Welding Tips and Tricks

Hello to All

I hawe telwin nordica 4.181 welder (btw is it good or bad one?)
Its an classic AC welding device, amperage 55 to 160A.

My problem: Wanna make costum exhaust for my 2t bike. And I am a welding beginer ... So I need as much tips you can give

Metal is about 1mm thick.

When I go on 55 to 70 amperage rod sticks to metal cant get arch. When i go more amperage it burns trought metal. I tried 2.5 and 3.2mm electrodes code 6013.

How to weld thin metal with ac welder propertly?


I know much of you would say to do it with mig mag or something else buth I cant aford myself one.

Hmmm(if I had to use stick) i would run it like an open root joint since it is so easy to burn through. we do them with 1/8" 6010 at 50. It takes some getting used to to avoid sticking but it does work. With 1mm thick 1/8 would be too much I think. But it gives you an idea for a starting point.

Best results would not come from a stick welder, but I think with some practice it could be done.
I have to wArn you i'm pretty new as well and I'm sure there aee others with more experience will chime in.

Welding that thin with AC stick is challenging, but possible. 6013 is a good choice, as it's not a deep-digging rod.

This rod is available in 1/16" (1.6mm), which should allow you to weld at the machine's low end.

My suggestion would be to make backing sleeves of the same pipe for each joint. A short ring of the pipe, with a piece cut out so it will just slip inside. This will be easier to weld without blowing through, and will be less of an obstruction to flow than the metal you'll push through an open root weld.

Good luck,

Steve S

Would it be possible to use a copper backer to disipate some heat?

Please explain me this little more:

"My suggestion would be to make backing sleeves of the same pipe for each joint. A short ring of the pipe, with a piece cut out so it will just slip inside. This will be easier to weld without blowing through, and will be less of an obstruction to flow than the metal you'll push through an open root weld."


My english es werry bad and google translate wont help for my language.

If it can be said in simplier english or some paint image i would be thankful

qwerty12,

I'll make an example at work and take pictures. I'll post them tomorrow.

Steve S

Qwerty12.

I am assuming that your fit-up of the two exhaust pipes will be a butt joint.

From your excess exhaust pipe, you may cut one a ring about 15 mm long. You would cut one ring for each joint that you need to weld. The ring will be positioned inside the two exhaust pipes, at the location that you will weld. The rings will not fit inside your exhaust pipes since they are the same size. So to make the circumference slightly smaller, you would cut one side of the ring, in order to slip it into location. Slide half of the ring inside the end of one of the exhaust pipes you need to weld. You want the ring to fit snug and tight against the inside of the exhaust pipe. It is important to not have any space between the outside surface of the ring and the internal surface of the exhaust pipe. If they are not tight, you will need to force them tighter, and then make a very small tack weld or two, just long enough to hold the ring in place. You may need to slightly touch those tack welds with a grinder to remove any weld metal and slag that might block the second exhaust pipe from sliding over the remaining half of the backing ring. You may push the two pipes together until they almost touch. Leave a gap between the two exhaust pipes, less than 2mm apart. Put two or three small tack welds to hold the three piece joint (2 pipes and one ring) in place. Slightly grind down the tack welds to make them smooth and to remove slag. Then weld around the joint. You should be able to complete the weld in one pass. You will be welding the two exhaust pipes to the ring. If you need to stop to re-position or change electrodes, slightly grind the last 8 mm of the weld where you stopped welding, and where you will be starting the new electrode.

Practice before you weld your good exhaust pipes. Make a couple mock-ups and weld them. This will help you find the correct current. Depending upon your electrode, you may be able to simply drag it along the gap without even having to worry about holding a stable arc length.

Alexa

Thanks to everybody.
@Otto please make some pictures

@Alexa...my english is bad so I donk know did I understood you.

In your text do you say that I should use some metal pipe inside of my new exhaust pipe chamber, than weld it and than remowe it?

Like on this picture


So to put help ring(blue) in roled thin metal(red) weld(black) and than remove help ring(blue)

Did you said that or I did not understad you? If so please just paint in ms paint simple scheme what I need to do...for my knowlege of english, picture is better than words maybe

Hey, If you have a steel backer it will come part of the pipe. This means the weld will burn into it and fuse it permanently . If you have a copper backer, the metal wont fuse to it because the melting temp of copper is higher than steel, but it will still be difficult to get out. A nice small steel one will be perfect. Remeber it will be a permanent addition to your pipe.

Mick

Did you mean something like this?

Qwerty12.

In the comment that I wrote, I spoke of a butt joint of two pipes, where there would be a 'circumferential' weld.

