Build log - SteveKos' Spindrift 11

[Designer]

Steve,

 

You are making great progress. The gunwales should go on before filleting and taping because they force the hull into it's final shape. If the angle between the side and bulkhead changes when the gunwale pulls the sheer line into shape it does not have to fight or force a rigid joint into another shape.

 

I like to glue in the breasthook first because it gives you something solid to anchor the gunwales to. Pre-fit the gunwales starting at the bow. Put in a screw as far forward as you reasonably can allowing for the final trimming shaping and not interfering with the screw on the other side. This screw is important because once you have glue on and everything is sticky and slippery it is hard to position, the screw will go back in it's hole and you will start with the front exactly in place.

 

As I have mentioned earlier, I like to let the gunwales stand  about 3-4mm above the sides at both ends for about 40 cm. This gives a taper when the excess is trimmed off. It lightens the gunwales visually and because of the flare in the bow it allows you to blend the top edge into the breasthook.

 

Put on both gunwales at the same time. The gunwales should be relaxed while you are fitting them at the bow, the aft ends should splayed out and resting on a chair back or whatever kind of sky hook or wife you can conjure up.  When both gunwales are buttered up and attached at the bow, bring them into the boat together clamping or screwing as you go.

 

Why can't you just put the gunwales on one at a time? Because the first one will force the boat out of shape. But the second one will force the boat back into shape right? Wrong, the boat is stronger once the first gunwale is on and it cannot force the boat back into it's true shape. I have put the gunwales on one at a time when I am short handed and it is too hot to get both on and clamped on in time or I do not have enough clamps for both. I just put glue on one side but bend both around the boat at the same time and putting most of my clamps on the glued gunwale. You can take off the other gunwale an glue it on after the first one is dry.

[SteveKos]

Thanks Graham. Perhaps you can make those steps a bit clearer in the instructions for your next revision. I think I can see that sequence in them now that you mention it, particularly with the photos you provide, but a more definite written step-by-step sequence for newbies would be helpful. The plans you've drawn are great and very detailed, but I feel the written instructions are a bit piecemeal.

[Hirilonde]

The gunwales are a primary force in fairing the hull.  Once taping starts things don't want to move much any more.  The breast hook and quarter knees are sound material to secure the ends of the gunwales to, so I did them just before.  I bedded them in a good bit of some what thickened epoxy (thicker than usual glue, much thinner than filler).  I used temporary screws to install the breast hook and quarter knees and a couple permanent screws at either end of the gunwales.  I don't tack anything.  It is just added work.

[SteveKos]

Thanks again Hirilonde. Yes it makes sense to strengthen the perimeter of the boat to get a good and strong shape to the hull. I'll go looking for some timber for the gunwale.

 

Do you recommend that the bow block goes in before the breasthook?

[Hirilonde]

Do you recommend that the bow block goes in before the breasthook?

I don't know that it matters, and I don't remember when I did mine.

[Designer]

Steve,

 

I am glad that the gunwale installation is clearer. I agree that the instructions could be improved, we are working on them when time allows or it becomes necessary. We plan on an overhaul when we finish the big cat.

 

A couple of other points; I like to have the transom reinforcement installed before going 3D, beside adding a bit more stability while folding this gives us something to  anchor the aft end of the gunwales to with a screw. I do not install the quarter knees until after the gunwales are installed. This allows me to fit the knees to the "as-built" boat rather than force the gunwales out of fair if there is any deviation. A fair boat is the ultimate goal.

 

Study the grain in the gunwales and avoid grain run-out in the forward third.

[SteveKos]

Study the grain in the gunwales and avoid grain run-out in the forward third.

 

By this do you mean the grain running to the 'outside' of the curve of the gunwale? I imagine that this would cause uneven pressure along the curve, which might distort the shape. I am going to look for timber with as straight a grain as possible for the gunwales, possibly meranti, hoop pine or something similar. Not too hard, but something durable.

 

I am happy with the fair lines I have achieved so far, so I don't want to interfere with what the cut has produced. I do have a little of a gap here and there, which will fill quite ok when filleting and taping. I haven't tried to push too hard for perfectly tight seams for the sake of it. When building my kayak the standard was to aim for a gap of around 3mm +- 2mm, which sounds bad, but this gap was filled quite ok when filleting and taping by using masking tape along the back of the seams. That allowed for some give and take in stitching and tacking to achieve a good overall shape, rather than having to be too ultra-precise in the cutting which isn't always achievable. In the case of this build I have a couple of spots along the CL and chines which might be 2-3mm. I'm not worried about that at all, as the boat is looking about as perfect as hand cut panels could hope to achieve.

 

(PS, sorry if I seem to be harping on about my kayak build, but if you want to test your boat building skills, a SOT kayak with an internal frame is a pretty challenging project, and I think a good way to learn stitch and glue ).

[LennieG]

Steve-

He means when the line of grain runs off the edge of the board. That creates a weaker spot and potential for splitting than if the grain lines stay within the dimensions of the board. The front third is where the most stress is because of the bend, so if you must use lumber with grain run off, don't do it up front.

[SteveKos]

Thanks for that LennieG.

