Removing steel screws broken off in spoilboard

Well, only days after installing spoilboard, someone used long, crappy steel drywall screws and busted one off deep in the table. Head's gone and shank ends about 1/4" below the surface. They tried to excavate it but only succeeded in digging a larger hole around it, but there's not enough room to get vice grips around it and needlenose don't have the leverage. It will probably destroy the resurfacing bit. It's not a situation for a broken screw extractor, that would just slide off. As would a drill. Well, I might use the CNC spindle with an endmill, but it's steel, and I don't know how long that screw is, I could end up making it harder than ever to retrieve the whole thing.

Any genius ideas for removing it? I thought of wetting the MDF (it already has a trench dug around it where they tried to dig it out). The idea being that it will turn the MDF to mush so the screw might come out, but I expect all it will do is ruin the MDF. I thought of maybe taking an aluminum arrow shaft, cutting teeth in it, and using it as a long hole saw. It's an interesting idea but I don't think the "teeth" would be strong enough. Maybe a thin-walled steel tube but I can't think of a convenient source.

Would an external stripped-bolt-removing cup work? I don't have a set of those, and this seemed much smaller than I remember the ones I have seen being. Smallest external is listed as 1/4", but I think that's the minor diameter inside (not sure), and that may be too large to grab that drywall screw shank.

maybe use an end mill to to cut a pocket around it big enough to get a pair of vise grips on the end of it and get as close to the screw as possible or maybe all the way trough it and once its out cut a plug and glue the plug in the hole then surface it.

1. RC hobbists use brass tube. Cutting teeth into the end of one of them might last long enough to cut a plug around the screw?
2. Touch the screw with a arc welding rod and then use the rod the unscrew the offender?

machinesdude's idea sound good as well.

..might work for ya. grind a slot for a screw driver
Attachment 448780

I would take a 1/8" endmill and route a small hole through the spoilboard around the broken screw. Then you can plug and resurface the hole if you like.

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Originally Posted by machinedude

maybe use an end mill to to cut a pocket around it big enough to get a pair of vise grips on the end of it and get as close to the screw as possible or maybe all the way trough it and once its out cut a plug and glue the plug in the hole then surface it.

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This would be my solution too.Then I'd hide the steel screws and leave a box of brass screws in the workshop.

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Originally Posted by routalot

This would be my solution too.Then I'd hide the steel screws and leave a box of brass screws in the workshop.

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Initially I did state that only brass screws were to be used. However, the brass stripped and busted all over. It's also difficult in that there are many more brass-plated cheap steel screws around than there are true brass screws.

I think Kreg washer-head square-drive screws intended for their pocket jig have a sturdy construction that comes in and out very easily, except that it does swell the top surface that persists after removal unless the spoilboard is predrilled, which is unlikely to get people to work out and use consistently.

Teks self-tapping washer head lath screws also seem sturdy. It's a Phillips head though. When used correctly, it's pretty hard to strip Teks, but there are a lot of looks-like-Phillips-but-isn't drive bits out there that are easy to accidentally use and the wrong bit can strip it easily.

We used aluminum nails to hold down out spoilboard; I was grateful for that when a project went a little too deep and I didn't wreck my cutter. Yes, just chip out around the offending screw until you can grab it with the visegrips.

This is what you need.
https://www.woodcraft.com/products/screw-extractor-1-4