Removing rusty self tapping screws

tommu56 · Jun 4, 2011

tcartwri said:
Angle grinder on the screw heads. It will easily chew through the decking as well. Then pull the boards off and zing off the remainder of the screws with the grinder.

X2

tom

Short Game · Jun 4, 2011

I, too, am looking at this same job. Glad I spotted the thread title. I would have been going at it, trial and lots of errors.

sandman2234 · Jun 4, 2011

From what I know of these screws, grinding the head off probably wont be easy because they are recessed and you would have to grind wood at the same time, unless you first removed it, which negates the reasons for grinding the heads off.
David from Jax

Scooby074 · Jun 4, 2011

sandman2234 said:
From what I know of these screws, grinding the head off probably wont be easy because they are recessed and you would have to grind wood at the same time, unless you first removed it, which negates the reasons for grinding the heads off.
David from Jax

Yup

whistlepig · Jun 4, 2011

If the screws are stuck so tight that they are breaking with an impact wrench I can not see a different result by sticking a rod to the top of them. Just a different method of breaking off the bolts. And even if the bolts were removed it is almost impossible to put new wood over the existing hole and drill a hole though the new wood that will line up with the existing hole underneath it. I have replaced a couple of floors and ramps on horse trailers. Its much easier just to break off the existing bolts, mount new wood, and then drill a new hole through the wood and the metal surface and use self tapping screws.

sandman2234 · Jun 5, 2011

Whistle, I agree that trying to reuse the original screw holes is going to be problemmatic, and no matter how he tries to remove the screws, due to the shear volume of them, the easiest way to tackle this problem is with an extra set of hands, lol,!
A couple of drill motors set up with drill and Torx driver and a box of screws from one of our local trailer repair shops and it wouldn't take long to nail down some new boards.
David from Jax

tungularafishcamp · Jun 5, 2011

JJ try a left handed drill bit just small enough to fit into the torx hole. U usually dont get a quarter inch into the shaft of the screw and sometimes less before it spins on out and if your careful you wont even mung up the threads.
Rick

HarleyScooter · Jun 5, 2011

JJ, interesting idea, I would not use to many amps because you don't want to melt the head I would start low and work my way up as needed. We use to thaw frozen water lines at work buy connecting welders to the lines. I agree I would not really want a bunch of holes in the cross-members either, I guess you could just drill a pilot hole from under the trailer once the new deck is installed. I will be watching to see how it works for you.

tommu56 · Jun 5, 2011

Drilling them might be problematic if they are the self tappers or self driller/tappers because they are hardened so they can cut the thread.
All the more reason to abandon them and do new holes with out the hardened screws in them unless you are going to go with larger hardware.

greasemonkeyok · Jun 5, 2011

Had the same problem with self tapping Torx screws in the floor of a storage container. What ultimately worked best was spraying a little Kroil from the underside one day, and using a 1/4" drive butterfly impact driver the next day.

Bigger is not better on the impact wrench, that just either ripped the heads off or gouged out the Torx head. The smaller driver vibrated the screws for a moment without ripping the heads off, then the screws would start to turn.