Drill out a carbon steel screw :-o

[Keithmac]

Something like that would do the job, or an Annular Cutter.

Basically cut the plastic out around the screw (like coring an apple).

You could in theory heat some 6mm pipe and push it into the plastic bung, pull it out with the metal screw in the middle.

Get as much remaining plastic out as you can then run a tap through the hole..

 

[Mottie]

How about holding something metal in contact with the screw and heating that up so that heat transfers down to the plastic and melts it? Maybe get one of those plumbers heat mats and poke whatever you are heating through that to protect the roof from the heat/flame that you are using. Or use the tip of an electric soldering iron or hold a smaller diameter bolt in some mole grips until red hot and then push on to the screw to melt plastic.

 

[Dave did what]

Something like that would do the job, or an Annular Cutter.

Basically cut the plastic out around the screw (like coring an apple).

You could in theory heat some 6mm pipe and push it into the plastic bung, pull it out with the metal screw in the middle.

Get as much remaining plastic out as you can then run a tap through the hole..

View attachment 243043

Thanks hmm it would have to be 4mm for this job, can't see any titanium cutters in that size?

 

[Dave did what]

How about holding something metal in contact with the screw and heating that up so that heat transfers down to the plastic and melts it? Maybe get one of those plumbers heat mats and poke whatever you are heating through that to protect the roof from the heat/flame that you are using. Or use the tip of an electric soldering iron or hold a smaller diameter bolt in some mole grips until red hot and then push on to the screw to melt plastic.

Thanks yeah I think the lining will have up come away for this job anyway. Will see if heating can soften the plug sufficiently to bash through

 

[cdbe]

Just chain drill the plastic away.

 

[Dave did what]

Just chain drill the plastic away.

Idk what chain drilling is and after watching an extremely Canadian video about it I still don't know. Anyway what you got to imagine here is a a 5mm plastic plug with a 3mm carbon steel core... That's why I posted in this section

 

[Keithmac]

Idk what chain drilling is and after watching an extremely Canadian video about it I still don't know. Anyway what you got to imagine here is a a 5mm plastic plug with a 3mm carbon steel core... That's why I posted in this section

Just drill all the way around the plug with a 2mm drill bit and knock it out.

 

[Tigercubrider]

Something like a dremel with a tiny bit, should be able to remove the plastic at the edges and bounce off the metal. That should loosen the screw.

 

[Sherco290]

As cbde says. drill out the plastic plug surrounding the screw, quite simple.

 

[Dave did what]

Just drill all the way around the plug with a 2mm drill bit and knock it out.

After accounting for threads there is less than 1 mm of plastic to drill through around it , so this is not possible

 

[Dave did what]

As cbde says. drill out the plastic plug surrounding the screw, quite simple.

Have a look at the picture again, the width of plastic you are talking about drilling through is less than 1mm after accounting for threads

 

[JohnD]

Thanks hmm it would have to be 4mm for this job, can't see any titanium cutters in that size?

I had some diamond-tipped core drills in small sizes. They were intended for tiles.

You can make your own core drill from a scrap of tube, notch the open end with a hacksaw. It will not be very good, but enough for a little bit of plastic.

 

[Dave did what]

I had some diamond-tipped core drills in small sizes. They were intended for tiles.

You can make your own core drill from a scrap of tube, notch the open end with a hacksaw. It will not be very good, but enough for a little bit of plastic.

Just to be clear... It would need to be 0.5 mm for this job.

I've used my smallest, a 1.5 , to remove all plastic I could. Still doesn't bash through. now I am going to try drilling the core again with some new bits

 

[JohnD]

A core drill is a hollow tube with a cutting edge, you want one that will drill round the screw. So not 0.5mm bore. More likely 4mm.

And run it anticlockwise to give the plastic plug a chance of winding out.

I think you will have to use a dental pick to winkle out the plastic. I suppose it is seized with rust.

I have a Peugeot where the roof bar fixings have a threaded steel insert welded to the body member. I have an idea they had a plated bolt as a filler.

You want a core drill that will pass through the threads of the insert without damaging them.

 

[Nozzle]

You could try masonry drills - it's the only success I've had when trying to drill tool steel. The masonry bits have special steel in the end, harder than the rest of the bit.
Getting the screw out is all very well, but the hole it came from might then be mashed up and you need to consider what happen next.

Nozle