Which glue to use?

Some idiot (I'm guessing a burglar who snuck in whilst my back was
turned) has overtightened a fitting that was composed of two female
threads joined by some M4 studding.
Although the idiot, I mean I, have managed to remove one of the snapped
bits, the other one is recessed and I don't have a stud extractor small
enough to get it out. I've decided to glue the part together instead
(it's a fixing for a wing mirror on a kit car).
What glue should I use? I was thinking Araldite, but would one of these
"liquid metal" type things (or the putty stuff you can buy) be more
suitable?
The metal is chromed brass, I think (although it might be steel). I
don't have any welding equipment and I don't think that would be a
viable solution anyway. Don't want to try brazing as it might ruin the
finish.
Reply to
Robin
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I have used "Araldite" and "JB Weld" for applications similar to this. I found that JB Weld was far superior. As an example, a cars VHF radio aerial hit a low flying tree and snapped half way up the radiator at a matching coil whose cross section was about 1 square inch. Araldite would'nt hold it at 5MPH, JB Weld is still holding it together after 10 years or so at speeds sometimes in excess of 100MPH. Its worth a try..
Reply to
Mike W
I'll second JB Weld. I've used it to, amongst other things, stitch a Land Rover engine and repair a Rayburn flue.
Failing that, you could try a low temperature silver solder - should be quite possible to achieve a good joint without affecting the plating. I've used this method with nickel plated items to good effect.
Regards,
Reply to
Stephen Howard
Not come across JB Weld, it sounds very good. Sounds similar to Belzona which is a metal filled epoxy which is used in industry to recover some nasty problems, though more often filling erosion damage or replacing cracked fragments of casting. I'd be concerned about just glueing unless there is plenty of area. Isn't it possible to drill out the offending bit of stud and tap oversize?
Reply to
Newshound
I've never used silver solder - is it melted with a torch or with an iron?
I've got a Sievert Propane/Butane torch - is that the kind of thing that I could use?
The joint is composed of, and bear with me, a recessed male part that joins to a female part, both of which have female threads in them...
...sounds like I'm getting it wrong... the "male" part is in the form of a hexagon (about 6mm if I remember) with an M4 hole tapped down the middle. Not sure why they made it like that, as it doesn't turn and there is no correspondingly shaped receptacle. This hexagon shaped stud is recessed in a ~12mm, um, recess which is the outer diameter of the other part. This second part is also recessed to the rough diameter across the points of the hexagon (wish I had a CAD program to hand) and has an M4 hole at the bottom of it.
Ah, a picture:
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It is the joint where the elbow meets the bracket
Both holes are blind and cannot be drilled through without spoiling the look of the piece.
Reply to
Robin
Not enough metal to tap oversize, unfortunately. I've already lost one of my expensive cobalt drillbits trying to get the studs out. I've bunged some Araldite on and I'll see how it holds out before I look at brazing...
Reply to
Robin
Couldn't view the pic - the page requires a login.
Silver solder will need a torch to achieve the temperature required to melt it. Your Sievert torch should be plenty adequate provided you use the correct solder ( and flux ).
From your description though it seems that the stud and socket overlap, in which case it sounds as though an epoxy fix would work quite well.
Regards,
Reply to
Stephen Howard
To increase your chance of success... can you drill out the stud oversize and glue in a bit of rod to replace it ?
Reply to
Jonathan Barnes
I still don't think there is enough metal to do that...
I've glued it with Araldite and bought some JB Weld in the States in case that fails. Might be possible to weld a piece of M6 studding in place, I suppose, but I'll see if the glue works it's magic first...
Reply to
Robin
JB Weld available here at Probuild ............
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Go to building materials and scroll down.
Bought some this week. Very helpful.
Mike
Reply to
Mike Whittome
I have bought some Auto JB Weld from Halfords
Reply to
Bob Walpole

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