Draining skin tanks and engine. Suggestions needed.

[Bugsworth Tippler]

As my Bukh engine is overheating and the problem could lie with the efficiency of the cooling by the skin water tanks I have decided to flush the water system. I plan to use Radflush.

The lowest part of the system would be the lower outlets of the skin tanks which are only 3-4 cm above the base of the boat and therefore it would be rather difficult to put much of a container underneath. I would like to avoid flooding the engine compartment when I drain the system.

Has anyone got any clever ideas as to how this might be done with the least amount of water escaping into the boat?

Suggestions welcome.

[nb Innisfree]

I installed a tee fitting on the skin tank bottom hose. branch was fitted with a valve and hose barb, a vacuum oil changer draws coolant out via hose barb.

[pearley]

My skin tanks are huge! Around 20 gallons I measure. Draining them via a vacuum oil changer would take a little time!

[Robbo]

Wet and dry vac, start on the top hoses. If you break the seal on the hoses with the nozzle of the w&d vac close by all the water gets sucked up!

 

In addition most w&d can blow as well, open a top hose into a bucket or overboard and put the nozzle from where the hose came from so it blows the water out. May need some rags to fill the gap between the nozzle and whatever as well.

 

 

Edit to add, overboard? Ofcourse I mean containers as coolant shouldn't go in the canal.

Edited July 28, 2014 by Robbo

[Robbo]

My skin tanks are huge! Around 20 gallons I measure. Draining them via a vacuum oil changer would take a little time!

If you had a tee valve you can always use a pump like a drill pump or whale gulper.

[pearley]

If you had a tee valve you can always use a pump like a drill pump or whale gulper.

Actually my skin tanks sit on the base plate and form the engine bed. At present the coolant is as clean as new but when the time comes when I need to change it I think wet and dry vacuum will probably be better than a pump. Besides, I could never get the drill pump I once bought to work.

[p6rob]

Invest in a wet and dry vac. Any other way will be slow and laborious and you'll still spill lots onto your baseplate. When you put it back together it would be a good time to add drain taps to the lowest points.

 

The drill pumps need priming before they'll work. I found it too difficult to get the pump head low enough to prime without risking liquid contact with the (electric) drill so gave up on that idea.

[Sir Nibble]

Connect pipe to outlet and feed to waste container and not in the least bit just hang it over the side no sir. I would dump it on the towpath but there you go.

Drill hole in old filler cap and fit valve from tubeless tyre.

Fit old cap with valve.

Inflate with bicycle pump.

 

Alternatively.

Dump in bilge,

Connect waste pipe to bilge pump outlet,

test bilge pump.

My drill pump works extremely well including self priming. In fact, it sucks.

[Bugsworth Tippler]

Thanks for all those comments. I'll look into a Wet and Dry Vac. I must admit a drill pump I had some time ago didn't work either so I might try another now I know about priming it.

[Bugsworth Tippler]

A cut down 5 litre plastic bottle was placed under the lower skin tank connection and a 12v bilge pump placed in it. As the hose was eased off, the bilge pump took the escaping water into a bucket. When the bucket filled the hose was pushed back on. This worked quite well with very little spillage.

 

As the water in the skin cooling tanks was clear with little sign of any sediment I decided not to use Radflush on the entire system, fearful it might do more damage than good.

 

An infrared hand-held remote thermometer has proved very useful in showing that the cooling system now seems to be working as it should and the engine, so far, has not been getting too hot. The oil pressure gauge gives a much higher reading since I cleaned the 40 year old DVO pressure sensor.

 

There may have been a lot of air in one of the skin tanks. Due to ignorance it had not been bled for 25 years! This may have reduced the cooling water flow through the engine. Certainly the water pump impellor had a few missing/cracked blades and was replaced. Whatever my problems were, I am optimistic that they are close to being sorted. I would like to thank Nick and Steve from T W Marine who have been extremely helpful and have rewired my control panel so it is now 'how it should be'.