Thread: Total defeat - attempt to MMA weld on gate hinges - what's gone wrong?

Where's the pictures?
Welding fail pictures are the best ones.

was it a vertical weld by any chance?

I put a set of those hinges on a gate I made for a mate a month or two back. They came from Bunnings, but I think they were Zenith too. One side was welded to a long flat 6mm plate that was then fastened to split-face brick, the other side welded to the 25 x 2mm duragal SHS frame. From memory they welded fine - no prep - I just burnt through the zinc - *but* I used MIG and all in the flat position. That said, they're essentially just a lap joint, and really shouldn't be too hard with stick?

You should say what rod, rod size, amps and welding position you were using.

On each hinge, two of the welds were vertical, then another was horizontal with stick down, and another horizontal with stick pointing upward. All were very poor welds.

Unfortunately I didn't take pictures, and already pulled the hinges back off (after the second failed attempt) then ground the remaining weld material back off the posts. The hinges are trashed - all curled back from being pulled off, and for some reason have seized up as well.

Welds were lumpy and lots of slag inclusions, especially along the edge of the weld on the hinge side. This happened a lot - I ground the welds back quite a few times, same problem every time. I'd have upped the amps except that the hinges melted so easily at higher amps (I tried that). The welds stuck well to the SHS but not well to the hinges. I was surprised about the poor adhesion to the hinge - I was intentionally weaving the arc onto the hinge to get a bond and would have expected a cleaner result - but it's almost as if the hinge metal was repelling the molten puddle.

Of course its easier to blame the product than blame my skills, but I do wonder if there was something about the hinges - as in, I'm sure a pro could weld anything, but maybe there was something about the hinge metal that defeated a mediocre performer like me.

Rods were Austarc I2P 2.5mm. Welder was set up at 75V, approx 60 - 65 amps.

Maybe what I can do tomorrow is weld the hinges onto a bit of the SHS offcut, and if the result is as bad as today, I can take a pic and show it here.

Were the hinges only zinc plated or actual galvanised? From what you describe I am betting they were galvanised.
Your power levels seem reasonably, a little low if anything and you couldn't get a sweeter electrode for what you are doing than 12P's.

Maybe the hinges are made from "cucumber alloy".......

Um yeh...been there, done that but not so bad.

At least mine stuck for a while.

I welded some of those or similar to the front of my wood shed.

Back in my stick days with the easywelder.

My welds lookd pretty good...but some months later they just peeled off.

Even though they are bright they are galvanised.

To get them to stick you have to grind ALL the gall' of the edges you are welding AND off the back of the hinge.

If you don't grind the gall off the back of the hinges the zinc vapour comes thru under your weld and contaminates your work.

One of the best lessons I have learned is to grind to clean material before welding.....even with stick.

Oh and if you are overheating the hinge and its jamming...yeh it happens.....slather some never seaze on the pin.

cheers

That makes good sense Soundman. That's the thing - even if I get good welds, the pins seizing is the other problem. So what is never seize?

Did you try again after the first hinges failed? If so did the second attempt work permanently?

No the door is still hanging off it hinges.

Never seeze is a metal fortified lubricant specifically designed for stopping stuff from seazing.

I put it on any but bolt or pin that might get hot or corrode.

cheers

i was about to reply that the hinges are probably unsuited for welding and was picturing you trying to weld some thin carpenter's hinges but back to your OP I can see you bought proper chunky Zenit gate hinges. Those are good hinges, nothing wrong with them. I am sure you can buy better but I built many steel gates and some rather heavy ones, heavy like 80 kilos each side, and used that sort of hinge. The package does not say the size and I gather they are probably 50mm (I used 100mm) yet I had no problem welding them...and no they are not dodgy alloy, see the manufacturer's weld on it.

Yes the galvo is heavy and is better removed before welding, but before you buy another set of hinges and try again, use the old hinges and weld them on some scrap and see what the problem is. Grind the galvo back, but don't go too heavy on the grinding, the zinc is there for a reason.
I am also lazy when I weld galvanised stuff and try to do it without cleaning it. Sometimes if you spot weld it first, then brush the burned zinc off, then spot weld again next to it (in the clean part and so on, you can get a clean weld without much grinding, (but with a lot of brushing). The fumes are not very nice though and a fan is a good idea.

