Anodizing fuel tank

I am new to the alky game and I just had a new custom fuel tank built for my blown alky BBC and the builder told me to have it and all hard fuel lines hard anodized, but I have another experienced friend telling me that it could risk flaking off and clogging up the fuel system.
Anyone have any experience or recommendations as to what is best? Also I will be cleaning the entire fuel system between races so it won't have much time to corrode anything.

Thanks,
Paul Vinyard

 

I'd leave it bare aluminum, especially if you are cleaning the system between races. Getting full anodize coverage inside the tank is going to be next to impossible anyway. The prime advantage for leaving it bare is the ability to rework it for whatever reason (cracked bung, revised venting, etc.) If image is important bare aluminum looks great polished.

Chris Saulnier - Team Tigges
Mechanic Falls, Maine

 

Much appreciated, I hadn't even thought about if/when it needs to be reworked. Plus I am more about function than looks any day.

 

Paul; (and Chris) anodize is not a coating that can flake off. It is basically a dye that seals the pores of aluminum to keep the very caustic, but slow reaction to aluminum. It is a submerged in solution, positive/negative electrical process, that will seal every square inch, inside and out. Yes, you can see stuff growing and eating into the surfaces in time, but you don't have too, if you don't mind spending lots of time draining, taking everything apart to blow dry absolutely every time you run the car. I had one customer who didn't do it, forgot to drain the tank, left 1" in the bottom for four months, then filled it up and ran the car, blew the blower off because every line, nozzle, and pump were destroyed! I had to cut the bottom off the tank to replace it.
Be sure you take it to a shop that understands they should clean it with mild cleaning solution, and NOT acid etch !
The story is much longer, but remember that alky is hydrous, meaning it sucks water out of the air, and actually right through unsealed pores of metal. (we call sweating on tank or drum). Notice insides of alky drums are sealed and outside is painted!

 

A guy that I work with was telling me that even though it would be submerged, the electricity doesn't get inside the tank all that well so it wouldn't give the desired result on the inside even if I had it done. Any thoughts on if that's right or wrong?
But I am always sure to clean every drop of alky out if it is going to sit for more than a week. In the past I just ran the car on gas to clean everything out and haven't had any issues.

 

Cleaning with gas or nitro does not effect aluminum, which is why cars that run that stuff don't always anodize.
Ask your guy at work if he's ever watched the process. I have only a few hundred times, or you can just watch on the hundreds of You Tube video's. Ever heard of somebody dying in the bathtub when anything plugged in falls in ? The liquid is the positive, the human next to the tank, rolls it (with a wood stick) while hanging on hook (negative) until no bubbles come out. It's impossible to not get 100% coverage, unless one corner is not submerged (holding a bubble). The guy who let that happen would not have his job tomorrow, unless he's the stupid owner who put too short a hanger wire to save .01 cent..........

 

I'll ask him if I see him today. So what would your thoughts be on anodizing vs hard anodizing? My understanding is that hard anodizing actually adds to the thickness of the aluminum by adding tin to the outer layer whereas standard anodizing doesn't add anything, it only seals the pores of the aluminum as you mentioned.

 

Absolutely correct ! Hard is not necessary!

 

I agree hard is not necessary, but would continue to argue anodize of any type is not necessary if you are cleaning out your fuel system during non-use. If you do go that route get recommendations for your plater. Any air entrapment (including small bubbles held on by surface friction) will not plate. The ratio of shops that do a good job vs. 'dunk & skunk' shops is about 10/90.

Chris Saulnier - Team Tigges
Mechanic Falls, Maine

 

send it to Aerodynamic plating in Gardena Ca They know how to get it done properly, alcohol will eat holes in the bare aluminum its just makes sense to do it

 

When I was in the aerospace industry, anodize was a requirement on nearly all aluminum machined components so I dealt with it for many years and I see a few misconceptions posted here.

All anodize penetrates as much as it builds on the surface so a .001 anodize would be .0005 penetration and .0005 build up.

Hard anodize was designed for aluminum that is near or submerged in salt water so it's pretty effective against corrosion. Hard anodize is also used to increase wear resistance and abrasion mainly where hardened steel slides and valves are used in aluminum components. It can also be used to repair worn/oversized bores but due to its hardness, has to be ground to finish.

If you anodize aluminum and there are critical fitness issues, allowance needs to be made for the build up.

Whether you need to anodize an aluminum fuel tank I think is based on scheduled maintenance performed, cleanliness of the entire fuel system and weather conditions, I'm in Arizona and the humidity is pretty low and the temperatures are warm to friggin hot so my maintenance is going to be different than someone in one of the Gulf states.