[mranderson881]

Hey guys,

I am building a metal security gate to fit over my existing shed door to add another layer of security.
My idea was to use some 1/8" steel box section, fabricate a frame and then weld on some 12 gauge (2.5mm) galvanised steel mesh to make a gate. With a few hinges welded on it would be bolted over the top of my existing wooden shed door.

Having never welded galvanised mesh before can anyone suggest the best way to go about this. (I will be wearing a suitable respirator.).

I have a TIG / ARC machine available but I am not sure which process would be the most appropriate given that the mesh is galvanised and would require significant time taking off the coating.

Is it possible to just fusion tack the galvanised mesh to the box section using a short pulse of the foot pedal with the TIG torch or would I have to take the coating off first?

Would arc welding be more appropriate?

How would you guys go about this?

Any help for this noob would be greatly appreciated.

Here is what I intend to be welding together.

20170507_181103(1).jpg (109.27 KiB) Viewed 2833 times

[Poland308]

It can be done. But it's a pain. The wire is so thin there's no point in trying to grind off the galv. Your tungsten is going to crap up really fast. You will probably be grinding tungsten every few wires. I would suggest you get some expanded metal that's not galv instead of the wire and then paint the finished project.

[mranderson881]

Thanks for the reply! I figured it would be a bit of a pain using TIG.
As annoying as it is having to regrind tungsten every few wires, do you think that TIG would still be better than trying to stick weld the thin mesh?

Unfortunately I have to use these materials because they are spare, and all I have available for this project. Doh!

[LtBadd]

Thanks for the reply! I figured it would be a bit of a pain using TIG.
As annoying as it is having to regrind tungsten every few wires, do you think that TIG would still be better than trying to stick weld the thin mesh?

Unfortunately I have to use these materials because they are spare, and all I have available for this project. Doh!

If you had some flat bar you could lay over the top of the mesh to capture it, then (bridge over the gap and) weld the flat bar to the frame?

[exnailpounder]

Like Josh said...galvie is a nightmare to tig. That project has mig written all over it. I don't stick weld so I can't give you an opinion but you're going to have your hands full tigging that. Good luck.

[Poland308]

If you had some flat bar you could lay over the top of the mesh to capture it, then (bridge over the gap and) weld the flat bar to the frame?[/quote]


Go with the added flat bar if you want to stick weld it. Probably a good place for some 6013

[cj737]

TIG before Stick. MIG is the right way to do it. Stick welding it, you'll be forever re-lighting your rod and the rod strikes will eat your mesh wire apart.

[mranderson881]

Thank you for your input guys. Ideally I would like each strand tacked to the frame to keep it pulled taught but I am aware that the galv mesh really isnt the best choice and I'm happy to slap some flat bar on there as suggested and run some 6013 beads along it as a last resort.

I'm going to stick weld the frame together this morning and cut the edges off the mesh so only the bare tips of the strands make contact with the frame and try tack them them on with TIG.

As the strands are freshly cut there is slightly less galv coating at the site of the weld and the exposed ends are bare steel I'm not sure if this will help at all but if it appears to be unworkable then im going to try use a dremel tool with a sanding disc to take off the galv coating just on the tips of the strands that make contact with the frame.

If still unworkable I will try putting a few tacks on with some 6013 rod, (lighting up on the frame first) and using a big heat sink on top of the mesh. If all else fails I'm just going to cover up the mess I've made with some flat bar and some 6013 beads to capture the mesh as recommended.

I may be wasting my time aproaching it like this but it will be a learning experience and hopefully others can learn from my experiences. I will post the results later on.

Thank you for all your help.

Regards,
James

[Poland308]

Before you cut down your mesh I would recommend you experiment with welding one side of it down. This way if it burns back or doesn't look the way you want it too you can grind it back and still have enough material to work with.

[mranderson881]

Hey Guys,
Terrible weather here recently hence the delay with this project. So I can quite happily say that I will never be welding Galvanised mesh again unless I absolutely have to! As expected it was a PITA!

Fortunately I have quite a bit of excess to have a practice with. I tried TIG, I tried cleaning off the galv coating and then TIG.. Nightmare as expected.

Initially I was prepared to do thorough cleanup and take my time but with the weather changing and other work commitments coming in, working outside, no shelter, quite a bit of wind and just about to start raining it just wasn't really practical at all.

I needed a quick and dirty fix so figured I would just end up slapping some flat bar on there but for a quick experiment before I did that I tried to light up some 6013 rod and tack the mesh on.

I was surprised to see that when the arc touched the galvanised mesh it sort of ignited in a big flare and continued to burn for a few seconds even after the arc was removed. It seemed impossible to get the 6013 to stick to the mesh though.

However a quick scrub with a wire brush and it appeared that all of of the galvanised coating had been burned off. Upon lighting up again it was actually really easy to stick weld on at 65 amps using some 2.5mm sticks.
After a few goes I was consistently lighting up the rod next to the mesh, a quick flick over the mesh to burn the coating off, a quick scrub with wire brush and then stick weld on as normal with no issues.

So, actually managed to do it reasonably well without the need for any additional materials and learnt something in the process - Avoid galvanised mesh in the future! The whole project could have looked a whole lot nicer under ideal conditions, being nicely TIG'd together but sometimes we just need a quick and dirty fix to get something done. cheers for all your input guys. Here's the result.

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[Poland308]

Glad you got it to work. That should help deter the gremlins!