bigcol Posted April 30, 2019 Report Share Posted April 30, 2019 Hi This forum and its members really does work! Through the forum I now own a beta 90hp engine it is keeled cooled, so I will need a engine room skintank what size minimum should this be made I have got space along one side under waterline which is long 1.5 mtr approx by 500mtr but what size the tank please? lenght x width x depth be nice not good on calculations etc also can this be welded tacked whilst in the water, as it would cost a lot lot for craning.due to getting crane in also who makes skin tanks ? looking for a fabricator any names prices. advanced thanks col Link to comment Share on other sites More sharing options...
Alan de Enfield Posted April 30, 2019 Report Share Posted April 30, 2019 I'm sure I have seen a 'quick guide' mentioned on here previously - something like one-square-foot of surface area per 5hp (or something like) If you do a search you may find it, or, someone with a better memory may come along. 25 minutes ago, bigcol said: 1.5 mtr approx by 500mtr I know its a big boat, but - Really ? Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 30, 2019 Report Share Posted April 30, 2019 1 sq ft of one side surface area per 4 hp as long as the tank is baffled to force the coolant to zig zag through the tank. Minimum thickness possible, say no more than 1". 90hp divided by 4 = 22.5 sq ft. You will get away with less at canal speed because you will only be producing a few HP, but may boil on a river or at sea. Skin tanks are not normally a seperate add on feature. Welders make then in situ. You can have two tanks if needed. They are usually put on the inside of the hull but can be put on the outside. You might also consider keel cooling pipes around the swim but the same area will be needed. Talk to Kedian of this forum but he may not travel to your location. Link to comment Share on other sites More sharing options...
bigcol Posted April 30, 2019 Author Report Share Posted April 30, 2019 (edited) 13 minutes ago, Tony Brooks said: 1 sq ft of one side surface area per 4 hp as long as the tank is baffled to force the coolant to zig zag through the tank. Minimum thickness possible, say no more than 1". 90hp divided by 4 = 22.5 sq ft. You will get away with less at canal speed because you will only be producing a few HP, but may boil on a river or at sea. Skin tanks are not normally a seperate add on feature. Welders make then in situ. You can have two tanks if needed. They are usually put on the inside of the hull but can be put on the outside. You might also consider keel cooling pipes around the swim but the same area will be needed. Talk to Kedian of this forum but he may not travel to your location. Thanks Tony , so 22.5 sq feet, I’m a thico lol, what does this mean in lenght x width x inch or inch and 1/2 please? Thankyou for your post, really appreciated. 17 minutes ago, Alan de Enfield said: I'm sure I have seen a 'quick guide' mentioned on here previously - something like one-square-foot of surface area per 5hp (or something like) If you do a search you may find it, or, someone with a better memory may come along. I know its a big boat, but - Really ? Lol .5 of a mtr ? ? ? i must try harder. imagining members seeing my new posts, think OMG here we go!!!!!. The Beta has 12v alternators, as members are aware my boats dusted is 24v. is there a step up joby 12v to 24v thingy? col Edited April 30, 2019 by bigcol Link to comment Share on other sites More sharing options...
Alan de Enfield Posted April 30, 2019 Report Share Posted April 30, 2019 (edited) 7 minutes ago, bigcol said: Thanks Tony , so 22.5 sq feet, I’m a thico lol, what does this mean in lenght x width x inch or inch and 1/2 please? Thankyou for your post, really appreciated. Example 3 feet x 7 feet would be 21 square feet 10 feet x 2.5 feet would be 25 square feet It would appear that : 50 minutes ago, bigcol said: I have got space along one side under waterline which is long 1.5 mtr approx by 500mtr Is not going to be anywhere near big enough It is (approx.) 4 feet x 1.5 feet so only gives you 6 square feet. You need something like 4x the size you seem to have available. You may have to consider getting her (IT) lifted out and external cooling tanks fitted. Edited April 30, 2019 by Alan de Enfield Link to comment Share on other sites More sharing options...
