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September 15, 2020, 07:03:44 PM
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dmont

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dmont's flatback build
« on: September 15, 2020, 07:03:44 PM »
I was planning on posting this rebuild once it was complete, just a one and done. However I am sitting here in hurricane Sally with nothing better to do and the electricity is still on, so what the heck. I will update as I can, boat work has been slow lately with the south alabama heat, but i am hoping to start again on it very soon. The previous owner had started to remove the center stringer and then stopped. The boat was full of water in front of the in deck livewell, it basically had nowhere to go.
Here are some pictures of the condition of the boat when i got it:






the decks and transom were in pretty poor condition. The windows in the hull were also removed by me. Someone had drilled holes in them and put drain plugs in. They were also cracked. They will be filled in with fiberglass from up top and below. The foam in the stringers was dry to my surprise. The starboard stinger was cracked pretty bad from where the old rigging tube was. There was also some delamination of the stringer from the hull in this area. The fuel tank (40 gal poly) will be placed in the area where the viewing window were.







The transom was brought up to gunnel height with a sheet of waxed melamine as a backer. After filling in the transom cut out I covered the entire transom with 1708 plus a couple extra layers in the corners and bottom edge, I figured most of the stress would be in these areas. I am using all polyester resin with a mix of 1708, 10oz cloth, and chopped strand mat. I also installed a 1" PVC pipe for the drain (as suggested by y'all). I then used a piece of 1.5" coosa board for the transom. The coosa was glued in with poly resin thickened with cabosil and 1/2" glass fibers, also used this for the filets around the edge. Mixing up this filet/glue material was a lot of work, so after this I purchased a 5 gallon bucket of Arjay bonding putty for the rest of my gluing and filets. Templates for the transom and everything else on the boat were made from strips of wood that were ripped on the table saw then hot glued together to make a template of what I wanted to cut out.





I then glassed the transom in with a few layers of 1708 and extra in the corners/bottom. I cut out some remaining 1.5" coosa to make transom knees that would tie in to the old stringers. I basically cut a taper in the old stringer so it would meet up with the width of the coosa, making a smooth transition for the glass. There were several layers of glass put in to tie the stringers and knees together, and probably more before the deck goes on just for extra insurance. There was also a 1.5" coosa top cap put on that tied the hull sides, knees, and transom all together. I figured this would give the transom some extra strength from wanting to flex long ways. The cap was also tied back into this coosa transom cap, I cut the flat part of the cap off and left the "ridge" in it that extends over the coosa transom cap. Hopefully this will be a good look once it is finished and faired.







The starboard stringer now needed to be repaired. All the old cracked and delaminated glass was cut off and ground down. The old remaining foam that was in good shape was cleaned up and sanded for a good bonding surface. I then made a form/mold (quick and dirty) out of plywood with plastic sheeting over it for the new pour foam (4lb). After the foam was poured and set, i cut the top off by using the good stringer as a template for the height. I shaped the new foam with a sander and filled in any low spots with Arjay bonding putty. A few layers of 1708 covered this repair. I also layed one layer of 1708 across the bottom of the boat from stringer top to top. I then made bulkheads the same way (other than the back one which was made out of some leftover 1.5" coosa. The bulkheads are on 2' centers to give the deck good support. I also glassed down a half round piece of 2" PVC in the bottom of each bulkhead before putting them in. I will do this with the remaining old bulkhead also. This will allow any water that gets below deck to drain into the bilge, unlike when i got the boat where it was all trapped in front of the livewell bulkhead.









That is where the boat currently is. Next step is to make cut outs for rigging tubes, then wrap bulkheads in 1708, and make one more bulkhead forward of my fuel tank compartment. I will then fill in where the old windows were and finishing out the fuel tank compartment. I am not shooting for a perfect fit and finish on this boat, just a tough fishing boat, with a decent look... haha.  Here is one other part of the project, a transom mounted livewell that i made out of an MDF mold. there will be a water pick up in the bottom (clam shell) and holes will be drilled at roughly the waterline of the boat so it will maintain that water level at rest, and not go over that level when on plane. The bottom flange of the livewell will be inside the livewell so it will sit flush with the bottom of the boat. i will probably lay more glass inside the livewell and work on the flanges (crooked at the moment). this mold was tough to make, considering the transom angle, and the slight deadrise of the boat, but it came out pretty well.



September 15, 2020, 07:37:51 PM
Reply #1

Capt. Bob

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Re: dmont's flatback build
« Reply #1 on: September 15, 2020, 07:37:51 PM »
Diver model.
You don't see a whole lot of them.

