Print washer separator question

[snusmumriken]

The separators in my 'archival' FB print washer have one smooth side and one textured. The manufacturer's instructions state that prints will be washed most [more?] effectively when their emulsion sides face the textured side of the separator.

That surprised me. Is it really true? My inexpert understanding was that the emulsion is relatively easily washed, and that most of the contaminants reside in the fibre base. So if the fibre side rests against the smooth surface of the next separator, I would expect it to wash less effectively.

Anyone know if there are studies on this, or have an insight either way?

 

[Pieter12]

I don't know about the particular washer you have, but my Zone VI washer is completely constructed of smooth acrylic. When the water is flowing through the washer, nothing should stick to anything.

 

[Paul Howell]

My archival is an off brand, made of smooth acrylic, but seem that that a textured surface would help prevent the paper from sticking the the separators.

 

[RalphLambrecht]

The separators in my 'archival' FB print washer have one smooth side and one textured. The manufacturer's instructions state that prints will be washed most [more?] effectively when their emulsion sides face the textured side of the separator.

That surprised me. Is it really true? My inexpert understanding was that the emulsion is relatively easily washed, and that most of the contaminants reside in the fibre base. So if the fibre side rests against the smooth surface of the next separator, I would expect it to wash less effectively.

Anyone know if there are studies on this, or have an insight either way?

If uncertain, always trust the instructions.

 

[logan2z]

I'm not sure which brand of washer you have, but I have a Nova Ecowash and it also has dividers that are textured on one side, and they also advise to insert the prints with the emulsion side facing the textured side of the divider. I've never questioned it, I just follow the directions.

 

[snusmumriken]

If uncertain, always trust the instructions.

Haha! Sorry, Ralph, but that goes totally against my nature. OK, as a starting point it seems the only supported option thus far, but I'm a scientist: I question everything until convinced. As the author of 'Way Beyond Monochrome' I thought you actually shared that tendency?

 

[snusmumriken]

If uncertain, always trust the instructions.

In 'Way Beyond Monochrome' [a really thorough book which has greatly improved my printing and presentation - thanks, Ralph Lambrecht] p45:
"Thiosulfate diffuses from the print emulsion, during washing, with relatively little resistance. Paper fibres and the baryta layer, on the other hand, have a tendency to adsorb residual thiosulfate, which can render washing into a rather sluggish process."

This is in part where my understanding of the situation comes from, but I have seen a similar statement from Ilford. If the print does not adhere to the separator at all - as in Pieter12's Zone VI - and water flow is plentiful, there is arguably no problem. My washer (a recent purchase) is a Nova Ecowash, as logan2z recognised. My experience so far is that neither side of the print sticks to the separator once it has been in there for a couple of minutes: you can bob the prints up and down by pushing on them with a finger. Sliding wet prints in in the first place can be sticky or easy, with no apparent reason - there may be a knack to this that I haven't yet twigged.

I guess the manufacturer's aim in using textured separators may be to make washing as effective as possible while being economical with water? But if the fibre side has the heavier burden of contaminants, wouldn't you expect to place it in against the textured side with the least risk of sticking? Or what might the point be?

 

[MattKing]

The flow is probably better away from the surface - whether or not it is textured.

 

[snusmumriken]

The flow is probably better away from the surface - whether or not it is textured.

Well yes, for sure.

 

[logan2z]

You may have already noticed this, but if you look at the surface of the water while washing prints in the Ecowash, you'll see movement/ripples. I assume those are caused by the water contacting the textured surface of the divider. Since, as you observed, the prints don't stick to the divider after a minute or two, I'm going to hazard a guess and say that both sides of the print benefit from this agitation of the water. But if you're in doubt as to the efficacy of the Ecowash, then test the washed prints using a residual hypo test kit like this:

https://www.freestylephoto.biz/030150-Formulary-Residual-Hypo-Test-Kit-100-ml

 

[snusmumriken]

You may have already noticed this, but if you look at the surface of the water while washing prints in the Ecowash, you'll see movement/ripples. I assume those are caused by the water contacting the textured surface of the divider. Since, as you observed, the prints don't stick to the divider after a minute or two, I'm going to hazard a guess and say that both sides of the print benefit from this agitation of the water. But if you're in doubt as to the efficacy of the Ecowash, then test the washed prints using a residual hypo test kit like this:

https://www.freestylephoto.biz/030150-Formulary-Residual-Hypo-Test-Kit-100-ml

I confess I hadn't noticed the turbulence caused by the textured surface. I will pay more attention. But then, if the texturing is critical, why has one of the 5 slots got two smooth faces: a side wall and the non-textured side of a separator?

I am not actually in doubt about efficacy, because I have done that test since buying the Ecowash. However, my prints also pass the test after washing (for somewhat longer) in the family bath!

It's only I'm puzzled as to why one is advised to place prints into the Ecowash that way round. Call it academic curiosity, if you like.

 

[logan2z]

I confess I hadn't noticed the turbulence caused by the textured surface. I will pay more attention. But then, if the texturing is critical, why has one of the 5 slots got two smooth faces: a side wall and the non-textured side of a separator?

I've wondered that myself. I can only imagine it wasn't easy to procure a divider with two textured sides

It's only I'm puzzled as to why one is advised to place prints into the Ecowash that way round. Call it academic curiosity, if you like.

If you get bored and want to solve another mystery, tell me why the dividers bow badly if there's any water left in the bottom of the washer. I can only imagine that the remaining water causes them to expand for some reason, which makes them wider than the available space between the vertical slots that hold them in place. Just a theory. They always do go back to their original shape once the washer dries out, but it is a bit annoying.

