Full Version: Doming - testing the waters.
From: Terry-Morris [#36]
4 Apr 2005
To: Stunt Engraver (DGL) [#13] 5 Apr 2005
--Too much heat can be a problem. Not only detrimental to bulb life, but if you're doming sublimated items, especially metal, too much heat can cause the image to blur.
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David, I have not tried laser sublimation but I have tested ink jet sublimation that was domed, placed it at a constant 200 F (50 f higher than UltraDome oven gets) and left it for 6 hours, no blurring was visible under a jewelers loop even on 8 point text. Remember that if you use metals not designed for sublimation (lacquer coated award metal) then this won't hold true.
--is the epoxy is curing, albeit slowly, as soon as you begin to work with it.
--If you work in more intense lighting, you have to "pour it on." Using the small applicator bottle (after curing) will reveal the pattern, on your domed item, in which you applied the epoxy.
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David, if you work under incandescent lights you have an unlimited working time. I got side tracked one time in the middle of doming and forgot about it until the next day, I went back and finished where I started, the epoxy had not started to cure at all even though the curtains were open and the lights (incandescent) were on, mind you the sun was not shining on the epoxy and the windows have UV protection (All household glass stops 50% to 80% of UV rays).
From: Terry-Morris [#37]
4 Apr 2005
To: Ken D. (KDEVORY) [#26] 5 Apr 2005
Ken,
This is a common problem. It is caused by either the ink or the paper having UV inhibitors (or both). Here is a simple test to help find out. Put some epoxy on the blank paper and try to cure it, if the same thing happens then the paper cannot be used with UV epoxy. If the paper dome works fine then make a print and let it sit for at least a week and then dome. Chances are if it's the ink and you let it dry for a week it will probably work.
Another choice if it's the ink it to try and force dry it, place it in an oven on as low a setting as it will go (or just the pilot light if it has one) and let it sit for a few hours and try it.
Even though you can rub your finger on the printed page without it smearing does not mean the ink is dried, many inks take weeks to completely dry unless helped along and the epoxy will soak into that ink and mix with the UV inhibitors causing it to not cure.
From: Terry-Morris [#38]
4 Apr 2005
To: Stunt Engraver (DGL) [#30] 5 Apr 2005
-- I'm finding my curing unit ( www.ultradome.com ) too small an effective area for mass production.
David, they are stackable units.... Sounds like you need a few more ;-)
From: Rodney Gold (RODNEY_GOLD) [#39]
4 Apr 2005
To: Terry-Morris [#38] 5 Apr 2005
Unless you use special resins that take literally seconds to cure , UV is a schlep for any sort of production. A simple doming dispenser and mixer using a much cheaper 2 part resin can do 1000's of items a day and you can just leave them to dry in racks. Even for small production a 2 part resin works perfectly , you dont need to build any UV housings etc , just load them in an old oven or keep em somewhere warm and level. You can even mix in a paper cup with a lolipop stick.We can dome and ship some of our urethanes with an hour or 2 turnaround time , and one person can do at least 500 an hour.
You have no heat and partial curing problems and no hassles with UV inhibitors etc. Its just a little messier/more difficult to mix unless you have a dispenser , and of course there is a pot life to the stuff , once mixed it begins to gel.
None of our flexibles dry tacky or if they are , its just the same day they cured but 12 hrs on , they are "dry"
As to flexible and rigid , we only do flexible if the item has a self adhesive surface and it doesnt sit perfectly flat stuff - everything else is glass hard unless specified otherwise.
From: Stunt Engraver (DGL) [#40]
5 Apr 2005
To: Terry-Morris [#38] 5 Apr 2005
Terry,
Thank you for lending your knowledge to this thread. I appreciate the help.
David "The Stunt Engraver" Lavaneri
DGL Engraving
Port Hueneme, CA
From: Terry-Morris [#41]
5 Apr 2005
To: Rodney Gold (RODNEY_GOLD) [#39] 5 Apr 2005
Rodney,
It is true, UV doming is best suited for smaller runs. If you are doing thousands of items then 2 part mixes are the way to go. But if you are doing small amounts like a hundred, dozens or even a single item then UV has some advantages, once you learn to dispense properly you literally have zero waste of material, zero clean up and it's convenient. For many people this is enough reason to pay a little extra for the UV resins.
I am curious and would like to find out more about your resins that are done in an hour or two, I tried about 6 brands myself and none set up in less than 24 hours which always gave time for every piece of dust or gnat to land in mine. I am also curious how well it degausses, The 2 part mixes I tried did not work well in my 60% humidity, many of the items I domed were ruined due to bubbles that were not there when I domed them, the bubbles developed during the 24 cure.
