Ask your WELDING questions here.

[KTM640Dakar]

Originally Posted by CR_TurboGuy

Any ideas on plastic welding? http://www.advrider.com/forums/showthread.php?t=212534

--JOsh

Sorry Josh,

I know there are Thermoplast and Thermoset types of plastic, and one type can be melted when heated and the other one burns if heated. But I can't remember which one is which. I think it's the Thermoplastics that can be melted. I have had very little experience with welding plastics. You can problaby google educate yourself about plastic welders. If it is anything like other bonding methods you probably need to have clean dry joints to weld together. Oil on the surface of the plastic will negatively effect the weld I would expect.

[Poolside]

This is great. A typical welding forum right here on our own ADVrider. Authentic too.

Whose the fella with the tripping breaker, benp1981? Do you have a voltmeter Ben?

- Jim

[Poolside]

Super deal gsweave, good work. Nice fillets for such a short stick weld. You sure tailed off the beads nicely, even while reaching the edge of the part, and going around a radius. Right about there is where I'd be burning a hole in the material.

- Jim

[BrushApe]

KTM - thanks for offering this service. Here is what I have for a problem. This is a 1999 BMW F650 Funduro. This is the outside of the swingarm pivot on the left frame side.
I just bought the bike in January and have not rode it. Somehow I missed this problem prior to buying the bike. I suspect it was cracked but the paint had not cracked until sitting in my garage and the temp varied. Or I just plain missed it. I don't think the seller saw it and the third party I had look at the bike missed it also. I have not rode it and I don't plan on riding the bike unless I think everything is right/fixed.

I ground the paint off with a dremel. - Now that I look at it not well enough. I will have to grind more paint and see if that vertical crack is travelling north.

It appears the crack is right next to the weld. I think the weird looking thing is a spider I scared out of the swingarm pivot.

How do I go about fixing this? Or more realistically if I take it to a pro welder what should I expect from him. I like to be a little educated in what work I am having done - not that I want to act like a know-it-all.

[Poolside]

Are you going to take the swingarm out of the frame? It's prolly cracked on the swingarm side of the tube too. Maybe remove some more paint and see what you can see. It could be a silver brazed join. It looks very smooth for a weld, but that could be the powder coat. Try a wire wheel to remove the paint, so it won't 'cover' a crack by pushing metal across the gap.

- Jim

[DustMeOff]

Originally Posted by roverjohn

I took the time to go look at the Panasonic machine the guy has and it appears to be inverter based but I could be wrong because they never call it that.

I also have a gunslinger 260 mig/plasma. it is a transformer machine with an SCR constant voltage and plasma circuit. it is not a multiple tap transformer machine. The manual calls for 60 amp slow blow fuses at 230VAC single phase. Modern breakers are slow blow right?

here is a scan of the schematic of this machine. i agree that an erratic high line voltage spike could be the problem. the clamping diode (is that what the 'Z' component is? 2 zener diodes for bi directional clamping?) on the input is always connected to the line voltage, so that's probably not the problem. on my machine the fan doesn't come on until you start welding or cutting, then i think it's thermostatically controlled.

i also have had zero problems with properly sized extension cords. we went as far as to measure voltage at the welder under load to make sure there was not excessive voltage sag under load. one thing i did notice on an udersized cord i once borrowed someone built was that you can hear the fan speed slow down as you weld.
what is the difference between properly sized wiring run in the walls and a properly sized extension cord? is it the extra resistance of an additional plug? i think most people cringe at the cost of buying the right gage wire for extension cord and end up with an undersized extension.

in BenP's situation, the extension cord may be acting like a soft start resistor, limiting startup current. BenP, you should try putting a voltmeter with min/max logging on your line and see what the peak voltage is over the course of a day.
also, you could just live with it. it's most likely only going to wear out breakers.