Tony Brooks Posted April 30, 2019 Report Share Posted April 30, 2019 .It means length x height must = 22.5 sq ft. That is for just one side, ignore the other. Also ignore the thickness. so say 2ft heigh by 10.5 ft long. Link to comment Share on other sites More sharing options...
alan_fincher Posted April 30, 2019 Report Share Posted April 30, 2019 As said 1.5 metres by 0.5 metres is only 0.75 square metres, or about 8 square feet. If well designed and well baffled, that might be adequate for a 30HP engine in a canal boat, but to make actual use of 90HP, you will need around 3 times that size. (People will come up with slightly different answers depending on which "horsepower per square foot" figure they choose to use, but this is in the right ballpark). Is this a canal boat, and why on earth would you want an engine that size in it? Link to comment Share on other sites More sharing options...
David Mack Posted April 30, 2019 Report Share Posted April 30, 2019 3 hours ago, bigcol said: also can this be welded tacked whilst in the water, as it would cost a lot lot for craning.due to getting crane in Blackrose had a second skin tank welded in while the boat was in the water. There is a thread about it on here somewhere. Link to comment Share on other sites More sharing options...
bigcol Posted April 30, 2019 Author Report Share Posted April 30, 2019 (edited) 7 hours ago, Tony Brooks said: .It means length x height must = 22.5 sq ft. That is for just one side, ignore the other. Also ignore the thickness. so say 2ft heigh by 10.5 ft long. Thanks all have spoken to keidian Martin, no way he could fit one big enough it will have to be fitted outside £785 for the skin tank 1800 for cranes, plus fitting etc. so have been on to Beta and can convert to raw water, for pump and heat stack(radiator) £700 or at worst £1150 for complete new radiator pump and bits the boat originally is set up for raw water cooled so I’ve done it again Co; Edited April 30, 2019 by bigcol Spelling Link to comment Share on other sites More sharing options...
bigcol Posted April 30, 2019 Author Report Share Posted April 30, 2019 totaly got this wrong im imagining 1 ft wide, and 22ft long just seems impossible doesn’t it lol so if anyone’s don the opposite with there engine,, and wants to sell me the raw water parts please contact me!!!! all the best col Link to comment Share on other sites More sharing options...
Alan de Enfield Posted April 30, 2019 Report Share Posted April 30, 2019 16 minutes ago, bigcol said: the boat originally is set up for raw water cooled Have you still got a raw-water pick up thru hull fitting ? (maybe with a sea-cock) - hopefully not welded up, which would entail a lift out. Link to comment Share on other sites More sharing options...
Phoenix_V Posted April 30, 2019 Report Share Posted April 30, 2019 Are you on the GU? a raw water system might pick up a lot of muck. I think there are cheaper places to get lifted out depending how far you will travel. Link to comment Share on other sites More sharing options...
GUMPY Posted April 30, 2019 Report Share Posted April 30, 2019 (edited) 1 hour ago, Phoenix_V said: Are you on the GU? a raw water system might pick up a lot of muck. I think there are cheaper places to get lifted out depending how far you will travel. Having run indirect raw water cooling on the GU for the last 17 years, neither of my systems picked up much muck. As a matter of course I would rinse the fine filter daily but there was never much in it. Only twice has a system got slightly blocked both times on the River Brent. After a couple of months on the mooring one year I did find a crayfish about 3" long in the fine filter, must have come in as a larve and got halted by the fine filter. Edited April 30, 2019 by Loddon Link to comment Share on other sites More sharing options...
WotEver Posted April 30, 2019 Report Share Posted April 30, 2019 1 hour ago, Phoenix_V said: I think there are cheaper places to get lifted out depending how far you will travel. With no engine I guess Col doesn’t want to travel very far... Link to comment Share on other sites More sharing options...
bigcol Posted April 30, 2019 Author Report Share Posted April 30, 2019 4 hours ago, Alan de Enfield said: Have you still got a raw-water pick up thru hull fitting ? (maybe with a sea-cock) - hopefully not welded up, which would entail a lift out. Yes Alan still got all the raw water sea cocks, so no no need to drill holes, got inlet and outlets exhaust col 1 hour ago, Phoenix_V said: Are you on the GU? a raw water system might pick up a lot of muck. I think there are cheaper places to get lifted out depending how far you will travel. Can’t travel haven’t got a engine! there is a site crane here, but it won’t lift the weight col 1 minute ago, WotEver said: With no engine I guess Col doesn’t want to travel very far... Crossed over lol same time posting it lol Link to comment Share on other sites More sharing options...
