acute MIG joints

Why not go with NO nozzle and use a separate hose to flood the area with gas ??? I never had such a situation, but it seems like this would work.

HTH

Jeff

Radical idea...

Depending on how many you need to do, could you rig up a box around the joint and flood that box with argon gas, then weld without the nozzle?

Assuming this is a vertical v shaped joint. I would envision a top and a bottom plate, maybe some sort of clear plastic or tempered glass. Then a vertical sliding seal plate with a hole in the middle, sized for your gun, run a hose from your Argon in somewhere, purge then weld with the argon running.

I've never tried this, but I would think it will work. I suspect the biggest trouble will be keeping the window clear enough to see the weld as you work, some kind of vent might be required.

Stuart

That is an idea alright but these joints are on trusses that are 33 metres long and about 1500 mm high. Each 6000 mm bay was four of these joints. I started looking around on the internet... I was told by the person who sold us the guns that there were no extended nozzles. Not so! I can get a nozzle that is extended and is only 12 mm OD at the end. I will let the office order the stuff we need with part numbers. I was all ready to cobble something together this weekend silver soldering bits and piece together. In order to remain civil I will not say what I think of some of the designers of steel and aluminum structures. The stuff goes together so easily on paper. They unknowingly design weld faults into the structure. Randy

Is it possible these joints could be welded 100% from the outside? Maybe using a backing bar?

GWE

I hope you were charging time on the company clock while you researched all this! (Ok, I know you didn't and can't but the thought was there!)

And I th> For a frist try, I'd just rig a tent that clamps on, remove the nozzle

I have a sub contractor who was doing exactly that joint by TIG instead. The results were fantastic.

Steve

AMF (bakery division) used to make their engineering staff install a couple of machines each year in the field.It was amazing to watch how fast an engineer can improve on something when he/she is the one having to kick and cuss it.LOL

The time taken is critical as we have seven more bridges to build, all around 30 metres long. Tig is not possible because of time and we are not set up or certified for TIG. Talking to European trained trades men I find that most engineers/designers have to spend a certain time period on the shop floor in order to qualify for their professional standing. The best ones take a moment to walk out on the floor and ask if we can see any problems doing the job. This joint problem blind sided us. We will sort it out somehow... After all we have seven more to practice on. :')))

I have a sub contractor who was doing exactly that joint by TIG instead. The results were fantastic.

Steve

--Maybe you guys should consider hiring Ernie!

Hi Randy:

I have come up against this same thing more than a few times doing stuff in boats as well as dock ramps. You are using a Binzel push pull, so I wonder if you are running it in front of a Powermig 300. If you are, what has worked for me in the past is to set a long preflow so the joint is flooded with argon and set your trim real low (almost ridiculously) so the wire manages to get into the joint before arcing on the top and bottom. Also set your arc control right to 10. Push your nozzle back as far as you can get it ( contact tip protruding about 1/4" ). It takes a bit of practice but once you get it, you may be surprised to see some of your best cosmetic welds in what appears to be the most difficult place to put one. (I am assuming that you are using .047 wire here) .035 doesn't seem to like doing this for me for some reason. If you are running conventional than just push tons of wire into it. Tons of wire speed (ridiculous amounts for the voltage) to push the wire all the way to the root of the joint. Just out of curiosity, is this a truss for a ramp or bridge?

Drew McEachren

We are using Powerwaves (.045) so have lots of control over gas and current. Can't go to pulse because of qualification limitations. Binzel does make an extended diffuser to move the contact tip out and a nozzle that closes down to about half inch. We will be trying all kinds of things this week. I personally like a simple wedge insert but we will see what management decides. They are walkways for dolphin access. Randy

I have come up against this same thing more than a few times doing stuff in boats as well as dock ramps. You are using a Binzel push pull, so I wonder if you are running it in front of a Powermig 300. If you are, what has worked for me in the past is to set a long preflow so the joint is flooded with argon and set your trim real low (almost ridiculously) so the wire manages to get into the joint before arcing on the top and bottom. Also set your arc control right to 10. Push your nozzle back as far as you can get it ( contact tip protruding about 1/4" ). It takes a bit of practice but once you get it, you may be surprised to see some of your best cosmetic welds in what appears to be the most difficult place to put one. (I am assuming that you are using .047 wire here) .035 doesn't seem to like doing this for me for some reason. If you are running conventional than just push tons of wire into it. Tons of wire speed (ridiculous amounts for the voltage) to push the wire all the way to the root of the joint. Just out of curiosity, is this a truss for a ramp or bridge?

Drew McEachren

Dolphins can walk????????

John Noon

LOL.. Longshoreman can't walk on water. This morning my welder made up a custom nozzle. We used a short length of

John Noon

Years ago, I did quite a bit of welding using an extention on a mig union carbide spool gun. I dont know who made the extentions. But they looked like slightly bent 3/4 inch copper pipe, that was joined to the original pipe shield. The inside electrode that carrys the electrode wire were longer also. They were designed for another model gun that was longer. However, you could simply join 2 shorter electrodes and silver solder them together to gain the needed length. John Jacob