Thread: Start Building Another Dutch GIS

Originally Posted by Boatmik

For the ultimate in waterproofness and reduction in maintenance the epoxy is the best solution by far.

Also there is a risk that the varnish may get on the ply in a bonding area with the glue sticking to the poorly adhering and weak (relatively speaking) varnish.

MIK

Fully agree with this. I have had several wooden boats for many years including a 1906 38ft classic wooden yacht rebuild myself.....epoxy on bare dry new wood is the best way to go. Lots of other things work more or less too, but epoxy keeps maintenance as low as it could be.

Today's update, coating and glassing several parts.

Centerboard foil has now 2 layers of 160gr/m2 glass
Centerboard case has 1 layer of 160 gr/m2 glass on the inside to protect, before assembly. Rest has a first coat of epoxy.
Ruddercase has 1 layer glass protection too, before assembly. Rest has also a first coat of epoxy
Transom has a outboard mount protection out of several layers of glass and a second coat of epoxy.
Frame 3 has a second coat of epoxy. I have made 6mm ply reinforcements around both big port-holes. This is a view from the stem and will be inside my "boxed" middle seat.

Pictures attached

another small step towards a great boat

Hi Watermaat,
I get the outboard cutout, but what is the smaller slot on the right hand side?
Skulling oar maybe?
-Al

Hi Al,

Yes,

I did that, trying to "balance" the design of this transom a bit......and sometimes sculling for a short distance is easier than paddling or rowing. It could also be used to keep the top of the mast in place when it is stored in the boat.
I need to find out if it is very usefull, but I think it looks better this way.

Ralph

I have filled the holes for the ropes in mast and yard with epoxy, to be shure they are well sealed inside.
I have drilled 13mm holes, taped one side to close them and poured epoxy in.
After curing I will drill 8.5 mm holes through these epoxy plugs.

I never did this in other projects, but I have found out that these holes could let moist in under the epoxy-coating, if you do not seal the wood in the inside very well.

NB I will use a rope loop through the mast to fix a halyard block.

Some very nice procedural pics here Watermaat!

Thanks MIK,

I hope it helps builders, as many other pics on this forum helped me to get idea's and get these things done.

Today I made my second foil, this time for the rudder.
I have already finished my centerboard foil, but did not make pictures how I shaped it.

I had already made a blank from fir staves with a hardwood front.Attachment 118673
First step is flattening one side of this blank. I use a strong beltsander with 40grid belt; great for speed and works very well if you are used to it...........if you are not used to it....the effect could be put in any horror-movie .

If both sides are flattened, I make a straight pencil-line in the center of both long small sides. These are very important to make a straight and symetrical foil.
I also cut the blank to required lenght and tapered shape towards the bottum.

Next step is making a rough shape with an electric plane. I make an angled flat surface towards the front ( leading edge ) and a second wider one towards the aft side ( trailing edge ). Then I turn over and start planing similar symetric surfaces on the other side. I carefully look to both centerlines and keep left and right angle symetrical. These angled surfaces are vital for an efficient shape of the final foil and need to be carefully positioned to match required foil shape. I have attached a picture with these surfaces marked with a pencil. Attachment 118668

I leave a 2 mm flat surface at the trailing edge ( after final sanding ) and a 11 mm flat surface at the leading edge ( about 50% of blank thickness ) Attachment 118672
and Attachment 118671

Then I start using my 40grid beltsander again to shape the ridge between trailing surface and blank. I prefer to shape both trailing edges first ( lots of material to remove ) and shape both leading edges later ( more carefull not to take too much material ). I look a lot to keep things symetrical and feel to check the smoothness of the final profile. I have attached pictures of the foil with flat surfaces on one side and final round shape on the other side.Attachment 118669 and Attachment 118670

I like this quick way and used it to make several foils in the past. It is certainly not a "beginners" way of shaping foils.....you can easy mess up a blank. And my barn looks like the inside of a dust-bin....

