Repair mug handle?

[Bob Eager]

I seem to have broken the handle on one of SWMBO's favourite mugs :(

It's a clean break and the handle fits back well. I would like to try and repair it (yes, she already knows).

What is the best adhesive to use? I'm seeing a lot of conflicting advice on Google/

- a lot of it says NOT to use cyanoacrylate

- some of it says NOT to use epoxy

I would ike to be able to put it in the dishwasher afterwards, so it needs to be proof against heat and also dishwasher chemicals.

I'm leaning towards a polyurethane glue such as Gorilla Glue, but all advice gratefully received.

[tabbypurr]

Prolonged wetting causes cyano to fail. Heat causes epoxy to fail unless set hot. But the standard advice is don't do it due to risk of a repeat fail & consequent injury out of all proportion to value of mug.

NT

[Tim Watts]

Having broken a china ornament when I was a kid and repaired it, superglue is probably the way to get the finest of joints - damp both faces before applying glue and have a rag ready to wipe off the excess with whatever solvent works the best (I forget - meths???).

Personally I would not try to repair a mug *and* keep it in use for hot drinks. Washing will weaken the joint and last thing anyone wants is a cup of hot tea in their lap. But if she were willing to use it for cold drinks only?

[Tufnell Park]

Best to get her a new mug, repair is a recipe for disaster if she wants to use it.

[The Natural Philosopher]

Right. Do NOT use CA. It softens under heat

DO use Epoxy but you need to do this very carefully .

Forest of all find one that is as clear as possible.

Secondly you MUST stove it, as it sets, at around 100C. Otherwise it will never withstand hot water.

The way I normally do these - and it is a regular thing - is to see if a rubber band or tape can hold the broken part in place without glue. If not uyou have tro find a way to do that - tape maybe.

Then thee job is easy.

Mix up a little epoxy - be absolutely careful to use EXACT amounts and mix very very thoroughly - and use a small amount to do the job.

Now use white spirit or acetone to wipe the joint clean.

Then put the support on.

Then into the oven at around 100C.

Even 24hr epoxy will set in under half an hour at that temperature.

Once its cooled down leave for 24 hours before doing anything.

[Martin Brown]

I would probably use a white filled epoxy in the thinnest layer to wet both the surfaces (assuming that the mug is fine china) trimming off any excess with a scalpel when the stuff has mostly cured.

Cyanoacrylate will fail on exposure to water so not a good idea. It will also mist over the glossy surface near where it is applied.

I think two part epoxy is probably the most resistant to chemical attack but there is always a risk now that the handle will fail again. A well made epoxy joint will be almost as strong as the original ceramic but if you subject it to daily thermal cycling and caustic in a dishwasher then eventually catastrophic failure is inevitable. Not good for a hot drink!

I doubt if a PU glue will cure satisfactorily to its full strength in a very thin layer away from the edges. Ceramics are quite impervious.

[The Natural Philosopher]

I agree in part. Wipe the excess off with white spirit or acetone, then stove.

Stoiving is the only way I have found to ensure it doesn't fall apart under heat.

If it sets at 100C it stays set at 100C

[Martin Brown]

Good point. I forgot to mention that and also that it has to be held in place very firmly whilst it cures as initially the reaction makes it thin and flow like water before it starts to gain strength.

The thinner the bond the stronger it is. Incidentally I also recall Aldi/Lidl had a bespoke ceramic repair glue in not that long ago.

[NY]

I would advise relegating it to a pen holder or a cold-water-only mug. I broke the handle off a very chunky mug (Marauders' Map mug from Harry Potter theme park at Leavesden). It was a clean break, apart from a bit of the glazed surface chipping off around the two breaks, so I glued it back on with superglue (cyanoacrilate) and it *feels* as if it is a very firm joint. However it is now a pen holder on my desk: I don't have the confidence that the glue won't weaken over time, especially with washing and with it holding hot liquids (heating/cooling the joint).

I should probably have used Aradite (epoxy), having read the other postings on this thread. I hadn't realised that CA glues weaken as they get wet. I didn't know about the trick of heating to 100 deg C to heat-cure epoxy. As with so many gluing jobs, holding the two parts accurately together until the glue develops a good bond to support itself - that is always the biggest problem :-) You need something that will not denature or expand under heating, so sellotape is not viable, and a metal support may expand (widening the crack) under heat.

[Muddymike]

Some 45 years ago when we were struggling with a 15% mortgage STWNFI broke the handle of one of our four mugs!

I used some two part epoxy resin adhesive that had been left behind by the previous owner (sorry cant remember the brand) to fix it.

That mug is still in use after 100s of dishwasher cycles.

Mike

[Robin]

I was told by a neighbour (former ceramics restorer) the answer if a cup is to be used (not just admired) is 2-part epoxy but with stainless steel pins inserted in holes drilled in each end of the handle and the body. Don't ask me how she lined up the holes; but I know her services weren't cheap.

[Martin Brown]

Back then there was only Araldite (Ciba-Geigy) now a Huntsman brand - and another reminder you want the original slow setting formulation for this trick *NOT* the 5 minute setting rubbish. The bond needs plenty of time to develop and with no air bubbles in it.

It is a risk that it will eventually fail though. Done well an epoxy repair can be as strong as the ceramic it has been applied to. It is

*not* recommended for food contact - which may be a consideration. (should be fine on a mug handle from that POV)

[Clive Arthur]

I imagine the holes don't have to be particularly well aligned, but oversize and epoxy filled. I'd use a bit of SS screw thread for grip.

Cheers

[Jethro_uk]

Sorry, I wouldn't risk it.

It's not so much that it *will* fail - it might last for decades.

It's more a case of if it does fail, the potential for serious injury is very high.

[Robin]

Well she did usually work with ceramics worth at least several hundred of pounds where there might well not be room for screws. But I'd assumed differential thermal expansion militated for the minimum amount of metal. And of course for an epoxy with a similar CTE to ceramics.

[Brian Gaff]

Yes, you basically need a ceramic adhesive that is good under tension I can recall a friend of mine going to the trouble of drilling the broken bits and inserting little metal pins and then glueing the other bit on that, getting it to line up was a challenge, three weeks later the whole handle split. Maybe if she promises not to use it a repair can be done that looks OK for display purposes.

I had the handle come right off of a teapot a couple of months ago while rinsing it out, and if that had happened with hot tea in it I'd have had to talk to the seller. Most modern teapots use a moulded in handle which is hollow but this has the disadvantage that the handle fills with tea and is hot. This particular one was good as it had a handle fastened in the old fashioned way with slip before firing, but obviously not really very well done as in thee end only the glaze was holding it together! Brian

[Brian Gaff]

In other words, you will be a mug to repair a mug? If its a particular pattern then you will be surprised at what you can still find around in charity shops. Brian

[michael adams]

Providing of course you can find rubber bands, tape etc which can withstand 100%

Next !

michael adams

...

[Clive Arthur]

While I would agree it's probably not worth doing, a cup of very hot water is hardly 'serious injury'.

Cheers

[Bill Wright]

Don't risk it. She'll get a burn if it fails.

Bill