Help! Snapped stainless steel screws in GRP

Scotty_Tradewind

Scotty_Tradewind

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I snapped some SS screws in my GRP cockpit sole when putting in some sole hatches last winter.

With time running out I was able to seal things down o.k. but would now like to get them out so I have a clean hole.
I wish to replace them with 4or 6mm SS machine screws.

I have some tungsten carbide drills but they make little impression and staying accurate over the snapped screw requires some form of guide.

What suggestions please?

ta
S.
 
I know there's lots of suggested ways of drilling them out, but unless they're size 14s I'd gouge them out with a sharpened implement, fill the holes with poxy and microballoons and then start again.
 
If they can be heated, perhaps by applying something like a solder gun it might help?

Otherwise cut some teeth in the end of a steel tube to make a core drill and quarry them out.
 
Have they snapped off flush with the surface of the GRP? IF not, you might be able to get a good pai of "Mole" grips on the end and take it ought. Also, is the underside of the screw accessible? You might again, be able to get a pair of grips on the BOTTOM of the screw and wind it either downwards and out or upwards enough to get the grips on the top.

You could try buying one of those wart frezing kits from a chemist. Put a hot water bottle on the area for a while (or some means of getting the fibreglass as warm as possible) and then freeze the remains of the self-tapper with the wart spray and see if that loosens anything.

If it was a big-ish screw, you might be able to carefully cut a screwdriver slot in the shank.

If it was a small screw and you're going to go through the same place with a bolt, could you drill a series of tuny holes around the edge of it through the fibreglass and then punch it right through and clean up the hole with a 6 or 7mm drill afterwards?
 
hacksaw or multi-tool a slot and hopefully unscrew the shaft. this is not so easy if you have no meat showing.

Drill the correct sized hole next time :rolleyes:


and yes I know how that reads, it's all in your heads you pervs!
 
xtiffer said:
Hole saw slightly bigger than screw then epoxy the hole.
Cheers,
Chris
Click to expand...

I think this may be the best of solutions to date.

There is no end showing either side to grip on so that means digging away 'til i can get a grip, but they really did break off exceptionally tight.

The silly thing was that I drove them in with an electric drill, with no light ratchet setting applied.
This way the screws went tight too quickly and the screwdriver bit destroyed the screw.
It only happened out of three of the 40 odd that I did but I am cross at my own incompetance for it happening at all. ( In a previous life I used to teach CDT and the smirks on my students faces would be there I'm sure if they knew.)

Thankfully it is in an area that will not be seen and can eventually be made to be solid and sound.

thanks all for the suggestions

ta
S.
 
xtiffer said:
Hole saw slightly bigger than screw then epoxy the hole.
Cheers,
Chris
Click to expand...

Using an epoxy filler.

You will need to add some Micro-fibres or small bits of fibreglass chopped up very fine to provide a secure plug that can take a screw or bolt.

Just resin alone will be very brittle.

Also note epoxy will degrade if exposed to UV light, so it will need painting or some other cover.

my normal method is to drill the hole at least 5 mm or more oversize, tape the bottom of the and use a caulking gun tube with a long narrow tip to avoid trapping any air.

Then, when still wet apply a suitable washer that covers the top eliminating the need to paint.

Tip, make sure you remove any excess with Acetone before you step away to let it cure, because this stuff is Very Hard to sand off later.

Avagoodweekend......:)
 
Dremmel do a line of small high speed burrs (and saws). I have used diamond burrs to remove roll pins and self tapping screws, S/S too, from a variety of materials.

There are flexible shafts available that makes the whole machine extremely versatile, rather like the instrument of torture used by dentists!

Any way, there are different shapes and sizes of burr available. Once you start using them it will become obvious to you what is going to work best.

73s de
Johnth
 
Just been playing with my Dremmel tools and found some very small diameter drill bits. 1mm. Would you believe anything that small could be sold to a mature student?

Any way, it occurred to me that very small holes could be drilled down the side of your screw into the fibreglass until there is enough space to move the offending debris about. Once it is moving there is a sporting chance it will come out.

Just an idea.

73s de

Johnth
 
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