Fuel cell inserts rusting

[Jean-Sebastien Stoezel]

I bought a custom wedge-style FuelSafe fuel cell in late 2009. There was a few issues with it originally (it came with built in surface bubbles that eventually burst and made the fuel cell leak), but I sent it back to FuelSafe and Jack Lawson (which I'm told is not involved with FS anymore) handled the repairs very well.

Since it was very expensive to buy, I took good care of the cell and followed instructions given by FuelSafe: empty the fuel cell in the off season, remove foam and rinse with water. Let dry with the lid open and store in a location away from excessive heat and sun. So for the past 3 to 4 winters I had kept my fuel cell in the basement (which is semi finished, i.e. it's not damp).
As well I would only use aviation grade fuel, no additives (I run a FV), removed from the car in between week-ends to ensure there was no stones stuck against it, and would only flush the cell with water (as instructed).

Last summer (less than 4 years after I bought it) I started noticing rust particles in the fuel filter... The rust comes from what looks like rivnuts in the cell that are used to bolt the 3 outside plates that support the fuel cap, fuel pickup and breathing valve. All of these rivnuts are now severely corroded (all turned orangey/brown).

Asking FuelCell what this is about, they are telling me that they have never seen this before and they have no idea what caused it. They've alluded to the fact that I might have used additives, which I can attest I never have.

I would like to know if anybody has ever seen this kind of issue, and check if this is a known issue with these cells. If this happened to you, how did you get the issue solved?

Thanks,
Jean

[BLS]

Jean,

No experience with this. Just a question. If the rivnuts are steel and the cell is flushed with water, would this not cause the rivnuts to rust?

[Jean-Sebastien Stoezel]

You would think it would. Though again I have been following FuelSafe instructions, and it says "flush with water" right on the bladder. The only way they see these rivnuts rusting is if I had used additives, which I didn't.

I cannot be sure but I think those rivnuts were of the kind that are coated with that goldish looking plating you see on grade 8 fasteners.

Jean,

No experience with this. Just a question. If the rivnuts are steel and the cell is flushed with water, would this not cause the rivnuts to rust?

[Brian C in Az]

Since it was very expensive to buy, I took good care of the cell and followed instructions given by FuelSafe: empty the fuel cell in the off season, remove foam and rinse with water. Let dry with the lid open and store in a location away from excessive heat and sun. So for the past 3 to 4 winters I had kept my fuel cell in the basement.

My only comment is that rinsing the foam with water then storing the cell in your basement would lead to very high humidity levels inside the cell. You would need to dry the foam for at least a week in a low humidity warm environment before re inserting it into the cell to eliminate all the moisture from the foam. In the future, keep some desiccant in the cell during the off season would be my advice.

[Jean-Sebastien Stoezel]

Hi Brian:

Thanks for the reply. I've always stored the foam seperate from the cell, to allow it to dry completely.

Jean

My only comment is that rinsing the foam with water then storing the cell in your basement would lead to very high humidity levels inside the cell. You would need to dry the foam for at least a week in a low humidity warm environment before re inserting it into the cell to eliminate all the moisture from the foam. In the future, keep some desiccant in the cell during the off season would be my advice.

[HayesCages]

For what it's worth: From what I've seen over the last 20 years FS has had a high employee turn-over...
After working with them for that long we're going to go somewhere else to get our cells.

I've never seen any steel components in one of their cells either. They've always had bonded cast aluminum plates for inner nut plates, never a steel riv-nut anywhere on them. That said, they were probably trying to save money by using something inferior.

One of the cells we got from them in 1994 is still in great shape. I never drained it but always left it full of fuel over the winter. Never drained between races as well. Never had a problem with anything. Still has the original foam too.

Next one we get is coming from here: www.harmonracingcells.com

Lawrence

[Jean-Sebastien Stoezel]

Here are pictures of the inserts, inside the fuel cell.

This is the back of the breathing valve:


This is the back of the fuel pickup:


I haven't tried to remove the back plates yet. The fuel cell came with the hardware aside (outside plates off), and I had to assemble it myself.
Can the inside plates be removed? Can the inserts be removed? How are they fitted to the back plates?

Thanks,
Jean

[HayesCages]

I cannot believe that they used those! Looks like some Galvanic reaction going on there...
Be the squeaky wheel and make Fuel Safe replace them.
The fuel pick up's used to come with a filter on the ends as well.

If you wanted to replace them you simply take the bolts out and remove the plates from inside the tank. They use no sealer (last time I had one apart). The bolt heads usually have a nylon washer under them to seal so when reinstalling don't over-tighten them.
The old cast nut plates were glued to the inside of the cell but who knows what they've done here.
Send them the pictures you posed too.

