Can’t screw into metal

[Piper]

Hi friends, I’m in the process of framing and insulating my walls, but it seems I’ve hit a wall. My bus is a 2001 Chevy Express StarTrans fiberglass shuttle bus. I’m trying to screw my 2x3 studs into the metal underneath my fiberglass wall and I can’t seem to drill through the metal to save my life. I’ve tried many different drill bits and self drilling screws but nothing will pierce it deep enough for the screw to latch on. I can screw into the fiberglass just fine but the wood does not stay secure at all obviously. Please could someone explain what I’m doing wrong or how else I can go about this. I’m clueless and overwhelmed while also on a time crunch, so I need to get past this obstacle asap. I’m at the point where I’m strongly considering picking up a couple of the dudes that hang around my Home Depot looking for work haha but I’m a lone female so not sure if I want to go to that extreme yet. Thanks in advance

[Piper]

Had to upload some shitty pics since they only upload sideways when normal.

[kazetsukai]

You can't get through the metal even with a smaller drill bit? Do you know how thick the metal is you are drilling through?

[Piper]

seriously I’ve tried many things and none of the drill bits can get deep enough. I’d have to assume the issue is that the metal is too thick. It seems pretty thick

[kazetsukai]

Couple more questions:
What kind of drill bits are you using? Metals have a variety of hardness ratings in addition to thickneses. You will burn through drill bits very quickly playing with metal.



Are you using a drill, or an impact driver? Impacts with self-tappers make the job MUCH easier than traditional drills in my experience.


If you are using Phillips head screws, they can cause grief just by virtue of needing to press on them so hard while chewing into metal. Consider hex head screws:

https://www.lowes.com/pd/Teks-14-x-2...ount/999977048
Or star drive screws:
https://www.lowes.com/pd/Power-Pro-1...unt/1000768216


With these, you don't need as much physical force behind the drill. I'm a pretty strong guy... but when I am drilling through things like floor joists I find myself struggling pretty hard.



If you are trying to drill through anything thicker than 1/4" you will need to make progressively larger pilot holes before screwing in, having tons of drill bits and even more patience.

[Rivetboy]

Are you running the drill in reverse? If the work is in front of you the bit should be turning clockwise.

[Rivetboy]

Also higher rpm for pilot holes say 1/8 or 3/16 and slower for dimension holes 1/4 3/8 ..

[johnbloem1974]

Have you tried to get the hole going first without screwing into the wood (either with a drill or self-tapping screw), then once the hole in the metal is started, you can screw on the wood piece? It may take a little longer to have to line up the holes, etc... but that's always worked for me.

John

[hrdcor32]

Look up nutserts as well. Basically rivets that will accept a bolt. That's what I'm planning to use for mounting to fiber glass where I have no other option.

[Tejon7]

Looks to me like you need a pilot hole no bigger than 3/16". Maybe only 1/8" - it's kinda hard to judge scale from your pics. Anyway, you should be able to drill holes that size fairly easily with the right bit and technique.

First, technique - slow RPMs and lots of steady pressure. You want the bit to carve away metal with each revolution but not get too hot. Battery powered hand drills don't always have the torque needed for this.

Second, drill bits - I burned up or shattered a whole pile of black and decker and harbor freight bits before I realized I needed quality bits to drill through 1/4" steel. I ended up getting some Bosch cobalt bits that are 1000x better than the budget crap I was using before. I mostly use the 3/16" bits and they'll last at least 50 holes through 1/8" - 3/16" steel before I switch out. I'm sure they'd last even longer if I bothered to use cutting oil.

Here's a link to the bits I use, but I'm sure any of the better brands would be just as good:

Amazon Bosch drill bit

[mmoore6856]

cobalt is your friend use no other

[peteg59]

X2 on the cobalt drill bits!

[musigenesis]

Are you using Teks wood-to-metal screws?

[DawgBüs]

It sounds like you're drilling it but it's not grabbing hold once the screw is in? You mention that it can't get deep enough. Nothing in there should be thicker than 1/4" and unless you're drilling into a structural support, my guess is you need something for the threads of a screw to latch onto. Someone else mentioned thread-serts/pems. Probably a good idea.

Otherwise, pretty much everything in that vehicle should be easily drilled. Oil/lube can help, even just wd-40 or motor oil. A small dab on your drill bits and intended hole location. If it's really that thick, keep adding oil as you go to keep drill tip lubed and cool. Heat will destroy bits in no time.

[DeMac]

Everything Tejon7 wrote. Like a machinist. All that, yes.

