November 7, 2017 Report Share Posted November 7, 2017 "How about I abandon the lower coaming ring and sew the polyester to the upper plywood coaming in the manner suggested for laminated coamings? " If I understand your question correctly, your coaming would be very flimsy, I believe. Quote Link to comment Share on other sites More sharing options...
benhardt57 Posted November 7, 2017 Report Share Posted November 7, 2017 Oh by-the-way, your FROG looks great! Quote Link to comment Share on other sites More sharing options...
Rich D Posted November 7, 2017 Report Share Posted November 7, 2017 I have used screws from underneath and just get as close as I can to the frame members at the front and rear of the cockpit. I've never had a problem with the coaming being loose in any area. I have also inserted threaded inserts into the upper coaming rings during construction and then inserted bolts from below. Neither method is entirely easy to do. Lately I have been using what is sold here as 'connector bolts'. They are easy to install, and while not flush fitting, I like the way they look. http://www.rockler.com/connector-bolts-black-oxide-connector-bolts?utm_source=google&utm_medium=cpc&utm_term=&utm_content=pla&utm_campaign=PL&sid=V9146&gclid=EAIaIQobChMI75q5ndqs1wIVirbACh3a0g5mEAQYBSABEgLbNfD_BwE http://www.rockler.com/cap-nuts-for-connector-bolts?utm_source=google&utm_medium=cpc&utm_term=&utm_content=pla&utm_campaign=PL&sid=V9146&gclid=EAIaIQobChMI75q5ndqs1wIVirbACh3a0g5mEAQYAyABEgKTM_D_BwE Quote Link to comment Share on other sites More sharing options...
andy00 Posted November 7, 2017 Report Share Posted November 7, 2017 I used 1-1/2" stainless steel flathead screws driven from the top. Fourteen in all. Screws were just a tad too long, so I filed off the tips. I stapled the skin to the bottom ring with stainless steel staples and applied some caulk before attaching the top ring. Top ring was overbored slightly and countersunk. No complaints so far. Quote Link to comment Share on other sites More sharing options...
DGW Posted November 8, 2017 Author Report Share Posted November 8, 2017 Many thanks for your advice guys. I have temporarily lashed the lower coaming section to the frame and I have added some new clearance holes and pilot holes in positions that are going to be more favourable (although still tricky) to inserting screws from below. If necessary, I can roll the polyester down and under the lower coaming ring and insert monel staples. I will almost certainly build another SOF and with the experience I now have I will make a laminated coaming next time. Cheers, Denis Quote Link to comment Share on other sites More sharing options...
Kudzu Posted November 8, 2017 Report Share Posted November 8, 2017 I really like the look of a laminated coaming but it is lot of work. Many of my customers simple don't have the skills to make one, hence the plywood coaming. I make a couple of molds with the intention of making laminated coamings to sell but they are just so much work I decided against it. I just didn't want to be making them all the time. Quote Link to comment Share on other sites More sharing options...
benhardt57 Posted November 10, 2017 Report Share Posted November 10, 2017 Denis, I was about at the stage you are when I decided to ditch my plywood rings and build a laminate coaming. No regrets. If I build another kayak I'll do the same. But Jeff is not exaggerating, it's a lot of work. A lot of the effort was because it was my first, though. You would need to make the necessary fixtures and buy a lot of clamps unless you already have them. It wasn't essential to radius the corners, but I wanted to. That required the purchase of some new router bits. Good luck! - Ben Quote Link to comment Share on other sites More sharing options...
Hirilonde Posted November 10, 2017 Report Share Posted November 10, 2017 2 hours ago, benhardt57 said: A lot of the effort was because it was my first, though. I have built 5 laminated combings and it doesn't get all that much faster. Though you do get to use the mold again. Quote Link to comment Share on other sites More sharing options...
DGW Posted November 12, 2017 Author Report Share Posted November 12, 2017 Thanks for the comments Ben and Hirilonde. I will press on with the plywood coaming for this boat but will probably have a shot at the laminated version for the next boat. Hirilonde, your comment about building five coamings using the same molds suggests that many of the Kudzu craft kayaks have coamings of the same size and shape - is that correct? Cheers, Denis Quote Link to comment Share on other sites More sharing options...
Kudzu Posted November 12, 2017 Report Share Posted November 12, 2017 4 hours ago, DGW said: your comment about building five coamings using the same molds suggests that many of the Kudzu craft kayaks have coamings of the same size and shape - is that correct? Yes, virtually all of the share them same coaming. Quote Link to comment Share on other sites More sharing options...
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