[Jean-Sebastien Stoezel]

Hi:

Thanks for the reply. I removed the outside plate, and I think the inside plate is glued, as you suggested. I might be out for quite a bit of money if I send the fuel cell back to Fuelsafe, between shipping from Canada and the actual repairs (they said they don't want to handle this under product support). They have the pictures I posted here...

So I might have to fix this myself.

What are the chances those inserts are threaded to the back plates? I see a seat on the outside of the inside plate. I took a picture of the insert as viewed from the outside, seems like there's no such a seat.





Do you think I can just use a grip wrench and undo those inserts from the inside?

Thanks,
Jean

I cannot believe that they used those! Looks like some Galvanic reaction going on there...
Be the squeaky wheel and make Fuel Safe replace them.
The fuel pick up's used to come with a filter on the ends as well.

If you wanted to replace them you simply take the bolts out and remove the plates from inside the tank. They use no sealer (last time I had one apart). The bolt heads usually have a nylon washer under them to seal so when reinstalling don't over-tighten them.
The old cast nut plates were glued to the inside of the cell but who knows what they've done here.
Send them the pictures you posed too.

[BLS]

Jean, I think those inserts are pressed into the metal ring. I'm not positive about that but fuelsafe should be able to answer that question. I believe the inside ring is glued in place and the outer ring has a gasket. At least that is the way mine seems to be made. If your cell is like mine there is a larger access plate that should allow you just a bit of working room. I think I would try to clean those up, put a bit of lube on them, and not flush with water anymore. Or flush with water, then dry and lube the parts to keep them from rusting further. I had the pickup plate off mine earlier and there was no corrosion like you have. I'm certainly no expert.

Regards,
Barry

[Jean-Sebastien Stoezel]

Hi Barry:

Thanks for the answer... It says right on the cell "flush with water" and I've always left it open to dry. I don't feel like I've done anything that would not be prescribed.

Anyhow, what sort of lube would you suggest? It would have to be insoluble in gas, and be neutral for both the foam and the bladder.

Right now there's large chunks of corroded metal falling off the inserts. I'm not sure those inserts are still good. When I removed the plate I noticed there was also corrosion inside the threads.

Jean

Jean, I think those inserts are pressed into the metal ring. I'm not positive about that but fuelsafe should be able to answer that question. I believe the inside ring is glued in place and the outer ring has a gasket. At least that is the way mine seems to be made. If your cell is like mine there is a larger access plate that should allow you just a bit of working room. I think I would try to clean those up, put a bit of lube on them, and not flush with water anymore. Or flush with water, then dry and lube the parts to keep them from rusting further. I had the pickup plate off mine earlier and there was no corrosion like you have. I'm certainly no expert.

Regards,
Barry

[BLS]

Jean,

I was thinking just a bit of oil that would get dissolved by the gasoline. I am assuming that the gasoline is not causing the corrosion and that absent water there would not be further corrosion. The oil would just be to protect it until you fill it with gas. Just my thinking, could be wrong. I understand the directions call for water flush and I can only guess your inserts are the wrong material.

If the inserts are bad enough I would try to get fuelsafe to at least send new plates and the right type glue for the inside. Assuming they are glued. Best I can remember when I took my outer fuel pickup plate off the inner plate stayed in place. I needed to re-clock mine. Maybe the new plates are not so expensive if fuelsafe will not warranty them.

I would think fuelsafe would at least want to provide you with definitive instructions, even if they feel there is no fault on their part.

Good luck,
Barry

[David Ferguson]

Those just look like steel rivnuts pulled into that plate from the front side. It seems like it could be pried off the cell wall, and replaced with an equivalent that wouldn't corrode. Like say a tapped stainless (or even aluminum) ring.

[problemchild]

Thanks for posting those pics. My opinion of FS fuel cell quality has plummeted from my previous evaluation of poor. Those look they are from a trailer hitch on a Canadian plow truck not washed since 2009.

Be the squeaky wheel. Send them a link to this site and post more pics at other sites. It looks like they were out of the normal cast rings and fabbed up some quickie parts to get a job out the door. They should be rushing replacement parts out the door to minimize your squeaking.

[Steve Davis]

I agree with David. 95% sure those are steel rivnuts. You can drill them out from the outside and then insert new (aluminum) ones from the outside. Get your new inserts first and use the drill size for the new inserts (what ever it takes to fit the bolt). It shouldn't take any significant force to hold the plates. Whenever I use rivnuts, I also put some jbweld or epoxy glue on the insert before .. inserting and seating it . That way it is much less likely to turn after time.

I would also be surprised if the inside plate was GLUED in place - I suspect it's just STUCK from being there for several years. Most likely, you can pull/pry a bit and it'll fall right off - then you can do the replacement work outside the cell.

