Drilling Through Metal

[mcspin50]

Hi all,
I've got the Herculiner on the bottom of my floor and am about to attach the floor assembly to my NT 5x8 No-Floor trailer which is made out of 2x2x1/8 angle steel. Got the 3/8" bolts, washers and nylock nuts ready to go.
Any tips/advice on drilling through metal? Type of bit to use? Someone said to lubricate the bit with oil when drilling and drill slow. How do you lubricate it? With machine or motor oil in a squeeze bottle? This sounds like it might be messy.
Also, can I secure the floor to the cross braces if the side rails aren't suitable/accessible?
Thanks in advance for your help/wisdom.

[Woodbutcher]

I have the best luck, step drilling with smaller bits first then move up to the 3/8 size. Hold on tight to the drill. Drilling metal can be tricky in that the bit often gets bound or stuck in the hole before you go all the way through. When this happens the drill itself will spin out of your hand. Keep a hold of it and keep you chin out of the way. Slow and steady wins the race.

[afreegreek]

what bit you use will depend on the power of your drill.. if you have a 1/2 or 3/8" electric drill you'll be ok drilling the hole full size.. if you have a cordless, you'll need to do it in steps... say.. 1/8, 1/4. 5/16, 3/8.. you can get a little can (3-4 oz) of cutting oil from auto supply for a few dollars.. it's a little messy but not bad. all you need is a drop at a time..

regular jobber twist drills are the type you want.. carbon steel will work for a few hole but will dull quickly.. high speed steel are a bit more money but last much longer..

*** Be careful!! ***

1/2 and 3/8 electric drills have enough power to really hurt you..the drill bit has a habit of jamming as it comes through.. make sure you have a good grip and position yourself so you won't slam/pinch your hand against anything if the handle torques around..

[Miriam C.]

I used a self starting Titanium bit. The hardest part was not bearing down and taking too big a bite out of it. If it gets caught on too big a piece it will stop suddenly and break your arm off. A bit of exaggeration but not much. Do it full size and buy a really good bit. Mine cost over $11...

It will get hot so don't touch it after...

[afreegreek]

cordless drills.. ya, if you have one and it's not a high power model like 18 volt, you're better off buying a cheap electric.. there's a good chance you'll burn up you cordless drilling 3/8 holes in steel.. pick up an old electric at a garage sale or second hand store for 10 bucks..

[afreegreek]

here's a vid for you..

http://www.youtube.com/watch?v=2O-kwi-KqvE

http://www.youtube.com/watch?v=od4tq3gvW4k

[Ageless]

Stop by the store and get parafin used to seal jam jars. Once you get started; touch the drill to the parafin and continue drilling. If you drill motor is variable speed, keep the speed slow.

[eamarquardt]

The center of a conventional metal drill does not cut but pushes the metal aside. If you center punch and go for your 3/8" hole in one shot you may or may not end up with the hole where you want it. Use a smaller drill (maybe 1/8" or so) to drill a pilot hole. This will keep you hole where you want it to be and will make drilling the 3/8" hole a lot easier.

Hope this helps.

Cheers,

Gus

[deceiver]

Hi speed steel drills are for drilling any material.

Titanium drills are High speed drills with a titanium coating. It will lubricate and make the drill a bit stronger.

Carbon steel drills are tough but not for metal because they are brittle and break if the drill locks in the hole which it often does.

Cobalt drills are extremely tough but are also brittle. Good for the toughest metals as long as you are careful and wear eye protection.

When I have a lot of holes to drill in metal I will do either of these things... One buy a few high speed steel drills and use a new one when the first one no longer cuts. Two: spring for a cobalt drill. It will drill many holes before it gets dull.
Also, some of the recommendations above are good too. start with a smaller drill, etc.

[planovet]

cordless drills.. ya, if you have one and it's not a high power model like 18 volt, you're better off buying a cheap electric.. there's a good chance you'll burn up you cordless drilling 3/8 holes in steel.. pick up an old electric at a garage sale or second hand store for 10 bucks..

This

Even if your cordless is a 18V, you are better off using an electric drill to drill through steel, esp. if you are drilling multiple holes. It will drain a cordless drill battery in a hurry.

[mcspin50]

THANK YOU ALL!!...for your input and wisdom on this. I feel much better prepared to tackle this part of the build.
I just talked to my neighbor and he's got a drill with an extra handle so I can have two hands holding the drill, thus will hopefully avoid any breakage of these ol' bones.
Hope that drill's not a cordless! I figured I'd be running through batteries if I used them.
Again thanks!

[caseydog]

I used a Makita corded drill with standard high-speed steel bits to drill the holes through my frame to bolt the floor down. That drill also has a second handle you can attach to hold the drill more steady, if you need it.

CD

[mikeschn]

Yep, they covered the bases pretty good.

I used a titanium bit in an electric drillmotor. When it jammed in the hole, it almost ripped my arm off. Thanks for reminding me Miriam!

Mike...

[MountainBiker]

Be careful if you get long chips coming of the drill bit...they will cut you like a knife ...learned that the hard way years ago
I would be careful though, even with the extra handle, it can still grab and whip, and the handle likes to find shins and ankles and knees
The secret is to slow down when you get close to going through the metal.
Also, different metals drill different ways, so if you are using many types of steel on your trailer, you wont get the same results when drilling. i.e. sheet steel, compared to chanel bar, compaired to aluminum

[dh]

One tip I have that was not mentioned, if you are not familiar with drilling metal, and lets say you are starting with 1/8" pilot holes, get a few spare 1/8" drill bits. It sucks when you break your only 1/8" bit. I doubt you will break the bigger bits going into a pilot hole, but those 1/8" bits are easy to snap and could create an O.S. situation at 9:00pm when everyplace is closed.

Also, make sure your bits are sharp, and keep them sharp.

I agree about the parafin, but really anything will work. I like tap magik, and have some water based cutting fluid (causes rust problems on machining equipment though) that works ok for drilling. WD-40, or any spray lube will work, I have even used silicone mold releas (it was handy) and Pam before, however, Pam creates an, uh, aroma that seams to make me hungry