Thanks!!
From: Ken D. (KDEVORY) [#42]
5 Apr 2005
To: Terry-Morris [#37] 5 Apr 2005
Terry,
Glad to see you on the forum. I hope its not a one time thing, and you stick around. Its amazing the variety of applications people are doing, and the variation of scale. For doming I'm doing single pieces. I love the convenience of UV epoxy. Others are dealing with large scale production where pennies add up. (materials vs labor.)
Last night I printed 2 photos one on the special paper, the other on my standard office paper. Today I domed them along with a blank sample of the photo paper. You were correct, it is the ink.
The plain photo paper worked perfectly. The office paper was interesting. It soaked in the epoxy and cured hard. except for the solid black hair. Same problem there. - It worked where the paper was able to fully absorb the ink and have absorbency left for the epoxy.
The photo on the photo paper - same as my first try. It won't be practical for me to wait a week; I'll need to explore methods to expedite drying. - You mentioned heat. I'll have to explore my options.
From: Harvey only (HARVEY-ONLY) [#43]
5 Apr 2005
To: Ken D. (KDEVORY) [#42] 5 Apr 2005
If you have a heat press running at 400*, close it for ten seconds, then open it and lay the paper, face up, on the bottom platen. Use a rag or something to prevent burned fingers and stroke it for about ten seconds. leave it there for maybe half a minute and it is well dried. The only time this might not work is if there is oil in the ink.
This is a process I use in sublimation.
If you have an old warming tray it might work, timing will be different.
From: Ken D. (KDEVORY) [#44]
5 Apr 2005
To: Harvey only (HARVEY-ONLY) [#43] 5 Apr 2005
Another reason to consider a heat press...
Does anyone know if the HP Officejet 7140 has oil in the ink?
If there is oil will it take longer, or heat won't work?
From: Rodney Gold (RODNEY_GOLD) [#45]
5 Apr 2005
To: Terry-Morris [#41] 5 Apr 2005
Terry we use a dopag dosomat dispenser with a variable stroke mix ratio and a mixing block and disposable mixing nozzles (tho we clean them with ethelen chloride and re use them). The resins are from National Urethane Industries in Johannesburg South Africa and work out at about $15 per kg mixed. (I dont have the website atm) They can modify the resins for you in respect of shore hardness values , pot life etc.
If we want a 1/2 hour cure , we elevate drying temps to 40 degrees C. We use pretty noahs arc drying racks , bookshelves with lights screwed under them that heats the shelf below and a nice heavy duty clear builders plastic curtain in front (a cardboard box with a globe would do to for small runs)
Degassing isnt a problem as we pull a vacuum in the feed canisters , but even if we dont , its still ok due to the fact that the stuff gets mixed in the mixing nozzle and the only time it sees air is at the tip of the nozzle as its being dispensed. (the cart guns have this advantage too). Moisture is always the problem , we dome in a climate controlled (read aircon) environment and de humidify. Once the stuff has gelled , then it shouldnt bubble or foam. But suffice it to say , foaming is always due to moisture absorbtion prior to gelling (a problem with long pot life stuff is that it takes a long time to gel , and you need long pot lifes if you hand mix)
Key to using 2 part quick cure urethanes is good mixing , precise ratios and a dry warm environment when curing.
Regards
From: Harvey only (HARVEY-ONLY) [#46]
5 Apr 2005
To: Ken D. (KDEVORY) [#44] 5 Apr 2005
"Does anyone know if the HP Officejet 7140 has oil in the ink?"
No idea if any still use it, the ribbon printers used oil soluble ink.
"If there is oil will it take longer, or heat won't work?"
If it is a very light oil it might evaporate also. Testing is the only to be sure of a specific combination.
From: Terry-Morris [#47]
5 Apr 2005
To: Rodney Gold (RODNEY_GOLD) [#45] 6 Apr 2005
Thanks for the info, It sounds like you have a good setup for mass production. I think I'll stick with UV for now as I don't do thousands, in fact my average domed order is 100 or less pieces, this does allow me to get a premium $$ for it though since large house don't want the work.
And I work from an office built onto my home so don't really have the space or money for the equipment. I like the idea of using book shelves with lights and plastic, I will have to remember that for future use.