NO WAY would I reassemble that using those corroded inside fasteners...

BTW - if you are not familiar with Rivnuts, THIS is what we're talking about, tho' I'm not sure you can get it done with a "manual" tool. If that is 1/4" or larger, you'll need a hydraulic 'setting tool' due to the effort required... something like this, but it might make more sense to just find someone who has one and borrow it for a few minutes .

Steve, FV80

[David Ferguson]

Here's a link to Rivnuts, showing how they are installed:

http://www.mcmaster.com/#standard-rivet-nuts/=qofloh

[HayesCages]

I'd pull that plate off and make new one out of 6061-T6 plate at least 3/8" thick, bore the center, tap holes for mounting and be done with it. That way you don't have to waste any more time dinking with FS and your problem is solved.
You may have to apply some heat from a heat gun for the glue to loosen from the plates.

As I mentioned before I think that the inserts are reacting with the aluminum and corroding, not caused by any water contamination.

And Fuel Safe is getting a bad reputation here and on other sites as well.

The people at Harmon have quoted us a new formula type cell (no enclosure) for under $700, fittings included...

If you need someone to make the plates we'll do it for a minimal charge, plus shipping. PM me the measurements if you want.

[Steve Demeter]

Contact Fuel Safe and promise them a campaign of FACTUAL INFORMATION about how their product was crap and how they would not make good on it. If that does not wake them nothing up, nothing will.

Oh I forgot, their reputation is already crap.

[HayesCages]

It's sad, they used to be so helpful.

When you call Harmon the owners answer the phone...

[Jean-Sebastien Stoezel]

I got a reply from FuelSafe today but nothing is really new. Again they said that something other than aviation quality gas attacked the treated inserts, while I keep asserting that I haven't put any sort of additives in there. For having the old fuel cell disintegrate and soak me with gas while I was driving I can insure that I am very careful maintaining this newer one (did I also mention it is custom and was expensive to purchase?).

FuelSafe has offered to conduct a thorough evaluation of the cell and rework it (they have advised they would apply a nominal fee). If it was my product that was showing unusual signs of wear I'd like to understand why it's failing, so here's a chance for them to see how a 4 year old cell looks like.

Hopefully they can figure out what's happening and check for themselves that I haven't filled this cell with anything other than good quality gas.

Jean

[HayesCages]

I wouldn't waste my time. If you try to send the cell back and it has ANY gasoline odor at all it will get set aside and not be delivered.
Ask me how I know this: I had to return a cell to FS as they mis-mixed the poly-whatever cell material and it leaked (sound familiar?) I drained the cell, washed with soap and water several times, triple bagged it, boxed it. It sat at the local UPS office not being delivered for over a week before I figured out what had happened. Their gas-sniffing meter pegged and they sat the box aside.

[Dick R.]

I wouldn't waste my time. If you try to send the cell back and it has ANY gasoline odor at all it will get set aside and not be delivered.
Ask me how I know this: I had to return a cell to FS as they mis-mixed the poly-whatever cell material and it leaked (sound familiar?) I drained the cell, washed with soap and water several times, triple bagged it, boxed it. It sat at the local UPS office not being delivered for over a week before I figured out what had happened. Their gas-sniffing meter pegged and they sat the box aside.

Interesting. A few years ago I sent a fuel cell to Eagle via UPS or FedEx (I don't recall which). I had rinsed it with water a few times to get the particles of old foam as well as the gasoline out but there must have been gas odor. I probably did wrap it up well in one or more garbage bags. Eagle sent me a new cell and repaired and returned my old cell. They bagged the cells in clear plastic I think.

Dick

[Jean-Sebastien Stoezel]

I sent the fuel cell today. This is the second time it goes back to FuelSafe, using Fedex ground. It doesn't smell much and I taped all the openings. Last time there was no issue with gas sniffing by Fedex, hopefully it ships well this time as well.

[HayesCages]

Let us all know how it works out please. It'll be interesting to see if their customer service will prove itself.

[DaveW]

.... Again they said that something other than aviation quality gas attacked the treated inserts, while I keep asserting that I haven't put any sort of additives in there....

If you used street gas, most of that contains ethanol, and that attracts moisture. So, anything in the cell that could rust (the steel Rivnuts) may have been affected by that during normal use. I don't think your washing with water was the cause, since you seem to have dried it properly, and the moisture was only there short-term.

Also, galvanic corrosion is not the cause, since aluminum is more reactive than steel, and would corrode around the inserts, leaving the inserts untouched.

[Jean-Sebastien Stoezel]

I sent the bladder through a ground courier and it's going to take a week to get there. I will update on FuelSafe findings whenever they get back to me.