WotEver Posted April 30, 2019 Report Share Posted April 30, 2019 4 hours ago, bigcol said: totaly got this wrong im imagining 1 ft wide, and 22ft long just seems impossible doesn’t it lol Or 2ft wide and 10ft 6” long Or 3ft wide and 7ft 6” long Or 4ft wide and 5ft 7” long Or one on each swim, each 3ft wide and 3ft 9” long etc. Link to comment Share on other sites More sharing options...
Phoenix_V Posted April 30, 2019 Report Share Posted April 30, 2019 2 minutes ago, bigcol said: Yes Alan still got all the raw water sea cocks, so no no need to drill holes, got inlet and outlets exhaust col Can’t travel haven’t got a engine! there is a site crane here, but it won’t lift the weight col Crossed over lol same time posting it lol 3 minutes ago, bigcol said: Yes Alan still got all the raw water sea cocks, so no no need to drill holes, got inlet and outlets exhaust col Can’t travel haven’t got a engine! there is a site crane here, but it won’t lift the weight col Crossed over lol same time posting it lol Sorry did'nt realise, what happened to the last one? From the comments raw water may be the way to go, I think 90hp is about the limit for skin cooling without the engine room getting uncomfortably hot. If you did decide to go for skin tanks I suppose you could connect the new engine to the existing tank and motor slowly to a more suitable place for craneage/drydock. I know it is a wide beam but I cannot see you ever wanting full power on the GU apart from when aground of course. Link to comment Share on other sites More sharing options...
Mad Harold Posted April 30, 2019 Report Share Posted April 30, 2019 1 hour ago, Loddon said: Having run indirect raw water cooling on the GU for the last 17 years, neither of my systems picked up much muck. As a matter of course I would rinse the fine filter daily but there was never much in it. Only twice has a system got slightly blocked both times on the River Brent. After a couple of months on the mooring one year I did find a crayfish about 3" long in the fine filter, must have come in as a larve and got halted by the fine filter. Yes,I rinse the inlet strainer after a day's cruising,and generally there is not much in it .However depending on the time of year and certain canals, ( like the Peak Forest in Autumn) blockages sometimes happen. It is no great issue,because well before the temperature gauge registers a rise,the water outlet ( a constant flow ) starts squirting intermitently. Link to comment Share on other sites More sharing options...
ditchcrawler Posted April 30, 2019 Report Share Posted April 30, 2019 Biggles who used to frequent this list built a very big md box/ strainer for his boat https://boatbuildblog.blogspot.com/2012/03/mud-box-mods.html Link to comment Share on other sites More sharing options...
bigcol Posted May 1, 2019 Author Report Share Posted May 1, 2019 (edited) On 30/04/2019 at 09:51, alan_fincher said: As said 1.5 metres by 0.5 metres is only 0.75 square metres, or about 8 square feet. If well designed and well baffled, that might be adequate for a 30HP engine in a canal boat, but to make actual use of 90HP, you will need around 3 times that size. (People will come up with slightly different answers depending on which "horsepower per square foot" figure they choose to use, but this is in the right ballpark). Is this a canal boat, and why on earth would you want an engine that size in it? I kept watering it, splashing soap on it and it kept growing. Edited May 1, 2019 by bigcol 2 Link to comment Share on other sites More sharing options...
Alan de Enfield Posted May 1, 2019 Report Share Posted May 1, 2019 Yup - who'd want a sewer tube on a muddy ditch when something like that's available ? Link to comment Share on other sites More sharing options...
bigcol Posted May 1, 2019 Author Report Share Posted May 1, 2019 I have tried to put new boat on profile pic, but when I try the file is too big? Link to comment Share on other sites More sharing options...
ditchcrawler Posted May 1, 2019 Report Share Posted May 1, 2019 2 minutes ago, bigcol said: I have tried to put new boat on profile pic, but when I try the file is too big? Well resize the photo, I use AxiomX PicSizer Link to comment Share on other sites More sharing options...
system 4-50 Posted May 1, 2019 Report Share Posted May 1, 2019 4 hours ago, Alan de Enfield said: Yup - who'd want a sewer tube on a muddy ditch when something like that's available ? Me for one. 1 Link to comment Share on other sites More sharing options...
Stephen Jeavons Posted May 2, 2019 Report Share Posted May 2, 2019 Back to the topic (sort of). What is the maximum RPM anyone has had to use on various rivers to maintain a reasonable canal-like speed? I realise prop-pitch has a bearing on this. Just curious. Link to comment Share on other sites More sharing options...
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