Mike

[gsweave]

Originally Posted by BrushApe

KTM - thanks for offering this service. Here is what I have for a problem. This is a 1999 BMW F650 Funduro. This is the outside of the swingarm pivot on the left frame side.
I just bought the bike in January and have not rode it. Somehow I missed this problem prior to buying the bike. I suspect it was cracked but the paint had not cracked until sitting in my garage and the temp varied. Or I just plain missed it. I don't think the seller saw it and the third party I had look at the bike missed it also. I have not rode it and I don't plan on riding the bike unless I think everything is right/fixed.

I ground the paint off with a dremel. - Now that I look at it not well enough. I will have to grind more paint and see if that vertical crack is travelling north.

It appears the crack is right next to the weld. I think the weird looking thing is a spider I scared out of the swingarm pivot.

How do I go about fixing this? Or more realistically if I take it to a pro welder what should I expect from him. I like to be a little educated in what work I am having done - not that I want to act like a know-it-all.

First the good news.

The Funduro is a great bike, I had a 97.

That piece might be cosmetic rather than structual. I have my fingers crossed for you.

Grind away the rest of the paint on the vertical crack.


The bad news.

It needs to come apart to know for sure.
Because of the needle sleeve it needs to be apart to weld.
Stuctual or cosmetic, it needs repaired


Question is, does the bushing gain integrity from that collar or is the collar just a protective piece for the Needle sleeve (#331723452830) and stud?

The micro fishe isn't clear enough to tell,

As you can see from 01 on, the swing arm attachment was redone, but I have never heard any weakness reports on the ealier frame design.



Photo is left side 01 650 GS swing arm attachment.





A replacement frame is $1080. But it would be a daunting task for most to swap one out.



best of luck.
Dan

[gsweave]

Originally Posted by Poolside

Super deal gsweave, good work. Nice fillets for such a short stick weld. You sure tailed off the beads nicely, even while reaching the edge of the part, and going around a radius. Right about there is where I'd be burning a hole in the material.

- Jim

Thanks,

I expected to burn through there too.

The Blue Max rod saved my embaressment.

It surely isn't perfect but should hold for another 60,000 miles.

[BrushApe]

Dan,
Thanks for the input. I kinda thought it would have to be taken apart to be repaired. I was a little worried that the heat from welding might distort that area and cause problems with the bearing fit. I don't think I would go the $1000 frame replacement route unless forced to. This is starting to not be as much fun as I had hoped.
Tom

[Poolside]

Originally Posted by gsweave

I expected to burn through there too.

The Blue Max rod saved my embarrassment.

It surely isn't perfect but should hold for another 60,000 miles.

You bet.

I thought you were using the McKay GP electrode? And Blue Max is a stainless steel filler if I remember. Did you use 309 or something?

Hmm . . . SS rods do use lower heat, and 309L for low carbon steel . . . I'm gonna have to try that.

- Jim

[gsweave]

Originally Posted by Poolside

You bet.

I thought you were using the McKay GP electrode? And Blue Max is a stainless steel filler if I remember. Did you use 309 or something?

Hmm . . . SS rods do use lower heat, and 309L for low carbon steel . . . I'm gonna have to try that.

- Jim

The same rod, I believe. The 3/32" rod is marked as GP, The larger sized rods are marked as 2100 Blue Max. Yep, they are both Stainless based.


I really like the control I get with them.

We weld lots of Stainless here at work, And they are really good for bonding M-2 tool steel to 400 series metals.


We have to weld some really odd metal combo's here, at times.
So if there is any doubt which rod to grab, grab the Blue Max.

I am sure Todd will cringe at that, but it seems to work for us.

[RT jim]

Originally Posted by KTM640Dakar

Yes use argon 100% and get some 3/64 Superglaze 4043 wire. You will also need a teflon liner for your torch and 3/64 or (.047inch) U-grooved drive rolls for your welder. When you get ready to weld set your drive roll pressure in the wire feeder so that it is enough pressure to push the wire but not bird nest the drive rolls if you fuse a tip. Usually you will set the drive roll pressure for aluminum a lot less than for steel wire.