 

[Andrew O'Neill]

My print washer has a bubbly flow, which helps prevent print from sticking on the dividers.

 

[snusmumriken]

I've wondered that myself. I can only imagine it wasn't easy to procure a divider with two textured sides

Yes, it must be a small volume production, and I guess they use off-the-shelf materials. Seems a bit lame, though.

If you get bored and want to solve another mystery, tell me why the dividers bow badly if there's any water left in the bottom of the washer. I can only imagine that the remaining water causes them to expand for some reason, which makes them wider than the available space between the vertical slots that hold them in place. Just a theory. They always do go back to their original shape once the washer dries out, but it is a bit annoying.

I had already reversed my separators so that I could see the images through the tank, before I read the instruction to keep them carefully in order. Then they bowed badly when re-assembled. I guess these things are hand-made and fine-tuned for each slot. I spent about an hour finding the right permutation again. So it it possible that yours have got out of sequence?

 

[logan2z]

I had already reversed my separators so that I could see the images through the tank, before I read the instruction to keep them carefully in order. Then they bowed badly when re-assembled. I guess these things are hand-made and fine-tuned for each slot. I spent about an hour finding the right permutation again. So it it possible that yours have got out of sequence?

It's done it since day one so I don't think so. I've also read other forum posts in which people mentioned the same thing.

Are your dividers no longer bowing after inserting them in their original orientation?

 

[snusmumriken]

It's done it since day one so I don't think so. I've also read other forum posts in which people mentioned the same thing.

Are your dividers no longer bowing after inserting them in their original orientation?

Affirmative, they aren't bowing now/at present. I can't be certain they are in their original orientation, but it seems to be a workable permutation.

I'm reluctant to say this in a public forum, but while it works OK, this washer has some puzzling features and others that annoy, given the price. I really expected it to be unconditionally archival.

 

[Pieter12]

Affirmative, they aren't bowing now/at present. I can't be certain they are in their original orientation, but it seems to be a workable permutation.

I'm reluctant to say this in a public forum, but while it works OK, this washer has some puzzling features and others that annoy, given the price. I really expected it to be unconditionally archival.

Now I'm curious. What makes it not archival?

 

[snusmumriken]

Now I'm curious. What makes it not archival?

Well, as explained, it supposedly works best if the emulsion side faces the textured side of the separator. But the fifth slot has no textured side, so what happens there? Of course I can (and will) test the result from that slot, but either (1) the textured surface is irrelevant, or (2) they should have made it a feature of every slot. In case (2), I am still unconvinced which side of the print should face the textured side.

 

[MattKing]

The flow may be different in that 5th slot.
Most likely the texturing is there simply to stop prints from adhering, when flow conditions tend to "squeegee" the print into the divider.

 

[Pieter12]

Well, as explained, it supposedly works best if the emulsion side faces the textured side of the separator. But the fifth slot has no textured side, so what happens there? Of course I can (and will) test the result from that slot, but either (1) the textured surface is irrelevant, or (2) they should have made it a feature of every slot. In case (2), I am still unconvinced which side of the print should face the textured side.

It still should be an archival wash if the fix is being removed, which I understand is mostly through the edges of the print.

 

[snusmumriken]

The flow may be different in that 5th slot.
Most likely the texturing is there simply to stop prints from adhering, when flow conditions tend to "squeegee" the print into the divider.

Matt, that is a very fair suggestion, credit to you. Does it follow from the second part of your comment, that it should be easier to drop prints in if I switch the flow off momentarily? I will try that.

All the same, my original question is unresolved.

 

[Pieter12]

Matt, that is a very fair suggestion, credit to you. Does it follow from the second part of your comment, that it should be easier to drop prints in if I switch the flow off momentarily? I will try that.

All the same, my original question is unresolved.

It could all come down to manufacturing considerations. The NOVA products use an acrylic that is waffle-textured on one side for their processors and maybe it is easier and more efficient for them to just use the same for their washers. From their website, it seems the extra slot is for a wash-aid or can be converted as an additional print-was slot. https://www.theimagingwarehouse.com/ProductGrp/Nova-Washmaster-ECO

 

[snusmumriken]

It could all come down to manufacturing considerations. The NOVA products use an acrylic that is waffle-textured on one side for their processors and maybe it is easier and more efficient for them to just use the same for their washers. From their website, it seems the extra slot is for a wash-aid or can be converted as an additional print-was slot. https://www.theimagingwarehouse.com/ProductGrp/Nova-Washmaster-ECO

No, no, the extra wash aid slot is another quite separate, smooth-sided one. The print washing slots include one with no textured side.

 

[MattKing]

Does it follow from the second part of your comment, that it should be easier to drop prints in if I switch the flow off momentarily? I will try that.

Try dribbling some water over the surface of the print as you insert it.

 

[faberryman]

The separators in my 'archival' FB print washer have one smooth side and one textured. The manufacturer's instructions state that prints will be washed most [more?] effectively when their emulsion sides face the textured side of the separator.

That surprised me. Is it really true? My inexpert understanding was that the emulsion is relatively easily washed, and that most of the contaminants reside in the fibre base. So if the fibre side rests against the smooth surface of the next separator, I would expect it to wash less effectively.

Anyone know if there are studies on this, or have an insight either way?

I think this is one of those instances where it is up to you to decide whether what the manufacturer is telling you is true or not. I'd start my analysis by trying to think what the manufacturer has to gain by lying to you about it. I am not coming up with anything, but that may just be a lack of imagination on my part.