Good luck. :thumright:
]
Capt. Bob
1991 210 Walkaround
2018 Yamaha 150 4 Stroke
"Reef or Madness IV"

September 15, 2020, 10:27:56 PM
Reply #2

Ulysses485

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Re: dmont's flatback build
« Reply #2 on: September 15, 2020, 10:27:56 PM »
Wow, lot of progress in a single post!  :thumleft: Great first post! Definitely looking forward to seeing this build and how it progresses. Are you planning on raising the deck? What are your power plans? I assume a bracket with the closed transom? Tower or t-top? Assuming you want it self bailing?
Thanks for sharing!

-Ulysses
1974' 240 CC - https://classicaquasport.com/smf/index.php?topic=15975.0
1970’ Flatback 222 - https://classicaquasport.com/smf/index.php?topic=15666.0
1981’ Osprey 22-2 - https://classicaquasport.com/smf/index.php?topic=15249.0
1971’ Flatback 222 - SOLD
1972' 240 Seahunter - SOLD

September 15, 2020, 11:05:08 PM
Reply #3

dmont

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Re: dmont's flatback build
« Reply #3 on: September 15, 2020, 11:05:08 PM »
I will use 3/4" honeycomb for the deck, placed on the original stringer height, so maybe 1/2" higher than factory.
Power will more than likely be a 115 four stroke on a 10" set back jack plate. I got a really good deal on a brand new jackplate so I am going to try to use that. i may not be able to tilt the motor all the way up unless the jackplate is in the raised position, but we will see. hopefully the 10" setback will be enough to keep the cowling from hitting the top of the transom at full tilt. I did not put any crown in the transom for this reason.
No tower or T top, just a bimini.
Yes i plan to put scuppers for it to be self bailing. i think it will be light enough so water wont back up on to the deck... but we will see.

September 18, 2020, 01:30:09 PM
Reply #4

Tampa Bay Mike

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Re: dmont's flatback build
« Reply #4 on: September 18, 2020, 01:30:09 PM »
Looking good. They make jackplate spacers that are cheap and will give you a little more setback if you want.

September 21, 2020, 02:01:46 PM
Reply #5

Ulysses485

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Re: dmont's flatback build
« Reply #5 on: September 21, 2020, 02:01:46 PM »
I will use 3/4" honeycomb for the deck, placed on the original stringer height, so maybe 1/2" higher than factory.
Power will more than likely be a 115 four stroke on a 10" set back jack plate. I got a really good deal on a brand new jackplate so I am going to try to use that. i may not be able to tilt the motor all the way up unless the jackplate is in the raised position, but we will see. hopefully the 10" setback will be enough to keep the cowling from hitting the top of the transom at full tilt. I did not put any crown in the transom for this reason.
No tower or T top, just a bimini.
Yes i plan to put scuppers for it to be self bailing. i think it will be light enough so water wont back up on to the deck... but we will see.

I cannot speak from experience but i assume you are like me and want to keep the build light and simple (while maintaining highest gunnels and shallowest draft) with a closed transom. My findings are that I have not found one self bailing flatback with a stock deck height and a closed transom. One member raised it about 1.5-2'' with a notched/transom mounted 150 Yamaha 4 Stroke (489lbs) and simple T-Top and it self bails. Build Thread: https://classicaquasport.com/smf/index.php?topic=12074.0 

 If you keep the motor mounted on the transom, it reduces transom weight, eliminates bracket weight, and changes the lever point of the motor to then have to be be offset by weight forward. These boats came with much lighter outboards (270-300lbs) for them to be self bailing along with a finished boat weight of 1750lbs. They came with a 28 gallon fuel tank inside the console. The only other unknown would be battery quantity and weight (considering i have only seen them at the back of the boat mostly when original). Most rebuilds gain weight due to more resin and glass being added than removed to ensure a good structural form and bond. and then there is the added features.

Inevitably, they gain weight but its a trade off and typically a good thing in most cases.  Just figured i would share my finding. 

Looking forward to following along on the build. Thanks for sharing!

