Why not switch fuel line from copper to A1 hose?

[rigspelt]

I am going through this refit decision too. I have an 8 foot run from tank to engine. There is also a short section of hose from a shutoff valve on the tank to the fuel/water separator filter. The main line appears to be original copper tubing from the fuel/water separator filter to near the fuel pump, terminating in another short section of hose to the fuel pump.

I have three references (with nice details about how to construct boat fuel systems): ABYC standard H-24 Gasoline Fuel Systems (I purchased it), the U.S. Boatbuilder's Handbook Subpart J Fuel Systems Title 33 CFR Sections 183.501–183.590 and the Canadian Construction Standards for Small Vessels TP1332E Transport Canada 2004. All three appear to share the same standards, from what I can tell. The TC standard says "Fuel fill lines shall be hose or metal pipe" and goes on to specify hose and metal types, connections, etc. The other two references also do not seem to specify any requirements for metal over hose in the main run in the fuel distribution system from tank to engine, and like the Canadian appear to specify no preference for hose over metal fuel lines (?).

To my mind, the disadvantages of copper are: much harder for a DIY'r to make sound connections than for hose, harder to insert new filters, pumps and valves in the distribution line, and harder to route around corners without risk of causing small breaks in the metal tubing. The main downside of hose seems to be that it ought to be changed every 5-10 years, but that does not seem like a big deal.

So, I too would like to know if there is any reason why I cannot remove the metal line and change it to A1 fuel hose throughout?

UPDATE: Since I posted this early this morning, I have removed all the fuel distribution parts and that old primary filter. I am using the old copper tubing as a model to make a new exhaust dry stack. So I am now committed to a new fuel line.

[kas]

Rigs,

What did you end up deciding? Did you swap everything out for the hose or replace it with a new copper line? I'm interested because I am debating the same thing?

Thanks,
Kas

[Al Schober]

Several years ago I redid a 38' diesel trawler. Repiped both engines and the gen set with hose. All is well to date. Oh yeah, also redid my A4 with hose from tank to engine.

Al

[keithems]

just redid mine, as noted in another thread.

replaced the copper tubing with rubber hose because now instead of several tubing - hose connections, i only have straight rubber hose from the fuel tank outlet to the water separator

[toddster]

I've spent an inordinate amount of time doing plumbing on my boat. Fuel, water, propane. It's insanely difficult in that the devices all come with different connections that it's almost impossible (in rural america) to find a consistent system of compatible fittings to do any job.

That said, I've been doing "wet" science (chemistry and biology) for over 30 years, which has a lot more to do with plumbing than you might think. For no-fuss rock-solid no-leak connections, it doesn't get much better than swagelok metal tube fittings. For low-pressure applications like pleasure boats, they're huge overkill, but sooooo much better than flakey "flare" fittings. They're used on everything from spacecraft to oil rigs. The only problem is that for copper fittings, you'll pay a lot, and for the stainless steel ones, you'll bleed.

But I just did the pressurized water system last week with hose and clamps. Considering that every hose fitting needs two or three SS hose clamps, I now think I should have just gone with swagelok for everything on the boat. Besides, you can sometimes find good deals on lots of used or NOS fittings and valves on ebay and the like.

[JOHN COOKSON]

The swages on the end of the copper tubing are usually held in place by brass ferrules.
If water ever got into the gasoline, with three different types of metal, there is a good set up for a lot of electrolysis.
Maybe I'm over thinking this.........
I think about the copper outlet tube in my aluminum fuel tank occasionally. Wonder if I should switch to plastic?

TRUE GRIT

[HOTFLASH]

Rigs and Toddster,

Your project and question called to my mind a related issue: I was told by my local A4 boatyard man/mechanic that there was some Coast Guard rule against using hose post fuel pump (into the carb). Of course that is where/how the polishing filter is located--with hose--a setup recommended by Don and other A4ians. Is there a way to use the tubing with the polishing filter?

