SM72 conventional modify to bareback

Hello all, i was wondering the ease -if any- of modifying conventional dampening system to bareback and if is it worth it -SM72 circa 1981-, also does any one have roller sketch since the manual has differences -2 transfer rilsan rollers extra, one with springs that hangs between 2+3 forms and one at form 4-

 

The one that hangs between 2+3 is 40mm and works like a bridge

 

Hi mantman,
The roller 2+3 you are reffering to is not bare back system, its Alcolor dampening system.
Also if you want to convert your conventional dampening to bare back, you need to remove the covers from 2 dampening form rollers and increase their diameter to 65 mm if I remember correctly. You need to leave the cover on ductor roller and also add chiller to your machine if you don't have right now.
Dampening form roller hardness must be between 25-28 Degree Shore A.
In my opinion its better to buy an Alcolor press than converting conventional dampening to Bare Back.

I hope this helps.

Regards
Asif

 

Thank you for your input asif, the mentioned extra rilsan rollers are bridge roller between 2+3 is at ink form rollers not water and one more touches ink form 4, the diagram i have lack those rollers.
65 mm is correct but, shouldnt they touch the bearer ring to get movement from oscillator and bearer?
I presume without chiller its not possible to use IPA since it will evaporate
One more thing what is the proper PH for European inks? 4,3-4,8 or 5,0-5,5?

 

Yes you need Chiller and IPA and fountain solution, I don't know if there is any specific pH for European inks.
4.5 to 5.5 is recommended by Heidelberg.
Most presses work OK in this pH window. You can contact your inks supplier if they recommend a certain pH.

And last, I couldn't understand your question regarding 65 mm diameter....

 

What i mean is the water form rollers shouldn`t be a little longer to so they are driven from oscillator AND plate bearer rings?

 

No need to make them longer. You only need to change the diameter.

 

Thanks asif i will make you some biryani

 

Thank you for this lovely offer, feeling hugry.