Galvanised plate

[blenkie1]

after some galv plate for a set of doors trouble is its not a size that's listed in my local steel stockist so just wondering if it would be available. If not what would be the best solution. It needs to be galv sheet as the rest of the buildings are done like this but open to options. The size I am after is 3.5m x 2m x 1mm thick. Longer than 3.5m would not be a problem, 2m is more than I need as I will just cut down to suit. Need x4 sheets.

 

[Welderpaul]

You will be able to get 4m x 2m sheets on special order. You might have to go to 2mm thick though.

 

[blenkie1]

2mm will be a bit too heavy I think they are fairly big doors. Trying to keep the weight to a minimum if possible.

 

[BrokenBiker]

cant you weld together some zintec sheets and then spray the welds with galv spray? i did this a while back to patch a door at the farm i shoot on and it is still holding well

 

[Welderpaul]

You will be able to get 4m x 2m sheets on special order. You might have to go to 2mm thick though.

You might not get that size in 1mm. It could be de-coiled from a 1mm roll but likely to cost a fortune and need a minimum order.
Or joint it.

 

[blenkie1]

You might not get that size in 1mm. It could be de-coiled from a 1mm roll but likely to cost a fortune and need a minimum order.
Or joint it.

Was thinking that could be the case. The only other way I was thinking was maybe just get ordinary mild sheet cut it to the exact size I need and then send it to get galvanised. Not sure of cost but might end up cheaper than a special order. yes might end up just putting smaller sheets on but not keen on a lot of joints if I can help it.

cant you weld together some zintec sheets and then spray the welds with galv spray? i did this a while back to patch a door at the farm i shoot on and it is still holding well

Also might be an option, it's not a show farm by any means but everyone drives past the shed to get to the farmhouse so are looking at it. To be honest I don't think it would bother the owner but it would bother me and maybe any potential customers that see it but most will be farmers and number one consideration for them is cost.

 

[Welderpaul]

The only other way I was thinking was maybe just get ordinary mild sheet cut it to the exact size I need and then send it to get galvanised.

1mm will come back from the galvanisers looking like its been in a train crash.

 

[blenkie1]

Thanks for that welderpaul. Thought that might be the case was not sure. Seen a small door sent to get galvanised with the outer skin welded on and it came back all rippled looked terrible. How do they normally galv sheet like that? Going to give the steel stockholders a ring in the morning and see if they can come up with anything just nothing close in the book for the size I need or otherwise a lot of joints will be needed.

 

[Welderpaul]

It's electroplated i believe. Definitely not hot dipped.

 

[ross1993]

we had a job at work where we sent a pump skid to the galvanisers . skid had 3mm durbar plate for the walkway.Was absolutely horrendous , when it came back it had distorted everywhere.we had to tell the sub contractor who was doing the fab work to cut it all out and put anti slip grating in .Was poorly designed but non the less it looked crap

 

[Welderpaul]

We've even had 12mm plate go bad after galv. They sometimes quench in water after galv so they can handle it straight away. Need to kick their arses if you find they do it with plate/sheet/delicate stuff.

Durbar is worst for it.

 

[Gareth J]

You don't have brace bars across that span at all? Going to be pretty wibbly I'd think.

My suggestion would be to split the 3.5m length into 3 sections with some box section then use three 8x4 sheets overlapped, all pop rivetted together.

Welding up bits of sheet is going to look way worse than a couple rivetted overlaps.

The box section you add can be very light - enough to take a pop rivet

 

[blenkie1]

1mm will come back from the galvanisers looking like its been in a train crash.

Mind you most of his sheds and buildings look like they have been in a plane crash so might be ok!

 

[ross1993]

We've even had 12mm plate go bad after galv. They sometimes quench in water after galv so they can handle it straight away. Need to kick their arses if you find they do it with plate/sheet/delicate stuff.

Durbar is worst for it.

yeah thats what we found out . we had 7 skids to galvanise . it took all 7 of them to be dipped to realise there was an issue ...

 

[blenkie1]

You don't have brace bars across that span at all? Going to be pretty wibbly I'd think.

My suggestion would be to split the 3.5m length into 3 sections with some box section then use three 8x4 sheets overlapped, all pop rivetted together.

Welding up bits of sheet is going to look way worse than a couple rivetted overlaps.

The box section you add can be very light - enough to take a pop rivet

No I have braces in. The doors are just under 3.5m long and high so total length of 7m its catching a lot of wind as it sits exposed on a hilltop so I have enough in just want it to be as light as I can really just would rather it was less joints as possible. Would look a lot nicer with just one joint running along the middle.

Not had a lot to do with stuff getting galvanised did a set of big dog kennels made out of 25x25 box and mesh and was worried about warping but it came back fine really pleased with it was just hoping the sheet would be the same.

 

[blenkie1]

yeah thats what we found out . we had 7 skids to galvanise . it took all 7 of them to be dipped to realise there was an issue ...

Is it Newcastle upon Tyne you are from? Was it birtley galv by any chance you got the work done?

 

[ross1993]

Is it Newcastle upon Tyne you are from? Was it birtley galv by any chance you got the work done?

yeah im from newcastle upon tyne . as for galvanisers i have no idea , would imagine it would be them , all depends on bath sizes available.

 

[Kent]

I have done a few big doors like this the trick is put your braces in were sheets join
Never overlapped just butted up and riveted personally
Just make sure you pre- handg the doors for fit before drilling or you can end up with perfectly squared sheets being all out of plum ( looks real bad)

 

[Gareth J]

I have done a few big doors like this the trick is put your braces in were sheets join
Never overlapped just butted up and riveted personally

I'd be concerned about water ingress. Overlapping lets water run off properly. It's important to lap the sheets the right way for the prevailing wing too if a sheet doesn't do the full width. Also you use less rivets and can use narrower frame material.

Tin sheet rots out quick enough around here without any excuses like lying damp on the joins unnecessarily.

Personally I also prefer to fit sheets on the flat. Not only is it easier, so long as you use the right size drill bit, the tin should provide lots of vertical stiffness so it can't noticibly sag. Each to their own though

 

[Kent]

I'd be concerned about water ingress. Overlapping lets water run off properly. It's important to lap the sheets the right way for the prevailing wing too if a sheet doesn't do the full width. Also you use less rivets and can use narrower frame material.

Tin sheet rots out quick enough around here without any excuses like lying damp on the joins unnecessarily.

Personally I also prefer to fit sheets on the flat. Not only is it easier, so long as you use the right size drill bit, the tin should provide lots of vertical stiffness so it can't noticibly sag. Each to their own though

Correctly fitted with a little bead of sealer to the underside prior you have no issues
Lord knows how many I have done but it's a lot
The fit up must be good no wonky donkey fab work