I looked and could find no reference to any such rule/prohibition. Any comments?

Mary

[67c&ccorv]

Originally Posted by toddster

I've spent an inordinate amount of time doing plumbing on my boat. Fuel, water, propane. It's insanely difficult in that the devices all come with different connections that it's almost impossible (in rural america) to find a consistent system of compatible fittings to do any job.

That said, I've been doing "wet" science (chemistry and biology) for over 30 years, which has a lot more to do with plumbing than you might think. For no-fuss rock-solid no-leak connections, it doesn't get much better than swagelok metal tube fittings. For low-pressure applications like pleasure boats, they're huge overkill, but sooooo much better than flakey "flare" fittings. They're used on everything from spacecraft to oil rigs. The only problem is that for copper fittings, you'll pay a lot, and for the stainless steel ones, you'll bleed.

But I just did the pressurized water system last week with hose and clamps. Considering that every hose fitting needs two or three SS hose clamps, I now think I should have just gone with swagelok for everything on the boat. Besides, you can sometimes find good deals on lots of used or NOS fittings and valves on ebay and the like.

Did somebody just say "Swagelock fuel control"?

[toddster]

Ah, now if the fuel lines were SS tubing in nice straight runs with swagelok connectors, that would be impressive.

[67c&ccorv]

That would be nice indeed...but I decided to go with marine rated flex hose so as to avoid cracks due to vibration.

[ndutton]

Regarding the use of stainless for metallic fuel lines . . . .

Code of Federal Regulations > Title 33 - Navigation and Navigable Waters > CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > PART 183--BOATS AND ASSOCIATED EQUIPMENT

§ 183.538 Metallic fuel line materials
Each metallic fuel line connecting the fuel tank with the fuel inlet connection on the engine must:
(a) Be made of seamless annealed copper, nickel copper, or copper-nickel; and
(b) Except for corrugated flexible fuel line, have a minimum wall thickness of 0.029 inches.

§ 183.562 Metallic fuel lines.
(a) Each metallic fuel line that is mounted to the boat structure must be connected to the engine by a flexible fuel line.
(b) Each metallic fuel line must be attached to the boat's structure within four inches of its connection to a flexible fuel line.

Sorry, stainless is not USCG compliant.

Hotflash:
I was told by my local A4 boatyard man/mechanic that there was some Coast Guard rule against using hose post fuel pump (into the carb).

Mary,
I looked pretty thoroughly and could find no such prohibition. I will say (apologies to Don) that the polishing filter is required to be supported independently of its hoses.

§ 183.570 Fuel filters and strainers: Installation.
Each fuel filter and strainer must be supported on the engine or boat structure independent from its fuel line connections, unless the fuel filter or strainer is inside a fuel tank.

[HOTFLASH]

Neil,

Thank you for your expertise--I did not find any prohibition either. Can anyone think of a way to support the Moyer-advised polishing filter from/on the engine?

Mary

[Wise4]

100s of ways to accomplish that.... One of simplest being a metal zip tie.

[ndutton]

What Wise said, really anything will do and it doesn't have to be fancy.

The reality is there have been, as far as I know, zero issues with the polishing filter mounted the Moyer way. I think any effort expended will be of no benefit other than appeasing the Coasties and that's only if they board you looking for it. The requirement covers all filters and it makes sense when considering the size and weight of our typical primary filter but the polishing filter is so small as to be inconsequential if you ask me.

[joe_db]

The polishing filter has a big advantage that might not be obvious:
When you take the carb off, LEAVE THE FILTER ON. When you pull the hose off the carb, the barbs rip tiny pieces of rubber off the hose that can end up in the carb. The filer has a smooth connection and would trap any debris anyway. So pull the hose off the far side

At one time I had all stainless braided fuel lines and Aeroquip fittings. I did some research and discovered that unless I fire-sleeved them all, it was much safer to use the marine rubber hose so I switched back.