Restore and Rebuild 74 Mariner 18? ( We Have The Technology )

ctriverfish

Petty Officer 2nd Class
Joined
Apr 16, 2012
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109
Ok so for 2 years I?ve been looking for a boat. ? Starcraft CC? Always find them but always asking Big $$$$ and always in need of a floor or something. So about 5 weeks ago I found this.
1974 18? Starcraft the boat was striped and the tin on the transom looked like someone shot it with a shotgun. Asking price with trailer $ 300.00
Now the saga begins. LOL
 

ctriverfish

Petty Officer 2nd Class
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Apr 16, 2012
Messages
109
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

So after getting her home this is what I hade.
IMG00040-20120501-1722.jpgIMG00041-20120501-17231.jpgIMG00042-20120501-1723.jpg

First things first What is it ???? Posted some Pics to iBoats and presto Mariner. Thinking what the hel* is that?

Yes you got it iBoats to the rescue. Lots of reading and then more reading. Ok now I know where to start.
 

ctriverfish

Petty Officer 2nd Class
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Apr 16, 2012
Messages
109
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

Started with the transom cut a template, then clean the tin and strip out the splash shield. Took the wire wheel to the transom and it ripped like a wet newspaper. Ok cut the bad out and then see what is left. Then I started thinking ?Wood Transom. No not ME. Being a welder fabricator working with alum for 30 years. Build it from alum, 1? sq tubing and ? ?? plate weld it solid all around; this is what I ended up with. Yes it can hold a small truck; But the 75 HP Suzuki I will power this boat with will never stress it.

IMG00044-20120502-1520.jpgIMG00044-20120502-15201.JPG
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,304
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

nice job I was thinking of the same thing...as we have a big welder at work...but thought for the use of my boat (trailered to just hunt seaducks a few times a year) I didnt want to buy the aluminum .. I had thought that 1/8th sheet on either side would be fine as long as all my holes went through the boxed tube of the frame....other wise the bolts may start to squeeze the sheets together if the hole wasnt right next to a frame memeber. after thuinking of all the possible holes...I just went with 2 layers of plywood... I figure if i need to in 5-10 years, It would only take me a weekend to redo the transom again..

luckily my hull doesnt have any pitting from corrosion....but the rivets were flaking off easily in places...


before you paint that boat go around and tap sideways on all your under water rivets, to make sure they are JUST ABOUT ready to give up the ghost


bob
 

ctriverfish

Petty Officer 2nd Class
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Apr 16, 2012
Messages
109
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

Transom finished and a big hole in the tin??? The fabricator in me took over. Back the cut out with 2” wide 1/8” thick strips of alum. So with a tube of 5200 and closed end rivets and what seemed like weeks “ 4 days “ working for a couple of hours after work this is what I have now. Filled her with water and only 6 rivets on the floor with small drips. Now its on to the splash shield. Drill out the rivets sand blast reinstall. Note to self more rivets lots more rivets. LOL

IMG00045-20120508-1218.jpgIMG00046-20120508-1219.jpg
 

ctriverfish

Petty Officer 2nd Class
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Apr 16, 2012
Messages
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Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

Thank you Bob will do.
 

ctriverfish

Petty Officer 2nd Class
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Apr 16, 2012
Messages
109
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

roscoe: Yes I did and thank you. Its raining here in CT so tonight after work I will draw it up in cad I think it will be alum also. LOL
 

ctriverfish

Petty Officer 2nd Class
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Apr 16, 2012
Messages
109
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

Just finished the print of the CC
sorry the print is not showing up.

conc.jpg
 

64osby

Admiral
Joined
Jul 28, 2009
Messages
6,799
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

ct, Great to see you rescuing a Mariner. That is one awesome industrial transom. Keep up the great work.
 

ctriverfish

Petty Officer 2nd Class
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Apr 16, 2012
Messages
109
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

Well it stripping time. Just stated stripping the Mariner and under all the old paint is a fine mist coat of Zink-chromate primer the yellow stuff. It’s stuck like glue. Stripper will take it off but only after all the other paint is off and a heavy coat of stripper is reapplied and let sit for 20 minutes, then a good sanding will bring her to bright alum. My question is should I try to remove it????
 