Sent from my HTC One X using Tapatalk

[SteveKos]

An update. It's been a quiet week with the weather here being too hot to do anything outside. I finally got back to the boat yesterday and today. Nothing major, but I filleted and taped the bow section interior, and cut and shaped one of the gunwales, and tonight I cut and fitted the breasthook, and began to cut the transom stiffener. One thing about the transom stiffener, I didn't fit it before attaching the transom, so it's going to be a bit more difficult to retrofit.

 

Anyway, here are some pics of my latest efforts:

 

Tacking the seams

 

 

Bow section filleted, taped and epoxy coated, and the breasthook glued in place

 

[SteveKos]

Some more pics of this week's progress.

 

Installing the transom stiffener

 

I used almost all of my clamps on the one side.

 

I fitted the other side with temp screws to balance out the stress.

 

The transom stiffener is fitted and looks pretty nice. I still have to fill the extreme edges with filleting material when I do the seams.

 

Looks nice and straight and even.

[LennieG]

Looking good. Nice progress Steve.

[Hirilonde]

It looks true and fair from your photos.  The extra time you spent getting clarification and then proceeding with confidence in your procedure seems to be paying off.  So much work in the future depends on what you do now. getting the boat true and fair.

[SteveKos]

It looks true and fair from your photos.  The extra time you spent getting clarification and then proceeding with confidence in your procedure seems to be paying off.  So much work in the future depends on what you do now. getting the boat true and fair.

Thanks for your input on this forum Hirilonde. It would be a waste of a valuable resource not to ask questions that don't cost anything but can avoid costly mistakes . This is such a pleasurable boat to build. It's not overly complex but there's still enough of a challenge to make a good result very satisfying. I hope I can achieve that. So far so good!

[SteveKos]

Tonight I made some good progress. I filleted and taped the inside seams in one session. It wasn't too difficult, I just had to keep a steady pace and it all went ok. The only challenge was the centreline seam. I had to lift the boat off the table onto it's side on the floor to get to it properly. I got it down myself ok, but I needed my wife's help to lift it back up again.

 

A word on the epoxy I'm using. I'm using West System this time with the slow hardener. I find that it stays workable for quite a long time, but when it does start to go off it does so very quickly. It is a good consistency for brushing, and is low odor compared to the Bote Cote I used last build. With the pumps on the bottles I think I'll get good economical use from my 6ltr kit.

 

[SteveKos]

Today I flipped the boat over to get to work on the underside. Sanded the edges smooth and flush, and filled all the gaps and holes. Not a difficult job, and after another sanding to get the filled areas smooth I will be ready to glass.

 

Another question - I am glassing the hull with 6oz cloth to above the chines by about 3". Do you recommend I still tape the seams, as the cloth will do the same job as the tape? If I tape the seams first it will mean a double layer at the seams, so will be stronger.

 

[mattp]

Wow, you are moving quickly!

On the cs17 it calls for two layers of tape. I substituted full glassing for the second layer. I think if I were back at that point I would do two layers plus glass just to have the extra wear resistance for beaching. To me that sharp chine seems vulnerable to wear.

[SteveKos]

Yes, I suppose I am moving at a fair pace, but it doesn't seem like I'm rushing. I just get a fair amount of time to work on the project. I work early mornings to mid afternoon, so I am home by around 4:00 most afternoons, and can put in an hour and a half or so before I need to get dinner on ready for when my wife comes home. Then I can usually work on it another hour or more several nights, as well as a few hours on the weekends.

 

Anyway, on the glassing, I decided about 5 minutes after posting that question that I would tape and glass the hull. The chines and bow need as much abrasion resistance as they can get.

[labrat]

Last time I looked at this thread was about 4 weeks ago when you were still looking at the plans. Today I thought I'd see if you had started yet and was very startled to say the least - first impression was that you were nearly finished. Of course there is still a lot to go, especially with the fiddly bits, but even so it is remarkable progress and looking very good. Can't wait to see it in the flesh.

 

Will the first launch be at West Lakes?

[SteveKos]

G'day Bob. Actually I've got alot to do yet, but this build is no Sabalo for complexity, so I am making surprising progress I think. (I like working with bigger bits ).

 

With this one there are not so many detailed step-by-step instructions, so it's a matter of judgement when to do some things. This week I taped and glassed the outside hull, but only one coat of epoxy. I'll finish it later when I come to the final stages.

 

Last night I shaped the mast collars and foredeck/seat. It took a bit of work to get the shape of the foredeck right, my plane and sander got a real workout as I knew I needed to cut it oversize to be safe (but I ended up with it just a bit too oversize, so I had to shape it back quite a bit, but it's a nice fit now).

 

Next will be the other little bits for the interior, like the notched cleats, Tank frames etc.

 

I am hoping to be all finished by Easter. I'm taking some leave then and I would love to give her a real shakedown on lake Alexandrina.

 

Some pics:

 

Sorry about the quality of these first two images, the light was low and my phone battery was low, so no flash.

 

Taped.

 

Glassed. I didn't have enough glass to do the whole hull, but I managed to grade the coverage from almost full at the bow to a few inches above the chines at the stern.