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TITAN 21'6'' ALLOY UPDATE this are some pictures on my progres ,spend 2 monts building my
doors/windows/and portligths from scrap saiving$4000aus dollars,playting soon be finish
then welding start on the hull, i maiking windows with lexsan and the central on the pilot house
on taffen/glass ,round corners are more nice on a tug ,but time is taiking on fabrication costum made
exstrutions,thanks to the prffecional advice of (KEVIN MORIN) a grate help to the metal builders,


cheers CARLOS BAIRO

Carlos, I'm sure everyone would enjoy and benefit from an article describing how you made your own very nice looking windows for your Titan project. You mention working in scrap then a custom extrusion, I'd be very interested to see your work up close and learn more about your windows first hand.

Glad that you're progressing nicely and the hull looks like its ready for some welding and a roll over?

Cheers
Kevin Morin

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Kevin Morin

Kevin,thanks for your support, my writing in English is very poor but i will
do my best to explain the method i used. All the windows were made on
a plywood gig ,through round corners cut from sheet of 3mm alloy,welded to 1''flat bars to form the frame exsterior ,then kept clamp on the gig ,the
outside frame made on 5083 grade,the glass/lexan frame made from
10x10x2mm chanal 6060 alloy soft to bend on a gig pipe of the radius
of the main frame,the pipe should be cut only half way of the diameter
in order to fit the chanal tonge ,2 cutsx2mm leaving 6mm space,the
bigger the radius the easy to bend ,the door made the same way but
the door frame i used a z exstrution and making corners a z from flat bar 1''x3mm and 3mm sheet hope this will give you the idea kevin ,and all
the builders on the forum to saving $$$$ cheers CARLOS BAIRO

kevin,,, i forget to descrive the portlights constrution on may windows
fabrication, theare more easy to making if are fixed ,cating the frames
from 5083 grade seeht alloy then 1''flat bar weld forming a T frame ,
to fit the lexan ,rivet/screw,then silcaflex ,this sistem only on
lexan/perspec windows ,
ps i used lexan on all my windows ,the only one a taffen glass to fit
the wiper on the central forward pilot house .


cheers CARLOS BAIRO

Carlos,

Dry exhausts in an inboard installation are longer lasting than wet (water injection mixture cooling) but do come with additional problems for the smaller size vessel. Even a vertical riser can radiate great amounts of heat if the pipe is uninsulated. So at the very minimum a vertical trunk with an insulated riser and air flow around the insulation bundle is required in most small inboards with dry exhausts.

Most commercial boats, rarely this size, have their exhaust 'blankets' begin at the end of the jacketed marine manifold and continue over the flex joint, along the pipe all the way up the stack or trunk to the top of the cabin. Some exhaust trunks are so large in comparison to the pipe that there may be 12" of clear air all around the pipe- where a 3" riser is centered in a 24" square duct/trunk/stack housing. If the engine room vents up the this size of opening and that vertical housing is open at the after end of the top in a grill or louver- the heat radiated off the pipe will create a very high air flow upward from the engine room and out the trunk top louver/vent grill. These risers are not insulated as the heat radiated is carried away by high air flow.

On the other hand, if a pipe rise will be housed in a 2x or 3x sized vertical stack housing, the heat of radiation would convect to the adjoining surfaces and may be "too hot to handle"? That is where the exhaust blankets are applied; where the stack housing/vertical exhaust enclosure is not large enough to tolerate the radiated heat from a bare exhaust pipe, but there is room for a blanketed riser.

The best possible method is to 'jacket' the pipe system. If you have time and energy - using the next size or two size large pipes and weld a entire double wall or jacketed system for the entire exhaust piping run. Then inject this jacketed area with sea water or included it in your keel cooler system to eliminate the heat. If your system will be mainly a J or and L shaped system, where the exhaust comes off the after end of the engine's jacketed manifold, and turns up to a riser, and then a top stack out of the tug's stack trunk; then jacketing the riser and parts is not as much work. At each flange the jacketed system has a tube/pipe/hose or two to carry the coolant over the flange joint to the next section of jacketed wall pipe.

Keel cooling a metal hull is surprising easy, especially in aluminum. The keel cools can be located in many different places on your hull and perform well. One very successful location is at the joint of the keel to the hull. By placing a plate at 45 degrees between your keel and the adjoining hull and welding at the edges continuously to the original hull materials, you will create a void that has a large surface area exposed to the water.

By pressure testing this void to 20-30 psig (1.4kg/cm^2, 2.2 kg/cm^2) you will have a pressure containing void that will stream line the hull between the keel shape and hull, hold the coolant for a small engine and in most cases is adequate radiating and conducting heat sink to operate the engine on the trailer-without being in the water.