Ulysses
1974' 240 CC - https://classicaquasport.com/smf/index.php?topic=15975.0
1970’ Flatback 222 - https://classicaquasport.com/smf/index.php?topic=15666.0
1981’ Osprey 22-2 - https://classicaquasport.com/smf/index.php?topic=15249.0
1971’ Flatback 222 - SOLD
1972' 240 Seahunter - SOLD

September 22, 2020, 03:50:21 PM
Reply #6

RickK

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Re: dmont's flatback build
« Reply #6 on: September 22, 2020, 03:50:21 PM »
Also, the FBs were designed for a 70 or 90 hp engine only and they run great with that. It's the need for speed that makes people go crazy with big motors - we've even seen 225hp on one and the owner said it was too scary at high speed.  The FBs like to bow steer and can be dangerous at high speed - you're going one direction one second, hit a wave and now you're going 90 degree or 180 degress in an instant.  The FBs don't jump up on plane, you don't have to overcome a bow wave, the FB just goes forward faster and faster, not really planing, just being on top of the water. I drove one with a 90 on it and it moved right along.
Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

October 22, 2020, 03:13:53 PM
Reply #7

dmont

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Re: dmont's flatback build
« Reply #7 on: October 22, 2020, 03:13:53 PM »
Also, the FBs were designed for a 70 or 90 hp engine only and they run great with that. It's the need for speed that makes people go crazy with big motors - we've even seen 225hp on one and the owner said it was too scary at high speed.  The FBs like to bow steer and can be dangerous at high speed - you're going one direction one second, hit a wave and now you're going 90 degree or 180 degress in an instant.  The FBs don't jump up on plane, you don't have to overcome a bow wave, the FB just goes forward faster and faster, not really planing, just being on top of the water. I drove one with a 90 on it and it moved right along.

I have run a couple boats with basically no deadrise, and it seems like they do ok with less power. That is my reason for going with a 115. She will not be fast by any means, but should accomplish what I want to do.

October 22, 2020, 04:28:47 PM
Reply #8

RickK

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Re: dmont's flatback build
« Reply #8 on: October 22, 2020, 04:28:47 PM »
She'll be plenty fast with a 115 on her.
Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

December 27, 2020, 09:38:09 PM
Reply #9

Ulysses485

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Re: dmont's flatback build
« Reply #9 on: December 27, 2020, 09:38:09 PM »
Hey Dmont, how is the build coming along?
1974' 240 CC - https://classicaquasport.com/smf/index.php?topic=15975.0
1970’ Flatback 222 - https://classicaquasport.com/smf/index.php?topic=15666.0
1981’ Osprey 22-2 - https://classicaquasport.com/smf/index.php?topic=15249.0
1971’ Flatback 222 - SOLD
1972' 240 Seahunter - SOLD

December 29, 2020, 07:43:16 PM
Reply #10

dmont

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Re: dmont's flatback build
« Reply #10 on: December 29, 2020, 07:43:16 PM »
Progress has been slow. We have a three month old daughter and she takes up a lot of our time (not complaining). I have done a little work here and there. I foamed the area around the middle stringer that I left forward of where I will put the fuel tank. I have also hot coated this with resin (I do this on all foam and composite board) and will glass over it soon.




next on the agenda is to glass over my bulkheads and put in a couple rigging tubes for controls and fuel.

December 29, 2020, 11:30:05 PM
Reply #11

Ulysses485

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Re: dmont's flatback build
« Reply #11 on: December 29, 2020, 11:30:05 PM »
Hey progress is progress. I am about to be in your situation regarding another little one on the way. Thanks for sharing.
1974' 240 CC - https://classicaquasport.com/smf/index.php?topic=15975.0
1970’ Flatback 222 - https://classicaquasport.com/smf/index.php?topic=15666.0
1981’ Osprey 22-2 - https://classicaquasport.com/smf/index.php?topic=15249.0
1971’ Flatback 222 - SOLD
1972' 240 Seahunter - SOLD

July 02, 2021, 04:21:47 PM
Reply #12

dmont

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Re: dmont's flatback build
« Reply #12 on: July 02, 2021, 04:21:47 PM »
Slowly working on the flat back. I was wondering what kind of coring was behind the bow eye on these boats? Is it a block of wood glassed in or just a bunch of bonding putty? Debating on cutting it out and coring with a block of coosa or just putting a big stainless backing plate on it, or both.

July 02, 2021, 04:27:20 PM
Reply #13

RickK

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Re: dmont's flatback build
« Reply #13 on: July 02, 2021, 04:27:20 PM »
Mine was wood - maybe balsa?  I replaced with a sculptured piece of 4x4 and glassed it in.
Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

July 04, 2021, 08:26:34 AM
Reply #14

Tampa Bay Mike

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Re: dmont's flatback build
« Reply #14 on: July 04, 2021, 08:26:34 AM »
Mine was wood too. I cut it out and shaped a leftover piece of 1 1/2" coosa from the transom and bedded it in with thickened epoxy, then used the 4" or so stainless backing plate that came with the new bow eye.

 

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