Jlawsen

Master Chief Petty Officer
Joined
Apr 22, 2012
Messages
810
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

In the later years they put stringers in them to support the deck and add strength. It's a pretty good upgrade if you want to spend the money and time. You can make them out of 1/16" 5052-H32 and form the lips on a press brake. Cut out for the ribs and weld them to the ribs so they float on the rest of the hull. On boats you never want to weld all around on a three axis contact point or it will become a high stress area and crack.
 

Brak

Cadet
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Sep 5, 2010
Messages
14
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

This thread brings up an interesting question...

Does anybody know the reasoning behind the factory installing a wooden transom in the first place?
I've often thought of doing the same thing with my SS.

I always figured the wood was there to prevent structural damage in the event of an accident, since the wood has a lower shear resistance (for lack of a better word) than the hull....

I guess i'm more curious as to whether there is a downside to adding a more ridgid transom, such as vibration, and whatnot...

Looking forward to more pics :D
 

barato2

Commander
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Dec 7, 2010
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2,956
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

i think the three reasons were cost, cost, and cost. Oh, and labor cost. skilled fabrication and TIG work like what ct did on his transom is really expensive compared to hiring a guy who can run a saw. given the quantities they were buying plywood in, wood transom prolly cost em <$10/boat and was plenty strong. ever heard of the WWII Mosquito airplane*? plywood. Marcos automobiles? plywood.

there is a possibility that the wood will help dampen motor resonances tho. ain't much that does uncontrolled resonance better than thin metal. this is part of the reason i'm coating inside of my hull with durabak, and i even considered gluing in some spare ashalt roofing (poor man's Dynamat)



*http://en.wikipedia.org/wiki/Mosquito_bomber

The oval-section fuselage was a frameless monocoque shell built in two halves being formed to shape by band clamps over a mahogany or concrete mould, each holding one half of the fuselage, split vertically. The shell halves were made of sheets of Ecuadorean balsawood sandwiched between sheets of Canadian birch, but in areas needing extra strength— such as along cut-outs— stronger woods replaced the balsa filler; the overall thickness of the birch and balsa sandwich skin was only 7/16 in (11.11mm). This sandwich skin was so stiff no internal reinforcement was necessery from the wing's rear spar to the tail bearing bulkhead.[60] The join was along the vertical centre line.[61] This split construction greatly aided the assembly of the internal equipment as it allowed the technicians easy access to the fuselage interior.[62] While the glue in the plywood skin dried, carpenters cut a sawtooth joint into the edges of the fuselage shells, while other workers installed the controls and cabling on the inside wall. When the glue completely dried, the two halves were glued and screwed together. The fuselage was strengthened internally by seven bulkheads made up of two plywood skins parted by spruce blocks, which formed the basis on each half for the outer shell.[63] Each bulkhead was a repeat of the spruce design for the fuselage halves; a balsa sheet sandwich between two plywood sheets/skins. Bulkhead number seven carried the fittings and loads for the tailplane and rudder The type of glue originally used was Casein resin, which was later replaced by "Aerolite", a synthetic urea-formaldehyde, which was more durable.[64][nb 8] Many other types of screws and flanges (made of various woods)also held the structure together.[61]

The fuselage construction joints were made from balsa wood and plywood strips with the spruce multi-ply being connected by a balsa V joint, along with the interior frame. The spruce would be reinforced by plywood strips at the point where the two halves joined to form the V-joint. Located on top of the joint the plywood formed the outer skin.[62] During the joining of the two halves ("boxing up"), two laminated wooden clamps would be used in the after portion of the fuselage to act as support.[62][67] A covering of doped Madapolam (a fine plain woven cotton) fabric was stretched tightly over the shell and a coat of silver dope was applied, after which the exterior camouflage was applied.[68] The fuselage had a large ventral section cut-out, which was braced during construction, to allow it to be lowered onto the wing centre-section. Once the wing was secured the lower panels were replaced, and the bomb bay or armament doors fitted.[69]


