Building Shesha, a Hunter Valley GIS, Australia

[MiddleAgesMan]

There are any number of things that might have caused that kink at BH 1 but the close-up pic of the sides gave me an idea that might help minimize it.

It appears you masked the sides from top to bottom at BH 1 before applying resin. Coating with resin makes plywood resist bending a little so you have a "soft" spot where the resin wasn't applied.

Here's my idea: let the gunwales loose and coat those bare areas. Once the resin is cured it should make those "soft" spots bend characteristics the same as the rest of the panel. I don't think this will solve your problem by itself but it might help.

I can think of only two things that might have caused the kink in the first place: (1) a void in the plywood at that point could cause it or (2) the angle or half-width of the bulkhead may be slightly off. Since you've got Joubert plywood I'd say a void is unlikely.

[john goodman]

I worked for a sail loft and we had a belief that if we didn't bleed on a sail during its construction it was not going to be fast. I did most of the hand stitching, so it was my blood most of the time. I hope that bleeding on our Goats will make them fast too!

I have approached the stem strength issue a little differently. If the stem splits open, I would rather it happen before the front tank top is glued on. It would make repair easier. My stem is western red cedar and I was concened that it would split. After curing for 2 hot days 68F, we have removed all screws and there is no sign of weakness in the stem joint. With the bottom now glued on it's even stronger.

[Boatmik]

Overtightening the screws can do it too - so back them out a shade so the heads are not distorting the ply.

Also temporarily clamping the gunwales in place can help too. If the chine and the sheer are fair then it makes it easier for the side to be fair too.

Try those first and report back.

MIK

[woodeneye]

Overtightening the screws can do it too - so back them out a shade so the heads are not distorting the ply.

Also temporarily clamping the gunwales in place can help too. If the chine and the sheer are fair then it makes it easier for the side to be fair too.

Try those first and report back.

MIK

Hi Mick
I presume you mean the screws into the stem as they are the only ones I have, so I'll remove them then? The gunwales have been clamped ever since assembly. The chine and the sheer are perfectly fair.

Did you see the pic of the bow from the front of the hull? The kink is hardly noticeable from that angle, but when you look down or set a straight edge across the inside (sheer to chine) at BH1, it is really obvious. There is lot of tension there that is unsupported as is the case with all the other bulkheads which have side arms. BH2 was the same but was fixed when the side arms were added.

Perhaps the Joubert ply is just stiffer than most other stuff? I see John Goodman had his crack during assembly, so this could be a likely cause.

[john goodman]

Perhaps the Joubert ply is just stiffer than most other stuff? I see John Goodman had his crack during assembly, so this could be a likely cause.

I have thought about how I cracked the plywood during the glueing of the stem and I have these thoughts.

A. I had preset my drill to release at a certain torque. My drill has settings 1-15 and I had set it at 11. We have had only 10 screws strip out so far. We would then come back and hand tighten them and replace the stripped ones.
B. When we glued the side panel to the stem I was looking inside the boat at the stem and plywood contact area while using the drill. I wanted good contact. I should of been watching the outside to make sure plywood was fair and matched the other side. Any gaps in the stem/ply contact area could of been filled later. I tighten it until good contact was made and the drills torque released at the same time it cracked.
C. The chine log pulled away from the ply at the it's end. This could of been a matter of not enough glue at the very end of the chine.
D. I had thinned the chine log to make it more flexible. I will be more agressive next time and take more chine log off. I might go half of the thickness and taper it back half the distance to bulkhead #1. I could add back structure if needed.

[woodeneye]

Thanks for your thoughts John.

In my case, I don't think screw tension played a part. My framing and chine logs are of Paulownia, which is very soft, so I had to be very careful not to strip screws. I was using square drive screws on a torque setting of 1/16. This was the minimum setting needed to pull the parts together and get squeeze out without stripping the screws.

I have decided that I'm not going to worry about it. Visually, it's not noticeable as you can see from the external view of the bow from dead in front. When I install the inwale, I'll see if I can spring it, but if not, so be it. Once the gunwale structure is there it will be very strong and unlikely to cause long term problems.

