Filter Press not Filtering?

Last Saturday I set up to filter the last 15 gallons of my bulk 2020 stored syrup. Reheated my syrup in 5 gallon batches in my huge 30l stock pot, added the DE, and started to pump (manually) through the filter back into the stock pot. Usually, within a minute, the syrup is sparkling clear, so then the hose goes into the bottler. But this time, no dice. I filled a jar to take a closer look. It was just as cloudy as the syrup in the stock pot. I kept pumping thinking the plates needed time to fill up, but no change. Everything seemed to be normal; no leaks, flow the same. ???

I finally gave in the broke down the press (no so much fun when it's 200F). I took the plates off one at a time, expecting to find a blown out paper. But there was none. One paper had a small tear on the outside edge which would not have been exposed to the open area inside the plate, and I may have torn it pealing off the paper. The plates were not full, but I had not run more than a few gallons through. Papers were coated about 1/4 inch, but not evenly, and the back plates not as much. It's not possible to put this press together wrong, due to the design. So I still had no evidence of what might have happed.

Everything was cleaned and reassembled with new papers. I added about 2 cups more DE to the pot and started pumping again. Within a few seconds, the syrup was sparkling clear. And so it went until I finished filtering all the remaining syrup.

Anyone ever have anything like that happen? I saved the papers and will take another look. Barring a mechanical assembly error, it seems like one or more has to have failed, allowing the cloudy syrup to pass through.

I bet something was assembled out of order or backwards. There are different levels of "not possible put together wrong" and you may have found an exception! Was it easier than normal to pump?

Pumped with the same effort and moved the same quantity.

On the Smokey Lake press, the hangers on either side of the plates are offset, so it would be impossible to turn them around and run the press. This is a short bank, three window plates, two solid inside plates, and an solid end plate. The first solid plate is not removable, and the end plate is obviously the end plate, but if you put it in early, it would just shorted the press, not cause it to fail.

However, it is always possible to screw things up, no mater the design. What bugs me is I can't figure out what it was.

I would lean towards you didn't use enough D.E. the amount of D.E required can change over the course of the season and the fact that you added 2 more cups is notable.or you had a tear in one of your papers and didn't notice it.

Although the hangers are offset the end plate can be rotated 180 degrees thus the outlet hole will be on top instead of bottom.We struggled with this same problem til we discovered this.Now we have end plate marked with arrow with "this side up" engraved on it.

i would bet, you did have a paper issues and couldn't see it. Under pressure a very tiny hole would let a lot through. And usually cloudy is very tiny particles

Here's what happens if you reverse a plate:

Attachment 21424

I'm leaning towards a paper issue of some kind. I just went back and looked at the papers again, but not seeing anything obvious. The plates leave an impression on the papers, so I can see they were all inserted correctly, with the holes aligned with the holes in the plates. Either that or not enough DE in the the first 5 gal batch. I think I put in 4 cups to start. The capacity is 9 3/4 cups.

<The plates were not full, but I had not run more than a few gallons through. Papers were coated about 1/4 inch, but not evenly, and the back plates not as much. >

Your answer is in the second sentence..."and the back plates not as much"
I think you may have been light on the DE and, if not, you didn't circulate long enough to coat the plates. You need at least a 1/4" cake to effectively filter...more is better
I don't think one minute is long enough to let the papers catch the DE., or let the DE build-up on the papers.

I have a Leader Clear Press (ask Fred!)...you'd be surprised at how long it can take to build up a cake on the papers...for me, it can be 3-4 minutes and that's with a fairly high-volume pneumatic press.

All of your responses just got me thinking about this more and more. So I just made a trip out to the shack to try something. While you can't reverse or insert the inner plates upside down, you can assemble the end plate upside down. Having done so, there is no seal between the filter paper and the inlet/outlet ports. So, the unfiltered syrup can pass through the inlet/outlet holes in the filter paper, and somehow find it's way to the outlet port. This explains why there was so little DE in the last chamber, as there was an easier way for the syrup to exit rather than going through the paper. Checking the filter papers again, I found that the one against the end plate did not have the same impression around the inlet/outlet ports as all the others, and it also had the least amount DE caked on the paper. I'll reaffirm this tomorrow when I have better light.

So you can put this together wrong with regard to the end plate, although you do have a 50/50 chance of getting it right if you are not paying attention. I will be embossing the "UP" side before I use it again.

I've seen a good number of presses where people will score, file, or grind a line across the top of the plates so they can see at a glance if all the plates are in correctly.

First boil this year we put the end plate upside down on our 10”.