Attaching hull panels

Preparing to Attach First Hull Panel

Posted by Paul

I got some very handy presents for Christmas that if I didn’t get as presents I would have bought so I will add them to the expenses list at their retail value so as to give a true indication of the costs to build. I guess we all know someone that can help in some way and I might get this for free and someone else might get that but in the end I think we should assume that we have to pay for everything required so that you know what each thing costs. I also bought myself a surform which is shaped like a hand plane but has a long rasp like base, they are easier and faster than rasps but I initially resisted because they are expensive for what they are but with a lot of long hull panels with tabs to remove it is much better.


Thanks to Helen (Jo’s Mum), Nat and Graeme and Trina and Darrin (Jo’s sisters and their partners) for the wonderful and expensive gifts. I plan to add a cordless circular saw to the battery kit that now consists of a cordless router, 2 batteries and a charger. I don’t look forward to using the sander!

I also got a wonderful gift from Jo that will also be very valuable, I got a sextant. Now with gps and electronic charts we will probably never use it but I want to learn how to use it and have it as a safety back up should electronic navigation fail us (loss of battery power for example).

As you can see from the picture below, we are almost ready to start attaching the hull panels to the bulkheads. I have placed the keel panels onto the bulkheads as I intend to temporarily attach them (dry) with screws so that, like we did when gluing the panels everything is marked and goes together faster when glue is applied. We have to glass the inside of the hull panels where they attach to the main bulkheads and Sean attached the panels to the bulkheads whilst that glass was still wet so that you get a chemical bond rather than a mechanical. I think it is a good idea but requires that you work fast because you only get about 20 minutes before the epoxy sets. It is for that reason that I am attaching the panels dry first and also some of these panels are almost symmetrical (same shape from each end or even upside down) so I want to be sure it all fits together without the time pressure of glue going off.

So the plan is to attach all of the hull panels (screw them only), mark them so that putting them back is easier and then remove them again, apply the glue (and fibreglass where appropriate) and re attach them with the screws until the epoxy is well set. There is a fair amount of torsional stress as the flat panels bend to meet the shape required, especially at the bow where there is twist and bend in 2 different directions. This is a job that cannot be done on your own. They are not heavy but the hull panels are too long to manoeuvre into place on your own and to hold correctly in place until screwed down. So progress for a while will be very much dependent on the availability of helpers.

This is probably a little cheeky but anyone interested in helping out in exchange for a first hand, hands on lesson in what is involved in building a Duflex panel kit cat and can make it to the Central Coast of NSW, give me an email! Come just after breakfast, bring your own lunch and go home just before dinner!….Kidding, we will feed you too.

As the cores are balsa and because of the stresses mentioned I think that the screws may not hold well enough so I have some timber cleats to screw down into along each of the bulkheads that create twist in the panels. (This was an idea suggested to me by Sean). The flatter panels I think will be ok except for the chamfer panel which I am told by Sean and other websites I have seen, has a big twist in it and will need a lot of force to pull, push and cajole into place.

A retrospective tip here is to mark the various hull panels as you cut them from the sheets as some are very similarly shaped and the plans show you which is which but it is much harder to determine which is which after you have cut them out and stacked them against a wall for a couple of months! I wish I had. Hans, another builder of the 1230 and has plan 6 (we have plan 5), we met at the Schionning Muster last November and he visited me as I was gluing my panels suggested I do this and I forgot to take his advise! Doh!

A small criticism of the plans here is a little lack of detail in the description of the various panels and exactly where and how they attach to the bulkheads. Whilst most shapes are self explanatory some (the twin keel panels and the very next ones to them either side of the hull) are extremely difficult for an amateur, building for the first time to decipher. I still cant figure out whether I have the keel panels in the photo below around the right way and I have turned them over 3 times, which on your own takes some doing! The bow is self evident but they are a subtly different shape from the centre out and I cant tell which face should run down the middle and which is to the outside of the hull, they have to twist to meet the bow shape which makes it hard for me to get my head around what shape does this correctly/easier/etc. Click here to see what I mean. I don’t want to find out the hard way, so I will wait to talk to Brett and the team when they return from their Christmas break on Monday.

Many people will say that boatbuilding is sometimes a “trial and error” pastime anyway, I don’t mind this theory but am keen to minimise the error part. Very happy with the trial, just not so keen on the error. The upside to these minor setbacks or shortcomings is that the Schionning team are extremely approachable and helpful, their after sales service is superb and as the plans of any new boat do, as builders such as Hans, Sean and I find the problems in the originals they will improve for subsequent builders. The Schionning team have a genuine interest in all the projects going on, and there are a lot of them, and are as keen as we are to see the boat go together well, especially newer designs like ours.


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