Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 13, 2025 ...

I discovered something today that some of you may already know.  I needed to drill a 7/16" hole into the chassis in order to attach a lateral support for my exhaust pipe.  I wore out three titanium drill bits and spent about 20 minutes getting only about half way into the metal when I realized I wasn't going any further.  Out of desperation, I tried using a self tapping hex head screw.  It immediately started throwing flakes of metal and went straight in.  I did a second hole with the same success.  I'm stumped as to why drill manufacturers (my bits are Milwaukee and Dewalt) haven't figured out what the fastener people know.  Next time you need to drill a hole because a bolt broke off, try it.

"Pulsate" the drill--in other words vary your speed. Start with a much smaller diameter drill, then go larger & larger. Main reason is that the drill point or chisel point of a larger drill has almost zero surface feet per minute (just like the center hub on a large coach or truck wheel) so the outside edge of a large drill can't cut because it's thick point isn't cutting, just rubbing. If you have the resources & ability you can thin the point web so there is less resistance. I prefer to use a smaller drill first.
Also, if you can put a 10 degree x maybe a 1/16" long chamfer (with clearance) on each flute--parallel to the drill axis-- your hole will end up cleaner, smoother, and the drill cutting edges will last longer. Almost like a two flute reamer.
(old tool engineer here)

About half of the bolts I've removed have broken off - don't try to remove any unless you are prepared to drill them out.  No fun drilling through an old bolt.  They may have lost their shear strength, but they're still damn hard.

About half of the bolts I've removed have broken off - don't try to remove any unless you are prepared to drill them out.  No fun drilling through an old bolt.  They may have lost their shear strength, but they're still damn hard.

Ya, what bolts are you trying to remove???

And are you making fresh breaks or are you just identifying old breaks (broken end rusted)

When I re-drilled all of my Bulk head bolt holes (about 25 new holes) I used a 90 degree drill attachment.
 I used a bar clamp mounted on the back of the 90 and in front of the drilling surface.
At a slow speed I was able to continuously tighten the bar clamp while shooting white lithium grease(cools,lubes and doesn't drip like oil and stays on a vertical surface) at the drill bit point.
This worked great especially when going through the thick angle iron.
I drilled all 3/8" holes without a need to down size the drill bit.
No drama, reasonably quick drill times, I used a new black tool steel bit every 5 holes ( drill bits were still good for less strenuous jobs), little fatigue on the driller (ME).