Brendons Zip Build

Outboard designs up to 14'

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gdcarpenter
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Location: Raleigh, North Carolina

Re: Brendons Zip Build

Postby gdcarpenter » Sun Feb 15, 2015 7:08 pm

My two cents - since hull ply is now permanently epoxied on - why install screws that need to be countersunk, filled, and covered over. Patch the existing holes where the screws were and be done!

The screws will add nothing to the structural integrity of the boat at this point, the epoxied connection is far stronger than any screws. My ZIP hull had NO screws in it whatsoever and after Two years of 5,000 Plus miles trailering and a lot of wave pounding she's tight as the day she was launched.
This is my first, last and only boat build.

http://www.gdzipbuild.blogspot.com

Flash
Posts: 80
Joined: Mon Feb 03, 2014 10:56 pm
Location: Eagan, MN

Re: Brendons Zip Build

Postby Flash » Tue Feb 17, 2015 1:23 am

Hi Brendon,

You are doing some beautiful work. I'm wondering if you framed your transom with 5/4 boards? I'm just starting a Zip and I was planning on using 4/4 with 3 knees instead of 1. Your thoughts please.

Thanks
Flash
Yellow Submarine II - Flying Saucer
Summer Wind - Zip

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Andy Garrett
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Location: Nampa, Idaho

Re: Brendons Zip Build

Postby Andy Garrett » Tue Feb 17, 2015 10:18 am

Flash,

Over-engineering is a temptation I wrestled with throughout my build. I kept thinking, "an extra 1/2" thickness here, and a big epoxy fillet there" would just make it better. This tendency was a result of my lack of experience both with woodwork, and Glen-L designs.

My original plan was a maximum thickness transom with 'knees' at the transom/sheer junction. I just kept having visions of the motor 'peeling' the transom off the boat. I had other 'upgrades' in mind as well. I guess I just wanted to be super confident that some 'weakness' would not humiliate me and send my Zip to the bottom when I had passengers aboard.

Then, something amazing happened. I flipped my hull by myself. I drug in out of the garage on the form, rolled it over with a rope and a blanket and pulled it up onto the trailer by myself. During that whole process, it never even creaked.

As I stomped around inside the hull building the interior, still no creaking or groaning (I weigh 250lbs). As I started tying the motorwell into the frame structure, I began to understand the simple inherent strength of the design.

In the end, my transom is 3/4" marine ply with the same as a motorboard and 1" nominal framing (actually 3/4"). My completed transom is 1.5 inches thick. I have no corner knees like I wanted. I have one main knee per design. My motor is over 270lbs. It never creaked once during installation or since. The water around here is very rough, so my Zip absorbs more violent forces than I ever imagined it would. It is simply an amazing structure.

Select quality quarter sawn wood. Cut, drill, and fair carefully and accurately, use quality screws and epoxy, and build per plans, and you will have as strong a boat as you'll ever need without creative over-engineering.

P.S. Think about how stitch and glue boats are made knowing that a few of those are similar size and performance as the Zip. Those are built very lightly to my mind, and they do just fine. That should make you very confident in traditional frame construction like your Zip.
Andy Garrett

Perhaps the slowest Zip build in Glen-L history...

bjfrater
Posts: 124
Joined: Sun May 04, 2014 9:13 pm
Location: Auckland, New Zealand

Re: Brendons Zip Build

Postby bjfrater » Wed Feb 18, 2015 7:28 pm

Hi Andy

I was having similar thoughts to you about how I could strengthen the design however now that its coming together I think it will be plenty strong. Especially with the added strength that will be added once the motor well is on. Its good to hear other people that think the same.
I did go with the three battens which is an option in the plans.

Flash,
My transom is the same as Andy's finished thickness is 1.5 inches. I did use Meranti ply for the transom and stem which is a more durable (and slightly heaver) ply than the Okume that Im using for the rest of the boat.

Brendon

gdcarpenter
Posts: 1325
Joined: Tue May 05, 2009 12:18 pm
Location: Raleigh, North Carolina

Re: Brendons Zip Build

Postby gdcarpenter » Wed Feb 18, 2015 8:12 pm

I also went with 3 battens per side, and I believe that, together with keeping the weight of my boat down, lets me get the speed I get. I run 30 MPH @ 5,600 RPM with a 1959 Mercuey Mark 35A - 4 cylinder/2 stroke. It's rated @ 35 HP at the crank, and compared to newer engines that are rated with prop shaft HP, my oldie Goldie is approximately equivalent to a newer 30 HP. Then again my vintage outboard only weighs in around 125-130 LB!

A well built motor/splash well does, in my mind, add strength to the transom. To take full advantage of this I attached the sides of my motor/splash well to the transom with blind sliding dovetail joints for extra strength and ran with 2 transom knees along with my existing 1 3/4" thick transom.