A closeup of the nose of a B Mk IV showing the clear nose and the bombsight: this view also shows the engine nacelles for the single-stage Merlin 23s and the undercarriage.The all-wood wing was built as a one-piece structure and was not divided into separate construction sections. It was made up of two main spars, spruce and plywood compression ribs, stringers, and a plywood covering. The outer plywood skin was covered and doped like the fuselage. The wing was installed into the roots by means of four large attachment points.[61] The engine radiators were fitted in the inner wing, just outboard of the fuselage on either side. These gave less drag.[61] The radiators themselves were split into three sections: an oil cooler section outboard, the middle section forming the coolant radiator and the inboard section serving the cabin heater.[70] The wing contained metal framed and skinned ailerons, but the flaps were made of wood and were hydraulically controlled. The nacelles were mostly wood, although, for strength, the engine mounts were all metal as were the undercarriage parts.[61][71] Engine mounts of welded steel tube were added, along with simple landing gear oleos filled with rubber blocks. Wood was used to carry only in-plane loads, with metal fittings used for all triaxially loaded components such as landing gear, engine mounts, control surface mounting brackets, and the wing-to-fuselage junction.[72] The outer leading wing edge had to be brought 22 inches (56 cm) further forward to accommodate this design.[70] The main tail unit was all wood built. The control surfaces, the rudder and elevator were aluminium framed and fabric covered.[61][71] The total weight of metal castings and forgings used in the aircraft was only 280 lb (130 kg).[73]
 

64osby

Admiral
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Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

there is a possibility that the wood will help dampen motor resonances tho. ....ain't much that does uncontrolled resonance better than thin metal.

1+ in my non structural engineer opinion, and no I didn't sleep at a Holiday Inn Express last night either, Wood will help dampen any vibration, wood will also flex. This should actually help the transom sheet and the associated fasteners last longer. My .02

On the other hand a Transom as shown if full width and secured properly would probably outlast the rest of the hull.

So flip of the coin maybe.
 

Brak

Cadet
Joined
Sep 5, 2010
Messages
14
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

i think the three reasons were cost, cost, and cost. Oh, and labor cost. skilled fabrication and TIG work like what ct did on his transom is really expensive compared to hiring a guy who can run a saw. given the quantities they were buying plywood in, wood transom prolly cost em <$10/boat and was plenty strong. ever heard of the WWII Mosquito airplane*? plywood. Marcos automobiles? plywood.

Cost makes perfect sense...
I can MIG like a madman, but never could quite get the hang of TIG, despite 3 semesters of trying. The cost of a good Tigger, is well warranted.

Also, cool info on the Mosquito... I'd never heard of that one ;)
 

ctriverfish

Petty Officer 2nd Class
Joined
Apr 16, 2012
Messages
109
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

:) So back to work on this old girl. After what seems like a week of rain I am back at it. Looks like she has 4 different coats of paint on her, Blue, Green, yellow, and the off white of the factory paint. A good coat of primer was put on before each paint color was added. Ahhh a labor of love or is it hate. No it?s a labor of lets get this over, and on to fishing. LOL
IMG00048-20120513-1308.jpgIMG00047-20120513-1307.jpg
 

FishNmemories

Petty Officer 1st Class
Joined
Apr 24, 2012
Messages
272
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

:) So back to work on this old girl. After what seems like a week of rain I am back at it. Looks like she has 4 different coats of paint on her, Blue, Green, yellow, and the off white of the factory paint. A good coat of primer was put on before each paint color was added. Ahhh a labor of love or is it hate. No it’s a labor of lets get this over, and on to fishing. LOL
View attachment 146823View attachment 146824

I hear ya on the fishing...the transom looks good...wow, lots of paint to strip. We are going to get hit with rain here after 2 beautiful weeks of sun...bummer
 

ctriverfish

Petty Officer 2nd Class
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Apr 16, 2012
Messages
109
Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

:mad: Rain Rain go away I would like to strip some paint today. :mad:
 

1973Chieftain

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May 31, 2010
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Re: Restore and Rebuild 74 Mariner 18?

Re: Restore and Rebuild 74 Mariner 18?

I hear ya, but you are making excellent progress!
 
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