Grommeting aluminum composite (aka Dibond, Alumapanel, Signabond, etc...)

[zmachine]

I have tried for quite a long time (months) to properly attach grommets to 3/4mm aluminum composite material with no lasting success .
Mind you these are real estate yard signs that hang on S hooks that take quite a beating from wind and weather, we also chain the sign to the post on the bottom side but that seems to make it even worse. These signs are also vinyl applied rather than flat bed printed.
I use a #2 die, self piercing grommets both standard & long-neck on a hand press machine and even with a basic hammer die to no avail. Have tried with and without pre-drilling holes and nothing will stay together. It doesn't take more than a week and the grommets are separating so I have gone back to not using them at all.
Should I be using another form of grommet that is not self piercing since I almost always need to pre-drill any ways?

Was wondering what other people have done that have experienced this situation or am I and idiot for trying?

 

[J Hill Designs]

I have had 100% success using hammer set non-self-peircing grommets on ACM, both 3 and 4 mm

 

[Christian @ 2CT Media]

We use a Hiker Grommet press and use standard grommets for 3mm and long barrels for 4mm and have never had an issue.

 

[signcrafters london]

I recently used self-piercing No. 2s on signbond recently. (Regular, not longnecks.) Pre-drilled holes. Gave them a few raps with a hammer just to make sure afterwards. As far as I know they are still good.

 

[synergy_jim]

the better question here is why grommet ACM ????

 

[Billct2]

We drill and use hand set grommets, works fine.
(and the reason we put grommets in ACM is because without them holes wear out)

 

[zmachine]

Thank you for all your responses, its much appreciated.
I will try some non piercing grommets and set them with a hammer punch next.

The reason for wanting to grommet them is to provide longer life since the ACM itself is not strong enough to withstand 30-60 mph winds for days or sometimes weeks on end. It is also because they are hanging on S hooks off a wooden post arm. I actually haven't been putting the grommets in them because almost all of them fail within a month. Its easier to just punch another hole if necessary rather than have a large gaping hole caused by the grommet.