A strange crust developed on my heating elements

[tpendergraft]

During the wash/drying phase I am developing a crust on the water heater element that I use to heat the liquids involved. Should I be concerned about this crust contaminating my process? I do filter as follows after drying:

200 micron inline screen -> 30 micron fuel filter -> 15 micron water block -> 10 micron fuel filter -> 2-5 micron fuel filter

I would assume that this will remove any crusties before I add the fuel to my tank.

[girlmark]

I gotta say you've got me on this one. I haven't seen this. However, filtration to 5 microns or so should take care of any particles so I personally don't worry about things like rust in a wash tank or other foreign matter before the filtration stage.

Mark

[Spencnaz]

Can you post pictures of this 'crust'? I have a feeling that there might be something flocculating on the heating element.

[tpendergraft]

The crust is hard to get a picture of but it is kind of like a hardened film that flakes off when you touch it. Similar to the burnt scrapings from the bottom of a skillet. I think the filtering should take care of it.

Its discouraging to see it though in the water heater/processor. I can only heat the oil in the processor up to about 100F and after turning off the processor and draining all of the oil into a barrel and then heating it up to 130F with propane am I then able to put the oil into the processor for conversion to biodiesel.

While the oil was heating in the drum with propane I took out the heating element and it was covered in this crust, which I guess was keeping it from efficiently heating the oil/methoxide mixture. I did verify that it is getting the whole 240V and the thermostat was even taken out of the loop to ensure that the element was heating. We also tested the thermometer in the system and it is accurate. I really don't know what to do about this. For now we are just heating the oil to be processed using propane, I hate to waste another heating element at $10!

Any suggestions?

[scottefontay]

Is the crust forming on the element when you are heating the oil prior to adding the methoxide? When heating and dewatering I have had instances oil was burnt by the element and formed a black and brown crust on it. The stuff came off the element when I bent it a little. It also dissolved in reacted biodiesel on another occasion.

[Huff]

I looked at a few elements the other day at Orchard Supply Hardware, most of the ones I looked at were zink plated, that may be the crust your seeing as the methoxide is going to chew the hell out of it.
I did manage to find a 3800 watt stainless steel one made by Kenmoore, can't recall the part number off hand but I still have it if need be. It was $17 and the others were around $7.