/ Undenting a stainless steel flask with Araldite?

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Timmd on 06 Feb 2013


I have a 1 litre Hi Gear Stainless Steel flask which has been used loads while out volunteering, and been treated pretty roughly, and it has a dent in the outer skin which I can feel heat escaping from.

Has anybody ever tried using Araldite to stick something onto the outside to pull the dent out with?

Sticking something on the outside to pull at the dent with is the only thing I can think of...
Andy Syme - on 06 Feb 2013
In reply to Timmd: I guess it might work, but a new flask is probably cheaper than the glue. Buy a new one I would suggest :-)
Timmd on 07 Feb 2013
In reply to Andy Syme:I've already bought the glue for something else in mind, am kind of attached to it too for some reason.

No idea if it's greener than a new flask, with it being glue full of chemicals, but i'll post if it works.
woolsack - on 07 Feb 2013
In reply to Timmd: Would boiling the whole thing in water (cap off) work the same as the method to undent ping-pong balls? Assuming it is a sealed vessel the air inside would have to expand and maybe push your dent out.

<usual disclaimers, DYOR etc etc>
Siward on 07 Feb 2013
In reply to Timmd: if heat is obviously escaping then you've probably lost the vacuum haven't you? Once air gets into the void between the walls you no longer have a vacuum flask, just a twin walled bottle. Buy new. Araldite costs about 4 a pack anyway.
mkean - on 07 Feb 2013
In reply to Timmd:
I have the sneaking suspicion your flask has gone to flask heaven. If you manage to pull a dent in a stainless flask using araldite I'll eat this report I'm writing (40+ pages with lots of graphs), you'll never get a good enough adhesion on a small point :-( Heating it won't work either.

If you were really desperate and really bored you could always try pulling it with a welding rod? Weld a bit of welding rod onto it, pull on that and then grind it off. I don't fancy your chances though.

I admire your make do and mend attitude though!
woolsack - on 07 Feb 2013
In reply to mkean:
> :-( Heating it won't work either.
>


<note to self> replying to posts late at night, please remember you won't expand much matter contained in a vacuum :)
timjones - on 07 Feb 2013
In reply to Timmd:
>
>
> I have a 1 litre Hi Gear Stainless Steel flask which has been used loads while out volunteering, and been treated pretty roughly, and it has a dent in the outer skin which I can feel heat escaping from.
>
> Has anybody ever tried using Araldite to stick something onto the outside to pull the dent out with?
>
> Sticking something on the outside to pull at the dent with is the only thing I can think of...

Not a hippie in hell :-(

Save your time and your glue!
timjones - on 07 Feb 2013
In reply to timjones:
> (In reply to Timmd)
> [...]
>
> Not a hippie in hell :-(
>

Predictive text. Got to love it :-)

Timmd on 07 Feb 2013
In reply to mkean:
> (In reply to Timmd)
> I have the sneaking suspicion your flask has gone to flask heaven. If you manage to pull a dent in a stainless flask using araldite I'll eat this report I'm writing (40+ pages with lots of graphs), you'll never get a good enough adhesion on a small point :-( Heating it won't work either.
>
> If you were really desperate and really bored you could always try pulling it with a welding rod? Weld a bit of welding rod onto it, pull on that and then grind it off. I don't fancy your chances though.
>
> I admire your make do and mend attitude though!

I fear you might be right, it's kind of a flat dent though, so I might have a go using some flat aluminium strip which is up at my parents. Took the base off to see if I could press it out from within, but it looks like it's made in one piece, it's not get-at-able.

It's the resources which have gone into making it which are in the back of my mind, it almost seems a shame to throw it out without having a go at undenting it.

I've already fixed the handle with an offcut of bike brake cable and a couple of nuts and bolts I inherited.

(:-))
In reply to Timmd: My flasks have plenty of dents but still work. If you can feel heat coming through surely the vacuum has gone? Or maybe it's so dented to the sides of the flask are touching allowing conducted heat loss?

Anyway, my flask was 4 from Ikea and works great. I'd replace it and put the old one in metal recycling.
deepsoup - on 07 Feb 2013
In reply to TobyA:
> Or maybe it's so dented to the sides of the flask are touching allowing conducted heat loss?

Or close enough together that radiation from one side to the other is (more) significant?

I'm inclined to agree with those who say it'd be a waste of time to try to repair it. But if it was my flask I'd waste that time - just for fun and to see if it works.
Timmd on 07 Feb 2013
In reply to deepsoup:
> (In reply to TobyA)

> I'm inclined to agree with those who say it'd be a waste of time to try to repair it. But if it was my flask I'd waste that time - just for fun and to see if it works.

That's my thoughts, i've not much to lose, can cut some strip and press it on, and leave a stone sitting on it as the glue sets and see if it works.
jkarran - on 07 Feb 2013
In reply to Timmd:

It'll be losing heat by conduction where the outer wall touches the inner not because the vacuum is degraded.

There's little to no chance the araldite will adhere well enough or be strong enough to pull out a dent. Best bet if you're fond of it is to ignore the problem, it now has character and history :)

If you must fix it then you could try moving/lifting the dent slightly by squeezing either side of it. It'll be ugly, hard to control and it might not work.

jk
toad - on 07 Feb 2013
In reply to Timmd: There isn't a decent clip on you tube, but is anyone else thinking of Father Ted knocking out the dent on the raffle prize car?


ok, only me then

There's this, but it's rubbish
http://www.youtube.com/watch?v=8mdwAkWvWMw
geebus - on 07 Feb 2013
What people will sometimes do with motorcycle petrol tanks is to fill them with water then freeze (if you've got a big enough freezer, of course) - thanks to water expanding as it gets towards freezing, this can pop dents out.

I'm not sure if the araldite would hold well enough, especially as it starts to move.
As it's steel, a car repair place could probably sort it - or an airline, a big bung and some heat.
jkarran - on 07 Feb 2013
In reply to geebus:

A flask is double walled with an insulating low pressure region between the walls, you can't push dents out by expanding something inside.

You may however be able to coax the dented outer skin out if the dent is toward the bottom of the flask by pressing on the inner skin and deflecting the whole inner vessel toward the dent then allowing it to spring back. End of a broom handle in a vice should do the trick. It won't work if the dent is near the neck, there won't be enough spring in it.

Again, personally I'd just ignore the problem, the walls already touch at the neck anyway, the dent won't dramatically alter the performance :)
jk
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Rigid Raider - on 07 Feb 2013
In reply to Timmd:

Just fill it with cold drink - problem solved.

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