[Boatmik]

If planning to paint the outside it would be possible to fair it through.

If leaving it clear finished it will be very hard to see - the dazzle of the wood grain and refraction makes it very difficult to spot bits of unfairness.

Best wishes
Michael

[woodeneye]

If planning to paint the outside it would be possible to fair it through.

If leaving it clear finished it will be very hard to see - the dazzle of the wood grain and refraction makes it very difficult to spot bits of unfairness.

Best wishes
Michael

I agree Mick. At the present time, it's looking like a clear finish all over, but will make that final decision in the coming weeks as the build closes in on completion .

My sail (made by Russell from Storm Bay Sails in Tasmania) arrives next week, so am looking forward to stepping the mast to have a look.

The hull build seems to have been very quick, as it was only started six weeks ago, and it's now looking like we'll get on the water before winter sets in, rather than my original estimate of October! As I only get a few hours a week on weekends to build, this has surprised me. The Goat is indeed a boat that the average person can build quite quickly.

[woodeneye]

This weekend, in between Easter festivities and my wifes birthday, I added the gunwales and knees. For the inwales, as I only had 19mm Hoop pine stock, I had to make plenty of shavings to trim them down to 15mm with the plane. I only need to add the gunwale capping and then I can trim the whole lot down.

Aren't the knees and breast plate fun? All sorts of angles to keep you on your game, but I'm happy with how they turned out and I managed to get a reasonably good fit. It took me a good few hours to make and fit them. They should look pretty good once they're all sanded down.

I was planning to do something different with the breast plate, but once I started cutting and planing that lovely piece of yellow Hoop pine that I had, I just knew it had to be kept simple.

OK, what else did I do? Aah yes, I cut the hole for the mast and I filleted the seats. Mmm, for the fillets I made up a paste of epoxy and micro balloons, tinted with some epoxy dust from the sander bag. It was looking OK until I decided to sand the fillets smooth, and they turned white! I don't think I've read about this before. If you look at the enlarged version of the picture, you can see the difference in the colour of the fillets on the rear seat (sanded) compared with the fillets on the mid and front seats (unsanded). AAARRRGGGHHH!

However, there are still no screws in the hull!

Attachment 134061

[SimonLew]

Bruce, try a coat of epoxy over the fillets. It might turn the white back to the original color.

[Boatmik]

Just wet the fillet by wiping on a couple of drops of water - I think it will probably go back to its original colour.

The water will dry of course ... but when you epoxy or varnish it there will be the same effect as if you wet it.

MIK

[robhosailor]

Hi Bruce!
Bravo! Great job and progress!

[woodeneye]

Just wet the fillet by wiping on a couple of drops of water - I think it will probably go back to its original colour.

The water will dry of course ... but when you epoxy or varnish it there will be the same effect as if you wet it.

MIK

Unfortunately this doesn't work Mick

What I think is happening with the microballoons is that the epoxy cannot penetrate the balloons, so when you sand the fairing mix, you expose the inside of the balloons, which are white.

This also happened when I used the fairing mix to correct the height of one of my bulkheads, to bring it to the same level as the side edge. I got some of the fairing mix onto the ply, didn't sand it ALL off and so when it was coated with clear epoxy, it was stained white underneath. This phenomenon does not occur with the WEST colloidal silica/cotton fibre mix, just with the micro-balloon fairing mix.

Something to remember if going with a bright finish

[woodeneye]

I didn’t think that this day would come, but the construction phase is now complete It’s a particularly satisfying moment.

This weekend I fitted the rubbing strakes, trimmed down the gunwales, cut the centreboard slot, attached and shaped the bow piece and the breast hook, fitted the bottom runners, assembled the rudder stock and fitted the transom gudgeons. Oh, and I faired inside the CB case so that the daggerboard self aligns with the slot.

Now I just have an awful lot of sanding to do before commencing the coatings
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[callsign222]

WOW.

Thanks for putting me to shame.

How long this take you? Four days? Seems like it.

Nice neat job, to boot!