Install of acm on enameled steel

[akuarela]

We're installing acm boards on top of some warped and very hard enameled steel boxes. The warp is the least of our worries as the client recognizes they are far from perfect.
Tried drilling with self tappers, pre-drilling, etc. Barely a dent on that stuff.
Plan B: glue them on and keep them clamped overnight. What type of glue would you recommend, etc?
Thank you ☺️

 

[chester215]

VHB tape??

 

[ChaseO]

How big of a panel? And that probably isn't enamel, but porcelain. I just went through that on a job. We found that you could take a pick and knock the top layer off with a hammer (only where the screw was to penetrate) and it would drill like normal. Or get a different bit.

 

[Gino]

Loctite Epoxy Weld Bonding Compound

 

[Billct2]

We ran into that when re-skinning and old sign that turned out to have been re-skinned once already over porcelain. We would whack it first with a nail punch, still went through a lot of bits

 

[akuarela]

VHB tape??

There's an idea that I didn't consider.

 

[akuarela]

How big of a panel? And that probably isn't enamel, but porcelain. I just went through that on a job. We found that you could take a pick and knock the top layer off with a hammer (only where the screw was to penetrate) and it would drill like normal. Or get a different bit.

The panel is 3'x10' (actually 2 of these, one on each side). We may try to see if any change trying the pick trick.

 

[akuarela]

We ran into that when re-skinning and old sign that turned out to have been re-skinned once already over porcelain. We would whack it first with a nail punch, still went through a lot of bits

I guess similar to what ChaseO was saying. Not much excited to go through several bits, as we're not exactly next to Lowe's at this job.

 

[JWitkowski]

Try drilling with a small masonary bit or a diamond-tipped one. Carbide-tipped drills are available and diamond Dremel-type bits may do the job of getting through the top layer.

 

[visual800]

if its porcelained and old your trying to drill thru old pot metal I bet, that gonna wear some bits out. Might wanna try some new harbor freight bits (to save money) and put drill on hammer function