Thread: Help- accidentally sawed through pocket screws

My guess would be that it's a home made job and the screws have been used for alignment of the boards. You drive the screw into the side of one board, cut the head off and then drive/clamp the boards together. The side that the head has been cut off is likely to be an unthreaded shank and much easier to remove. The screws should be at 90 degrees to the timber in both planes. If they are pocket hole screws (driven at an angle from one board into the next) then you should be able to find the screw heads or a plug/filler where they have been covered, but from your description that doesn't sound likely. Are the screws at relatively regular intervals?

The easiest way to remove the threaded end will be to carefully excavate around the screw with a chisel until you can get a pair of vice grips on it to unscrew it. A couple of small flats filed on the screw can help the vice grips get a good hold. Yes it's a PITA, but it does work.

Thanks, that's a great diagnosis! I didn't consider screws work their heads cut off but I suppose that could be used for alignment. Is this is the case it would be much easier, although still tedious to excavate. I'll excavate it further to see if it is straight.

I'm not sure if it home made or commercial. I suppose commercial furniture would have biscuits or dominoes. That said, I've seen some boneheaded stuff done as shortcuts in commercial. Homemade stuff usually exhibits more care, especially if they are able to achieve a good looking result. I can't see any case where someone capable of doing a tight glue up would resort to this

Originally Posted by aldav

Are the screws at relatively regular intervals?

Yes, there are about 6 along the 1.8m length

Edit: Come to think of it, if you are correct, then the screw threads should only be on one side of the board. This I'll have to check, but I don't recall seeing any circular (non-threaded) screw cross sections

Just leaving this here.....

My stud finder has a metal setting and I always run it over used timber. It has picked up some reasonable small broken nails and hasn't missed anything yet.

One way to remove those is to drill a hole alongside the screw then with a nail punch or old screwdriver or the like knock the screw shank over into the hole you just drilled and extract.
I think most of know the feeling when you see sparks fly off the saw blade. Get a metal detector and always suspect things may be lurking in old wood.
Regards
John

Most times i’ve seen screws used in tabletop glue-ups it has been of Asian origin - village level stuff. Typical source is Bali, though I did have a bed head made of old-growth teak from India which was ruined for recycling cos of screws.

The timber looks to me like rubberwood (not rosewood, sorry) which would support Asian origin.

Originally Posted by Arron

The timber looks to me like rubberwood (not rosewood, sorry) which would support Asian origin.

really? It has a nice contrasting grain, aalthough I do think it has been stained

20190923_190521.jpg

edit: I just calculated the density of 2 pieces. They came out to 770 and 810 kg/m^3

I was going off photo 2 in your original post - which looks hard boney white, like rubberwood.

Rubberwood is very really figured though, so maybe not.

It will be interesting to see after it’s been through the planer.

Where did the identification as rosewood come from ?

Originally Posted by Arron

I was going off photo 2 in your original post - which looks hard boney white, like rubberwood

Going along the edge grain, it actually changes colour from really white to reddish brown in patches

Originally Posted by Arron

Where did the identification as rosewood come from ?

It was second hand furniture sold as rosewood. The price was more like rubberwood, so I could've gotten stooged. I'll never ever be good at identifying timber, but I did all I can to make sure that what I saw was the real wood, and it looked pretty good to my eyes.

See at the bottom of the pic I posted, I chipped away at a knot to make sure it's a real knot? it's a real knot

One possible avenue to get the pieces of screw out is to try and drill down their centreline with a small left handed drill bit. As the cutting edge of the drill bites into the metal, it is applying a torque to it that is trying to unscrew it from the timber. Haven't seen it applied to a screw in timber, but it has a fair degree of success in removing broken bolts, studs etc threaded into metal. Biggest issue in your case would be that you need to be close to the centreline and inline with the screw, as if you drill through the side of the screw, you defeat what you are trying to do because because the bit effectively pins the screw into the timber preventing rotation and winding it out.

Originally Posted by yoboseyo

Going along the edge grain, it actually changes colour from really white to reddish brown in patches

It was second hand furniture sold as rosewood. The price was more like rubberwood, so I could've gotten stooged. I'll never ever be good at identifying timber, but I did all I can to make sure that what I saw was the real wood, and it looked pretty good to my eyes.

See at the bottom of the pic I posted, I chipped away at a knot to make sure it's a real knot? it's a real knot

Ok, i’m Leaning towards it not being rubberwood.

Cheers
Arron

Originally Posted by malb

One possible avenue to get the pieces of screw out is to try and drill down their centreline with a small left handed drill bit. As the cutting edge of the drill bites into the metal, it is applying a torque to it that is trying to unscrew it from the timber. Haven't seen it applied to a screw in timber, but it has a fair degree of success in removing broken bolts, studs etc threaded into metal. Biggest issue in your case would be that you need to be close to the centreline and inline with the screw, as if you drill through the side of the screw, you defeat what you are trying to do because because the bit effectively pins the screw into the timber preventing rotation and winding it out.

The left handed drill bit is very similar to a screw extractor kit I tried. The problem was punching a hole to get the drill started. Do you know of a good tool to do that? whatever I use just slides off the screw and into the wood.

A center punch

Originally Posted by yoboseyo

The left handed drill bit is very similar to a screw extractor kit I tried. The problem was punching a hole to get the drill started. Do you know of a good tool to do that? whatever I use just slides off the screw and into the wood.

The issues with a screw extractor are that you need to drill a hole to insert it in, then when you insert it and wind on it, they tend to expand the screw as you wind the taper in to get it to catch. A left hand drill will generally catch and wind the screw out during the drilling stage, and certainly should not expand the screw as a screw extractor might.

I would suggest a file to get a flat surface followed by an automatic centre punch to create a starting point.