I have only heard of one ZIP that allegedly had transom integrity issues. As I recall it was built by 'professionals' that apparently omitted the transom knee, which, combined with a big 'wonkin' motor hanging off the back end (possibly without an engine support for trailering) caused some fracturing.
This is my first, last and only boat build.

http://www.gdzipbuild.blogspot.com

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Andy Garrett
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Location: Nampa, Idaho

Re: Brendons Zip Build

Postby Andy Garrett » Wed Feb 18, 2015 8:32 pm

I misspoke. My motor is about 170lbs. I typed 270.
Andy Garrett

Perhaps the slowest Zip build in Glen-L history...

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Andy Garrett
Posts: 1275
Joined: Tue Aug 31, 2010 11:44 pm
Location: Nampa, Idaho

Re: Brendons Zip Build

Postby Andy Garrett » Wed Feb 18, 2015 8:42 pm

I agree that an extra batten will stiffen and thus quicken a hull.

Being very careful to keep smooth water and not a turbulent mixture of water and air hitting the prop will also help a great deal.

Thoughtful skeg design and placement, proper engine elevation to keep the cavitation plate and keel perfectly aligned, and a fair aft hull will certainly be worth any effort.

A sharp edge at the transom bottom is also key. You don't want any radius there to 'suck' you down when you want to be planning on as little surface area as possible. You could shave with mine. :wink:
Andy Garrett

Perhaps the slowest Zip build in Glen-L history...

Flash
Posts: 80
Joined: Mon Feb 03, 2014 10:56 pm
Location: Eagan, MN

Re: Brendons Zip Build

Postby Flash » Thu Feb 19, 2015 12:04 pm

Thanks for the great information!

I'm guessing that you guys thought of every thing.

I think my plan for 3 knees and 1.5 total inches for the transom will work fine.

I would have paid admission to see that solo flip. Most guys need about 8 people for that.

On Tuesday, 2 of my best friends, my wife and I flipped my Flying Saucer. I hung 4 ratcheting tie down straps to the garage joists. We hoisted it up on 2 braided ropes covered with flannel. Then we turned it 180 degrees in the ropes and lowered it on the trailer. The 3 of them were pretty skeptical but it worked like a charm. I will send pictures when I figure out how.

Thanks again,
Steve
Flash
Yellow Submarine II - Flying Saucer
Summer Wind - Zip

bjfrater
Posts: 124
Joined: Sun May 04, 2014 9:13 pm
Location: Auckland, New Zealand

Re: Brendons Zip Build

Postby bjfrater » Fri Mar 06, 2015 11:12 pm

Iv been working on the battens and am about to fair them up. It took me a bit to tidy up the notches which they sit in and shape up the ends so they look how I want. They are just held with temporary screws at the moment as I still need to do a bit of sanding.

Here are some pictures of the progress.
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chugalug
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Location: top of mn.

Re: Brendons Zip Build

Postby chugalug » Sat Mar 07, 2015 1:23 am

:D You think the zip flip is interesting-try an 18 ft. Bo-Jest one man flip! I installed front bow eye, then figured out where outboard motorwell drain hole was ,then added heavy threaded rod creating front and back pivot points.
Working on regular-sized Bo-Jest


"If it's not crooked,It's not mine

Flash
Posts: 80
Joined: Mon Feb 03, 2014 10:56 pm
Location: Eagan, MN

Re: Brendons Zip Build

Postby Flash » Sat Mar 07, 2015 2:06 pm

Like a chicken on a spit?
Flash
Yellow Submarine II - Flying Saucer
Summer Wind - Zip

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chugalug
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Re: Brendons Zip Build

Postby chugalug » Sat Mar 07, 2015 4:28 pm

:D More like a big turkey;good thing I was standing behind it when it went.went slowly until I got it high enough.Then Zoom;I almost jumped out the window :lol:
Working on regular-sized Bo-Jest


"If it's not crooked,It's not mine

Sensless
Posts: 5
Joined: Fri Nov 07, 2014 3:10 pm

Re: Brendons Zip Build

Postby Sensless » Sun Mar 15, 2015 9:39 pm

Hope its all going well, hoping to build one myself starting at the end of this year, hoping you could give me a heads up of the gear i'll need, especially for shaping the frame, i live in auckland as well so any advice on supplies or cost would be great

bjfrater
Posts: 124
Joined: Sun May 04, 2014 9:13 pm
Location: Auckland, New Zealand

Re: Brendons Zip Build

Postby bjfrater » Fri May 08, 2015 2:24 pm

I now have the bottom on. This was quite a big job as I scarf joined the bottom panels together and attached each whole side in one go. I had a helper to mix up the epoxy.
I ran out of 3/4" screws and was short by about 150! thats not very good as I bought the fixing kit from Glen-L and i would expect that it would be enough to complete the bottom of the boat. If you read this Gale I suggest you add another two packs of 3/4 screws to the kit.
Anyway I ordered a bunch more and made sure I had enough for when i will be working on the deck.

Im really happy with the lines of the boat and I think the effort i put into fairing has paid off. It will be interesting to see how it comes up once I get epoxy and paint on it. Its exciting to see the true shape of the boat now.

Here are some photos of my progress.
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bjfrater
Posts: 124
Joined: Sun May 04, 2014 9:13 pm
Location: Auckland, New Zealand

Re: Brendons Zip Build

Postby bjfrater » Fri May 08, 2015 2:25 pm

A few more
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