Wetting agent...?

What is a wetting agent and why would you use it to develop?

How would you make it?

Cheers.

I wetting agent such as photoflow, disperses water so it does not bead up. If you do not use a wetting agent you are more likely to get water spots on your negs. Its pretty inexpensive , and lasts forever. Some people use a drop of soap, but I never have.

I wouldn't make it. Your negs are important and are worth thesmall amount of money it costs for the commercial stuff. Some folks use jet-dry, dish soap, etc, but these contain additives that may harm your negs.

 

Go to apug.org and do a search for "photo engineer". He's a retired Kodak guy and goes into some great detail on why you shouldn't use the home brews for a wetting agent.

You don't use it to develop film and it's not a DIY product. I've tried the drop of dish detergent trick, and it doesn't work so well. When used properly, wetting agents will eliminate those annoying marks left behind when the water evaporates. Some people claim that the wetting agent leaves marks too. Well, all I can say is that I've never seen that happen. The trick is to use only enough to allow the water to sheet off the film, but not enough so that it foams up.

It's just for the final rinse. Helps water sheet off smoothly with less risk of water spots.

 

Use less than the manufacturer suggests. I use the Ilford in-tank wash method, with one tiny drop in the final tank. If you get a bunch of foam after agitating it's too much. Distilled water with the final rinse and wetting agent helps too.

 

Suspend your film diagonally to dry. Water will be pulled toward the lowest edge and drip off the lowest corner. Learned this trick from Roger Hicks. Works great.

I used to use Paterson Acuwet but, following difficulty obtaining it, I changed to Tetenal Mirasol. In addition to all of the above, take the time to determine the optimum amount of wetting agent you need to use. Aim to use the smallest amount which thoroughly disperses the water but which doesn't create excess foam. I use a small bottle with an eye-dropper in it and measure out 3 drops Mirasol per 100 ml of rinse water. I mix up the wetting agent in a separate jug and then dunk the reel of film in it for about a minute, with gentle agitation, after the final wash.

Yet another contribution. Wetting agents are surfactants. They reduce the surface tension of liquids. Edwal makes a "low foam, non-ionic" wetting agent called LFN. So what you say? Well, for folks that have continued issues with air bells on their film, this product can be added to the developer as well as the final rinse. When added to the developer it reduces the surface tension of the developer thus reducing the chance of forming air bells. I agree that it is not worth trying to make your own.

Edwal LFN, $7 USD for 3/4 oz. Kodak Photoflo 200, $7 for 16 oz. Oy! Thanks but no thanks.

In addition to all the good advice above-one other thing. If you use a reel or hangers

either one, be real sure you clean all the Photo-Flo off before your next session. If any

is left on your hardware, your film can be fogged. Can't explain just how it does it, but

I'm assuming it's got something to do with changing the liquid's surface tension.

Maybe some chemist-type can chime in?

Frank is correct. But at 2 drops per liter, 3/4 oz goes a long way and may work out to be closer in price per roll than it first appears. My point was that LFN can be added to developers, for whatever reason, without changing their working properties. I don't know if this is currently true of PhotoFlo. It was not the case in the past.

the wetting agent also puts a very thin shiny layer over the negative, this not only

helps in avoiding drying marks (which also depends on how 'hard' the water is you are

using), but once the films are dry this becomes an anti static layer over the film, so

that dust particles won't readily stick to the film. after rinsing out the fixer, i use two

washes with filtered, (soft water) and the very last wash also in filtered (distilled is even

better) water and wetting agent.

Hmmm. I had excessive drying marks when I started developing my own (all of 6 months ago). Adding the teensiest drop of washing up liquid to the final rinse eliminated them completely. I therefore see no reason whatsoever to use a 'real' wetting agent.

 

But as always YMMV.

Here My first bottle of photoflo was 25 cents for an 8oz glass bottle when Eishenhower was in office ; the last bottle I got had a shocking price of 9.15 for 16oz when Clinton was in office. Depending on ones water hardness the amount of rinse agent can vary from nil to alot. In the scheme of many decades of developing film the cost of my photoflo has been a couple of rolls of film; about what I have spent on rubber washers for the garden hoses. Its an expense down in the weeds; up their with the cost of the clothes pins to hang negatives. Here I have used other soaps and wetting agents in an emergency. I have also hand made rubber gaskets for hoses by hand in an emergency too. The cost of what I HAVE SPENT on photoflo is in the noise compared to all the other photo consumables.<BR><BR>There are some folks that have used wetting agents in developers; where the water is super hard. I am not sure if thats what this question is about. Most all folks use the wetting agents at the final rinse stage; fater fixing; after washing; to reduce streaks.<BR><BR>This question is abit loaded since the water hardness around the world varies alot.<BR><BR>The formula for photo-flo changed awhile back too.<BR><BR>A canned answer that wetting agents are not required can cause a newbie to ruin his negatives. In areas with poor/hard water one can get alot of drying marks unless a wetting agent is used. I cannot imagine shooting a valuable roll of film and being so cheap about a penny and ruining a roll due to drying marks. In a commerical lab this would get one fired.

