Storage Sludge?

[Robert Administrator Find all posts View Profile Close Robert]

Yesterday I filled up from some of the remaining containers I had in the garage. Since the pickup last month, I've had the bulk of the biodiesel stored in a steel drum, with some smaller quantities in smaller plastic containers.
I have a hand pump, which I left sitting in the drum for about 4 days.
There are 2 things that concern me:

1. As the drums were storing oil before, I did expect some of the old oil to get mixed in the fuel. It is actually not really such a great concern, but I've noticed that one of the plastic containers that I has biodiesel stored in got a nice black residue on the bottom. There was also a small amount of grit and stuff that I guess the fuel fitler will take care of. The plastic container was 100% clean before filling, so it came from the steel drum it was pumped from. It may be worth thinking about this, as your fuel filters may get blocked a bit quicker from this.

2. What did concern me was the sludge that started to grow on the pipe of my hand pump. Is the biodiesel reacting/oxidising with it? Would I be well advised to add some biocide now? I did not seal the drum, while the pump was still in it, so it has been getting fresh air for a few days. Has anyone seen this sort of stuff before? It was a little bit gelatinous and gooey. You can see the line on the pipe where the level of biodiesel was up to inside the drum. I also ran my finger along the pipe and picked some up.

As this is all quite new to me, I'm not sure if this is normal or not, so I just thought I'd share it here and see what everyone else thought.

[Terry Syd Senior Member Find all posts View Profile Close Terry Syd]

Re: Storage Sludge?

Robert, I don't know what that stuff is. The picture of your finger told me more than the other pictures. It looks like it could be glycerine or unprocessed grease.

Take some of the 'stuff' and see if it is water soluable. If it dissolves into a white liquid, then it is glycerin/soap left over from the processing. (which would be unusual as the biodiesel you have is supposed to be commercial biodiesel)

If it does not dissolve in the water, try heating it in a spoon. If it melts than it is likely it is unprocessed grease.

[Robert Administrator Find all posts View Profile Close Robert]

Re: Storage Sludge?

Great idea, but silly me -cleaned off the pipe after I took the photos

It was suggested that perhaps the biodiesel was a little acidic hence the reaction with the pipe. I don't have any means to test the PH, besides my pool water test strips. I'm sure that these are highly unsuitable, but I tried anyway - nothing to lose and they showed 7.

I might go and see if I can scrape some gunk off the inside of the pipe and see if I can do the suggested tests with that.

The pipe has definately had a reaction, as after I wiped the gunk off the pipe, the metal has discoloured below the line of the level of biodiesel it was sitting in.

[dillyman Senior Member Find all posts View Profile Close dillyman]

Re: Storage Sludge?

Hi Robert

I have seen this reference on an overseas forum. The suggestion I believe was that galvanised steel can have this kind of reaction. I personally dont know but I wonder if it is a possibility, any one with some know how, care to comment, will follow comments with interest.

Rgds,

Dillyman

[Robert Administrator Find all posts View Profile Close Robert]

Re: Storage Sludge?

OK. I went and looked on the inside of the pipe, which I had not cleaned off to look for some more sludge to test.

No sludge there

Why not?

I disassembled the hand pump, removed the pipe and unscrewed the 2 sections. There was nothing at all on the inside of the pipe - completely clean. The outside of the pipe however still shows a definite discolouration from below the level that the bioiesel covered it. I tried washing the pipe with water first, then with detergent. Now I have nice clean pipes, but the discolouration is still just as clear as it was before.

I've decided that the outside of the pipe was probably painted/treated to make it look nice and shiny. I'd guess that petro fuels would not harm this paint or coating. However, biodiesel eats it.

After I'd removed the pump, I left the bottom of the pipe sitting in a small jar to catch the drips and stop them staining my garage floor. As the biodiesel collected around the base of the pipe, it ate even more furiously (probably reacted faster due to more contact with the air in the transfer.)
I've attached one more shot, where you can see the silver paint/coating has been removed at the very bottom. You can also see blotchy bits further up where the paint/coating has been eaten less. Additionally, you can see some of the inside of the pipe through one of the holes, which is completely untarnished.

I'd guess the sludgy stuff in the little gelled clumps were the bits of oxidised coating.

Lesson learned: Don't leave your pump/pipes in the drum when you are not using it.

(sorry, I just saw Dillyman's post sneak in while I was writing this one - yes, it looks like you were right!)

[Terry Syd Senior Member Find all posts View Profile Close Terry Syd]

Re: Storage Sludge?

Robert, now this is weird. I had heard of the zinc in galvanising developing a slime when it was in contact with WVO or SVO due to the FFAs in the oil, but never biodiesel. This was one of the reasons that when people put together a processor that it is recommended that only black iron pipe be used.

Here is a link to something Tony posted over on inforpop -

http://biodiesel.infopop.cc/groupee/...4951#433604951

I am beginning to think that biodiesel you have contains FFAs in it. Hmmm, now how could that happen? Perhaps a commercial decision to have a short acid wash to quickly get rid of residual soap in the biodiesel???

If you are going to pick up some biodiesel from Rutherford, then maybe you can try duplicating the same scenario with the Rutherford fuel. Just put a length of galvanised pipe in the fuel and see what happens.

If you start making your own biodiesel this shouldn't happen (especially with unwashed biodiesel). If you wash, you just leave a bit of soap in the fuel to neutralise any acids in the fuel system.

[Robert Administrator Find all posts View Profile Close Robert]

Re: Storage Sludge?

Strange. Do you think there might be any tests that could be done on it to determine what the real story is? I wonder if this biodiesel really does meet spec?

I'd be happy to drop around a sample to anyone capable of having a go at testing it.