From: Terry-Morris [#48]
5 Apr 2005
To: Ken D. (KDEVORY) [#47] 5 Apr 2005
Ken,
I just had an idea, if you have a heat roller type laminator you could try to use it to dry out the print. I would sandwich the print between two pieces of plain paper after it had air dried for 30-60 minutes then run it through the laminator once or even twice, I would think that would force it dry. Of course it might also destroy the print but it would be worth a test.
Just an idea!!
From: Ken D. (KDEVORY) [#49]
5 Apr 2005
To: Terry-Morris [#48] 5 Apr 2005
Interesting idea, unfortunately I don't have a laminator. But it got me to thinking about the iron I've used for waxing my skis, wonder where it is. It looks like there've been plenty of ideas for heat sources, now I need to do some of my own experimenting.
Where can I get the MSDS for the epoxy. I'm hoping getting it on my skin isn't much of an issue. :-)
From: Harvey only (HARVEY-ONLY) [#50]
5 Apr 2005
To: Ken D. (KDEVORY) [#49] 6 Apr 2005
Good idea. A dry iron set just below the boiling point should remove virtually all of the moisture in the ink and paper also. Just be sure that the coating on the paper can take the heat and you are set. It should take less than 20 seconds for each section, then a partial minute to cool and expel the moisture.
We used to bake stacks of 2,000 record labels at 150* overnight to expel all moisture. 200* and one thickness of paper should take those few seconds.
Good luck, and let us know.
From: Terry-Morris [#51]
5 Apr 2005
To: Ken D. (KDEVORY) [#49] 6 Apr 2005
You can get the MSDS sheet here http://www.epoxies.com/msds/60-7155uvresin.pdf It is listed as "Mild skin sensitizer and mild eye irritant".
Some people are sensitive to it and should wear latex gloves. Myself I have had no reaction to it after handling it for 4+ years now. By the way you can use rubbing alcohol to clean it up.
From: Ken D. (KDEVORY) [#52]
6 Apr 2005
To: JayBeeOz [#24] 6 Apr 2005
John,
I believe you have UVA and UVC reversed. After reading your posts I decided to try and get an 'A' bulb. Found out blacklights are UVA, and sterilization lights are UVC.
Don't know if the UVC will help with the epoxy sold by Ultradome and Coast Graphic Supply. They're formulated specifically for a blacklight, with a cure frequency of 365nm. (Their supplier has other broad-spectrum high intensity formulas too. I suspect you're using a broad spectrum formulation given the information in your various posts.)
From: JayBeeOz [#53]
7 Apr 2005
To: Ken D. (KDEVORY) [#52] 7 Apr 2005
Ken
You are right, my apologies, in my original post where I described the lamps, I did get the A & C back to front. UVA is the normal Blacklight, UVC is the dangerous one. In one of my other posts where I described the commercial unit, I did get the bulbs the right way around.... Oh well...At least I know that my cabinet is germ free!!:-)
I'm not sure about the curing frequency of the Epoxy that I use, only that UVC alone will not cure it completely. It will only skin the surface of the epoxy (It does this within a minute or two). Before I fitted timers to the cabinet, I forgot about a batch of badges that stayed under the UVC Lamps for about 6 hours. It may have made the skin a micron thicker, but the epoxy still remained liquid under the skin. I think the advantages to using the UVC are a clearer looking Dome, quick skinning stops dust and bugs from settling on the surface, and from what I have read, seems to remove the tacky feeling of the soft epoxy, plus the fast curing times.
I will stress though, to anyone thinking about experimenting with the UVC lamps, they may look innocent enough but they ARE dangerous, even short exposure to them can burn your skin or the retinas of your eyes. PLEASE be careful.
John
From: Ken D. (KDEVORY) [#54]
7 Apr 2005
To: JayBeeOz [#53] 7 Apr 2005
I did my first piece with the flexible epoxy yesterday. I forgot about it after the timer went off. I think it was under the light for 40 min. It doesn't feel tacky to the touch. It was 2" from 2 15W blacklights. I'm wondering if the tackiness requires more time/power to cure. Since I'm doing single pieces under a very small box dust and bugs are not an issue. Now if I had to scale up production...
A quick film would allow me to make a higher dome. My box gets a little warm and the epoxy flows off if too high.
From: Harvey only (HARVEY-ONLY) [#55]
7 Apr 2005
To: Ken D. (KDEVORY) [#54] 7 Apr 2005
Best way to keep the heat down if it affects the product is to put a small whisper fan over a hole over a lamp socket blowing out. Lay the product on a small furnace filter so air and not dust will be drawn into the box.
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