vasya

Steve-H71 If you like working by your hands, you can buy small elecric household water heater like ~20 liters volume and throw away the electric heater. Instead of him you need to install a copper spiral from the plumbing store or air conditioner store. The spiral you need connect to engine cooling system. It will be safe! Sorry for my language, english is not my native.

Yesterday I tested my engine cooled only by tube (50 mm X 3 meters) with ~2100 rpm of speed. After 40 mins the temperature of coolant was 72 degrees. But water in river still cold, recently freed from ice. The boat was tied to the pier. In this case, more power is required than when the boat is moving. The propeller is 560 mm diameter and 420 mm pitch.

This tube is 3m long and 50 mm diameter. And i have four tanks on skin inside the hull, two 300x600 mm and two 300x400 mm, but this tanks still not connected to cooling system. The boat is: http://canalworld.net/forums/index.php?/topic/67424-skin-tank-design/#comment-1332211

I have the place 0,53 quad meters of heat exchange. The engine power is 49 hp at maximum speed 2500 rev/min, the cruise speed is 1600 rev/min and power is ~28 hp.

Hi, Neil. It's not my engine on movie. I have the outboard tube for cooling. I do not have a sea water circuit. I need to install the oil cooler of hydraulic gearbox in my cooling system. The oil cooler must be fitted first after exit of cooled antifreeze behind the board from outboard tube. But I'm affraid that the gearbox may can be overheated because the gearbox must be cooled by river water directly. After I do it I try to test the temperature of gearbox by infrared thermometer.

Thanks to all. I just watched this video since I finished my cooling system. But here the water is supplied under pressure video

Hi there. I installed Perkins 3.152 engine in my boat. The engine is from loader. What is direction of movement of the coolant? From the lower branch pipe of the pump to the thermostat housing or from the thermostat housing to the lower branch pipe of the pump? I have outboard cooling system, is the tube under the water line. Now time i just testing the engine after installation in boat. When thermostat is opened the tube from the thermostat housing to the outside of boat is hot, the tube from outside connected to the pipe of the pump is warm. I was surprised because I always thought that the cold water has to go in the cylinder head because the cylinder head is the most heated part of the engine. I ask because I need to correctly put the heat exchanger of the hydraulic gearbox - to the coolant exit from outside of hull. I'm so sorry for my english. I'm from Russia.

Thank you, blackrose! Originally i wanted to do so. As you can see on picture that you quoted, hull has a longitudinal stringer. So i have several compartments between stringer and engine foundation. Above the stringer i have compartments between waterline and stringer. In the part between the stringer and the engine i can place the box 20x60 cm, and between of the waterline and stringer i can place the box 20x40 cm. 20x40 cm + 20x60cm = 2000 sq cm = 0,2 sq meters in one quadrat between the waterline and the engine. Even for 1,16 sq m i need 1,16/0,2 = 6 quadrates, it is six boxes 20x40 and six boxes 20x60. The boxes must have the covers for opportunities for revision of their condition or repair punctures of skin of hull without lifting the boat up on shore. This covers should be such as in the photo. Because the skin of hull is not straight and look like “U”, the vertical walls of boxes need to repeat this “U”. Therefore, boxes are difficult to manufacture. I tried it to experiment. Imagine how would look the floor in engine room with 12 boxes and their pipes? I could not get down there.

Thank you, BEngo! My old skin of the hull had many of dents between quadrat from front until mid of hull. In some places, even the frames were bent by skin sheets inside the area of hull. But I do not know whether it was during use me or the previous owner. Once the boat was lying on a stone seawall because of a sharp drop in water level. That's why i am afraid of damage of skin tank. About the big waves - i just have a picture of the same body as mine in the big waves. Actually on our inland waterways we have only three big lakes in all of country where there are sea sailing conditions. Even on large artificial reservoirs formed due to the construction of large dams are floating riverboats. Sometimes when the wind blows along such reservoirs, floating of small or unsuitable boats may be prohibited. I know that in UK you have small canals and rivers, therefore you have a long and narrow boats named “narrowboats”. In Russia we have a rivers that larger than UK canals, but are not navigable.

