Protecting copper pipe

[snowleopard]

I have a fair bit of copper pipe on board - gas lines, fuel lines etc. They all seem prone to corrosion with the surface going green and flaking. I recently replaced a section of gas pipe and on the fitter's advice coated it with varnish. Less than a season later that had also gone green and the surface flaked off.

I have had a couple of fuel lines develop pinhole leaks, possibly as a result of being covered with self-adhesive carpet and now my fridge has lost its coolant, possibly as a result of the pipe between compressor and plate corroding.

What can I coat these pipes with to protect them?

 

[VicS]

Difficult to coat copper. You need a suitable primer for the job. I dont know what that would be these days.

Maybe a epoxy coating direct onto a clean and abraded surface as for aluminium.??? Have to consult the coatings manufacturers websites

Keep out of contact with seawater the first rule I'd think.

Maybe use plastic coated pipe.

 

[Ubergeekian]

Maybe use plastic coated pipe.

The liquid side of my car's LPG system uses 6mm copper pipe with a thick plastic coating, for protection and insulation. Would that be allowed on a boat?

 

[markdj]

Use plastic coated copper for gas as I think that may be the requirement now and have fuxings every 8 inches to stop vibration.

Im surprisedt the boat is so damp to have green within a year.

Giving the pipes a rub with a wd40 soaked rag should help.

 

[fastjedi]

I'm sure someone will come along to explain why it is a bad idea but ....
I installed a 10mm underground copper oil pipe (tank to boiler) at home in 1999 and removed it in 2007 when we built an extension. It was coated in petroleum jelly + passed through an old hosepipe. Looked like new when removed.

 

[electrosys]

I guess you could run the pipe through some adhesive-lined shrink-wrap - but you'd still have the joints to deal with.

 

[snowleopard]

Im surprisedt the boat is so damp to have green within a year.

It's the bit that goes through the gas locker which is of course ventilated and drained to the outside.

 

[Deleted member 36384]

Corroding Copper

Just an observation - I had some sections of copper fresh water pipe which had to be replaced at the start of the season (freezing and burst pipes). The pipes were probably no more than domestic quality if that is relevant.

One section was almost paper thin and the copper came away in large, curved but thin flakes that were more reminiscent of iron oxide rust. There was an obvious distinct pink colour to the remaining copper.

The worst section was a vertical length in the back of a cupboard that was firmly secured in the corner i.e. wood on two sides. The cupboard was under the sink but dry, well above the bilge and no where near the batteries.

This is the first time I have ever noticed copper deteriorate like this.

 

[vyv_cox]

Denso tape has incredible anti-corrosion properties. I have seen ferrous pipework submerged in the North Sea for months emerge bright and shiny after being wrapped in it. The starter motor of my windlass, also ferrous, is wrapped in it with great success.

Its problem is that it is very greasy and not something you would want to handle. I wrap mine in polythene and adhesive tape.

Many builders merchants seem to stock it, or it can be bought on-line.