Re: [PPLetterpress] Fat lines
- I really think that fat lines are more likely to have something to do with too little exposure or a film problem or contact problem. It seems like bad brushes would simply give you the problem of not washing out to the bottom quickly enough. For lines too thick I would check vacuum and be sure all your lights are going. I could be wrong, but that's what sounds like the hierarchy of your trouble to me.I recently had a mystery that cost me about $110 before I figured it out. My film supplier was giving me negatives that were not dense enough. This resulted in some exposure of the plate, making the entire washout take too long and ruin thin lines during the washout. It took me so many tried before I considered this because for years I had never had a bad negative from my source. They fixed it as soon as I pointed it out to them.--ScottOn Jul 9, 2013, at 3:49 PM, Peter Bruce wrote:
- You could wash a plate by hand, just rotating it on the brushes until everything 'is washed away. That will tell you if it is the negative or the brushes causing the problems.Assume your vacuum and kreen (sp) are in good shape and you are getting definitefull contact between the plate and the film.
- Have you checked the exposure with a stouffer scale? When I changed the bulbs in my Polimero A4 to Sylvania black light bulbs the exposure was all over the place. It took quite a while for them to 'burn in' and stabilize. In fact it still varies with ambient temp. and how warmed up the machine is.
Let us know how your new brushes work out. I may need new brushes in mine, sooner or later.
--- In PPLetterpress@yahoogroups.com, "Ian" <ductormanpaperboy@...> wrote:
> Hello everyone
> I have been using the same plate maker for a while now and think it is time for new brushes. I am starting to get fatter lines and reverses are not washing out. I am concerned that there may also be an exposure issue.
> I know that the brushes are finished but I am wondering if this would also cause the fatter lines? I did try reducing exposure times but am finding no difference.
> The raw photopolymer is from Boxcar and are KF95 plates exposed at 3 minutes with a washout between 4-5 minutes.
> I replaced the bulbs about 4 months ago. I was unable to get the same bulbs as the machine is from Europe
> (Polimero A-5) so I put in black lights with the same wattage. These have been working fine but I am wondering if it is possible they may be also starting to cause problems.
> Sorry for the short book