After I have finished with my beltsander, I make a round leading edge and bottum by hand using 60-80 grid sandpaper. After checking overall smoothness and straightness I will put a first coat of epoxy, do some sanding and filling of smaller gaps and bumps and put one layer of 160gr/m2 glass in epoxy before finishing.

Watermaat, thanks for the informative pics, which are quite timely for me.

Today I cut my centreboard and rudder staves and glued up the rudder blank, so I'll tackle the shaping next week end.

I take it you don't use the template in the plans and are just referencing the shapes drawn on each end? Also, are you just free-handing the shaping without clamps, ie. holding the board with one hand and planing/sanding with the other? Or do you have a clamping system?

I don't own a belt sander or electric plane so I think I'll be losing some sweat next w/e

Here is by blog I started.. http://oztayls-shesha.blogspot.com/

Hi Woodeneye,

I would probably do a similar procedure with a handplane and using a 40-80 grid sanding-belt on a piece of wood ( torture board ) for fine tuning.
You can use the template for calculating both flat surfaces and mark them on the blank. This planed flat surface is more important for the trailing edge, since you need to take away most material in that part. It is also important to realize that you need to have an almost flat surface towards this 2mm wide trailing edge ( water needs to be able to follow the shape to the end ). I like to make this octogonal (?) shape ( meaning square blank with 4 tapered flat surfaces ) to have better visual control before rounding things. As soon as you start rounding you loose that control.

Perhaps MIK has some valuable tips? Well shaped foils are very critical for performance.

Nice blog!
I have one too on Watermaat with my current "fleet" and a few links to it.
but I put most recent GIS updates in this thread.

Good Luck in shaping! it is really nice to see and feel a well shaped foil in bare wood, one of the nicer things in woodworking ( well worth this sweat and dust )

Today I have been finishing the oars.
I have made them of two 18x45 fir planks and 9mm ocoume ply blade and spacer.
Handles are halfway tapered from 45mm towards 25mm in one direction.
Attachment 118809

After cleaning from glue I also planed a taper in the other direction towards the blades.
Attachment 118810

I have used an electric router to make 12mm diameter round corners and used 60grid sandpaper for finishing shape of handles and blades. A first coat of epoxy has been applied. After this has been cured I will make barrel-shape handles, sand it and finish with several coats of epoxy and varnish.
Attachment 118811

I also put a first coat of epoxy on the rudder foil.
Attachment 118812

Another step towards (GIS) "paradise"

I made the handles and finished woodwork on my oars. Still several coats of Epoxy and Varnish to go, but I think they look pretty good.
Again I did lots of sanding on frames and other parts before another coat of Epoxy will be applied. Temperature has dropped below 15degrC, so I ordered a can of "fast" harder to be able to continue using Epoxy. This "fast" harder can be used from 5degrC.

Some pictures how I made the stem. I used two 18x45 pieces of fir glued together.
Used marking lines and handplane to get it done.

I also put one layer of glass on the rudderfoil.

Yesterday I have made butstraps and chines on the sidepanels and butstraps on the bottumpanel. Attachment 119728

And today I could not fight anymore against this temptation..............I did a dry fit of sidepanels, stem, frames and transom.
My GIS is finally 3D .........with the usual oh's en ah's when I saw the lines of this great design.
Attachment 119729 and Attachment 119730

And suddenly my barn is full of GIS and I still needed to put epoxy on my oars and glas my rudderfoil. Attachment 119731

It was a little pain to get stem and frames lined up and fixed singlehanded. I have used two low workhorsed placed carefully horizontal and used a few blocks on them to force the chinelogs into position. Starting with stem and then fixing frames from stem to stern as per plan.

It's a bit tricky to get the right height of the frame. I placed a workhorse under the position of the frame. I used pieces of 9mm ply as spacer on top of this workhorse to keep the frame 9mm above the lower corner of the chinelogs. Then I fixed this frame with a few screws and placed the workhorse under the next frame position.

Next step is to remove frames and epoxy-glue them back into their postion...this will be a sticky day