Hey guys,
I have a GMC bus with a 8V71 Detroit in it that I am converting.
My questions are:
- Can copper be used around WVO? I heard it would do something to the oil.
I want to make a "tube in tube" inline heater using engine coolant. I also want to make a heat exchanger in the tank right at the outlet to help heat the tank and start the line heating.
I am also considering an inline heated filter and/or a flat plate heat exchanger.

- I am also making my WVO tank, 200 gallons, for in my bay and wanted to know if plain steel would be ok or if I needed to use stainless steel? ( I have a welding fabrication shop)

And one more quick question: Is the low linolenic soybean oil that KFC uses ok to use. I will be centrifuging it to clean and de-water it. (I have excellent access to this oil)

Thanx!!!!
Chaz

https://www.greenroadenergy.com/images/vegetableoilasfuel.pdf

might want to read
vegetable oil as fuel
by Joe Beatty

good luck
Omar
www.omarsales.com

This message has been edited. Last edited by: Omar,

Skulptor,
Copper is highly reactive with VO and should be avoided, as should mild steel, brass, zink, and lead [solder]
Stainless steel and aluminum are the best choices, and fortunately, aluminum tubing as much cheaper than copper.

It's available @ www.mcmastercarr.com

KFC oil will be fine, so long as it's heated sufficently to melt the "animal fats" that will be suspended within the oil.

I use mild steel all over the place in my system and it gets a slight buildup of funky brown stuff on it.. mostly where the oil is in the presence of air (like in the tank) However, mild steel is cheap and easy to work with, whereas aluminum and stainless are more difficult because they require dedicated equipment.

quote:

Copper is highly reactive with VO and should be avoided, as should mild steel, brass, zink, and lead [solder]
Stainless steel and aluminum are the best choices, and fortunately, aluminum tubing as much cheaper than copper.

Highly reactive is a misleading term. IMO "reactive woudl be more accurate.

Certainly you don't want to make an entire fuel tank of copper or brass. Nor do you want to mix finely ground metal of any kind into VO unless you want to promote polymerization. But use of these metals have not been shown to cause any actual problems except in very rare cases. The most serious problem that has been reported due to polymerization has been excessive filter clogging...and this has usually been associated with high water levels in VO fuel COMBINED with use of these metals. High water levels in VO fuel will cause much more serious damage than polymerization possibly can.

Even aluminum and stainless steel are reactive with VO.

You have entered into a debatable area. You'll just have to read and decide for yourself about copper, and mild steel. Some would say that Pir8Darryl's statement of "Copper is highly reactive with VO and should be avoided" is a gross overstatement based on the large number of wvo powered vehicles that are successfully running with copper thru out there plumbing. While others might say that statement is half true or less if the oil is properly dewatered. With the caveat that the less dewatered, filtered etc. the more that statement becomes fully true. Reading up on copper and polymerization will help you decide what degree of risk your willing to take by using any copper. A lot of copper you can avoid though as mentioned with aluminum.

Mild steel's reaction with WVO (polymerization) seems to me to have a lot to do with air or lack of it. Reading of threads in here on Polymerization will help you decide what degree of risk your willing to take by using mild steel.

One of the debates of Mr. Beaty's report is that the method used to "accelerate" the polymerization so the test would not last 10-50 years.... is not real world enough. Thusly some feel the polymerization in the test that did occur.... in real world use it might not have at all or may have only done so to a small degree which would end up being of little significance. This is such a new field there are no cut and dry answers. It's growing and revaluating itself all the time.

Check the thread Omar started that is a collection of ideas for tank construction etc. Some great suggestions in there that could help you further avoid some of the metals that are debatable when building your tanks; like mild steel.

HIH or HOH is another full debate. One advantage of HOH is there is less metal at all used. It can most all be; using the proper synthetic tubing, completely non reactive to the oil. This may greatly lesson the risk of a few copper things here and there.

As to zinc and alloys with zinc in them... Most everyone agree's about galvanized pipe etc is a big no nocause of its zinc content. Alloys w/zinc in them is sorta like copper. Lots of it in use out there (filter heads) w/out problems and some who feel their problems had something to do with their zinc content) Not sure you how much you can avoid this one though (alloys w/zinc). So just dewater good (*in a manner takes the acids out too) and keep your eyes on the filter heads looking inside them at times to decide if it looks or feels like their structure is breaking down.

*for example just steaming it out leaves acids in the oil. Only the H20 escaped.

This message has been edited. Last edited by: jeepin, moggin Jessup (coachgeo),

Hey thanx guys!!

That was a great link, Omar. But I'm kinda bummed that copper and mild steel should not be used, as it is more readily available for me, but I want to do what's best. Aluminum seems to be the next best choice altho I love working with stainless.

Thanx for the link, Darryl. I may use them if my supplier can't get me what I want.

