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What's a good cleaner for Coroplast (aside from alcohol) to remove fingerprints/oils?

tedbragg

New Member
I use 90 and 70 proof ISA, and microfiber cloths. But lately it seems every sheet we get has fingerprints and skin oils that won't come clean. I'm aware not to scrub too hard to not damage the printable corona, but this is getting tiring -- light colors and full fill backgrounds look horrid and I'm losing production time.
 

Boudica

Back to "educational purposes"
are you wearing gloves when you clean them? Is is possible the finger prints are occurring post-cleaning?
 

Gino

Premium Subscriber
If you're talking about 4x8's, you must move along in sections. You spray it on, wipe it clean and keep wiping that area until it's thoroughly dry. Then, move to the next area and repeat. One person can do a full sheet in four passes. Do not let the alcohol air dry. That does nothing, except accentuate the problem areas even more. We use 91% and plain paper towels. Remember.... this is the cheapest sh!t you can use for a customer, so it can't be too much of a concern.
 

tedshock

New Member
If it's just oil and fingerprints, we've had success mixing Ajax Triple Action Dishwashing soap, specifically the Orange one into a spray bottle of warm water (about 4 tablespoons). Acts like a degreaser and doesn't do any damage to printed surfaces. Seems like sometimes that works better than 91% for getting it off. We get it for $1.25 at Dollar Tree.
 

netsol

Active Member
i guess this calls for the white cotton gloves we used when we had a photo lab/framing shop.
my partner often asks how i can touch a print without putting a pair on
 

Gino

Premium Subscriber
Question is..... if this is for flatbed printing, why worry about it. Sure, you want a good product, but if they don't wanna use a good substrate, why should you knock yourself out to make a piece of sh!t beautiful ?? It's all relative.

I just made arrangements with a guy this afternoon to letter his truck next week. We had a cancellation and I have an open window of a few hours net thursday. He sent me files for what's going on the truck and asked for the price to do it. I specifically said, how much to make the graphics and put them on and I said, in our shop. He wrote back that everything looks good and sent me his credit card information for the deposit. Before I processed anything, I called him to verbally confirm everything. Then he says, now you're picking it up or doing it here ?? Nope. That'll cost ya extra. That wasn't figured in for lettering it. Then I mentioned.... as the quote says, the truck must be washed before bringing it in. He said, it's clean. I said, we only give it an alcohol bath. That... does not remove dirt and certain other contaminants. If you want us to wash it, that's also an extra cost. People don't listen or should I say don't read very well or they just opt to tell ya they didn't understand after the fact.

Why quote a cheap material then spend money and time making something nice for someone who is a cheap d!ckwad ??
 

Notarealsignguy

Arial - it's almost helvetica
He said, it's clean. I said, we only give it an alcohol bath. That... does not remove dirt and certain other contaminants.
I wipe the doors with the T-shirt that I am wearing and it works great. Sometimes when my hands are full, I have to settle with the back of my forearm. Little tricks of the trade
 

RabidOne

New Member
We had issues direct from our supplier (Grimco) so they started selling us prepacked stuff direct from the manufacturer. That and always handling with gloves took care of the issue.
We also printed for a real estate agency that was really picky about the quality of their A Frame inserts so we charged them extra and flooded the background with white.
Never any issues doing it that way but not a lot of people want to pay that cost.
 

DL Signs

Never go against the family
Used to print hundreds of sheets of coro at a clip for large orders. The only way you'll ever get halfway clean stuff IN the door is to order pre-packed like RabidOne does, or by the skid where no one touches it between the Mfgr and you (which is what we did). Ordering by the sheets, it's like everyone from the pickers at the suppliers to the delivery people just ate a big ol' greasy burger & fries before handling em', to them it's just a piece of plastic. Flood printing with white first gets rid of a lot of problems, but it's costly, and so is all the time you spend cleaning it. Another option to try is something like Fujifilm's UviJet adhesion promoter/ primer, just wet a rag with it & wipe the sheet down before printing, quick, simple, it both cleans and leaves a primer coating. Got some free with our first UV printer, and always kept a gallon in stock. Good for problematic substrates, helps inks stick over stuff like fingerprints (if they're not too bad), there's probably other chemicals like this on the market too.
 

r2d3henry

New Member
Was ordering foam boards from Uline for a while their new supplier had countless issues. Extra glue on the paper, hand prints in the middle of the boards, marks all over. These were sealed cases from the manufacturer but this was when foam board was hard to come by. Now I'm seeing better quality come through but it was driving me nuts when I wear fresh white cotton gloves and prints would come out with fingerprints and handprints. Personally I use iso alcohol for cleaning plastics before they go into the printer. Medical tissue paper to wipe.
 

White Haus

Not a Newbie
As already mentioned, buy by the skid and only handle with gloves. Even then you can still run into issues with light colors if you're running a finicky inkset but it GREATLY reduces the risk.

We've always used 50/50 isopropyl and water with varying results. (Thanks for the potion recipe tedshock, I'll give that a whirl)
We'd spray a microfiber rag and half of the sheet, wipe it left to right then immediately follow w/ a dry micro-fiber rag. Move the gantry and do the other half.

If you're not super careful/methodical about your strokes this will just result in visible streaks instead of fingerprints depending on your ink coverage.
 

ProColorGraphics

New Member
I use the Supply55 2155 cleaner/adhesion promoter and never had any issues. I spray the sheet, then use a swifter with a microfiber towel attached to it.
 

netsol

Active Member
it is worth mentioning, i recall Gino, a couple years ago, mentioning that there is some sort of coating on coro, to make it flat bed printable.
i also remember Gino saying that the coating has an expiration date.
so, that would be the SECOND reason that "always buy coro by the skid" might not be the best advice given out on this site

i will absolutely stipulate that no fingerprints is one of the advantages of having enough volume, being able to buy by the skid.
 

White Haus

Not a Newbie
it is worth mentioning, i recall Gino, a couple years ago, mentioning that there is some sort of coating on coro, to make it flat bed printable.
i also remember Gino saying that the coating has an expiration date.
so, that would be the SECOND reason that "always buy coro by the skid" might not be the best advice given out on this site

i will absolutely stipulate that no fingerprints is one of the advantages of having enough volume, being able to buy by the skid.
It's Corona treated. (Not to be confused with the virus :rolleyes:)

It does have an expiration date but I'd rather printed on "expired" coroplast than print on new crap that's been handled 10 times by people that we're just eating chicken wings for lunch.

We don't print a ton of coroplast but still buy by the skid when we can. It's a small price to pay (monies and floor space) to increase the odds of being able to print sheets without prepping them.
 

parrott

New Member
We print truckloads of corrugated. Never handle with any special care nor clean with alcohol. It’s a matter of having the right equipment with correct ink setup. No fingerprints, adhesion or color issues.

Gino makes a point but I don’t agree with him. If you are trying to compete with online vendors and spending time cleaning and handling with extra care, you are losing money. If you are selling at a good price, take the time and give your customer a good product. I would never send anything out than a top notch looking product. Just because it’s a cheap material does not justify giving something that looks like crap.
 
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