Yes, i did not understand what you're talking about a distance of 20-25 mm between hull and sheet of skin tank. It is good height of skin tank. Do you really think that if i have ribs with 50 mm between them the skin tank will not be damaged? What do you mean by spacers? If it the steel strip or several strips of 12 mm thick (fig. 1) it is very good for active corrosion. Corrosion occurs very active between two osculating strips of metal that are parallel. Such corrosion is much faster than just a piece of unpainted metal in the water. Paint between the stripes is impossible. If like in fig. 2 i think this is not so strength. Thank you for your welcome. This is 34 years old fishing boat. Box into the back of hull is made by myself. This hull is optimal for me, because i can boat on rivers and goes to the big artificial lakes with big waves. The hull can carry waves up to 1.5 meters. In this pic you can see hull like mine on Baikal lake, this is so far away from me. I use my boat on river named Oka, it is located 100 km south from Moscow and connected to Volga river.

I have seen construction of skin tank inside of hull on this forum. Unfortunately it’s impossible for me: the hull have a developed ship framing. In this picture not my boat, but same as mine. It would be very difficult to hermetically weld skin tank on frames from metal corner. And i cannot cut the frames for skin tank - this will weaken the strength of hull. Thank you, BEngo. If 20-25 mm of thickness then height of tank will be big, because i have to keep the flow section of pipes of the engine. Diameter of pipes is ~40 mm, then square of pipes is 1256 square mm, if thickness will be 25 mm height is 50 mm, it very high. Tubes is not good solution because they can be damaged or torn off from hull. Sometimes in river i meet sandy or clay shallows. Tubes have a small contact area with hull and can not be firmly welded to hull. I guess if i meet shallow when the boat is moving tubes can be torn off or flattened. I was thinking to cut the tubes in half lengthwise, this will increase the strength of tubes and reduce the area of heat exchange. Small spacers between the tube and the hull will greatly enhance corrosion between the hull and the spacer - fitted to each other strips of metal is very highly susceptible to corrosion. After this i thought that it will be easier to use metal corner instead the tubes.

Hi all. Sorry for my bad english. I write here from Russia. I find this forum by “skin tank water cooler” request in google. I replaced underwater skin on my boat. Simultaneously with this i installed other diesel engine. This is engine from loader and have only fresh water circuit. Given this, as well as operating conditions (fast flowing shallow river with a sandy bottom. When i have old engine with two circuit cooling system, sometimes i got sand filled heat exchanger), i decided to make a keel cooler or skin tank outside of hull. For my engine 50 h.p. i need 2,5 square meters surface of heat exchange. The easiest way for me to do a skin tank by size 1x2,5 m or something in the location shown on this pics: But i fear that this skin tank can be damaged during a stop at the shore. As i wrote above the river is fast and shallow. As the boat approaches the shore and stay, hull all of his weight lies on coastal shoal. Hull touches the bottom of the river just the place where i wanted to weld a skin tank. I'm afraid that it just crumple when i come to the shore or by waves from another boats which will pass near me. The hull always touches the bottom of the river in the stay point. You can see a typical place of rest on this picture: As you see the place of installation of the skin tank “lies” on the bottom. To make a skin tank in the rear of the hull IMHO is impossible because the hull has a complicated forms. Best solution would be use the metal corner welded it to the hull. Metal corner is never been damaged. To get the necessary area of cooling i need use length… 11 or 12 meters of metal corner 60x60 mm… So i need weld six pieces of corner of two meter long disposed one above another. I guess it would be difficult connected to each other. You have a lot of experience using skin tanks. My question is: what do you think if i make skin tank with many ribs, which i weld perpendicular between hull skin and skin tank cover? Maybe it protect skin tank from damages? Ribs will divide skin tank to many sections – it will be better for cooling. Thickness of the hull plating is 4 mm, the thickness of the cover may be the same. Boat weight is between 8-9 tons. Many thanks for your advice.