Backglass disaster - looks like uv ink is a total failure

[greatwichjohn]

Sorry guys, I didn't see this coming. So I will focus on playfield restorations only.
http://groups.google.com/group/rec.games.pinball/browse_thread/thread/47fcab52fe3ec6ff?hl=en#

[shansta]

Reading the answers/comments on RGP, sounds like you may be missing something real simple?

(Ignoring the rattle-can comment!  )

Don't give up because you learned something! 

Go play with inking some playfields, you will probably stumble upon an answer?

Read the PM I sent you.

[Retropin]

Sorry to hear that you didnt get the results you had hoped for. Im not convinced the process is a total write off though.
Seems there was some milking in the score displays after curing?? This is not present where the ink was applied??
Whatever causes this milking is obviously not IN the glass but on it.

I dont know what inks you are using, or what wavelength UV you use to cure, but i did look into UV inks myself for BG's and got shown UV ink on beer glasses etc - albeit screened though. point is that UV process should not be milking the glass unless there is an unknown medium here somewhere.
In all honesty, id be looking at my glass rather than faults in the process..

Wish you all the best... good luck with WMS!! 

[Strangeways]

Don't give up John, as others have stated - You have learned something and you could be one or two more tests from perfection 

[pinnies4me]

Jumping on the encouragement band wagon John - way too close now!!

[greatwichjohn]

It might be a matter of time, but unless its bullet proof its prudent to back off. There is definitely something wrong with the end result not being durable. The last thing I want to do is produce something that doesn't last many years & durable to pinball use or abuse. I will keep looking into it but it looks like I will have to wait on my main printer getting new equipment in a year or two.

On the positive side I can focus on playfield restorations & getting through the backlog. Prove that it is an affordable alternative for those that can't personally fix up or touch up their playfields. Thanks guys for your positive support!

[greatwichjohn]

Thanks guys for the encouragement & I will continue on. Had a good talk with Kim at Illinois Pin Ball, & told her I was continueing on. Here is the latest on my projects: http://groups.google.com/group/rec.games.pinball/browse_thread/thread/ae6041251ed18ae2?hl=en#

If any of the guys from Australia are going to Texas next week. Please say hello, & hopefully grab some beers & food with me. The only time anyone calls me a drunk is Wayne Gillard, who has never seen me in person, & few others on RGP. I love drinking beer!

[shansta]

Sorry John - I was supposed to get back to you Monday...

The following are comments from my mate the surface coating specialist, his name is John Clowes... Enjoy!

[BEGIN]

KEY POINTS TO COATING A GLASS SUBSTRATE.

1   The glass must be totally cleaned, there should be no oil, water, or foreign substances. This will adversely affect the coatings ability to “WET” the glass. Thus will effect the general adhesion of the coating
2   The class of coating will normally dictate the grade of adhesion promoter you need. There are quite a few new systems out there I would imagine, but here are a few to consider.
3   Printing Inks can range from, Polyamides, Urethanes, Acrylics, Alkyds, silicones, N.C Lacquers, UV cured, (solvent less).
4   The chemical makeup of the ink will based around 2 things, 1.The chemistry and physics of substrate and 2. The environmental requirements (Heat, Flexibility, interior, exterior etc…)
I would assume that the printing device you are using is designed for the function of printing to glass. So really the only thing that should need to be done is pre treat the glass to accept the UV cure ink.

The blooming, or Blushing as it is some times known is usually due to water precipitating at the interface of the coating and the air(interface) In solvent based coating it is generally due to the dew point. This is in the vapour phase of the solvent release.
The most efficient way to control blushing is to make sure the environment is under 60% R.H and all aspects of the process are at a temperature equilibrium. This means that the glass, the ink, the air are at relative the same Temp. It is normal to have a temp of 20~25 @ 60~65% RH. It is most commonly the glass temp that is the issue. I would suggest a pre heating of the to a substrate temp of around 30Deg C’. This will not only keep blushing to an absolute minimum but will also help with the wetting of the ink and adhesion.

Adhesion loss is most widely due to not being able to “WET” the surface, A bit like trying to paint over oil. The surface is too low in energy that the tension of the coating system is too high, thus coating will not only delaminate but will normally do a thing called “CRAWL” across the surface trying to be paint. This the key concept of Hammertones. The material has in the resin system a product that cannot intergrate with the chemistry due to it not being compatible.

The can be said of anti fogging. This is basically a coating that interferes with surface tension (energy) that create fogging. The water cannot accumulate because the water's affinity has been interrupted by the silicone based chemistry.

Key items to check
1 Check UV ink chemistry, (Poly amide, urethane, acrylic etc), is it compatible for the glass surface?
2..Find a Adhesion promoter that will work with the ink system you are using.
3 Clean the substrate again and again until you are totally confident of it cleanliness.

Last but not least.. Trial before committing, the coating should be allowed to totally cure before performing adhesion testing. Well I think most of this is correct or it used to be!!!!!


[END]


Now do you understand why I need a dictionary to talk to this guy? 

He has lent me his surface-coating bible - 900 pages of WORSE than the above...

You really need to get me more info on the ink! (Give me your printers email/phone - I will get my guy to talk to him?)

Shane.

[Redback]

Wow,

Nice post, learning something here.  Not sure what.

Regards,
Red

John, beer drinking is a social activity in Aus like it is in CDN.
Hope to catch up for a beer or 7.

Red

[shansta]

Hey Red!

I can't take credit - that is the email cut & pasted - I understand about 1/2 of it!

You want to try talking to this dude... Backglass stuffed? "Just screen it yourself - it's really simple".
Color match touchups on glass? "Yeah easy, you just dilute it with clear - blah, blah, blah...." (He's NOT into pinball at all BTW)

Seriously, any technical stuff about painting or printing - this guy is a walking encyclopedia!

Obviously - I am happy to pass on any questions you or anybody else has?

[Redback]

Shansta,

Well my blue chip backglass will need redoing.

Might have to catch up (have a few beers) and dream,

Red

[greatwichjohn]

Thanks for the information. My screen shop is going to do further testing the middle of April. Screen 4 color process. Not sure if it will go uv ink or solvent ink.

On the plus side, I got to talk with Gene about my glass projects & translite projects at the Texas Pinball Festival. He went out into the crowd & pulled in John Youssi for a conversation. That was very interesting, & I showed him the Twilight Zone test sample translite. Both Gene & John Youssi, got one. Gene had a TAF translite to compare, his is a different way of doing it. Hopefully the TZ will go to WMS & see if my printers process is exceptable.

Here is a video of TZ sample done last year: http://s36.photobucket.com/albums/e28/greatwichjohn/?action=view&current=029.flv

More pictures here: http://s36.photobucket.com/albums/e28/greatwichjohn/?start=40

[shansta]

That's good to hear John.

You have my email if there is any questions the "other" John can help you with.

Good luck! When it's working - you can make me a caveman glass...