Re: Tiny Bubbles In The ... Gum

Michael Koch-Schulte wrote:
>
> I don't think it's contaminated paper if that's what you're getting at.

No, that's not what I had in mind at all; I think that's most unlikely.

 I
> thought maybe foam brushes might cause this because of the rough bubbly edge
> surface.

 I would agree that foam brushes could put air bubbles into the
emulsion, but I understood you to say that you had the same problem with
a hair brush.

>I'm wondering if the paper is releasing air because its dry.

Extremely unlikely, in my opinion.

My
> paper has not been pre-shrunk or sized in any way.
 
Since you're using the paper unsized, it's also quite unlikely that the
problem is beading caused by too thick a coat of gelatin, as I suggested
before.

I switched to a hair
> brush but it didn't seem to make much difference.

Is this a soft hair brush or a boar bristle brush -- it could make a big
difference. Softer is better in my experience.

I don't want to "work" the
> paper too hard because I'm afraid of roughing it up.

What paper are you using?

I've read that most
> people lay down a quick coat and then smooth it out.

Yes, that's what I do, like Dave described.
 

I'm having problems
> with the smoothing out part it just seems to make things worse. If my mix has low
> visocity could that cause it? ie too runny?

Yes, in fact my first thought was that perhaps you had added too much
water, until I saw that you hadn't added any water at all. But I'm not
sure how you could get low viscosity if you're using 14 baume gum with
no added water. (Yes, I remember Gordon; viscosity and specific gravity
are not correlated, but still I have a hard time seeing how this could
be.) What are you using for gum?

Sorry to be answering with more questions instead of easy answers, but
this is how it often works with gum.
Katharine
Received on Sun Aug 28 20:34:51 2005