Finishing gum in fount solution

[cole]

Hi All
This is a theoretical question, is there anybody out there that could tell me the type of problems that would occur if finishing gum were to be added to the fount solution? The ratio of 1L to a 90L tank.
Any bit of advice would help. Thanks

 

[Cornishpastythighs]

theoretically it should be ok. If you want to add extra gum to your fountain solution the supplier can do this for you under controlled conditions or you can use 14 Baum Gum Arabic.

 

[Green Printer]

Hi All
This is a theoretical question, is there anybody out there that could tell me the type of problems that would occur if finishing gum were to be added to the fount solution? The ratio of 1L to a 90L tank.
Any bit of advice would help. Thanks

What problems are you experiencing to bring you to the conclusion that finishing gum in your foutnain soution will help?

 

[Alois Senefelder]

Answer

Answer

Hello fellow Lithographers,

In theory yes - BUT adding Gum Arabic/ Plate Finisher into a modern

F/S Concentrate is not recommended, certainly not 14 Deg. Baume Gum Arabic.

Use 8 Deg. Baume Gum Arabic only as a last resort.


The addition of extra gum into acid type F/S, can and will cause - 1) Image Blinding 2) Roller Stripping

3) Excessive Ink Emulsification.



Regards, Alois

 

[BeauchampT]

I be been there and true that and will never try again.

I leave fount formulation to fount formulator

 

[cole]

What problems are you experiencing to bring you to the conclusion that finishing gum in your foutnain soution will help?

we are experiencing stripping and emulsification cause i suspect that guys have been adding finishing gum to the fount sol. So , i am not intending to add any gum but rather am trying to figure out why some would add gum to the tanks. Thanks for the reply.

 

[cole]

Thanks Alois

 

[Dan Roll]

Finishing gums often contain ingredients intended to help the gum adhere equally to the image area and background. While helpful to the performance of the finisher, these ingredients will ruin the fountain solution leading to emulsification of the ink at best and blinding and scumming at the same time at the worst. Also these materials do not rinse out of your system easily.
Gum Arabic is safe to use if the levels are kept below an ounce per allon or so.
14 and 8 degree Baume gum are just gum at 25% and 12.5% solids, respectively. Remember, gum is a solid in its natural state, when sold as a liquid the Baume reading is used to determine the concentration.