Jean

Let us all know how it works out please. It'll be interesting to see if their customer service will prove itself.

[john f]

If you used street gas, most of that contains ethanol, and that attracts moisture. So, anything in the cell that could rust (the steel Rivnuts) may have been affected by that during normal use. I don't think your washing with water was the cause, since you seem to have dried it properly, and the moisture was only there short-term.

Also, galvanic corrosion is not the cause, since aluminum is more reactive than steel, and would corrode around the inserts, leaving the inserts untouched.

The riv-nuts were most likely galvanized steel which is more reactive than aluminum. The street fuel combined with the aluminum/galvanized assembly could be the problem. Just my $0.02.

john f

[BLS]

Jean said he only used Avgas.

[DaveW]

The riv-nuts were most likely galvanized steel which is more reactive than aluminum. The street fuel combined with the aluminum/galvanized assembly could be the problem. Just my $0.02...

True, but that doesn't explain the steel, itself, rusting, which it certainly did to turn brown and rough. Maybe once the galvanizing got used up, any residual moisture would have attacked the steel. In any case, they should never have used steel Rivnuts.

Jean said he only used Avgas.

Well, that eliminates my street gas theory...

[Charles Warner]

Actually, he said he ran "aviation grade fuel" which may, or may not, equate to Avgas. It could be a case of water seeping in around the filler cap if the car ran/sat in the rain or even water entering the fuel vent in some way.

[DaveW]

Actually, he said he ran "aviation grade fuel" which may, or may not, equate to Avgas. It could be a case of water seeping in around the filler cap if the car ran/sat in the rain or even water entering the fuel vent in some way.

Also, temperature variations cause the air in the tank to shrink/expand and air to be drawn into and expelled from the vent. This could draw in moisture along with the air even w/o the tank exterior getting wet. Interior moisture would tend to condense on cool surfaces, such as any exposed metal. As an aside, preventing pulling in moisture is one of the main reasons most sources recommend that for winter (especially street-vehicle) storage the fuel tank should be stored full.

[HayesCages]

Also, temperature variations cause the air in the tank to shrink/expand and air to be drawn into and expelled from the vent. This could draw in moisture along with the air even w/o the tank exterior getting wet. Interior moisture would tend to condense on cool surfaces, such as any exposed metal. As an aside, preventing pulling in moisture is one of the main reasons most sources recommend that for winter (especially street-vehicle) storage the fuel tank should be stored full.

My thoughts exactly: When cold fuel meets warmer, humid air (like early mornings in the NW) water can condense at the top of the tank causing the rust to form. What happened at the bottom plates though? Who knows, just that it did.

[Tiago Santos]

Most of the theories sound like stuff that happens under normal use anyway.. This really shouldn't have happened no matter what. I'll wait to see how this gets resolved, but I need to order a custom cell (same as Jean's, funnily enough) and I'm not too impressed with Fuel Safe right now.

[HayesCages]

I specifically asked Harmon what they use for nut inserts and they answered with "stainless steel", just as it should be.
Ours is on order with an expected delivery in 2 weeks or so.

[BLS]

I specifically asked Harmon what they use for nut inserts and they answered with "stainless steel", just as it should be.

I'm guessing Jean did not get SS.

[steve zemke]

There are two types of stainless steel, magnetic and non magnetic. I suppose the magnetic will rust and the non magnetic won't. See cheap Chinese stainless steel knives in my kitchen drawer for the ones that will rust.

[Jean-Sebastien Stoezel]

Initially the fuel cell was supposed to be delivered today but the latest update shows it departed St Paul MN on the 22nd. No further information except that now the latest delivery estimate seems to be scheduled for Thursday 27. I will provide an update when Fuel Safe gets the bladder and gets an opportunity to review it.

Jean

[Jean-Sebastien Stoezel]

Fuel cell delivered this morning to Fuel Safe, now it's in their hands. We will see what comes out.

[Jean-Sebastien Stoezel]

Fuel Safe reviewed the bladder shortly after they received it.

In their own words they are still baffled by the corrosion they are seeing, which is very unusual and generalized. They have offered to replace the 3 internal nut rings, the 3 gaskets and bolts on the unit at their cost (no labor charge) for $24.

They reviewed the bladder quickly , they're offering to fix the issue at their cost. It seems like a reasonable way to handle a product deficiency. While the cell is there I might have it reinforced on one corner that's a bit shady. I don't need the FIA re certification (which expires at the end of the year) so I may not take their offer to extend the life of the cell by 2 years.

Jean

[HayesCages]

I would've done it at no charge and paid for your shipping both ways, I suppose it could've been worse... Glad it worked out for you!