Greasy,
I would still like to use mild steel, but not sure if it is a good thing or not. From what I read, I am a little hesitant. But I am also curious about what the "real world" experiences are. Plus, I wonder if having a 200 gallon tank in a bus would have any other impact? Like, should I keep it full? Or drain it when not using it? I won't be using it as often as someone would their car.
Thanx again guys. I really appreciate you and your time.
Chaz

Thanx George. Our posts must have been at the same time!
My guess on copper would be that if it passed thru - such as a tube - it wouldn't be so bad, but I don't think I would want to have it in contact "long term", such as in a tank.
I was thinking maybe coating a steel tank. Any suggestions on what to use there? I would have to weigh the cost and time involved. I'll look into Omars thread if I can find it.
I'm not sure about the synthetic tubings. I guess mainly cause I just don't know much about them. But PEX is easy to use.
Thanx again,
Chaz

Time, temp, air, type of VO, and metals can all cause your VO to oxidize and polymerize (in decreasing order of importance.) The metals you use is one easy thing to control, so thats one place to focus even though its the smallest factor. And the tank is the main place to focus since thats where there is lots of air. The other variables I list are harder to control and your results will vary hugely depending on how you control them. VO sitting in a steel tank for a long time leads to many poly stories I have read, and have personal experience with.

quote:

Originally posted by Skulptor:..
I'm not sure about the synthetic tubings. I guess mainly cause I just don't know much about them. But PEX is easy to use.

Don't have to go that fancy. Quality regular newer style fuel hose work fine with WVO fuels. That's all the special synthetic you need for HOH. Bundled tightly with quality coolant hose and insulated well you should be good to go.

Think the term you want is Butyl? when getting fuel hose/line that is compatible with WVO. Search for that in here to see if my memory is right.

Thanx again guys!!!

Sun,
While I may have you attention right now, I just want to give you my heart felt thanx for all you have done in this area! Seriously. And I know there are many others to echo my sentiments.
I have read MOST of the long thread on your centrifuge project and was so inspired that I have my centrifuge coming in tomorrow (I think).
I would love to post the whole plan for my WVO intentions (gathering, processing, use in my bus, use in my heating oil stove) so you -and others- can critique it at some point. I'll post it in another thread soon. But for now, I need to figure out my materials. Since time , temp, air and type VO are all things of concern, I guess I should look at all that before I get started also.

Thanx George. I'll check that out. I have 2 buddies that own different auto parts stores. They should be able to help me. But I was also wanting to "fab" up some cool "stuff" and maybe even come up with something I can contribute to the "community". (I have a welding fabrication shop) But as with anything, I need to first get an basic idea of whats going on and what can be done. I don't want to have to "reinvent the mousetrap".
Thanx for the help so far!

Chaz

Having ditched metallurgy class I'd appreciate some 411; I read a lot of mention of "mild steel" and wonder what this includes? I've seen tanks made from what I call sheet metal 12 to 18 gauge, is that mild steel? Likewise eight and quarter inch what I call plate steel; it that mild? Aren't there a great number of systems employing original OEM diesel fuel tanks in vehicles for veg oil which incorporate small 6 gallon dino tanks for starting and purging? What are those tanks made from, are they mild steel? Earlier I mentioned that I had been advised that 1/4" plate was overkill but no one said anything that I recall about plate steel having metallurgic issues with VO. If "mild steel" is a real and serious issue and not a 'chicken little' calamity, what if anything has been shown to be an effective coating/sealant for mild steel? Folks are welding two ends of metal drums together; are they mild steel? If aluminum is the only safe bet or something inert like a plastic, will someone just spell it out for me?
Choice of material for a tank is my last major step I need to get finished before I can start installing. It has ended up being the last thing as it has from the beginning, for me, been the biggest unknown.

Basically everything you mentioned in your post is mild steel. As far as i know, stock tanks are mild steel, also refered to as just steel, unless they would happen to be plastic.
I'm new to this also, but my guess is steel can be used just fine. Aluminum is better and stainless is also good.
There is a tank sealer called Red Cote (seen it on another thread and have used it on my harley tank) that is supposed to be ok for WVO. I love it on Harley/bike tanks. You could do that to hedge your bet.
1/8" or what is known as 11 ga. is WAAAAY overkill for most tanks. I may go with something close to that because I am talking 200 gallons. But as for your question, steel is steel. Unless they specify something else. (IE. stainless, etc)
Hope that helps!
Chaz

With respect; I have read enough posts stating what seemed to me to be clear warning against the use of mild steel. I'd like a little stronger assurance then a guess. Lacking scientific references to data on the subject a little empirical evidence would be good.

Thanks for the clarification on steel is steel, that helps. I think I need to find a chart on metal thickness and what gauge equals what, I never knew 1/8"=11 gauge.