Be spendy on the blades.
Lube your expensive new blades. Every cut.

Drill a tiny (5/64") hole first.
Ream the hole a 1/32" larger at a time until you reach the finish size.

Pressure and speed affect how much material is removed per pass as well as friction induced. Small amount of material per pass. Not coils.

Every material has a speed rating.
Plastic - walking slow 500 rpm
Aluminum - Slow 1200 rpm
Stainless steel - Medium 1500
Heat treated - Medium 1800
Wood -MediumFast 2200

Only Wirebrush/Polish - Full speed 3000+
Speed Kills

*Lube*Lube*Lube*
Can't stress the lube enough
Cutting oil
Bar & Chain oil (*thick & sticky)
Motor oil

...or wd40, mmm, maybe, ok
but lube every cut and your blades will last a 1000 holes.

[cadillackid]

Originally Posted by DeMac

Everything Tejon7 wrote. Like a machinist. All that, yes.
Be spendy on the blades.
Lube your expensive new blades. Every cut.

Drill a tiny (5/64") hole first. Ream the hole a 1/32" larger at at time until you reach the finish size.

Pressure and speed affect how much material is removed per pass as well as friction induced. Small amount of material per pass. Not coils.

Every material has a speed rating.
Plastic - walking slow 500 rpm
Aluminum - Slow 1200 rpm
Stainless steel - Medium 1500
Heat treated - MediumFast 1800
Wood -MediumFast 2200
Wirebrush - Full speed 3000

*Lube*Lube*Lube*
Can't stress the lube enough
Cutting oil
Bar & Chain oil (*thick & sticky)
Motor oil

...or wd40, mmm, maybe, ok
but lube every cut and your blades will last a 1000 holes.

**THIS***


turning the drill on highest speed when it doesnt go is the BIGGEST way to destroy a drill bit.. I see it time and time again..



and YES to cutting oil.. it makes a mess but it truly works and saves your drill bits.. your expensive drill bits.. dont buy cheapie drill bits for hard metals.. they wont last one hole..

[Rivetboy]

I wonder if the bit is going in to the side of the hat channel.

[Piper]

Thank you all for offering your help! It’s a bit overwhelming.

I have tried drilling just the metal by itself and still couldn’t get deep at all. I can see my mistake of burning out the drill bits, I guess slow and steady wins the race. I’ll definitely have to look into the cobalt drill bits. I’m assuming I just need to go ahead and get an impact driver. I’m using self drilling flat head wood to metal screws. The TEK screws sold in my area do not come in 2”, only too short and too long. I can’t find them anywhere, so I’m using a different brand. But I will invest in some cutting oil as well.

I would assume the metal I’m attempting to pierce is part of the structural support. Does that change things? Sorry if that’s a dumb question, I saw that someone mentioned that. It’s a mostly fiberglass shell with little metal to grab onto so I would assume that most of the metal in my bus is structural.

[musigenesis]

Originally Posted by Piper

Thank you all for offering your help! It’s a bit overwhelming.

I have tried drilling just the metal by itself and still couldn’t get deep at all. I can see my mistake of burning out the drill bits, I guess slow and steady wins the race. I’ll definitely have to look into the cobalt drill bits. I’m assuming I just need to go ahead and get an impact driver. I’m using self drilling flat head wood to metal screws. The TEK screws sold in my area do not come in 2”, only too short and too long. I can’t find them anywhere, so I’m using a different brand. But I will invest in some cutting oil as well.

I would assume the metal I’m attempting to pierce is part of the structural support. Does that change things? Sorry if that’s a dumb question, I saw that someone mentioned that. It’s a mostly fiberglass shell with little metal to grab onto so I would assume that most of the metal in my bus is structural.

The self-drilling screws should not require pre-drilling (in the metal) or cutting oil or anything like that. You do want to pre-drill the hole through the wood, though, so that the screw will go through it without its threads catching the wood (which will draw the wood away from the metal). If the screw is too short for the wood, you can drill a bit of counterbore in the wood with a bit just larger than the head of the screw - this will allow the screw to sink deeper into the wood and also deeper into the metal.

It would help to wedge the wood against the wall with a long 2x4. You also need to get a good bit of force/weight behind your drill to run the screws into steel.

There shouldn't be any metal in your bus body that is too thick for these self-drillers.

[Slickster]

I'm working on the same style bus, the metal framing isn't too difficult to drill, the builder used a ton of #12 self drilling screws all over the bus....not self tapping, self drilling....if I make an 1/8 hole, they work no prob....why the framing?