Heat Exchanger Guy

Not neccesarily, this kind of market research takes place all the time. In the last year I took part in one for Saros Research (Go and register on their site) which was about selling on Ebay. We arranged a time and met in Birmingham, I turned up, gave them my name, they gave me an envelope with £50 cash and said "we'll call you through soon, help yourself to drinks and food while you wait". They called us through, about 6 or 8 in the group, we answered questions in an informal group discussion for an hour and a half (with another plate of food and drinks in front of us!) and then went home and never heard anything back, no "now we need you to..." or "would you be interested in".... the only thing I have heard back is invitations to more research events. Personally if I were a boat owner, I'd take them up on this offer, If you're in doubt just make sure they give you the cash before you start your "interview".

Have you tried ASAP Supplies? http://www.asap-supplies.com/

Shame to see the trees being destroyed :-(

I guess it is easy to underestimate the dangers of the canals and rivers some times, I imagine that most people who aren't farmiliar with boating wouldn't think to have a check list of essential parts.

Flat plate heat exchangers come in two varieties, brazed plate (usually full stainless steel construction and used in food processing, pharmaceuticals and beverage production) and gasketed or bolt-up plate (often found on power generation and district heating systems) The problem with brazed plate is that they have very narrow channels and can't be taken apart for cleaning so should only be used with very clean/filtered water, a gasketed version can be dismantled but even the smallest designs are generally too big for narrow boat engines and can be expensive. If cooling with raw water then it is always best to use a shell and tube heat exchanger as their design makes them far more practical to use in this environment. They are made from materials which prevent them from corroding and can be easily taken apart for cleaning. Some marine engines do have plate exchangers attached but they themselves will often be connected to an off-line shell and tube cooler to provide a clean cooling water circuit. For more information, just ask or click on the link in my signature to see our website.

Assuming it isn't the Thermostat as Laurie suggested then it could be an air lock. As stated above some details about the engine may be beneficial.

As a competitor to Bowman I should be saying buy one of our (Thermex) coolers instead ;-) But not everyone has the means to do this, so you could try using a pipe cleaning kit made specially for the heat exchangers which can be supplied by Easy Products Ltd (No affiliation to us or Bowman) http://easyproductsltd.com/tube_cleaning.php If you give them the part reference of the Bowman cooler you have then they may be able to advise the best kit to use based on that. There are several cleaning fluids available, be careful if you go down this route and some fluids have a negative effect on the materials. A Caustic solution for example will dissolve the aluminium baffles if is dipped.

Catweasel, the header tank in the pic has a groove for an O Ring within the body which forms a seal against the filler neck when it is placed in to position and screwed in to place. If you use a Gasket (traditional or liquid?) then you should be able to get a good seal against the flush flat base of the filler neck. The bolt threads can be sealed with something like Loctite (http://www.loctite.co.uk/homepage.htm) which you can usually get from a local James Listers, Screwfix and other trade shops if you haven't already got any.

They can be bought online here from Thermex (Located in Redditch, UK) http://store.thermex.co.uk/filler-neck---flange-22-p.asp The pic shows a CAD model but they do exist and are aluminium, just check the dimensions to make sure it will fit.

A Marine Heat Exchanger usually has curpo-nickel (commonly 90/10) internals with/or bronze and gun metal for the raw water circuit. This is an effective conductor and provides resistance against erosion. Stainless steel can be used in some instances although not all grades are suitable for raw water but this really depends on where the boat is being operated. It can also be an expensive alternative so a heat exchanger built specifically for a marine engine is the best option, you could also talk to a Lister Petter dealer who may have come across the same problem before such as; Marine Engine Services - http://marineengine.co.uk/ Sleeman & Hawken - http://www.sleeman-hawken.co.uk/ Hope this helps,