Large vinyl murals on foam core advice

We are installing large vinyl backed murals onto 1/2" foam core. Large as in 7 feet by as low as 7 feet side by as long as 13' wide.

The foam core is preassembled with tape on the back and thickened epoxy at the seam. The core has low shear, so the epoxy is supported by the tape and eventually the mural itself.

We tested various adhesives and all wallpaper adhesives failed to bond well. We also realized we needed to seal the foam core and are using Roman 999. The glue we are using is actually flooring adhesive. The flooring adhesive passed our test which was to have a shear failure in the core. All other adhesives failed to bond well to the mural.

The only issue is the adhesive application is with 1/16th or 1/32 trowels and we are getting quite a bit of air pocketing. Due to the size of the mural; they are rolled onto a pvc tube and rolled off onto the glued surface carefully to help stay square to the core.

The resultant parts looks good, but I am wondering if anyone can advise a way to improve.

Some ideas....

Use a wide glue roller and roll the glue on flat and without the lines which are air, or after troweling; roll the glue flatter. This sounds ez, but a little daunting to end up line free.

Use a weighted roll off tube. Our roller is a piece of 3" pvc. We could put some sand in it and cap it on the ends. The table is designed specifically for the mural height.

Use a different glue? I don't see this is an answer, although a spray adhesive might have less air pocketing; the murals are too heavy to slip sheet and we would need to wear respirators and build a spray chamber and we might still get some bubbling.

Thank you for allowing me to post. I can add some pictures later.

 

About 7' x 7', glued today, glue became contact like after drying too long and we got creasing on rolloff...tube on table



This creasing below is nothing bad and we can work out.



Thank you for replies. We rolled a mural/icon today. We discovered that contact adhesives are less than ideal. The first two we did; we used varying thicknesses of glue and we allowed an induction time today of 20 minutes and the glue became like contact cement and did not work well for us. We will apply next time no induction time and let the glue dry overtime. Here are the requested pictures and you'll see some of our application troubles on close look.


This is a 7'x7' icon already on the wall. It rolled out better than the 3rd one. A second mural rolled best and will be applied to the building ceiling tomorrow.

 

Contact glues offer no forgiveness on rolling off the tube as we discovered flooring adhesive behaves as contact glue if allowed to dry a bit too long and we ended up with wrinkles.

Would we be able to make corrections and lift the mural up if it is wrinkling or creasing? It seems like a minor delta in rolloff tension results in creasing. The floor adhesive allowed us some ability to pull errors out on our first part. The third one dried too much and became like contact glue and we had no chance to lift off and fix wrinkling.

Thank you both for commenting.

This is quite an adventure. We are putting up about 650 square feet of icons.

 

They are pvc vinyl.

There is no adhesives on them. The general use of these are as grommet banners. We ordered them no grommets, of course.

The memes are cute, but not the professionalism I had hoped for.

My credentials are not what I was asking about.

The walls are uneven plaster from turn of the century and in poor shape and would cost quite a bit of money to prep.

And as long as we drifted into memes and such; we tried to find Michaelangelo; turns out he died. Who knew?

They are indeed 4x8s, but bigger. We seamed them to support the larger sizes.

I did misspeak. The smallest mural is 7' x 7' or so; the largest is 7'x13'.

Again, thanks.

I am an unpaid volunteer; do be kind.

 

Sorry-the murals are as small as 7'x7' and as large as 7'x13'.

The wall is not good enough condition. We are double sided taping and framing the prints 12' off the ground on the wall/ceiling. It is on an angle.

We tried mounting directly to the wall and it failed due to the surface being poor; high texture, rough plaster, etc. The foamboard hides all the issues well.

We tried many wallpaper adhesives and they all failed a bond test. The Roman xtreme tack did okay, but bond failure still occurred between the vinyl and the Adhesive. Floor glue did not fail a bond test and sheered at the core.

 

Again, thanks for any advice.