Not WM's fault for selling something that is made for use in the fuel systems. But I think the issue is the ever constant choices between being and doing "best" verse just doing "good".

 

This is good info I never knew. I swear, I replaced or repaired quite a few copper fuel lines in my earliest cars, as a kid. Perhaps the issue is how long the fuel remains in contact. In a car, burning a tank or two per week, is it less of an issue? In a powerboat, it may be similar, if the boat is used often (most don't seem to be). Much longer sit time in a sailboat, for sure.

I will have to take a look at mine. The tank is either SS or aluminum. Most of the visible fuel line is hose, but I'm not sure about the fittings at the tank.

Interesting stuff. I don't know why you call out WM, I dare say every chandlery in the nation carries the same stuff.

 

Exactly. A few weeks in a car don't matter. A line that goes one-way from a #2 tank to a home furnace does not matter.

No, I have no special criticism of WM. That was unfair. I actually like West Marine. But I do think this is something they could communicate, as they do many things.

 

All I can say is that my copper fuel lines and brass valves are 34 years old and seem to be doing just fine????? My Racor fuel filters are made from cast aluminum???

 

The copper acts as a catalyst, they say. So it is not consumed or harmed in the reaction that damages the fuel.

In Diesel engines the fuel is recirculated thru the copper fittings every few hours. So catalyzed fuel is returned to the tank to cause problems later rather that being burned as in a typical gasoline engine. As said above.

Are the Racor filters made of aluminum or zinc pot metal? Plus, many aluminum alloys contain copper...

Are not most tanks on fuel trucks made of aluminum?

 

Almost all my fuel lines are copper....

While I'm listening and learning I'm not yet worried enough to replace them sll.

Which additive stabilizes this problem?

Sent from my SAMSUNG-SGH-I537 using Tapatalk

 

Interesting discussion but with an aluminum Tank and rubber lines and proper filtration I am free to move on to other maintenance issues with a clear mind. Copper (flared) is fine but old school, I don't know how many people I have talked to with fuel supply or run issues that didn't get fixed until the lines were replaced Its the first thing I do on a new boat. Copper is great even when it turns green but with long term vibration and stress it will fail. Supply lines will shut the motor down return lines will contaminate the bilge.
After 30-35 years everything but the hull needs service of refit.

 

I have a Monel tank 1/4 in Monel I plan for fuel lines will this be problem with Diesel fuel

 

Only problem with black iron tanks ( I know you are talking fittings ) is they don't last that long compared to Alum. tanks . My dad had a Grand Banks 36 with black iron fuel tanks , it was about 20 yrs. old when he sold the boat , it passed survey . We saw the new owner about 3 mos. later , the tank leaked and needed replace . In order to get to the tank it was necessary to dismantle a large part of the boat , cost was over 30K . My dad was shocked and offered to pay , but the owner refused .

 

Here's a recent tech paper on the degradation effect on (bio)diesel vs. the various metals in the OP discussion. Although this paper's focus is for bio-diesel, the degradation is the essentially same with petro-diesel although at an exponentially lower reaction rate, even with the absence of the very aggressive organic acids sometimes found in 'bio-diesel'.

Although copper, etc. has been the 'usual' in recreational boating since Methuselah, the small rates of corrosion are usually 'insignificant' .... if you understand that all fuels have a limited 'shelf life' after exposure to air/oxygen and water uptake.... and are infected with biologicals.

Further and from a practical standpoint, be VERY aware - especially, during those financial/market periods when common diesel is 'super-costly'- that unscrupulous fuel dealers have been known to 'dilute' petro-diesel with reclaimed (and sometimes un-reclaimed) used cooking oils ... and which will exceed by MUCH MORE than the 5% standard limit for blending 'reclaimed' cooking oils into petro-diesel which are sometimes 'marketed' as bio-diesel 'blends'. These 'reclaimed' oils contain very aggressive 'organic acids' (Oleic Acid, etc.) and which besides affecting the catalysis/degradation of the fuel also are an incompatible HELL on the common polymers (hoses/gaskets/O-rings) used in diesel fuel systems. Hint: use your nose at the end of the fill nozzle before filling.

Article: Influence of light, temperature and metallic ions on biodiesel degradation and corrosiveness to copper and brass

 

Steel vs. aluminum. There is absolutely no reason not to use aluminum for many fittings, with consideration given to galvanic corrosion where relevant. Most filter housings (Raycor) and antisyphon valves are aluminum.

Those that already have copper. One hint would be to subscribe to Practical Sailor. There are several articles over the past few years regarding additives. However, you will find that Star Tron, Stabil D, and Valv Tect will all reduce the problem by an order of magnitude. There are also additives that will make it worse. The NMMA is pushing for standards for additives, because they have found that more than 50% of additives on the market do more harm than good. I agree with that, based on what I have seen.

RichH. I need to study that article. Several quick thoughts:
1. Water and salt are major factors. If the fuel is REALLY dry, copper reaction will be slower, no question. They ran the tests at significant moisture levels, though within biodiesel spec.
2. Actual corrosion is not required, just an active surface.
3. Oxygen. Because of recirculation, if there are any leaks, oxygen saturation may be high. This is another reason why returns must be submerged.
4. Cheap biodiesel. Everything you said. Another problem we see occasionally is cross contamination with ethanol.
5. pH. I've seen a lot of low pH fuel (4-5), probably related to the above. Doesn't help.

 

SS tubing is NOT USCG approved. It is in the regs.

Copper corrosion is not required, only an active surface, from my understanding and experience. Like Pt in a converter.