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Old 3rd Mar 2017, 11:46 pm   #1
Refugee
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Default Dent in expanded aluminum

What method have you used to get dents out of expanded aluminum?
I would like to know how well each method worked and choose the one that worked best so that I get the right one for my job before I start.
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Old 4th Mar 2017, 12:00 am   #2
The Philpott
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Default Re: Dent in expanded aluminum

God, if I look at that for too long it's like one of those magic eye pictures!

I, personally, would leave it alone. It coped with the stress imposed during manufacture, clearly, but any further attempts and it will almost certainly crack.

That's not damage, it's patination!

Don't overlook that this exact style of pierced aluminium is still being made. (I have seen it but do not know where it is being made.)
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Old 4th Mar 2017, 12:12 am   #3
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Default Re: Dent in expanded aluminum

DAC90A grills suffer with dents all the time I have removed dents with nothing more than my fingers slowly a bit at a time .

Pushing into dense foam helps.

You sometimes need to use a small pair of pliers with long thin flat jaws like those used for stroking relays to correct the angle in the "slats"

Flat grills I never seem to be able to get totally flat again

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Old 4th Mar 2017, 12:55 am   #4
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Default Re: Dent in expanded aluminum

I was thinking of the foam method but with an old towel folded up to make a pad to work on. They will have to come out for the cabinets for them to get a lick of paint.
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Old 4th Mar 2017, 4:37 am   #5
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Default Re: Dent in expanded aluminum

Place the expanded sheet on a hard flat surface front side down. Smear the rear side with a little vaseline as a lubricant, and rub over with a small flat piece of wood. Press firmly, the grille will be as new.
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Old 4th Mar 2017, 10:47 am   #6
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Default Re: Dent in expanded aluminum

I use a tuning cord hook to pull out that type of grille
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Old 4th Mar 2017, 11:15 am   #7
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Default Re: Dent in expanded aluminum

My preferred method for flat grilles is to carefully remove it from the set and place it on a hard, flat surface and give it a few goes with a wooden rolling-pin. Obviously this is not recommended for dished grilles!
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Old 4th Mar 2017, 12:59 pm   #8
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Default Re: Dent in expanded aluminum

I get the impression that the flat surface needs to have a slightly soft finish in order to get it consistently flat again.
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Old 4th Mar 2017, 1:56 pm   #9
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Default Re: Dent in expanded aluminum

I was thinking of the vinyl sheet which covers my wooden drawing board - which is basically a piece of lino. Put that over a flat lump of board / kitchen worktop / table?
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Old 4th Mar 2017, 2:38 pm   #10
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Default Re: Dent in expanded aluminum

That sounds quite good. Just soft enough to allow the mesh to flex when rolled with a rolling pin but not enough to spoil the shape of the holes.
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Old 4th Mar 2017, 3:13 pm   #11
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Default Re: Dent in expanded aluminum

It isn't just dented - it's deformed and the metal will be slightly stretched, as will be seen by looking at the individual 'holes' in the mesh, and comparing the dented section with the shape of the 'holes' in the undamaged area of the mesh. Hence, when rolled or pressed flat, each out-of-shape hole will be clearly noticeable and will need to be carefully manipulated into shape with a home-made 'podger' - basically, a stick of hardwood about the diameter of a pencil, shaved to a taper to the same profile of an undamaged mesh hole using a craft knife.

If you look at the profile of the holes, they aren't the same at the top as at the bottom - the top is sort of 'diamond' shaped - the bottom in rounded so the podger will need to follow that profile precisely. You can use that podger to wiggle it into each of the distorted holes to get them back into shape. If you simply flatten the mesh, all you'll get is a two dimensional version of the distortion which is evident now - a flat version of out-of-shape holes, which will be noticeable.

Commercially, 'podgers' are just a spike at the end of a spanner - the podger being used to line up say two panels so that a bolt, screw or whatever can be driven home. Like these:

https://www.cromwell.co.uk/shop/hand.../podger/030804

Hope that helps.

Best of luck with it.
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Old 4th Mar 2017, 3:44 pm   #12
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Default Re: Dent in expanded aluminum

It just goes to show that you are never too old to learn. 76 now and in all my years I've never heard of the term 'Podger'.
Do I thank you for this information, David?
Of course!
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Old 4th Mar 2017, 4:13 pm   #13
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Default Re: Dent in expanded aluminum

I like the name of the tool. I will need one with a curved slot in the end.
I guess that means three parts bolted together. I machine tool small enough to make the slot would be a challenge.
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Old 4th Mar 2017, 5:28 pm   #14
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Default Re: Dent in expanded aluminum

They used a lot of Podgers at Avro's when they were building the Vulcan, I remember seeing them in use.

I used them when I had my carpenters hat on for pulling framing joints together.

Beware of the Bodger with a Podger...

Lawrence.
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Old 4th Mar 2017, 6:17 pm   #15
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Default Re: Dent in expanded aluminum

A bodger with a podger is one whom improvises with a screwdriver.
It looks very much like I need to make a custom tool.
I have been thinking about using the spine of a disposable E-cig tank with a spacer between the two halves and fixed to an old tool handle.
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Old 6th Mar 2017, 1:56 pm   #16
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Default Re: Dent in expanded aluminum

Quote:
Beware of the Bodger with a Podger
.......Roger and out !
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Old 8th Mar 2017, 4:24 am   #17
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Default Re: Dent in expanded aluminum

The trick when repairing dents in flat aluminium mesh is, after the usual pushing and shoving flattening process has been exhausted, to then pull apart the mesh. I explain in detail in this thread where I wrote about the method wrt the side speaker meshes on a Grundig 3028: http://www.vintage-radio.net/forum/s...d.php?p=713945 . It works because once stretched, you can only 'de-stretch' the aluminium so much (you're trying to force it 'back into itself'), so you then have to gently stretch all of the surrounding mesh to even it out, to match it. You can achieve a perfectly flat mesh using this method.
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