Are the gaps in these hull planks too wise ?

I have had to replace some of the pine hull planks because they were a bit soft. I got some timber cut and machined to the same size as the boards I pulled off.



I am placing them on - see the photos - but the gaps seem to be rather wide


I will need to use cotton caulk, but is 1/8 - 1/4" too much of a gap to caulk ? Should I get some slightly wider planks or will these ones swell up sufficiently when in the water ?

The planks are only temporaryily attached at present.


Would really like some help on this as I have to decide what to do within a day or two !



Thanks

Dave

 

You have several issues besides the opem seams. The pine you used has pitchy black knots.
They will rot if they don't fall out.
I am guessing this pine you used is a home improvement variety and judging by the wild grain totally unsuitable for planking in the first place.
You also have patched in what must have been a rotten area, but it is unwise and asking for trouble to land so many on only two frames. Ideally, you run them in long/short staggers, even if cutting into good original planking, and even more ideally, those landing on the same frame should be as far seperated as can be managed.
There are varieties of pine suitable for this repair, unless the wood is actually cedar. Look for no knots or light brown knots no bigger than a fingerprint, no cracks, pitch pockets, shakes, presence of pitch, and lastly, avoid flat grain (which is all I see in the photo).
Nothing will stay long in between those boards with their large gaps.
I would suggest you do the repair with cedar, or possibly clear straight-grained pine, staying away from kiln-dried wood if possible, and avoiding flat-sawn pieces.
They should be fitted tight, but with a small narrow V on the outer 40% of the thickness, so that maybe a 1/16" crack shows. Then they can be caulked with cotton string, tamping moderately with a dulled putty knife and filled with 3M 5200 or similar cauking compound.
The Turkish woods you can get are unfamiliar to me, so ask a local boat builder for advice.
What you are doing is not a simple repair. Normally it would be a job for a professional. The fits are extremely important, as well as the wood used, and the manner of fastening and sealing.

Alan

 

Thanks Alan for the detail you have gone into.

Although it looks like a complete disaster - it won't be. If I hadn't done this yesterday - I wouldn't be leanring how to do it right!

Looks like I have to change the wood. The timber merchant did offer me ceder but I thought it best if I stick to the same type of wood that the boat is made out of.

So, I'll get some more wood. And it will have to be wider, with no knots etc.

With regard to the placing. In my photo, the 3rd plank from the left, if that one is made longer - down past the length of the others (will be about 1.5m long), would be the correct placement ?

Thanks again,
Hopefully I'll get there.
Dave

 

Again, you would want to weave in the new planks so that no two adjacent pieces land on the same frame, and even better, go one, two three, one, two, three frames across.
I believe in your case, if no pine of good quality is available, and clear or very nearly clear cedar is, cedar should be alright.
Fit each plank tight (tap into place) with no gaps. I'd also recommend landing planks halfway between frames and using a butt block to join them. The butt block should be shaped to follow the hull curve and be a couple of inches wider than the plank and twice as long as the width, with a space of 1/2" at least between it and the frames that it lies between.
A row of three screws in the old plank and the new plank should be fine, two if the plank is about 4 1/2" or less. Use bronze screws if you can get them, same size as removed, set in a bit and puttied. Stainless as second choice.
You can nail into the old frames and transom with bronze ring nails, set heads and putty, but screw the butt blocks.
If you take your time and make careful tight fits, caulk with some soft cotton string saturated with oil-based paint, and finally fill the seam with seam compound, you should have some nice pictures to show of that boat floating.

 

I'm not sure of the size of your boat, but cedar is only suitable as planking on small craft. Many of the lighter pines are also only used as planking on small boats. There are some denser pines that will work on thicker planking, used in larger vessels.

Generally, you want your butt joints to fall between frame bays and no adjacent butts, on the same frame bay, for at least three planks (better if more). If scarfing the planks into place, these can fall over a frame, if your clever, you can arrange the seam to be hidden by the frame itself.

Rift grain planking is preferred, quarter sawn is also a good choice. Straight, tight grain, with few if any defects will be necessary.

Both the thickness of the plank and the height (width) must be milled greater then the existing planking. The repairs will need to be "backed out" to conform to the shape of the frames, the edges planed to pickup the bevels and caulking seams and the installed planking repairs will need to be planed to fair the hull area. This is why it's necessary to use thicker stock.

To an experienced person, one who's hung many planks, the job is reasonably easy. To an amateur, it's a difficult and tedious job of fitting, through trial and error.

Caulking is another matter. Done properly, it can last many years. Done improperly, it will spit out its caulk and a big leak will result. Driving caulk is an art, which requires considerable skill, because the job is done entirely by "feel", which can only be developed, through the experience of hundreds of feet of pounded seams.

You'd be strongly advised to seek help with this repair, from a skilled boat carpenter.

 

Thanks for the advice.
Maybe it will be better if I get the marine carpenter to do the job. I can watch him and learn. Maybe next haul-out if nec. I can do it.

The only problem is, I am a bit suspicous of these "carpenters" here in Turkey. At least now I know how the job should be done. As regards butting on the frames - maybe because the frames are doubled and about 4" thich - they usually do the joints on the frames.

Thanks again.

 

give her a go

Well don't get so discouraged get some clear or reasonably clear ceder, if it has knots shellac the knots before you prime the bottom take your time plank by plank and fit them use dolfinte at the but ends to seal the joints and butt blocks shaped to the bottom hull shape and use dolfinite as a bedding compound before screwing or clinch nailing them together. take your time and do it your self unless you have lots of money and are in such a hurry to get it on the water . good luck just my own personal opinion

 

Surely, with 4" frame dimensions, this isn't a small boat. If this is a Turkish design, traditionally built, there will be carpenters who know the methods by which the boat was built. No doubt, as anywhere, a good boatwright is a rarity, but claims of expertise are very common.
Planks landing on frames would generally make for a hard spot. See if the old planks are thinner at the ends--- by fastening the plank onto a shaped frame so that the plank would ramp up at the end and then be planed down. It might explain the wide frames also. Frames would then land on half of a slight V, a straight run from the last frame, but fair smooth. Stock has to be thick enough to allow for such shaping. Some pines (Southern Pine) are good boat planking material--- better if with only small tight knots and vertical grain. Such pines are extremely tough and strong and resistent to decay. Turkey may grow such woods, I don't know.

Alan