Fuel Cell baffling/foam revisited.

[BadDog]

Ok, we've all seen the posted problems with fuel cell foam and pump gas (or whatever you attribute the problems to). I was working on getting my used fuel cell into my truggy, and took out the foam that was in there from the p.o. The bottom looked like it was liberally sprinkled with coarse black sand, particles of the foam that was in there. The sock would probably keep most of the problems at bay, but not what I want to trust or depend on.

I've also seen where people run quart oil cans with the top and bottom cut out, and packed into the tank to act as a baffle.

And, I saw where a guy had cut up some plastic pipe (I believe it was something like 3" PVC?) and stacked in standing vertically like a 24 pack of beer cans on its side. Question is, will common PVC stand up to constant and long term emersion in gas?

What other solutions do you guys know of other than "build a baffle". That's certainly an option but I really don't have equipment to do a good job in aluminum, and don't feel like building a steel tank at the moment. And putting a steel baffle in an aluminum tank has it's own issues, so I would rather avoid it...

This is not about keeping fuel at the pick-up point, baffles alone are really no good for that anyway. It's only about fuel slosh and aeration control.

 

[dyeager535]

I started thinking of 1 liter coke bottles and such, but then something else came to mind. I've noticed that starting the last couple of years or so, plastic bottles are apparently not made the same way they used to be. It's very common now to see the layers of plastic containers "seperate" as it is flexed.

Oil bottles I'm guessing are made of something else, they seem more pliable/softer, plus they have to stand up to petroleum products.

I can't come up with anything better than the oil bottle idea...trying to fit baffles in a tank after it's put together is very difficult. You can tell GM did that when the tanks were still in two pieces.

Problem I see with PVC, regardless if it will be fine in fuel, is that the wall thickness of all PVC I've seen is pretty substantial, especially when compared to oil bottle thicknesses. Maybe it would only amount to a gallon or two (depending on size of fuel cell) but with these rigs, fuel capacity can never be too much IMO, and even a gallon can make a big difference on a hill climb.

 

[miniwally]

Russ I and Stephen have both been using the foam for several years. (I have only had the buggy together for a year and a half) We try to keep the tanks full or at least above the foam level during storage, and we have had no problems so far.
We did put the fuel filter before the pump and I know that Stephen has not changed his for several years.

We are running the external fuel pumps.
Just something to think about. I think the foam needs to be wet all of the time to stay together.

I would not trust PVC to not start coming apart in some manner over time. I don't know what the amount of time would be for it to dissolve to a non suitable level.

I don't have any good ideas for you right now but will think about it some.

 

[Jonny-K5]

never heard of the foam problem. wonder if i should take it out of my fuel cell.what is the fuel cell in? ure trail rig? if so, does slosh/aeration really matter?

 

[tx_sub]

i would say a 24 pack of beer cans sounds perfect because they are aluminum. however, too flimsey. what about aluminum baseball bats. how does that strike you? thicker, and maybe easy to find. best place to find them might be consignment stores. the older ones have a longer straight barrel compated to the new club looking ones. maybe aerosol cans cut up. stronger than al cans but easier to find than baseball bats. this may pose an environmental concern for chemicals released when you cut them up.

one more might be aluminum siding stripped of paint. That's all I can think of now.

 

[BadDog]

Main thing I want is zero maintenance or worry.

The foam I have has already begun to deteriorate based on the "sand" in the tank. It's also been dry for several weeks, so it can't go back in. And there is probably a local source for foam, but I would rather find something else if I've got to buy something anyway.

I would definitely go with the oil cans since they seem to be certain to hold up to the petroleum products (based on usage and other people claiming to use them). But I don't have nay way to get that many quart containers. The shops all use 5 gal and larger these days. I myself always buy in gallons.

PVC worries me about holding up eternally submerged in gasoline. Any chemist/engineer out there who knows or knows where to look? I tried looking up on the net with no luck. I'll try again... As suggested though, depending on the diameter and wall, I could loose significant capacity.

I use an in tank pump, so the filter before the pump is the sock, that's it.

Fuel cell foam has been reported to break down over time. Theories of why it breaks down vary, but generally amount to "because you let it get dry" and "due to additives in pump gas". Brandon mentioned they have no problems when keeping it submerged. I have no idea what the real problem is, I can only say the foam in my cell is breaking down. And if you remove the foam, you'll probably want to replace it with something else. Uncontrolled slosh can actually rupture the cell and aeration can cause drivability problems.

The 24 pack comment was not intended to imply that I would put in beer cans, though it is an interesting thought I was just describing how the tubes would fit "stacked" together. Thin wall aluminum tube is an interesting prospect though, if I had a ready and inexpensive source.

I'm really starting to wish I had just built my own out of steel based on the design I posted a while back.

 

[ntsqd]

snip.....
what about aluminum baseball bats. how does that strike you?

bwahahahahahaha

About 15 years ago a fuel tanker truck went off the side of Hwy 33 in the mtns behind me. The canyon it fell down into had an outlet back to the same hwy. A guy who used to live across the street from my Dad came up with the idea to use PVC to get the fuel out of the truck and pipe it down the cyn to another truck. Big concern was that the PVC pipe would 'melt' from the gasoline. The guy who proposed the idea said it would, but not so fast that they couldn't use it to solve the problem. It didn't melt immediately, but it almost didn't last long enough either.