Otherwise, I will definately have a go at the same bit of pipe in some of the rutherford fuel, if and when we can get some.

[Gunner Donating Member Find all posts View Profile Close Gunner]

Re: Storage Sludge?

OK. I went and looked on the inside of the pipe, which I had not cleaned off to look for some more sludge to test.

No sludge there

Why not?

I disassembled the hand pump, removed the pipe and unscrewed the 2 sections. There was nothing at all on the inside of the pipe - completely clean.

I am wondering on the condition of any of the seals or O-Rings in the hand-pump? I thought the black sludge may have been from a reaction with natural rubber seals in the drum bung or hand pump being dissolved. Were the pump seals swollen or tacky at all?

[Robert Administrator Find all posts View Profile Close Robert]

Re: Storage Sludge?

I wondered the same thing, but when I pulled the pump apart, inside it was squeaky clean. The pump was brand-new and it has hardly pumped that much biodiesel yet. Also, only the pipe was sitting soaking in the biodiesel, the pump was above it and dripped dry. No seals look damaged or swollen at all yet.

[Cameron Moderator Find all posts View Profile Close Cameron]

Re: Storage Sludge?

Hi Rob,
When I was changing my fluids and filters on the weekend I discovered some yucky dark sludge in the glass bowl of the CAV filter in my landrover defender.

I stripped the filter unit down and cleaned it all and replaced the filter element.

The scudge I cleaned out of the filter bits and pieces was VERY similar to what you have described in words and pictures.

Same biodiesel batch as yours. Yes Terry - commercial bd from Central Coast plant.

VERY glad I had the CAV filter so I could see what was in there and drain it off. I saved it into an empty softdrink bottle.

Will have to check the fuel sedimenter too now - I am worried about it! I would have checked it before but I have had the little plastic bleed screw out a few times without incident and I hear they break pretty easily and so didn't want to tempt fate. A couple of new spares have arrived in teh post so will plan to drain out the sedimenter in the next day and strip down and inspect/clean the sedimenter better as soon as I get a little bit of clear time.

The fuel in the glass bowl looks good now. Will keep an eye on it.

For the record I ALWAYS add biocide to my fuel to seperate any water and clear out any algae just in case. Generally I use Fuel Doctor.

Any sludge coming through in my car shouldn't be dinodiesel sludge cause I have hardly had any dinodisel in it for about the last couple of years.

Will be keen to keep an eye on it all .... would be good to hear news from other group members who also got fuel from that first pick up.

Cheers,
Cameron

[Robert Administrator Find all posts View Profile Close Robert]

Re: Storage Sludge?

I'm currently conducting an experiment on the same piece of pipe that got the sludge before. I checked on it last night, but could not see any change. I'll give it a few days and see if I can get the same symptoms to appear. It's a little worrying that you've got stuff in your CAV that you've not had before. At least you've kept a sample. I've also managed to get my old dead pump back, so I'll cut it open and see if I can find what killed it - there may be sludge there.

[geewizztoo Senior Member Find all posts View Profile Close geewizztoo]

Re: Storage Sludge?

Robert, I may be missing something here but have you tried washing the the two biodiesel samples with water? If the commercial bio is unwashed then the sludge may be Glycerine and will be caustic (alkaline). As you probably know, alkaline solutions attack aluminium and zinc (galvanise). Try mixing equal quantities of the bio with warm tap water in a pop bottle. Gently invert the bottle a few dozen times, leave stand for a few hours. If the water turns milky white then there is still soaps, & maybe glycerine/methanol suspended in the bio.

[joe Moderator Find all posts View Profile Close joe]

Re: Storage Sludge?

Robert, I may be missing something here but have you tried washing the the two biodiesel samples with water? If the commercial bio is unwashed then the sludge may be Glycerine and will be caustic (alkaline). As you probably know, alkaline solutions attack aluminium and zinc (galvanise). Try mixing equal quantities of the bio with warm tap water in a pop bottle. Gently invert the bottle a few dozen times, leave stand for a few hours. If the water turns milky white then there is still soaps, & maybe glycerine/methanol suspended in the bio.

Nice answer. How did you go with this Robert? If the bd has been washed well enough the water should remain clean and clear.

Joe

[Fat Man Junior Member Find all posts View Profile Close Fat Man]

Re: Storage Sludge?

Hi Cameron

This may sound silly but what is a CAV filter and where do you get them, I remember old 60's holdens used to use some kind of glass bowl as well, I think they were the fuel pump but not sure

The Fat Man

[Gunner Donating Member Find all posts View Profile Close Gunner]

Re: Storage Sludge?

The CAV filter is a stand-alone fuel filter unit with replaceable cartridges and a glass sediment bowl. Lucas/CAV have been bought out by an American company and now trade as Delphi. As soon as I can work out how to put up some pics, I can show you. The benefit of these units (Vary between $80 and $100 depending where you buy them), is the cheap cost of the filter cartridges (From $4.50 to $8). This good feature has been used by Denco Diesel in Wagga who have made adapter units to use the filter cartridges and fit them to the standard factory fuel filter mount in most diesel 4wd's and commercial vehicles. These adapters are available from Denco Diesel or from many diesel mechanical workshops and 4wd stores around the country.

The filter elements are widely available as the following part numbers:
Lucas/CAV: 7111-296
Delphi: HDF 296
Ryco: R2132P
Fleetguard: FF167A

PS I note that Denco's pricing mentions a discount for bulk purchases. Would there be any interest in a few of us getting together for a bulk buy? You only ever need one adaptor and you just change the filters, so there's no need to buy more than one for yourself, unless you are interested in reselling them on e-bay!