Other methods are to pressure test the keel, using a portion of that volume as a keel cooler housing, however, you may have to have that ballasted so it may not have the free volume for keel cooling? Half pipes can be welded along the inside or outside of the hull, angle shapes are also used for this purpose on planing boats. Outside the the hull, shapes create more drag but offer greater (relative) surface area to be cooled and are therefore shorter in length. Inside the hull longer runs are needed (compared to outside the hull) to dissipate the same heat and the added inconvenience of intersections with the structural framing means much more labor and much less simplicity in the entire installation unless they were planned from the initial design to contain pressurized liquids?

Last but not least are "seachest" type keel coolers where a pan or shallow box shape of metal is inverted onto the inside of the hull and welded. These usually have a series of baffles that force the water to meander or follow a very long involved path like a maze or labyrinth to expose the hot water to the hull over the maximum distance of travel, and cooling, before the water/glycol comes back to the engine coolant pump at the suction side.

Depending on the hull's framing, all interior fitted cooling elements are more work than exterior since the welding access and work of fitting the cooler's parts intersects with framing instead of being out side on smooth hull. I'd suggest you look carefully at the joint between the keel and the hull and discover if a 4" wide bar/plate could be laid along that joint to form the keel cooler?

At both "ends" (liquid in & liquid out) of any keel cooler will be a welded fitting usually threaded. I use 1/2 of a pipe coupler of aluminum TIG welded to the hull/cooler wall and thread SS hose conversion fittings into those welded fittings. These fittings also give the method of connecting the pressure testing fittings and allow maintenance of the keel cooler hoses or valves.

Hope this helps with your planning? If you need sketches or more details about one part of these remarks please let me know?

Cheers,
Kevin Morin

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Kevin Morin

kevin,,,
i have to decide weare to fit the kooler,inside or outside beafore turn the hull,
the space between frames 2'1'' x10''between longitudinals i think to small for a box kooler,
the idea of 4'' bar look more appropiate and i think that could be fit brtween frames inside.
i need to know the aprox length of the kooler and if will be port& starboard build.
to make the sistem outside of the hull it will be more easy but my consern is with drag and
banged's the playting on titan bottom is 1/8'' in order to reduce weigth i make longitudinals
4mmx40mm T to kept the strength of 3/16'' playting bottom, this is to give you the idea to
help my with a design sketch that you think is more suitable for my progect .
kevin i have no idea of keel coolers dimensions o constrution,on the other hand on insulation
more confident ,i have been followed your article's on the forumn's thanks for you valuable
knowledge. cheers crlos bairo

Carlos,
http://www.metalboatbuilding.org/phpBB3 ... f=53&t=323 this link goes to a discussion similar to ours here.

A general rule of thumb is to provide about 1.5 ft^2 per 10 horse power or 1 meter^2 per 30 kw engine power as a guide for designing the cooling surface area in a displacement hull. A 4" wide plate will give 1 ft.^2 in three feet of cooler length. A 100 hp engine will need 100hp/(10 ft.^2/hp)= 10 ft.^2 [10ft^2 x 3' length/ft.^2 = 30' total length] 15' per side of the keel,

or; increase the face plate to 6" width? now 2 (linear) ft. of cooler length gives 1 ft.^2 of area so the 10ft^2 x 2ft. length/ft.^2 = 20 ft. total length = 10' per side. With some air cooling inside the hull, and an expansion tank at the top of the engine's cooling circuit this should be more than enough cooling- even in warm cruising waters.

The angle of the plate between the keel and the hull does not have to be 45 degrees, the angle could be greater and still have the same surface to the water- and the hull adjacent the cooler will conduct heat away from the cooler as well.

By placing the cooler between the keel and hull you will not increase drag; you will reduce it by streamlining/filling that joint's hollow space, the added area- of the cooler's surface- is not significant compared to the overall wetted area of the hull.

There are sketches of the suggested cooler layout in the link above. 1/8" plate is fine for this application and the keel cooler as an outside plate over the keel to hull weld will give the added benefit of allowing that hull weld to be pressure tested! I would avoid using hard pipe to connect the coolers from side to side, as discussed in the link, as hose is more flexible and less subject to thermal stresses from contraction and expansion when heating and cooling with the engine coolant.

I'd suggest internal fittings, inside the hull, on the walls of the keel or flat of the hull plates near the keel joint-at the both ends of each 'void' which have been created outside the hull and keel joint. The after pair of internal fittings are used to allow coolant flow from side to side while the forward set are inlet, on one side, and outlet(pump suction) on the other side. I suggest you include a small (welded on) tapped block at the after lowest point of each void or cooler under the hull. In each tapped block, I would install a flush head hex socket recess pipe plug to seal the coolers but allow them to be drained and flushed if future maintenance required.

A further benefit is the keel to hull joint would become 'reinforced' by the addition of the keel cooler plate which will work to increase the weld area between the two plates and thereby reduce the stresses in all the joints in that area.

Cheers,

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Kevin Morin

kevin''' thanks for you information,i will make the keel kooler acording
to the detail's that your advice me,
the length of the kooler will be 100mmx3mt/1.5mt on each side .
2x1/2pipe welded flat on the keel conecting the void's.
the zize of the kooler will be suffice for a 25hp to 30hp
cheers carlos

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