Best Way to Put Holes In Headliner?

I have a 1995 F150 that I want to install a ham radio in. I have the radio (Yaesu FT2800M) and the little bracket to surface mount it. I want to mount it overhead, between the sun visors. Ford pickups of this era have a second roof skin that extends roughly 7" back from the windshield header. My plan is to install four rivnuts there and bolt the ham up. My headliner is pristine so I have some qualms about messing it up. Should I just run my drill bit through both materials or is there a better option?

Shotgun

But seriously,  is the second skin strong enough to withstand a solid strike from a hammer and a hole punch without denting the roof?

What about 4-6 rare earth magnets? Sure the headliner will dampen some of the grip, but a 30-40lb magnet is pretty gnarly. 4-6 on a piece of sheet metal ought to do the trick.

Use a drill stop, for sure. Otherwise things may get ugly fast. Seen it many times. Even with experienced guys in the field. Its super cheap insurance against having a pimple in the roof skin.

Also drilling thru the headliner material may wind up as a mess... Depending on what it is,  using a circle punch slightly oversized of the  drilled hole will save from the material unraveling and other nonsense, if you can without dimpling the outer skin.

Also sometimes  depending on the material getting it (circle punch) hot can help seal up and prevent unraveling of the material, if it is that type of material. I've also used a soldering iron with a wood burning type tip to cut odd shaped holes in things like carpets and headliners before... 

Again, no guarantees on anything as I work on older stuff, and cant say ive worked on one of those trucks... but the same philosophies and ideas apply. 

New, and I mean brand new razor blade. If you have an exacto knife with a new, and I mean brand new blade you'll be fine. 

Assuming it's got some nylon in the headliner... I think using an exacto knife to make the cut (slightly bigger than the rivnut) and then hit the edges with a soldering iron to melt the material and prevent it from ripping. 
 

Edit: have a wet sponge handy in case it burns

What about heating a circle punch up with a torch/lighter and melting through the headliner, that way you get a nice clean cut and the edge is already melted in a uniform fashion? 

Is there a trim panel that you could remove to test your method on a hidden piece of headliner? Maybe a trip to a local junkyard would be worthwhile as well to test methods :)

What is the headliner made of?  Is it fabric or cardboard or...?

These are no joke magnets and have 1/4-20 threads ready to go. I used one to keep a gopro on the roof of our Jeep for an entire day. I put a layer of duct tape on the bottom to protect the paint. It was rock solid.

https://www.amazon.com/dp/B07JKWCVTX/ref=cm_sw_r_apan_glt_i_Z4Y4PESZ64QPZ79885SC

I was gonna say cigarettes but the ideas mentioned above seem better.

I'd remove the "mouse fur" covering with an Exacto knife and then use a hole saw on the substrate. The substrate ought to be some sort of glass mat composite, pressed fiber or a formed plastic sheet.

Nick Comstock said:

Shotgun

But seriously,  is the second skin strong enough to withstand a solid strike from a hammer and a hole punch without denting the roof?

I think so. There's like a 1/2" gap between the two pieces. Other forums say that panel exists so the ambulance conversations and such have a place to mount their things. Not sure I totally trust them though. 

To be honest, this whole thing makes me nervous. Overhead consoles are cool in a big rig kinda way, I just don't want to berkeley up in such a visible area. The last three vehicles this radio has been installed in all had double DIN radio openings, so I'd just plop it in under the head unit. The dash on this Ford doesn't have that size of opening so I actually have to think about where to install it.  

In reply to GaryC83 :

Circle punch, that's the word I was looking for.  

thatsnowinnebago said:

Nick Comstock said:

Shotgun

But seriously,  is the second skin strong enough to withstand a solid strike from a hammer and a hole punch without denting the roof?

I think so. There's like a 1/2" gap between the two pieces. Other forums say that panel exists so the ambulance conversations and such have a place to mount their things. Not sure I totally trust them though. 

To be honest, this whole thing makes me nervous. Overhead consoles are cool in a big rig kinda way, I just don't want to berkeley up in such a visible area. The last three vehicles this radio has been installed in all had double DIN radio openings, so I'd just plop it in under the head unit. The dash on this Ford doesn't have that size of opening so I actually have to think about where to install it.  

If it were me I'd use a circle punch bigger than the hole you need.  It may not cut all the way through but should give you a good guide to finish the hole with a sharp exacto knife blade.  

Been a while since I messed with one, but I remember a buddy pulling his headliner out after he removed the trim pieces from around the lip of the roof on his '94.  Have you just tried doing that?

In reply to Mr_Asa :

I haven't. What's the benefit to pulling the headliner over putting holes in it in situ?

In reply to thatsnowinnebago :

Would have more control with it on a bench, and you'd be able to more accurately place the holes in the metal and perform clean up?  I generally go to disassembly as a first step when I'm modifying stuff.

Also, if it's anything like my '93, the headliner probably needs to be repaired or replaced anyways

Mr_Asa said:

In reply to thatsnowinnebago :

Would have more control with it on a bench, and you'd be able to more accurately place the holes in the metal and perform clean up?  I generally go to disassembly as a first step when I'm modifying stuff.

Also, if it's anything like my '93, the headliner probably needs to be repaired or replaced anyways

Gotcha thanks. That makes sense.