Speedmaster PH

[ajr]

I've been asked by my pressman to find out the ideal PH of his water once he has added his alcohol. I know this may be opening a can of worms but I would like to see what people suggest. The press is a SM74 circa 2000.

Thanks

AjR

 

[Dr Who]

Are you in the US, UK or europe

 

[ajr]

In the Uk!

AjR

 

[danos]

As far as I know anything between 4.8 to 5.3

 

[rbailleu]

that kinda of depends on your setup. plates, ink, etc.

 

[Dr Who]

Danos is correct in normal circumstances between 4.8 - 5.3 is fine most inks and plates work well within this range. Achieving the proper pH level varies with the fountain solution manufacturer's recommendations but also with the chemical composition of the water that is being used. Unfortunately, a pH reading alone often will not give a true indication of a fountain solution's strength or concentration. That is better accomplished by measuring conductivity. However most suppliers will evaluate your water and set up your fount for free so I would get in touch with your supplier, Historically the UK and US run at lower pH than in europe

 

[RGPW17100]

With the way fountain solution is buffered I would think the alcohol would have little effect on the PH. Conductance on the other hand will have a big effect with the alcohol. A good start is around 7 percent alcohol and work from there. We are using an anchor emerald product and run 3 oz per gallon of fountain and run 7 percent alcohol. With this and new rollers we run our all colors around 30 percent in the morning and as high as 40 toward the end of the shift.

 

[andreisarbu]

PH

PH

We had very good results with 4.8-5.2 and I think it should work with most dampening solutions. In some cases a higher PH is requested when printing metallic inks for a more "metal like" look.

 

[billy gold coast]

between 4.5 and 6.0 no probs

 

[prasadhh]

water with fount and alchol, 4.5 to 5 of pH with conductivity of 800 to 1200 will give very good ink and water balance. One more factor also influnce the quality of printing is hardness of the of the water. Hardness should not be either too hard or too soft (if u check with hardness strip, hardness indicator is two red and two green) is good for printing.

If pH increases up to 5.5 also give good result.

After exceeding that u can get emulsification problem.

 

[prasadhh]

Hardness should be checked before mixing with fount and alchol

 

[Albert Noel]

i find ph also depends on the plate being used.
the plates we use, work best at much lower 4.2-4.5 ph

 

[Paultheprinter]

hi there,

im a UK Printer and find most founts are buffered between 5 to 5.5, the best way to know you perfect onductivity/ph is to do a simple controlled mix. I use syringes to make up 3% fount 10% ipa with non ro water (as we dont use it, if you do use ro water just check microseimens first and compare to german degree hardness i use 250-300microseimens as a base), i do this every few weeks or if theres any issues, i use this as my baseline as press circulated fount is always dirtyer and compare the two if im geting emulsification problems then i reduce the fount if im getting lubrication issues then i add more. Just to add, fount increases conductivity and alcohol decreases conductivity but does not affect ph. Fount does, the more you add the closer to the buffer you get within reason and the degree of hardness of the water but even if you add 10% fount in a hard water the soloution may never go down to 5. My final point is that your conductivity and ph may be specific to your press conditions and asking for everyodys elses may only muddy the water my ph is usually 5.5 ish with a conductivity of 1400-1900 ms

Paul.... i hope this helps