Malahini chine issue

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theGreek
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Re: Malahini chine issue

Post by theGreek » Sat Nov 08, 2014 12:54 am

Hi All,

Thank you all for your reply. As I understand I need to add more material at the stem and thus the planking will have more room to sit on. But what happens at the chine part? I dont think it will have enough room for the planking to butt correctly. Will it?
The following picture is my understanding of where you suggested I should add more material. Am I right?
IMAG1798.jpg
Normally in your own builds, is there a gap at the stem where the two side plankings butt join?


Thank you

Konstantinos

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billy c
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Re: Malahini chine issue

Post by billy c » Sat Nov 08, 2014 6:58 am

the boatbuilding with plywood book will help you out alot!
http://www.boatdesigns.com/Boatbuilding ... /12%2D430/
Image
here is a picture of a tool made to gauge where your battens will line up with the center of the stem when it is faired. pretty difficult to attach anything to the stem without this. yes add material to the stem and scribe a fair curve back into the stem getting the sheer and chine landings back before any more work continues
Image
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Roberta
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Re: Malahini chine issue

Post by Roberta » Sat Nov 08, 2014 7:08 am

This set back tool is also shown in the instruction booklet that came with the plans. A very simple and helpful tool for properly aligning shears and chines to the stem. Then the stem is faired into the chines and shears for a flat surface for the planking.

Yes, The area you have blackened out is where you need to laminate and build up the stem. You need to go back towards the keel far enough to provide enough material to re-create a nice, fair stem line. Use the tool Billy showed you to determine the depth of the laminations, then you will have the proper shear and chine setback. Then you will be able to fair the stem to a point to line up with the shears and chines and be able to properly apply the planking.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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Roberta
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Re: Malahini chine issue

Post by Roberta » Sat Nov 08, 2014 8:00 am

Here are some pics showing the setback and fairing with some notes attached.

Roberta
Attachments
Chines done 002.jpg
This shows how the chine looks after it has been properly set back on the stem. The area of the stem in front of the chine will be faired to a point to blend into the chine. This is why you need to laminate the stem so you can create this area that needs to be faired into the chines and shears. Because you did not set back the shears and chines, now you need to add something to fair into.
fairing2 004.jpg
Here you can see how the stem is faired into the chine to create a flat transition and the stem is faired to a point.
fairing 3 002.jpg
This shows the completed fairing and how the stem is faired to blend into the shears and chines to provide a flat land for the planking to set on without having to bend it around a curve.
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

theGreek
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Re: Malahini chine issue

Post by theGreek » Sun Nov 09, 2014 1:57 am

Thank you!

Now I understand what I need to do. I already have the book but I guess I skipped that part :).


Thank you all

Konstantinos

theGreek
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Re: Malahini chine issue

Post by theGreek » Sun Nov 09, 2014 2:19 am

Hi all,

I remembered I had another question. Should I add more material on the chine log in order for the planking to rest properly on?
I understand the alignment of the chines to the stem but I have to fair the chine in order to align with the sheer in the end. It seems to me that I wont have enough material to do so.
This picture depicts where I should add more material.
IMAG1798.jpg

Thank you

Konstantinos

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Roberta
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Re: Malahini chine issue

Post by Roberta » Sun Nov 09, 2014 6:19 am

You shouldn't need to add anything to the chines except to fill any gap between the end of the chines and the stem. This can be done with a small sliver of wood and epoxy. Your chines and shears are well anchored to the breast hook and chine hook.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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billy c
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Re: Malahini chine issue

Post by billy c » Sun Nov 09, 2014 6:47 am

hi Konstantinos-
the chine should have turned outward to follow the angle of the stem. yours followed the same angle of the last frame and did not twist to match the stem. what you have now is a chine that landed with the top edge (nearest the sheer) that is too short where it lands on the stem. ...so yes, the fix will be adding another layer of material to the chine and fairing back into the stem. here is a picture from the Malahini builder gallery that shows the sweep of the chine to match the angle of the stem
looks like it's time to get back to work! :D
-Billy
Screen shot 2014-11-09 at 8.50.23 AM.png
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Roberta
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Re: Malahini chine issue

Post by Roberta » Sun Nov 09, 2014 2:48 pm

Billy is right. The chine needs to roll over to match the slope of the stem. The chine blocking also needed to be beveled to accommodate this slope. Then the chines are cut to match the mating angle and set back before they are anchored to the stem and blocking. The shears are generally layed flat to the sides and faired to a diamond shape past the last frame and up by the stem and breasthook. As you reconcile the issue with the setback of the shears and chines, you will need to address the shape and angle of the chine so the planking lays properly as it transitions from a lap joint to a butt joint along the chine as it nears the stem. It might be necessary to cut the chines loose from the stem and blocking and re-anchor them in the proper orientation or a lot of creative laminating and fairing.

Roberta
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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rbrandenstein
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Re: Malahini chine issue

Post by rbrandenstein » Mon Nov 10, 2014 8:52 am

Yes, this issue of the chine alignment has happened to many of us building for the first time.
My chines did not twist out enough. This can be visualized in this picture.
_3338.JPG
I had to epoxy additional wood to the chine to correct. I ripped some wedge shaped strips and epoxied to the lower half of the chine. Then faired to align with the sheer.
IMG_0400.JPG
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