3M 468mp for acrylic letters to wall installation

[ArtisanFab]

Hi All,
My name is Ian, I'm new to the forum. Really excited to have found this resource, I look forward to reading posts and contributing if/when I can be of help.

Today's issue:
We normally (i suspect like many of you) use [HASHTAG]#VHB[/HASHTAG] for mounting CNC/laser cut acrylic letters to an interior wall. However, this time we had a little mix-up and now have a large number of 2" to 8" tall x 1/4" thick acrylic letters with [HASHTAG]#468mp[/HASHTAG] transfer tape instead of VHB tape.

3M tech support didn't think it would be an issue, but they also didn't have direct experience.
Does anyone here have experience with using this 468mp for permanent indoor application on painted drywall? I hope we don't have to recut the letters, but that would be better than a call back because they're falling off the wall!

thank you!
Ian

 

[Rydaddy]

VHB is really what is called for here. The [HASHTAG]#468mp[/HASHTAG] works great for it's intended purpose. I believe you have a high percentage chance that you will have failure. (letters falling off the wall).

 

[bigben]

VHB is really what is called for here. The [HASHTAG]#468mp[/HASHTAG] works great for it's intended purpose. I believe you have a high percentage chance that you will have failure. (letters falling off the wall).

I second that.

 

[ArtisanFab]

Ok copy that! thank you for the fast response Rydaddy and bigben
We will recut those suckers, definitely don't want a callback.

 

[CanuckSigns]

we use 468MP on acrylic letters we cut on our laser, it works great for drywall applications, I've never had an issue in 12 years

 

[Gino]

We don't use the 468mp, but I don't see a problem using it. It has great shear strength and unless the walls were recently painted, you should be fine.

You mentioned a mix-up. What actually happened ?? Do you produce these in-house or do you sub the fabrication part out ?? Seems like if you've had a method for doing things, someone went out of their way to bungle this up by being too smart for their britches..... or they know something many of us don't know.

Like to know what happened.

 

[Johnny Best]

That tape is used for overlays and nameplates according to my 3M reference guide. Why not get some VHB tape and put on backs instead of recutting new letters. The VHB will stick to the 468MP good and also to the painted drywall, 4941 VHB is good to use.

 

[printhog]

any wall install should have a tape adhesion test for any adhesive application. there are paints that can interfere with adhesives radically. you should test the wall surface for adhesive issues before deciding what process or material to use. 3M™ Adhesion Test Kit for SMOOTH Substrates

In general VHB works best on rough surfaces as it conforms into the texture and the load is spread by the foam or vinyl core. it has 15 lb per in adhesion.

For smooth surfaces, like sign faces, 468MP is a standard use and works great allowing you to machine right thru it in reverse for labor savings and get a closer bond to the surface preventing vandals form prying off letters. it has a 5 lb per in adhesion.

 

[ArtisanFab]

Hi All, thanks for all the responses!

We ended up installing the original letters with the 468mp after hearing from CanuckSigns that they haven't had any issues in 12 years of using this product for this purpose.

I also applied 2 extra letters from the batch above my desk so i can monitor their success
I will update this post in the future if we receive a call back, or if a letter falls on my keyboard while at the office

Cutting VHB strips and applying to the back of letters works fine for large pieces but if the letters are only a couple inches high, it can be pretty tedious.. especially compared to applying the tape prior to laser cutting.

They are high up inside so not worried about vandals, and 5lb per sq in will be more than sufficient.
The tape adhesion test is a nice idea also.

 

[signbrad]

3M product bulletins can be invaluable.
Installers sometimes blame the product for a failed install. "We got some bad vinyl (or adhesive)," you'll hear them say on occasion. Or, "It has ALWAYS stuck in the past."

But paint formulations are changing constantly, especially in these days of low VOC. I am sure many of us have finished a job on a wall only to go back the next day and see it lying on the floor. The client is not happy and the installer is convinced that vandalism is responsible. Adhesion testing can keep a job from becoming a loser.