Russ, look into the cost of the foam. It may not be worth trying to devise some other solution. FWIW all of my off road vehicles except one (& it's is sitting on the fab table) run a Marine water separating spin-on fuel filter. The one on the DB has been on there for ~12 years w/ no appreciable change in weight.

 

[BadDog]

So, you are supporting that the foam is not a problem right?

I'm guessing Brandon (and others) are right about the foam just needing to stay wet to keep from breaking down. But my biggest thing is not really the cost, I expect it's not that expensive, but rather having to pay for it and then wait for it to arrive. Of course as slow as this is going, it would be here in plenty of time. Still, if there is another alternative, something that is comparably priced without the "keep flooded or it will break down" issue, then I would rather go that way instead.

Sure would be nice to find an inexpensive and better alternative. Not likely I guess, but like many other things, it's still worth investigating. Who knows, somebody may come on here and suggest a cheap source of 3" diameter 20 guage stainless tube scrap that would make a perfect solution? Yeah, right...

 

[BadDog]

BTW, to OT my own thread.

What's the deal on the spin on water separating filter? Will it handle volume sufficient for TBI pressure regulation?

 

[rubbinz raczn]

russ i would think placing tubing some other metal object in tank could cause other problems. if you have an in-tank fuel sender that could be damaged. the pickup sock also. a lesser issue might be the metal to metal contact from whatever you place inside causing wear/shavings.

 

[retroblazer]

Fuel cell foam

First, how old is the fuel cell? Second, I replace my foam in my race truck every four or five years. www.rafforacing.com. The foam is pretty cheap and readily available. Most of the foam I've used is red. If you're not using additives in your gas, the foam will last a long time. No need to reinvent the wheel.

 

[BadDog]

Actually, your absolutely right about the metal. Metal tubes wouldn't be a good idea at all. Wasn't thinking I guess when I posted that last night, but the metal-on-metal issue is one reason I discounted building a metal baffle to start with. I thought about having some tabs welded in to bolt a baffle to, but decided to see what else might come up.

The fuel cell is several years old I guess, not sure exactly.

I guess I will likely just order some new foam from Summit or something. Like I said earlier, the memory of people talking of using oil cans and other stuff just got me thinking about other options that would completely avoid the foam break-down potential problem. The foam I have clearly requires replacement, so just investigating options before rushing down that path, especially with as many reports of foam break down as I've heard, and now seeing it for myself.

 

[mosesburb]

BTW, to OT my own thread.

What's the deal on the spin on water separating filter? Will it handle volume sufficient for TBI pressure regulation?

Yes it will. Think diesel filter and you'll have a visual. If you need one let me know as I can get the filter and housing setup (not terribly priced either).

 

[ntsqd]

So, you are supporting that the foam is not a problem right?

The foam becomes the problem, no denying that. If keeping the cell full is key to longer life of the foam, then it suggests to me that ozone or oxygen, and not the fuel, are the real problem. Race fuel seems to be more kind to fuel cell foam than pump fuel does. Not sure why. Like Chris says, the foam isn't a huge expense. How long did this foam last? Think you'll still have the cell in the vehicle in that time period ahead?

BTW, to OT my own thread.

What's the deal on the spin on water separating filter? Will it handle volume sufficient for TBI pressure regulation?

This is the filter I use:
http://www.westmarine.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&productId=55979&catalogId=10001&classNum=219&subdeptNum=68&storeNum=6

Do not know if it will withstand EFI pressures. I think it will, but I haven't tried it. Only EFI vehicle I know of with one has the filter b4 the frame rail mounted pump.

The water separating feature is of little consequence unless you're buying fuel out of drums, like in remote parts of Baja. (Which is why my Sub has one and Patch is about to get one.) It's the easy changing and the size of the filter that appeals to me. Picture a half height SBC oil filter and you've got the spin-on element's size. I periodically spin the one off the DB, empty it of fuel, and compare it's weight with a new filter. Hasn't changed much in 12 years.

 

[Stephen]

I vote for getting new foam, adding a filter and calling it good.
The big problem with mine is really not the baffling, it's the lack of a sump, I run out of gas with 7 gallons left in a 22 gal cell when I'm at severe angles, it's just because it's got a big flat bottom and there's not really any easy way to fix that. So I just keep it more full than that. In a pinch I can reach in there and put the pickup in the fuel and keep moving.

 

[CyberSniper]

Years ago I used windshield washer fluid bottles for baffles. Back in the day fuel cell foam was obnoxiously expensive. Took like a dozen of them and cut the top and bottom out so you have a bunch of cylinders. Use a hole punch to put some holes in them near the bottom so gas can move around a little. Then just stuffed them in the tank. They end up honeycomb shaped.

I don't know if I'd trust the plastic in modern day windshield washer fluid containers though. Probably dump some gas in them to make sure they still hold up.