I built an Appleseed, and have made about 400 gallons of biodiesel.

I let the last batch mix for an hour or so while I had dinner. When I came back out, the pump wasn't running. I checked breakers and the plug, and finally took the cover off the wiring block. It was all black inside. The pump burned out.

Anyone else had such short lifetimes with Harbor Freight 1" water pumps? I'm loathe to replace it with the same thing, if it's just going to die after a few tens of hours of use.

My theory is that pumping oil is too much work for it, especially since the weather has turned cold. But if others have been using it for long periods without problem, I'll chalk it up to a bad sample and replace it with the same.

There's been a lot of reports of this lately, whereas I don't remember hearing that much about this problem in the first couple of years of the Appleseed. I think perhaps there has been a rash of poorly-built HF's more recently? It seems like the Northern Tool pump hasn't had any such problem.

You are lucky. Mine nearly burned my garage down, but then again mine wasn't on a proper GFI outlet. RickdaTech sells a similar pump with thermal protection.

Thanks for the good info.

Now that I have to replace it, I'm thinking twice about having any kind of a centrifugal pump in there, Harbor Freight or other. It is very difficult to prime at times, when I'm filling the tank from a dip tub into my 200 liter collection barrel. I end up putting the whole thing under vacuum in order to get it going. (Once it's primed, I can take the vacuum off.)

So I'm thinking of putting a positive displacement pump in. I have one of those 12V Northern Tool fuel transfer pumps, but I'm concerned about its 30 minute duty cycle. They get quite hot when pumping dumpsters during collection. (It would be a much more expensive burn-out than the HF water pump!)

Any recommendations?

Stick with a centrifugal pump and use a gear pump for moving liquids around. Fill your processor some other way.

I have no problem priming the pump (this might vary based on the amount of biodiesel that stays behind when you empty the last batch out of the tank), but what I do is stick the short fill/drain hose into a bucket, clamp the hose in place so it can't flop out, get the pump started, and pour cubees of oil into the bucket before the pump empties the hose from any one batch. If you're already storing the oil in a drum this isn't a good solution of course. Having a standpipe-style tank as a hopper for dispensing your oil into your pump is another good solution.

I use the vacuum method to prime the centrifical pumps too. It works pretty well and doesn't take that long if you are filling from a drum or other big container.

quote:

Originally posted by girl mark:
Stick with a centrifugal pump and use a gear pump for moving liquids around.

Just curious why you say this, Maria. Is it because positive displacement pumps are more expensive?

Certainly, there's not much danger of building up high pressure in a mixing application -- unless you do something stupid like close all the valves. Okay, I guess I get it. :-)

quote:

I have no problem priming the pump... stick the short fill/drain hose into a bucket, clamp the hose in place so it can't flop out, get the pump started, and pour cubees of oil into the bucket before the pump empties the hose from any one batch.

My problem is that I don't get my oil in small containers; I'm pumping out of drums. With one exception, restaurant owners here are unwilling to change their habits one bit for me. One restaurant is putting the oil into two 20 liter buckets for me each week. But the others, I pump from a drum, then pump it into a 1000 liter fuel oil tank as an input buffer, then I pump it into the processor.

I plan to elevate the input tank enough to gravity-feed the processor, but I'm not there yet.

So it sounds like the consensus is to avoid the Harbor Freight pumps, even though they look identical to the Northern Tool ones.

I use the sucker tank's refrigerator compressor to pull a slight vacuum on my processor thus priming my harbor freight pump; then it will suck my oil out of my storage barrel.

Okay, I talked to the great folk at Fisher's Supply, in Canby, Oregon. After describing my application, they said the critical issue was the motor temperature rating -- motors like those in the Harbor Freight 1" clear water pump are not designed to work at the ~150 degree fluid temperature of the Appleseed processor.

They sold me a Taco 007 (James Bond edition? :-) It is designed for (among other things) heated water pumping. It is a flanged pump, so you don't need a union between the pump and input manifold. It is also small, lightweight, quiet and efficient (81 watts). It is rated for a maximum fluid temperature of 115C (240F) at up to 125 psig.

It is a sealed cartridge pump, with all moving points immersed in the medium, and all electrical parts physically isolated and non-moving. It's rated 15gpm at five feet (about the head of this application).

I've made three 120 liter batches since I put this pump in, and it seems to be working well.

It has similar priming characteristics to the Harbor Freight pump -- I still use vacuum to load the charge. But the quiet operation alone is worth the switch to me. (Although it's kind of scary to be able to hear all the gurgling that goes on within an Appleseed... :-)

However, at $90 (including flange kit), it is three times the cost of the Harbor Freight pump. But if you just spent over $200 for a water heater, it seems like a tiny incremental expense for a pump that was actually designed for heated fluid service.

I was a bit concerned about it's ability to handle viscous fluids. Indeed, at near freezing temps, it would not pump cold oil into the tank; the vacuum pump did most of that work. The salesman assured me that from the pump's point of view, the viscosity was immaterial, since it was rated for "infinite head" -- in other words, pumping into a brick wall.

I'll try to get some photos up here if there's any interest. Since you can get the flange kit in different sizes, it also eliminates the two 3/4"-1" bushings required by the Harbor Freight pump.

Plus, it's made in Canada, rather than China. So Americans should buy these before the US Dollar really tanks! :-)

I'm curious, I see that you have quite a fleet of diesel engines. With 120 liter batches, are you able to keep up with your demand?

quote:

...you have quite a fleet of diesel engines. With 120 liter batches, are you able to keep up with your demand?

The "fleet" doesn't move much. I'm collecting from five restaurants, and have way more than I need. I distribute it to friends and neighbors for voluntary contributions.

There, fixed my signature so it's not so embarrassing. I hate it when people have signatures longer than their messages, but I slowly went there.

My most recent addition is a3" "semi-trash" diesel-powered pump. I plan to use that to bring irrigation water up to the garden from our pond.

Let me know if anyone is interested in photos.