Perforated sheet warping

[dan.taylor.1]

Hi folks

Not sure if this is the right section. Basically I've made some shelves with a pretty rigid frame (40x10 and 20x10) with a 1.5mm perf sheet top (10mm holes on a 30mm spacing?) but some of them have warped in between supports, some haven't.

Pic attached, the shelves bolt into the panels, they're 40x10 sides and rear, with a rolled 20x10 front on its flat edge to minimise height loss, then there are 3 20x10 braces from front to back, again on their flat edge. They're all pretty much tacked/short stitch welded all the way round, including on the braces.

How can I remove the warp. I've got heat but no staging gear to put like a cross in the open area to make it more rigid. Also they're going to be galved so needs doing now as it'll be impossible after!

Any help appreciated.

Cheers,
Dan

 

[gaz1]

from my point of view your shelves are too thin should be around an 1" on the fold to give it strength

folded shelves use this method

 

[Kent]

Over welded not enough support. Sorrry but its looking like a do-over job.

Jeeze just read they are going to Galv! Deffo re-think this one. What we would normally do is Galv the frame then purchase suitable Galv or plated mesh. No more than big tacks and spot finish with cold Galv or similar .
Used to do egg trays for Yorkshire egg production in the 80s very similar

 

[dan.taylor.1]

@gaz1 they're not folded, the perf is tacked to the top of the frame.

@Kent, there's only 300mm x 300mm unsupported area, I've dexion shelves that are way more made of thinner stuff that's not warped so it's the welds. Might try cutting the back ones off see if it moves.

It's done other than this issue so need it sorted asap!

 

[Hopefuldave]

Dexion shelves have a nice deep, stiff flange bent around all 4 sides though, that's what gives 'em rigidity... When I lashed up my metal storage shelves I started with dexion uprights (angle) for the frame, messily welded at every join, then tacked the shelves in (not Dexion shelves, but with the edges folded into a flange) into the spaces between the Dexion - they're rigid enough to climb on as well as support loads of lumps and plates.

Dave H. (the other one)

 

[dan.taylor.1]

Think I've sorted most of it. I heated along the braces and ends and quenched it to shrink it. They're all within 1/2mm ish of flat now, from being 5/6mm out. Here's hoping the galv doesn't pretzel it again!!

 

[Welderpaul]

I would be surprised if they came back from Galv without looking like they had been in a train crash

 

[Kent]

Big mistake sending that to Galv. Especially when you have beggerd about flame straightening .
Take a breather have a think.. It's about to be dunked in molten zinc by folks who really don't care and you will still get charged

 

[eLuSiVeMiTe]

Hope your not planning to keep anything heavy on those. :/

 

[dan.taylor.1]

Hope your not planning to keep anything heavy on those. :/

Why not? Already had a load of weight on them and they didn't move.

Anyone know if you can age bzp electroplating like galv with t wash if I were to get the shelves done like that rather than galv. The frame has to be galv as its what the customer wants to match his zinc bar top.

 

[Hitch]

I'd be looking at remaking, a decent framework, then pre galv perf sheet notched and folded edges (preferably a double fold along the long edges)to sit over the frame and hold themselves in place.
Not what you want to hear I'm sure, but welding thin sheet onto frames like that usually doesn't end well.
If you had to try and rescue, just straighten up the frames gently with a mallet, galv them and see what happens. A bit of warping if the mesh is inevitable I reckon though. A bit of post galv straightening will be needed too for sure.

 

[Kent]

Why not? Already had a load of weight on them and they didn't move.

Anyone know if you can age bzp electroplating like galv with t wash if I were to get the shelves done like that rather than galv. The frame has to be galv as its what the customer wants to match his zinc bar top.

For a bar you have just taken a bad turn. Think this through. No point in spending more on the job if they are going to end up in your shop as storage.
We don't really see the full story but perforated sheet onto a dipped frame is 99% likely to end badly for purpose.
On the face of it I should say send the frame while you re assess the the mesh (I suggest you try zinc like the existing or something else that's already dipped )

Retail catering places can be very particular

If it was me I might see if I could dip out gracefully if I couldn't come up with a perfect solution after having an honest chat with the client..

Have you ever been inside and watched the people and process? It's worth it if you can

 

[dan.taylor.1]

I've been experimenting this morning with bzp and t wash. It works the same as galv so I think that's the answer. There's a spot near me in Lancaster that does it with a big enough tank. There's that little of the shelf on show from the front you'll never notice it. I'll get the end panels and mid panel galved still. As they're 40mm end on so more visible.

I havent any folding gear, though I could get it done locally.

 

[-Matt-]

It's about to be dunked in molten zinc by folks who really don't care

Probably the best description tbh. Ones we use are rough as and that's fairly normal.
I would have thought galving perf would put it back to sheet form!
Be interested in seeing after the dipping.

Could you make up one of those angle sheet brake things that lots of people seem to make for their sheds? I don't know if they're any good though.

 

[dan.taylor.1]

I got them electroplated in the end. It's for inside anyway so the longevity of galv wasn't needed, just what the customer specced as a finish. T washed these will look the same as galv once it's t washed.

 

[Kent]

I got them electroplated in the end. It's for inside anyway so the longevity of galv wasn't needed, just what the customer specced as a finish. T washed these will look the same as galv once it's t washed.

Depending on what zinc electroplated process was selected. Just had a tour of an electro platers this afternoon and an expp
explanation of all the different types and do and don'ts as regards fabrication and process selection.
Very interesting

 

[Bsmith]

Think I would have been considering galvanised cable rack for shelves.

http://www.directchannel.uk.com/cab...MI5J-7ncPy2wIVA57VCh39OQc-EAQYAiABEgKPrfD_BwE

 

[Paul.]

I would have just used pre galvanised perforated sheet, as I have done many times before.
http://www.fhbrundle.co.uk/groups/03PG__Perforated_Galvanised

 

[dan.taylor.1]

Depending on what zinc electroplated process was selected. Just had a tour of an electro platers this afternoon and an explanation of all the different types and do and don'ts as regards fabrication and process selection.
Very interesting

The guy said they did 3 types of zinc, this is clear (the silver type) then there's gold which is the yellow type on screws and bolts sometimes, then nickel zinc which again is yellowish. He also said they're outlawing chrome plating which I find hard to believe, I understand it's dangerous in fume form, but anyone who welds stainless is in contact with it, are they going to ban that too, and what about hydraulic manufacturers, rams are all chrome plated.

 

[Kent]

The guy said they did 3 types of zinc, this is clear (the silver type) then there's gold which is the yellow type on screws and bolts sometimes, then nickel zinc which again is yellowish. He also said they're outlawing chrome plating which I find hard to believe, I understand it's dangerous in fume form, but anyone who welds stainless is in contact with it, are they going to ban that too, and what about hydraulic manufacturers, rams are all chrome plated.

Its EU involvement. Gold zinc is actually banned by the EU . My man yesterday explained this but said there was still a big demand that could not be ignored and you could still buy all the stuff (he then showed me a massive batch they just finished ).

Of course it's probably correct but as legislation goes crazy do you think someone won't supply ? Not being funny but the authorities have lost the plot with weed growing so chrome platers are way down the list!
Do we really think nobody will supply the classic car and motorcycle markets?