I've been testing the pH in our fountain solution for our Heidelberg PM74 and Shinohara 72 and getting a reading of around 7. I know the pH is supposed to be around 4 but I don't know the best way to bring it down. The conductivity is at 2000 which is to the specs of our fuji solution. We're having a lot of drying problems and scuffing and marking when jobs get into finishing. I think the pH is to blame but don't know the best remedy. Thanks for your consideration.

A pH of 7 is neutral... not acidic and not alkaline, right in the middle. You need to add more etch... fountain solution
to get down around 3.5 to 4. Just on the acidic side.
Good Luck

We run 5.5ph and conductivity at around 1650, alcohol 4%.

Scuffing and marking problems? Is the stock matt or silk or is it gloss?

the stock we have the most problems with are the matte, dull, or silk papers. we sometimes have to run the fronts of some dull paper at the end of the day and back them up in the morning.

I don't think your marking issues have much to do with the fount (that's a bit 'last resort')
I'm guessing you're using conventional inks, there are inks that are specifically formulated to dry harder on matt/silk materials.

If you don't have them have you tried a water based sealer, either inline if you have a 5+ unit press or separate run thru?

we do use gloss varnishes on many of the covers we run. we have recently used some 100% oxidizing inks on a synthetic stock. that job turned out really well. I'll recomend we try those inks on our matte jobs. Thanks for your help.

While oxidising ink will do the job... a better set, IMO, would be one that is formulated specifically for matt stock.

They wouldn't be so prone to premature setting on the rollers or duct. Ask your ink rep.

try PH 4.5-5
get theconductivity down to 1100
get your Alcohol down to around 6-7%
and then start enjoyig fast drying and no scratches

good luck
Meny

Meny - although your settings are fine in themselves they won't address the drying & scuffing problems on matte/silk stock.

As you'll know, looking through a microscope will show the surface of these materials to be composed of 'hill & valleys', these scatter light and give a 'velvety' feel. However, when inks are applied they fill up the 'valleys' but the 'peaks' get a thinner layer of ink. It's because of the thinner layer that these papers are prone to scuffing.

What's needed is an ink set that dries harder not necessarily faster - unless you accelerate the drying time via infrared or catalytic additives failing which a good quality water based seal varnish should help considerably.

I'm guessing Meny either has IR or it's pretty darned warm in Israel!

Yes it is warm ....hot in Israel but every home , car & print shop has AC so temp is 25c (+/- 1c).
yes we all have IR dryers as they are supplied by the press makers (all)
but no , we do not use them - normaly not even connected to the mains.
IR has no cure for veg' based ink - the regular inks used today in the western world so it is just money down the drain using it (and then more money to cool the place back with more AC).
the way we set our dampening systems we get faster drying on any paper.
yes they are not all the same as some take in more of the ink and some just keep it on the surface but when it is dry quicker , it gets less marks & scratches and a much better final result.
this way you also get less imusification with the ink , less glaze on the rollers , more stable print on long runs and more.
Will be happy to help over the phone if requested....comming back to the UK only with an insurance policy for good wether :-)
Meny

00972523201671 any time

PS - Richard = skippy ????