Vertical up

[Richard.]

Yes thanks I did get that but is a heat sink à tool to learn open root more easily (less keyhole risk)

With open root your thinking more of a backing bar rather than heat sink. A heat sink is there to suck heat out of your joint and prevent it burning away. More so when you don't want to punch through
A backing bar is a there to punch through on to. It supports the root coming through to the back side to prevent excessive root reinforcement
Ceramic tiles can be used with sticks but they certainly don't act as a heat sink. They are brilliant with fcaw where open rooting is very difficult without that support on the back. Solid wire v up again they work but like sticks I prefer to do it with out.

 

[olek]

With open root your thinking more of a backing bar rather than heat sink. A heat sink is there to suck heat out of your joint and prevent it burning away. More so when you don't want to punch through
A backing bar is a there to punch through on to. It supports the root coming through to the back side to prevent excessive root reinforcement
Ceramic tiles can be used with sticks but they certainly don't act as a heat sink. They are brilliant with fcaw where open rooting is very difficult without that support on the back. Solid wire v up again they work but like sticks I prefer to do it with out.

Thanks so that is even better than using a copper plate at the back of the open root weld. (that was my initial idea)
But the backing bar need to be grinded or cut if all I want is both plates (prolongation). It stay in place usually if possible I suuppose

 

[Arclikeharrypotter]

So a quick play today . A little rough to say the least and really I should of fathered the tacks, arrows indicate the ins. Some more practice and fingers crossed it'll come out looking a lot more consistent!

Please ignore far left! First attempt travel speed way to fast, so when I went to put in second pass i just blew straight through!

 

[Brad93]

So a quick play today . A little rough to say the least and really I should of fathered the tacks, arrows indicate the ins. Some more practice and fingers crossed it'll come out looking a lot more consistent!
View attachment 122012

Please ignore far left! First attempt travel speed way to fast, so when I went to put in second pass i just blew straight through!

That looks pretty good mate.
I personally go off the sound and just watching the puddle. Did you use strong backs? The biggest problem with open rooting anything is your root closing up

 

[Richard.]

Looks good that.
What's the back side like.

 

[Arclikeharrypotter]

That's back side of root, only took photo of second pass, then banged in 5 passes without cooling! So you can imagine the state of the cap!

Yes brad the tacks where nice and beefy, and your right about listening to it, I could sort of tell when I was getting decent reinforcent with the sound.

 

[Arclikeharrypotter]

This is second pass, you can see where I blew through the root, that was bit where I was moving way to fast.

 

[olek]

Very even and nice. Why 5 passes is it so thick?

Looks like there is enough with the 2 first (?)

 

[Arclikeharrypotter]

It's 12mm plate, 2 more to bring close edges and then 3 to cap. I struggled with the cap, I need to get my eye in running stringers overhead again.

 

[Richard.]

So a quick play today . A little rough to say the least and really I should of fathered the tacks, arrows indicate the ins. Some more practice and fingers crossed it'll come out looking a lot more consistent!
View attachment 122012

Please ignore far left! First attempt travel speed way to fast, so when I went to put in second pass i just blew straight through!

Yes of course it is. Sorry I was looking at it through an inch square pic. It's a decent root imo.

 

[Arclikeharrypotter]

I'll grab a different piece of plate and have a go again some point. Just beveling 12mm takes a wee while and makes a hell of a mess!

 

[Brad93]

I'll grab a different piece of plate and have a go again some point. Just beveling 12mm takes a wee while and makes a hell of a mess!

The hardest bit about rooting is the need for a consistent root gap and face. The best cheap way is with a straight line gas torch/burner. I'm useless at grinding bevels and hate it with a passion.
With the gas torch at work it's an absolute breeze. Set your angle light her up away you go. Tickle it with a grinder and set your root face with a file.

 

[olek]

gas burner is possibly for some future day, but is that a good solution for not too thick (soft) steel ?

 

[Richard.]

gas burner is possibly for some future day, but is that a good solution for not too thick steel ?

