Copper vs. Rubber fuel lines

I'm getting ready to install a Racor dual filter in place of my single. The fuel lines are all copper. Rather than dealing with cutting/flarring my plan is to replace all lines with rubber and barb fittings. Copper is probably a much better system; but I also intend on changing shutoff valves, etc.. Barb/rubber will save me a ton of labor. Eager for any advice before I dive in.

I switched to rubber...yes took minutes not hours to do....

May not last as long...but easier to fix short and long term. Probably will reroute lines before either need actual replacing.

Happy with the result, also easier to mod a little if you need/want to reroute a little if you leave a loop/slack.

Just put 2500 miles on the new copper fittings manifold and plain old USCG compliant fuel hose from any marine vendor.

Yes, rubber for me too.

My boat is plumbed with copper between fuel tanks and manifolds and with rubber elsewhere.





Seems like a practical/flexible solution.

Thanks guys. I feel much better about upgrading.

Rubber

And I like your set-up Mark. I always stagger my hose clamps 180 degrees too. Wish there was a better hose clamp that is economical. I'm referring to my hose clamps.

If you go with hose, I'd use clamps with no perforations and made of 316 SS.

AWAB Marine Grade Fuel Hose Clamps

This blue stuff for us.

Buy extra hose and clamps so repair/replacement will be easy.

DRAW out your intended fuel line diagram and attempt to figure all worst case scenes.

Foolproof may be impossible but the system should handle a mistake with ease.

Swapped out to rubber here too:

Greetings,
Mr. psneeld. Am I seeing Teflon tape on some of your fittings (post #2)? I thought there was a thread somewhere that strongly suggested NOT using Teflon but some sort of pipe dope instead. NOT a criticism, just an observation.

I just used Thread-Lok Blue.

RT Firefly said:

Greetings,
Mr. psneeld. Am I seeing Teflon tape on some of your fittings (post #2)? I thought there was a thread somewhere that strongly suggested NOT using Teflon but some sort of pipe dope instead. NOT a criticism, just an observation.

Click to expand...

I also use teflon tape, not an issue properly applied (leave first 2 threads bare).
Someday I might change to a loctite type.

RT Firefly said:

Greetings,
Mr. psneeld. Am I seeing Teflon tape on some of your fittings (post #2)? I thought there was a thread somewhere that strongly suggested NOT using Teflon but some sort of pipe dope instead. NOT a criticism, just an observation.

Click to expand...

The issue with the tape is that small pieces of tape can break off and enter the fuel system. Possibly not when you first put the fittings together, but when you later take them apart.

This is not something I have personally experienced but it's advice I've read from experts and it makes sense to me. Since fuel rated pipe dope is just as easy to use as tape, I use the pipe dope.

My fuel lines are all copper but I will probably do it in rubber when I re-pipe it.
It allows for more flexibility to make changes easily on the run if ever required.

Teflon tape is great IF you use a quality product and apply it properly. Use 2-3 tight wraps clockwise (looking at the end of the fitting) and as said don't cover the first tread or two.
I use it at work on oil and gas fittings up to 10,000 psi.

N4712 said:

This blue stuff for us.

Click to expand...

Those look like reusable fittings with the left hand thread that screws into the hex hose fitting and then has a female hyd fitting on the end ?

Pack Mule said:

Those look like reusable fittings with the left hand thread that screws into the hex hose fitting and then has a female hyd fitting on the end ?

Click to expand...

Say what? They look to be hydro fittings, I'll see if I can get a better picture.

Yes they look like the orange hose I used for hyd steering .. except blue. That hose I purchased from a commercial dealer specializing in hydraulic fittings for back hoe's and the like.

I worked for a bearing house for a while and customers used to bring hoses in like this for repair . Most of the time they didn't know the the fittings were reusable. It's kinda exspensive to start out with this kind of hose and fitting but I think it probably pays off in the long run if your going to use a hyd type hose .

Tom.B said:

Swapped out to rubber here too: https://flic.kr/p/jH4Epe

Click to expand...

Don't want to derail the thread, but what's the flow rate of that pump?

PacMule,
You mean guys are using hyd hose for fuel line?

manyboats said:

PacMule, You mean guys are using hyd hose for fuel line?

Click to expand...

Ours are.

Some of mine are hydraulic hose. I had a crap load of it given to me so I used it where I could.

manyboats said:

PacMule,
You mean guys are using hyd hose for fuel line?

Click to expand...

The picture looked like hyd hose with reusable fittings .It take a special hose when using reusable fittings .The hose might be good for both hyd oil and fuel . I'm not sure . Most of the hoses we repaired were for hyd oil .We sold the hose loose also that way you could repair in the field and not have to have a crimper or swedge .

RT Firefly said:

Greetings,
Mr. psneeld. Am I seeing Teflon tape on some of your fittings (post #2)? I thought there was a thread somewhere that strongly suggested NOT using Teflon but some sort of pipe dope instead. NOT a criticism, just an observation.

Click to expand...

You are cool RT....no criticism taken...

You know me...I think well outside and hopefully usually well above the box....

Yes tape could be an issue and I didn't use any downstream of the engine mounted fuel filter. It's what I had handy the day I was putting all this together and my son had stolen back the great thread sealer he had given me and I forgot.

But if careful where the tape is on the threads...and there is still a filter downstream of the tape used...I don't see a big deal and now after 2500 miles...I may change my prototype out anyway.

Good catch though...but despite a few who don't think so...I think long and hard about even the little issues before I press on or stray from the "recommended".

Teflon® tape (polytetrafluoroethylene or PTFE tape) is used in sealing pipe threads. It is wrapped around the exposed threads of a pipe before it is screwed into place and acts a little like putty under compression to make a seal.
Teflon® tape is only effective on tapered threads and should NOT be used on straight threads.

Do use on tapered threads Don’t use on straight threads

Teflon® tape should NOT be used on CGA fittings of compressed gas cylinders, because these fittings have straight threads (a CGA fitting connects a compressed gas cylinder to a regulator or transfer line). Mis-application of Teflon® tape on a CGA fitting may be hazardous. It can prevent an appropriate seal and cause gas leaks and pieces of tape can easily break off and form a foreign body contaminant that could jam a valve seat, causing valve failure.
Questions? – Contact Risk Management & Safety (621-1790) University of Arizona

N4712 said:

Don't want to derail the thread, but what's the flow rate of that pump?

Click to expand...

60 gph... Same as the filter.

Tom.B said:

60 gph... Same as the filter.

Click to expand...

Oh ok, thanks.

Fuel rated hose or hydraulic hose is fine for diesel and if protected from chafe tends to last longer (but doesn't look as purty) as copper etc. It does, however increase your vulnerability in case of engine room fire. Most commercial small ship survey regulations require an automatic, fire activated, self closing valve upstream of any non metallic fuel reticulation. It's actually pretty easy to achieve. Find a suitable sized spring loaded to close valve and tie open the valve handle with a piece of suitable sized flammable cord. Fuel line catches fire, cord burns, valve closes, hopefully minimal damage from a fuel fed fire.