DIY Advice Please - Broken Glazed Pot

I asked this one the end of another thread post, but I think it's got a bit lost (and it was in the wrong forum really, and the thread was nothing to do with DIY, so that may have had something to do with it too).

I bought a damaged glazed pot the other day from Homebase (I knew it was damaged when I bought it, it was reduced by 75% so I couldn't resist it :D). The crack is a hairline one that goes right through the rim of the pot, and down inside the post for about 15cm, which is around a third of the pot's height. The crack goes right through, so you can see it on the unglazed inside, and the glazed outside. But it really is just a hairline crack, I was looking to see why they had reduced the price, and it took me a while to find the crack. The glaze around it isn't chipped, and the pot feels secure. It was bashed around a bit as it was manhandled to and from the car, and it survived all that.

So I was thinking I could DIY repair it by filling the crack with a PVA or exterior wood glue/water solution first before running a line of clear enamel varnish over the top of the crack on the inside and outside of the pot. (These are the materials I have to hand.)

Will that be enough? It's a 48cm pot so it'll be left where it's planted up. I can't really keep shifting it under cover in bad weather, so the repair has to be weatherproof.

Ta.

Jo

 

Hi Jo,

You're right about it needing to be weather tight, if water gets in there and freezes that'll be the end of it.

Ideally i'd use a thixotropic resin glue, that would find its way into the crack, but thats not cheap.

Don't know if pva would set in the crack as the air can't get in there, so a glue with a catalist would be best.

 

I don't think wood glue would stick pot, do you? What you want is a very liquid (low viscosity) glue that will flow into the crack and not just sit on the surface. A few winds of copper coated wire around the pot may llik 'interesting' and strengthen the pot. Cheers, Tony.

 

Hmm. Looks like I need to go to a DIY shop and get some more stuff then. This pot might not be quite such a bargain. :(

You live, you learn.

 

I find Milliput (epoxy putty) good for ceramics, but maybe not for a hairline crack. If the crack did open up, or break into pieces, Milliput is good for filling and attaching pieces.

 

Just a thought, but if the crack only runs about a third of the way down, and you can barely see it, is it worth going to the effort of fixing it?

Me being the lazy sort, I wouldn't bother. Or if I was worried about moisture getting in, freezing, expanding and then making the crack bigger, I'd be very tempted to give the crack a light spray with some water repellent penetrating oil, such as good old WD40, just to keep water out of the crack. But truth be told, I doubt I'd even do that. I'd just take it on trust that it would probably be ok.

 

take it to one of those places where they teach kids how to make pottery

they will sort it for cheap

 

I'm tending to think its not going to last long, you could try something along the lines of Epoxy by the Leading Epoxy Manufacturer | WEST SYSTEM Epoxy

Give it a coat on the inside and the outside.
But in buying that it would probably make the "bargain" a bit expensive.

I like Tony's idea of the copper wire, mechanical fixings are more practical and cheap.

 

Pity you're so far away, i've got some you could use.

 

Thanks for the thought, Ziggy.

I've been having a further think about what to do with this hairline crack. In theory, the whole pot can't be taking up water in a capillary action, can it? I mean that would mean the whole pot would be prone to freezing and just exploding, wouldn't it? So, wouldn't that mean the water is only going to get into the pot at that hairline crack. In which case, don't I just need to make a fairly waterproof seal over the top of the crack and not really worry about trying to seal the inside of it. In which case, wouldn't the enamel varnish over the crack do the trick on it's own? Or am I being a bit Bodgit and Leggett? It's been known. If it saves money. :D

 

RS, Quick set Epoxy Adhesive. comes in small box pack containing-- Two Tubes. one Tube has quick set Epoxy Resin,the other tube has Quick Set Epoxy Hardener. Mix two together in the same quantity, Apply, smooth, dry in 5-10 mins. Cost £2-3, you will only use a small amount so if caps are put back on properly you can have several uses for it in the future. It can be used for metals also..

 

Jo
just leave it , if its a hairline it could last for years until it goes. If it does break then Evostik / Bostik ( other contact adhesives are available) This will repair it permanently . I have lost a few pots due to the wind breaking them all repaired with Evostik , all still going strong . Works on plain terracotta as well

PS : Do not buy the solvent free contact adhesive , it is next to useless !

 

Have used a waterproof adhesive tape inside pots which have lasted for a couple of years to date - use a tape wide enough to get some adhesion to the pot then fill with whatever compost you intend to use......

 

Jo - you have to think about what it is that makes a pot crack - other than just dropping it. :D I believe there are two reasons why terracotta pots fail:-

1) If they are unglazed they will absorb water - most noticeably on the top rim. Then when it freezes the water expands and you tend to get slivers of terracotta falling off. This exposes more surface area which will absorb more water and subsequent frosts will then make it worse. But I don't think that this will cause the whole pot to crack. The benefit of glazed pots is that they tend not to suffer from this.

2) The reason that a whole pot will crack is because it is full of wet compost. When the water in the compost freezes it expands. And this will cause a huge pressure to build up, which is capable of splitting your pot in two (especially if it is already cracked). In this case glazed pots can burst as well as unglazed ones. It is exactly the same mechanism as a burst pipe in the house - and they are made of metal. Glueing the crack up won't help, as the water gets into the compost from the top. And anyway most glues such as epoxy resin eventually come unstuck in wet conditions.

I would suggest that the solution would be to stop the compost getting wet. If dry compost freezes there is no water in it to make it expand. I have a very large unglazed pot that is too heavy to move so I just put a bin bag over the top. It has never suffered any damage - and the bin bag also stops the rim getting wet, so I never have slivers coming off either.

 

What about standing a slightly smaller ordinary plastic pot inside, using the fancy one just as a cover?