Bubble issue on corrugated plastic sign

[haishan67]

Hello,

I am a newbie to sign making. I am having a bubble issue with vinyl sheet on the corrugated plastic sheet.

I used the Big Squeegee to apply a 18x24 vinyl sheet on a corrugated plastic sheet, and it came out perfectly right after the application, without a single bubble. However, when I use my small squeegee next, the bubbles came out all over the places! I tried to squeegee them out, not working! I tried to layout the vinyl on the corrugated plastic sheet again, this time with the application fluid, still got bubbles. So my conclusion is that whenever the small squeegee touch the vinyl on the corrugated plastic sheet, the bubbles came out.

I watched several videos that showing other people did the exact same thing, with the Big Squeegee laying a vinyl sheet (not just the lettering) onto the corrugated plastic sheet, no bubbles! However, no one mentioned or did use small squeegee after laying the vinyl onto the sheet.

So my questions are
1) Do I need to use small squeegee to tighten the bonding of the adhesive after applying the vinyl onto the sheet?
2) How those corrugated plastic political signs are made? They seem very nice and flat without any bubble?

Any help or advise would be highly appreciated!

 

[AF]

Help us help you. What vinyl are you using, what laminate and what premask?

It may just be that you need more practice.

 

[Pixels Are Bad Mmmkay?]

For applying vinyl graphics to coroplast you need a felt squeegee or big squeegee and you want to apply the vinyl while pushing the squeegee the opposite direction to the direction that the flutes run. So if your flutes run up and down, you want to squeegee from left to right or vice versa. Using a standard plastic squeegee will give you bubbles every time, as will using application fluid.

Political signs are large runs and are typically either screen printed or digital printed, most often screen printed.

 

[Mosh]

+++run across the flute with the BS. Most political signs are screened of direct printed.

 

[haishan67]

Thank you for all your quick response!

I also tried the squeegee with the felt, not working either. But I went back to my book Vinyl Sign Techniques and found the answer. It's suggested to use a rivet brush because the squeegee will form bubbles in the flute's valleys. I don't have a rivet brush, but I tried a similar type of brush, and it worked! So I would like to share my experience here.

Thanks again for all your suggestions!

 

[Z SIGNS]

sorry can't help

a long time ago when I worked in a sign shop and vinyl came on the scene my nickname was "bubbles"

 

[Techman]

I have never had a problem with bubbles on a coro sign. No matter what direction the squeegee goes. I do not use any app juice either and do not have bubbles.

It all has to do with technique. A sharp squeegee is a must. A brand new one out of the box will not be the best. it has to be sharpened.

Removing the trans tape does create a lifting effect that can create blisters.

In the end a few small zits will not matter. They usually go away after a while. IF the blisters are not going away that suggests a technique problem with air getting compressed under the vinyl that slowly raises a bump.

 

[bob]

Bubbles are invariably due to poor squeegee technique. It doesn't matter how large or small the squeegee, if you use proper technique the vinyl will go down without any bubbles regardless of whether you squeegee with or against the flutes.

First, there is no need for a felt squeegee, you want a good sharp rigid squeegee. Personally, I don't care for teflon or any other slippery squeegee material, they don't give the right amount of drag. The premium 4" 3M gold is about as good as it gets.

Next, you need to perfect your technique. Let the squeegee put he vinyl in contact with the substrate and never, ever, squeegee unplowed ground. You always start a stroke completely on the last stroke and you finish that stroke half on that previous stroke. To start out, assuming you're using a hinge of some sort, assume the hinge is the last stroke and proceed accordingly.

Finally, keep the angle of the squeegee and the pressure constant.You really can't push too hard but however hard you are pushing, don't vary it. And keep your eyes on what you're doing until you're done.

 

[S'N'S]

As Tech & Bob said,"squeegee technique"....I use a gold squeegee (on masked vinyl) with lots of pressure and have no bubbles. You quite often hear from people who don't know any better talk about static causing bubbles, it's BS. I just done 20 coreflute signs so I tried an experiment and tried rubbing with a rag until I got static....no bubbles, I also applied across & with the flutes ....no bubbles. Use paper mask and plenty of pressure and there won't be any bubbles...(clear mask is crap).

 

[Pat Whatley]

I used the Big Squeegee to apply a 18x24 vinyl sheet on a corrugated plastic sheet, and it came out perfectly right after the application, without a single bubble. However, when I use my small squeegee next, the bubbles came out all over the places! I tried to squeegee them out, not working!

Eliminate the small squeegee step. Problem solved.

The big squeegee is not going to mount vinyl as firmly as a small squeegee will. You can't apply enough pressure across the width. What's happening is that you're going back and compressing the air that's trapped under the surface and instead of it being evenly spread you're turning it into tight little bubbles. Use the big squeegee then leave it alone. The vinyl is adhered well enough and will settle down solidly.

 

[DizzyMarkus]

Try not pushing so hard :0). The big squeegie provides equal even pressure across the flutes. I personally believe when your hitting it again the small squeegie it is pushing down on the soft part of the flute creating air pockets....check out where the. Ubbles are next time. Oh yeah and practice hehe

Markus

 

[haishan67]

I have never had a problem with bubbles on a coro sign. No matter what direction the squeegee goes. I do not use any app juice either and do not have bubbles.

It all has to do with technique. A sharp squeegee is a must. A brand new one out of the box will not be the best. it has to be sharpened.

Removing the trans tape does create a lifting effect that can create blisters.

In the end a few small zits will not matter. They usually go away after a while. IF the blisters are not going away that suggests a technique problem with air getting compressed under the vinyl that slowly raises a bump.

Thank you again for all your helpful input! I sure have learned a lot from this forums!

My scenario is that I need to put some cut vinyl on top of a vinyl sheet. I had no bubbles (perfect) after I applied the vinyl sheet on the coro sign sheet (without transfer tape). And then I applied the vinyl cut letters on top of the vinyl sheet, when I removed the trans tape, zillions of bubbles came out, I believe it matches what Techman said it's the lifting effect brought up those blisters. They're bigger than blisters, that's why I call them bubbles.

I don't know if those bubbles will eventually go away, but I sure don't like to deliver a product like that to a customer and had to explain it to him "the bubble will go away…", and squeegee millions of bubbles doesn't seem a good practice for business either.

Therefore, I am seeking the alternatives that may work with my scenario. What if I apply the vinyl cut letters on the vinyl sheet first, and then apply the vinyl sheet (with the vinyl letters on it already) onto the coro sign sheet, in this case, the transfer tape won't get involve with the coro sheet, and I hope this way would avoid the blister problem, any suggestion?

Thank you!

 

[bob]

...My scenario is that I need to put some cut vinyl on top of a vinyl sheet. I had no bubbles (perfect) after I applied the vinyl sheet on the coro sign sheet (without transfer tape). And then I applied the vinyl cut letters on top of the vinyl sheet, when I removed the trans tape, zillions of bubbles came out, I believe it matches what Techman said it's the lifting effect brought up those blisters. They're bigger than blisters, that's why I call them bubbles...!

If the first vinyl sheet is properly applied the app tape from subsequent applications isn't going to disturb it.

Ergo it should be obvious to even the casual observer that your first application isn't properly applied. You might try masking and applying the first layer just as if it were any other vinyl image. Not only will the vinyl be properly applied to the coroplast, you get a chance to work on your squeegee technique.

 

[S'N'S]

Pull the masking tape back at a 45 degree angle (or sharper) and it should not cause bubbles if the first layer was squeegeed down properly.