Instead, from your sketch, the weld in black, seems to be a butt joint, where there will be a 'longitudinal' weld, and in this case my comment about backing rings would not be valid.

Alexa

Hey,
Okay, after looking at your drawings a little better, I understand you better. Our method was for joining two pipes, not making the pipes. If you are making a pipe you can acess both open ends. You can place a solid bit of material, be it steel or copper or aluminium, and clamp it against the pipe seam. The thin sheet will melt and solidify long before you get enough heat into the solid round bar to fuse it to the pipe, so you be able to pull it out. Jody has a video of this with TIG but its the same idea. I will try and find it.

Mick

@Alexa we misunderstood. I will have both stright and circular welds....so please make a paint of your idea. Exhaust will be welded on these red lines:

Hey,

Here is the video i mentioned. Is is for stainless steel with tig but it will suit your application. The bit you want is the thick AL backing bar. It will support your weld on the thin metal, There is not much trouble with accidentally fusing the backer because it is so thick.

http://www.weldingtipsandtricks.com/pro ... -shielding.

Looking at your paint picture, the method shown in the video will work for making the cone segments and straight pipe.

For joining the 3 segments, you could make a backer ring to fit just inside the joint, to increase the thickness a little or make the diameter of the straight pipe slightly smaller so the joint is a little off set. this will give you a little more metal in the joint to stop it burning through.

Note: Welding thin metal with an AC stick welder is difficult as the arc will not run smoothly at low amps. So dont be too hard on yoursef.

Mick

Welding mike sorry buth your link does not works it opens empty page.

And If I understood you it is better to use weld like on the uper image

the lower image wil burn trought ?

Hey,

Yes the top image will make it a LITTLE easier. You should also be able to buy some 1.6mm electrodes/ rods to make it easier to maintain an arc at low amps.

Here is the link again, hope it works this time,

http://www.weldingtipsandtricks.com/pro ... lding.html

Mick

Thanks Mike.

I been playing some time and best results I got when I bend 2 sides of weld and hamer it so on weld placce metal is thicker.



it welds ok buth when i make hole game is ower. Cant weld hole it gets just biger.

How to fix holes?

Gwerty12.

Concerning the sheet to sheet longitudinal welds.
The 'butt joint' with thin material and using manual stick welding is not recommended due to difficulty in welding.

Weldingmike27 showed the sketch of a 'lap joint'.
The gap between the two surfaces should be in contact with one another.
Clamping, tacking, and slight hammering the tack welded sheets together, before welding will help.

Another option is an 'edge joint'.
Again, the edges of the two sheets need to be in contact.
http://www.spartanmechanics.net/images/ ... Joints.JPG

General note.
The heat from the weld will be absorbed faster into an edge of a sheet of metal, and slower into the flat surface of a sheet of metal. So when you have the 'lap joint', that edge will get hotter much faster than the flat surface. That is one reason the two pieces should be in tight contact, in order to allow the edge to lose some of the heat quicker. You will notice during your practice welding of the mock-ups, that you will be orienting (pointing) your electrode more towards the flat surface, in order to put more heat there, instead of on the edge. It is as if you were welding a single pass on the flat piece immediately next to the edge. While welding that pass along the joint, one side of the puddle will flow into the edge of the sheet. Once you get the knack of it, who will laugh about all those holes that you previously made.

Holes can be done with a patch. But again, placing a patch is an example of a 'lap joint'. Clamp, tack and hammer down the edge onto the other surface. Probably placing a support against the internal surface, may help you avoid deformation from the hammering. If you hammer while the tack is still hot, it will be easier.

Alexa.

I have managed it to weld sheet metal into a good joint. Cant separate them eaven with a hamer.

Buth I cant get it withouth holes

It holds good buth the smoke from the engine will come all over the exhaust

Holes are giving me hard time

maybe the problem is in my welding device its range is from 55 to 160 ampr

is there any way to make it weld on les than a 55 amps ?

Hey,

AC welders at low amps are hard to get an arc start because of the polarity constantly changing. There is no EASY way to fill holes in sheet metal with a stick welder. Only just welding a small spot and stopping then cleaning and letting the material cool. Its a slow ugly technique but its about the only real way i can think of.

I dont know about lowering the amps, I am not an electrical minded man.

Mick

thanks wery much

Hey,
Pleasure. Hope it works. If nothing works consider increasing metal to 1.6 mm or 2mm. thick. Heavier of course but easier to weld.

Mick

But harder to bend in a exhaust curve

Unfortunately , yes.
Keep on practicing then.

Mick