The hardest part about MIG welding aluminum is getting the wire to feed through your welding gun, so keep the welding cable of your gun as straight as possible so the aluminum wire will not have to go through too many curves in the gun cable/liner. That is why you use a Teflon gun liner to reduce friction. There is also a sticker on the inside door of most Lincoln welders that has recommended settings for different thicknesses of metal, as well as different weld wires (like 3/64 dia, Aluminum wire).

If you are using the smaller SP175 220V machine then you might have to use .035 diameter wire.

The best way to MIG weld aluminum is with a spool gun or push/pull gun.

forgot most important thing with aluminum welding clean material, use only stainless wire wheel or brush thats used only for alum. BIG diffrence in welding clean vs dirty . Dirty is not dirt it's corrosion on aluminum . (i'm hands on welder not Engineer sitting behind desk)

[RT jim]

Originally Posted by roverjohn

You've got it wrong again I'm afraid. First, when you add a resistor in series(the cord) it causes a voltage drop farther along the line. So, the voltage is not "maintained", it is reduced at the 1rst posters welder. Reduced voltage at the welder will cause less current not more, just use Ohm's law. It really is kind of illogical to think a welder has the capability to "ask" for more voltage from a wall plug. Secondly, we know adding resistance(the cord) to the line helped the guy's problem so there are a couple of guesses that would be a lot more helpful than removing what helped.
A. Have the first poster check what his line voltage actually is. I see 128vac at my house all the time and that would be a far more likely reason for high inrush currents, per Ohm's law. I've had to redesign the power supplies in all my old tube audio gear that was designed for the 115vac you are presuming to keep them from overheating.
B. The guy might want to call the welders manufacturer after measuring wall voltage to see if there isn't a possible modification to his welder and this is assuming that such a current limiting circuit even excists in his unit.
C. replace the breaker first. It's cheap and can do no harm unless the first guy electrcutes himself.

John.....

Long cord machine poops out 110v machine not worth much.

[Poolside]

Originally Posted by gsweave

The same rod, I believe. The 3/32" rod is marked as GP, The larger sized rods are marked as 2100 Blue Max. Yep, they are both Stainless based.

I really like the control I get with them.

We weld lots of Stainless here at work, And they are really good for bonding M-2 tool steel to 400 series metals.

I like the idea. The 2100 isn't just a AWS 309 for SS to carbon joins. It says it works on virtually every steel. I looked at the data sheet and it did not have an AWS number listed. It must be a 'special blend'.

The test results look good for what I need it for. 92kpsi yield and 22% elongation.

I always use low-carbon, so 92k is plenty strong enough. I'm gonna get me a sample.

Hey there KTM, can a Blue Max 2100 too-much-absorbed-moisture flux coating can be dried in an oven?

- Jim

[KTM640Dakar]

Originally Posted by Poolside

I like the idea. The 2100 isn't just a AWS 309 for SS to carbon joins. It says it works on virtually every steel. I looked at the data sheet and it did not have an AWS number listed. It must be a 'special blend'.

The test results look good for what I need it for. 92kpsi yield and 22% elongation.

I always use low-carbon, so 92k is plenty strong enough. I'm gonna get me a sample.

Hey there KTM, can a Blue Max 2100 too-much-absorbed-moisture flux coating can be dried in an oven?

- Jim

The Lincoln Blue Max 2100 is actually a 312 series stainless. It has lots of chrome and nickel in it which makes it very useful for many steel applications. Many companies make 312 stainless electrodes that they say will weld any ferrous metal (iron based). If you can afford to buy it then use it!

Regarding mositure, water, oils, zinc coatings, rust, mill scale, oxides, grease, or any hydrocarbon on the metal you are welding. You should never let stick electrode get wet. It is even bad to keep it out more than eight hours in a humid environment. If you have a rod oven you can probably get away with drying it once.

The real reason that moisture (and all of the other listed contaminants) is bad for welding is because H2O is a source of hydrogen. The problem with hydrogen is that it is the smallest atom we know of. And if you introduce it to a molten weld puddle, and the puddle freezes back to a solid the hydrogen will diffuse out of the solid weld, and leave behind a hole where it used to be. This is called porosity and it is an unexceptable defect in a weld.