Down to 10 possibly 8mm it’s spot on. We also have one at work and it prepares plates lovely
Lower than 8-10mm and it’s not such a heart ache to prep up with a 9”.
The trick is to use the correct nozzle for a start, set a nice pressure on the bottles, sharp flame with the primary O2 feed and travel speed is key. It’s not gonna match a plas prep on really thin gage but it’s a priceless tool if your preparing plates for a nice job.
A carbide burr like you show in the pics is a very very long drawn out way to do it unless your working with sheet metal in which case mma wouldn’t be the best weapon of choice for welding

 

[olek]

Down to 10 possibly 8mm it’s spot on. We also have one at work and it prepares plates lovely
Lower than 8-10mm and it’s not such a heart ache to prep up with a 9”.
The trick is to use the correct nozzle for a start, set a nice pressure on the bottles, sharp flame with the primary O2 feed and travel speed is key. It’s not gonna match a plas prep on really thin gage but it’s a priceless tool if your preparing plates for a nice job.
A carbide burr like you show in the pics is a very very long drawn out way to do it unless your working with sheet metal in which case mma wouldn’t be the best weapon of choice for welding

Thanks, I made a new thread for choices among models and processes of oxy fuel or oxy acetylen equipments

cutting and beveling can be done "free hand" (I mean using a concrete guide to stabilise the hand ) ?

Or is it worth buying directly a chinese cutter (delivered with a torch I think about 280€ . They can be driven by a simple PC software I suppose, or even without software for straight run ?

I opwn a cheap plasma cutter, it is just effective up to 8 mm max and is difficult to drive (but it may be possible to modify the 2 wheels "trolley" I have , to angle the cut (on thin 6mm metal then I suppose)

Sorry , BTW what is "sheet metal" is it only a gauge question or the steel quality differs too from plates ?

Regards

 

[olek]

Hello, sorry for the OT I will erase it later

I think I could buy that second hand kit, I will know tomorrow what capacity are the tanks, and if some pressure/gas remains in them
WHat do you think The price is not that high , the 7 nozzles goes from 40 to 400 liter/hour (0,66 to 6,6 liter min), with a cutting torch provided.

AT 280€ is it a good idea ?

https://www.leboncoin.fr/vi/1324549780

No intensive use planned, but I will be happy to be able to do brazing and other process, , and cutting too.
(if 0,5m3 bottles, , is it still OK, and can I upgrade later for taller bottles with higher content ?)

How much liters/minute the cutting torch use ?
those are 1m3 bottles , Oxyflam a common kit here.

Thanks for your help

 

[olek]

Hello,
After doing a corner up 3/32 x2 7018 70A then 1/8 7018 x2 96A https://photos.app.goo.gl/7uFlXmuWVpyCExHd2

I did make my first "open root" with 2,5mm 7018 , a 6 mm gap 3mm land (1/8) but I did use 65A (could not weld with less the 48.00) but I did put arc force at its max, as hot start, and it seem to work fine. May be I will success using 60 or 55A , the arc force allow to dig well the bottom, then in the middle amps are lower so it does not get too hot I think
NOt too frustrative for a first try - I had 2 tie in at the root pass so it is not as nice looking I'd like (I did make a small weld along the original to start the rod, then turn when in position- grindib later)
https://photos.app.goo.gl/QRBkhFnvkFmvmb3B3

 

[Bonser]

Lots of good advice on here, i don't like weaving. No weaves on here. Just 7018 Low hydrogen in a heated quiver even though were in Dubai and saudi, at 40 degrees temp the humidity does the damage. This was done by a Miller gold star 602 machine. Keep practicing play with those amps up and down and you will get to what suits you and your machine. That second pass is getting there.

 

[Brad93]

Hello,
After doing a corner up 3/32 x2 7018 70A then 1/8 7018 x2 96A https://photos.app.goo.gl/7uFlXmuWVpyCExHd2

I did make my first "open root" with 2,5mm 7018 , a 6 mm gap 3mm land (1/8) but I did use 65A (could not weld with less the 48.00) but I did put arc force at its max, as hot start, and it seem to work fine. May be I will success using 60 or 55A , the arc force allow to dig well the bottom, then in the middle amps are lower so it does not get too hot I think
NOt too frustrative for a first try - I had 2 tie in at the root pass so it is not as nice looking I'd like (I did make a small weld along the original to start the rod, then turn when in position- grindib later)
https://photos.app.goo.gl/QRBkhFnvkFmvmb3B3

Turn your arc force off, put it on zero to 10%.
If you’re using ESAB Ok 48.00 ⅛” rod (3.2mm), you want around 105A for your vertical up fillets.

For a 2.5mm rod you want 80-90A, 0 arc force.

Hold a tight arc, rod pointing dead 90 or a slight push angle.

 

[Brad93]

For your open root you need a 35* degree bevel +/- 2.5*.

⅛” gap, 3/32” root face, 85 amps, 0 arc force.