There's some practical knowledge to be had from old oil-paint preparation methods. Oils were boiled with different metals, then mixed with pigments to make oil paints that dried quickly. This is also known as oxidation and polymerization.
Lead in paint is a powerful drying agent, followed by iron, but they made the paint dark, limiting the pallet of colors. Zinc and copper reportedly initiated polymerization fastest, so they needed to be used immediately before needed, or they'd dry in the pot.
Mild steel contains iron, which will initiate polymerization in a nice controllable fashion, for painting purposes, but that's really quite different from our concerns. Oil that's boiled with iron or lead has a shelf life as paint of weeks or months. When spread as paint and exposed to the air, it will setup in a day or two. That sounds frighteningly fast when I think I'm putting that stuff into a fuel storage tank I expect to last for months. What's the difference?
To make paint, first choose a readily oxidized oil, like linseed oil (I hope you've heard of "boiled linseed oil"). To prepare it for paint use, heat to 450F (boiling) in a pot open to the air with a large quantity of iron flakes or lead balls for a day or two. Let cool, mix with pigment, seal in a jar, and it must be used within a few weeks.
This is so far from what we do when making SVO or biodiesel that the results should be dramatically different, and they are. Our soy oil (less easily oxidized than linseed) is only heated to perhaps 400F in the stainless steel fryer for a day, without iron flakes or lead balls. After we get it, it's heated to perhaps a maximum of 250F (to boil off water) in the presence of mild steel (containing significant iron, but not "pure iron") for a few minutes, then filtered or otherwise processed. It is then stored in mild steel at room temperature, commonly without much air circulation.
Under those conditions, it would be expected to take months to oxidize/polymerize enough to effect it's fuel characteristics (viscosity being the principal one). In my experience, a year of storage in a plastic tote is safe for SVO, and up to one year in plastic tote followed by one year in mild steel is safe for biodiesel.
Extrapolating these items, I would postulate that svo that has been exposed to copper, lead, zinc, or iron for short periods at temperatures less than 250F, followed by storage in the presence of mild steel at room temperature, is suitable for use as svo.
In addition, I've read reports that indicated that the characteristic "painty" odor of aging oil preceeds polymerization by hundreds of hours. So, if "painty" odor is noticed during refueling, go ahead and use it, but begin watching for signs of increased viscosity.
I'd even go on to predict that oil stored in galvanized (zinc) or coppper tanks will develop "painty" smell sooner than oil in steel, and the best storage tank would be plastic.

quote:

Originally posted by johno:
In addition, I've read reports that indicated that the characteristic "painty" odor of aging oil preceeds polymerization by hundreds of hours.

Hundreds of hours would be about 8 days?

I have had dewatered, filtered VO stored in a half full steel barrel at room temp develop large amounts of poly in 2 months. Such as a thick skin on the top and chicken skin on all the sides. Plastic barrels have always been fine with the same conditions for at least a year.

On the other hand I have stored prefiltered dewatered wvo for over 2 years with no signs of polymerization at all. I have found that the degree of dewatering is VERY important in inhibiting long term polymerization.

quote:

develop large amounts of poly in 2 months. Such as a thick skin on the top and chicken skin on all the sides. Plastic barrels have always been fine with the same conditions for at least a year

That's about the same as I've seen. I'd like to emphasize that my references to "polymerized oil" mean the bulk of the oil thickening, not just a layer of "chicken skin", which (as I understand it) is polymerization driven by oxidation, which happens quickly when exposed to air. The presence of the steel does seem to accelerate it, although the metal will also promote condensation a bit more than plastic, and the water doesn't help. I've had best luck storing in a tote filled nearly to the top and sealed. After a year it smells "sweet", like fresh oil (and started as filthy used cooking grease, stored for a few weeks in wet steel drums, then boiled dry at 250F, ran through a copper heat exchanger, filtered through a Luberfiner filter, then pumped into the tote).

Without the polymerization report in front of me, I don't recall the actual time scale between smell and onset of bulk polymerization, other than it took several hundred hours (a few weeks) before a change in viscosity was detectible, and might have been into the low thousands. The thickening due to polymerization then progressed exponentially, but didn't double in viscosity for a time period roughly equal to what it took to become detectible, as I recall. My own observations support this rate.
Dry, filtered oil stored in sealed plastic seems to keep for very long periods, certainly up to a year safely, in my experience.
Thanks for the supporting info.

I don't know if this was mentioned but the Grainger catalog has a chemical compatibility chart. They have about 1000 different chemicals rated with about 25 different components they then rate 1-5 on how compatible they are. It includes about 5 different types of veggie oil. I couldn't find the chart online but you can order a catalog online.

Just in case any others are considering building a tank, here are the prices my steel supplier faxed me today. This is for 4'x8' sheets:
1/8" aluminum- $179.20
1/16" 304 stainless,- $268.00
1/16" C.R.(mild steel) $45.20

I do believe steel will be my metal of choice! But I think I will Red Cote it also.