As far as the pin seizing, I wonder if the earth arked through the pin somehow? It would be better if you weld the hinge separately, and protect the hole on one side and the pin on the other from spatter (and don't drop the bearing that is inside).
I am sure you know how to position the gate with its half hinge already welded to it on blocks, clamp the bottom half of the hinge to the post, spot weld, remove the gate and weld.

Hi Marc, I'll hopefully get another go today - I didn't get to it on the weekend. Your comments on the Zenith hinges (yes these are the 50mm ones) as being quite ok is encouraging. I will indeed have a go with the existing mangled hinges, grinding off the gal underneath as per Soundman's suggestion, as well as around the edges. It's true that I had got used to welding Duragal, where you can just burn through the gal and get a good weld. The zinc on the hinges must be a lot thicker, so you can't do that. True about the fumes - zinc fever is is risk . A P2 respirator is a help (coupled with a fan and ventilation).

In my previous effort, I had clamped the fully assembed gate and hinges together onto the post with everything lined up and then welded, attempting to do it all in one go. For preventing seizing of the hinge again, your suggestion to weld the mating parts separately (except for a spot weld) is a good one. The seizing is not total (as in, fusing of the mating parts together) but is just they become extremely stiff. Might be distortion of the hinge through overheating?

Originally Posted by Gunnaduit

Might be distortion of the hinge through overheating?

That would've been my guess. So short runs and letting it cool before the whole hinge assembly gets red hot is the only way I can think of, or clamping a big heatsink to it as you weld. Not sure how you could fix it now except for pulling the hinges apart and redrilling the holes.
Cheers
- Mick

Originally Posted by Gunnaduit

Hi Marc, I'll hopefully get another go today - I didn't get to it on the weekend. Your comments on the Zenith hinges (yes these are the 50mm ones) as being quite ok is encouraging. I will indeed have a go with the existing mangled hinges, grinding off the gal underneath as per Soundman's suggestion, as well as around the edges. It's true that I had got used to welding Duragal, where you can just burn through the gal and get a good weld. The zinc on the hinges must be a lot thicker, so you can't do that. True about the fumes - zinc fever is is risk . A P2 respirator is a help (coupled with a fan and ventilation).

In my previous effort, I had clamped the fully assembled gate and hinges together onto the post with everything lined up and then welded, attempting to do it all in one go. For preventing seizing of the hinge again, your suggestion to weld the mating parts separately (except for a spot weld) is a good one. The seizing is not total (as in, fusing of the mating parts together) but is just they become extremely stiff. Might be distortion of the hinge through overheating?

Those hinges are hot dip, not electroplated, way thicker and better galvo. A fan (or a bit of a breeze) is probably enough.

The way I weld hinges to gate and post is as follows (not the only way mind you). THis is to fix hinges on the face of the gate and post. You can also fix hinges to the inside of gate and post like it is done on wooden doors but you will be restricted to the gap that the closed hinge gives you.

You must first determine the gap you need to have at the hinge side. If it is more than the gap provided by the barrel of the hinge, you must make this provision now. Otherwise, you weld the top side of the hinge to the gate (the one with the pin). You can lay the gate on the side providing it is less than 1.5m wide. Take the complete hinge and position it on the gate side, with the top on the face of the gate and the bottom against the edge of the gate at 90 degree. This way your hinge pin will be lined up with the edge of the gate and positioned at the right distance from the edge.

Spot weld and remove the bottom section of the hinge. There is still a chance that your top hinge is too close and you need to grind off and reposition, so make decent size spots that will hold the gate but don't go troppo.

Now for the post side, position the whole gate on blocks, bricks, assistant toes or any other way that gives you the right distance from the ground, that is plumb and at the right distance from both post.
Now take the bottom hinge, make sure the ball bearing is in it, slide over the pin all the way and clamp in position. Place the earth on the post, not the gate and make a few strong spot weld and test the gate carefully. If everything works, take it off the hinge and finish welding. Once your gate swings happily you can weld or screw the latch on the gate and then the striker to the other post.
If it is a double gate, the procedure is slightly different since you must align both gates. I hope it is just a single gate.

PS
Of course you can also screw those hinges to the post. Arm yourself with decent sized self tapping stainless steel screws, ( the normal one are way too ordinary for this) pre drill the hinge and drill the gate and post with the SS self tapping screw. Afterwards, get the welder and spot weld for good measure. Of course if you choose this method, repositioning is a bit of a problem.