With a homemade photoflo replacement the stuff one uses may work ok or may leave crud. One should experiment on crap film before trying bloopers soap. The last thing you want to do is trying to save a penny per roll and ruining the roll with streaks. Soaps have all sorts of other stuff in them; if your quest to save a penny per roll works; you can squirel away these pennies. If you shoot 100 rolls per year you can buy a coca cola at McDonalds; or a quart of gasoline for the lawn mower.

The entire "thing" about photoflo being expensive seems real bizzare from a historical standpoint. It seems very odd. Its abit like worrying about what cost of cleaning ones windshield on a car like its a real big deal compared to gasoline, tires, oil and depreciation. In areas with poor water I have had to use distilled water as the final rinse; in our commerical lab we had to install a water filter to capture fine grit. These costs are radically more than the cost of the wetting agent or clothes pins.

Don't mix up a batch of photoflo and expect to use it for very long, or it will develop "Floaties" and be useless.

Gary, there are some myths and disinformation surrounding the use of wetting agents, washing tanks and reels, etc. I don't think anyone is deliberately passing along bad information, but I see a lot of things being repeated that "someone read somewhere that someone else heard about from another website that mentioned something this other fellow read in a book or heard about..." etc.

 

Wetting agents - surfactants - aren't much different from what we call "soap." In fact, they're less troublesome than soaps and detergents because photographic wetting agents contain no oils, dyes, perfumes, lye, deodorants, abrasives, etc.

 

Photo-Flo and other wetting agents won't contribute to some sort of weird, ghastly buildup on reels, plastic or stainless, unless used full strength and allowed to bake in the sun until reduce to a sticky goo. We're talking about one tiny droplet per tankful.

 

BTW, this is assuming one uses either the Ilford type method of washing in the tank or leaves the film on the reel while dunking it in a bath of pre-diluted wetting agent (which is not a good idea for reasons already mentioned - it goes "bad" quickly and will develop jellyfish-like floaties). If one removes the developed negatives before using a wetting agent, the stuff is unlikely to mysteriously migrate to ones reels. Just wanted to clarify that.

 

There's a logical solution to this problem, seldom mentioned: fill the tank and emptied reel with warm water. Just plain warm water. Shake it up like a martini. Dump, let dry. Problem solved.

 

There just isn't enough residual developer, stop bath, fixer or wetting agent on the reels and in the tank after a quick and simple rinse to make any difference.

 

I'm not discounting the possibility that plastic reels can deteriorate. I've seen it in my own plastic reels. Some of 'em turn slightly brownish or lose elasticity. But I doubt it has anything to do with residual chemistry. Some plastics deteriorate. FWIW, I've never seen this happen with Paterson reels, only with no-name types.

 

The "fogging" sometimes blamed on "residual chemistry" on reels is almost certainly due to light fogging (easily done with rollfilm during loading and unloading the camera), misalignment of film on the reels or poor agitation techniques. Agitation that is either too timid or too vigorous can produce odd effects that are most noticeable along the film margins where they contact the reel flanges. But I seriously doubt that "residual chemistry" or wetting agent has anything to do with this.

 

Anyway, not fussing at anyone in particular, just hoping to dispel some misinformation that seems to be the currency of the internet.

"There's a logical solution to this problem, seldom mentioned: fill the tank and emptied reel with warm water. Just plain warm water. Shake it up like a martini. Dump, let dry. Problem solved."

 

Are you suggesting that not everyone is cleaning their tank and reels after use? :-)

 

Seriously, I agree that washing with warm water afterwards will reduce any contamination to an insignificant level. I always put the wetting agent in the tank and never had a problem with film sticking. I have noticed one thing, though, the Paterson reels seem *slightly* less slippery after they have been used for some time, but I would rather attribute this to some release agent which have been used during manufacturing being washed off. When they are completely new, it feels like there is a slight coating of some slippery stuff, like silicone.