Removing rusty self tapping screws

[J_J]

Is it feasible or has anyone done this using a stick welder.

I have tried removing these rusty screws from a trailer bed. They are self tapping and have been there a long time. I have tried to use impact and have twisted some off.

Has anyone used a carbon rod in a stick welder and touched the screw until it was cherry red, and let it cool. My thoughts are that it would burn the rust between the screw and the frame, and when cooled, would allow the screw to turn more easily.

How many amps would be required to heat a number 6 screw about 2.5 in long.
.

 

[sandman2234]

Don稚 know about the amperage, but your question brings up more questions. Why would you want to remove them, except to replace the wood? Rotten wood tends to harbor fire so be careful with the heat. I removed some from a trailer a while back and the wood suffered from the heat. I finally took a right angle grinder with a 9" blade and cut the protruding part off from underneath. The heat from cutting seemed to loosen up the now shorter screw so it took less work back on top of the deck. I really wanted to cut them with a torch but that tended to mess up the thread which made it impossible to back out. The Torx screws the used were hardened on the face so drilling them from above was not an option.
David from Jax

 

[J_J]

Yep, I need to replace the deck boards, and they are Torx screws. The other option is to use a 1/2 in hole saw and cut around all the screws and lift the wood out, then use penetrating fluid and vice grips on the screws. I really don't want to drill new holes.

 

[Shield Arc]

I had to do this very thing to a neighbors flatbed trailer a few years ago. I'm not a very patient guy:laughing:, so I used my bridge crane with a shake out hook in the hoist's hook, and ripped the boards off. Took a zip disk on a 4-inch grinder and cut the screws off flush with the cross members. When replacing the boards I used a little different screw pattern.

 

[Scooby074]

cut out the boards with a chainsaw, circ saw or equivalent .

Get a prybar and remove the remaining pieces around the screws.

Go back with a angle grinder and cut the screws.

No shortcut that i know and ive redecked a couple. Using a torch (welder etc) will never get heat down to where its needed.. plus youll end up spending half your time putting out fires.

 

[xtn]

How about this...

Flip trailer over. Hit each screw briefly with an angle grinder to knock the tip off down flush to the angle iron. Then punch each one out.

 

[tcartwri]

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.

 

[Mybota3400]

How about using a Torx socket with a six or eight inch extension, and hit with a hammer a few good licks. Take a pull-handle and rock it back and forth. I hope it works, cause I have to do the same thing next year.

 

[Sandlot]

As others have advised, holesaw or the like to get most of the wood off, angle grinder to knock the tops off flush. Replace wood planks, use these to screw'em down.

McMaster-Carr

 

[travis potter]

I think you could use a grinder to cut down on thescrew head then pry the board off the screw. After the boards are off hit the sceew with a big hamer on the side and they wil break off. Trying to reuse the old holes will take a long time measuring and driling the wood and you will still mis on most of them. The new screws should be self driling so all you have to do is dril them in.

 

[tommu56]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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.