Bad welds

[PTvor]

...because the weld (molten metal) is only being used to mirror another surface. Look at the pictures posted above. Where the welds have come away, they have left a fairly decent impression of the surface they were supposed to fuse to.

Why weld when you can cast, have a wider choice of alloys and maybe mould release agents? OK, casting steel requires high temperatures and the mould has to take them, which you avoid with this process. But this sort of welding requires skill even though the result is rubbish and having a lot of this weld over lettering could easily result in a big weak weld, strong enough to damage whatever was being moulded as the weld was removed and there could be welding defects (bits where there was a genuine weld). Doing this sort of weld in a straight line is one thing, especially when making a good weld would be an unexpected bonus. Following lettering where you don't want a proper weld, quite another.

How about metal spraying for what you are proposing? I've no experience of it myself, I'm just vaguely aware of the process. I have an idea the gear is expensive.

 

[Delgado]

Not sure if it would work, but could you make the mould to be copied from copper, and then weld over it to make the surface casting?

 

[knoba]

Right... I'm reporting myself for being off topic...

How hard is it, for the diy guy, to make letter stamps similar to these...



I propose that one may be able to;

Stamp (engrave) a custom design into metal plate (see below - actual size could be 19mm x 6mm).
Run over it with this poor welding technique.
Hit the blob with an 'ammer while it's hot to get a good impression.
Release it.
Trim the waste away leaving a small stamp.
Fix it to a shaft.
Temper & harden it.
Use it as a branding stamp for custom metalwork products.



It's just an idea, PT, of using a welding power source as an instant casting technique. Not many people have the facility to do their own castings at home.

...is there, alanrob?
http://www.mig-welding.co.uk/forum/showthread.php?t=24693

This poor welding (spot casting) technique may have more applications, that other members might shed some light on...

 

[PTvor]

It's just an idea, PT, of using a welding power source as an instant casting technique. Not many people have the facility to do their own castings at home.

I'm not sure how they make letter punches. Drop forging or hot pressing I'd guess, which involve making a die in steel, and as I recall they use spark erosion and machining rather than casting. The right grade of steel and heat treatment will be needed as well.

As for making a custom stamp, it depends what you want to do with it, use it to print or brand as in the cowboy films.

Anyway it's clear you are intrigued by this bad welding/cast welding technique so why not see what you can do with it? If no one had ever persevered with something which maybe at first wasn't promising, we wouldn't have any sort of welding.

Maybe if you scribble with a soft pencil over the thing you want to weld/cast you'll get even less of a weld? Maybe some other sort of coating to prevent proper welding. Give a thought to whatever fumes it might create.

 

[knoba]

Neat idea, Delgado. If pursuing the idea, with a copper moulding, maybe a wood router could be used for the engraving?

I really do appreciate the support, PT. "Weld-casting" just seems to fit into a niche that wasn't there before. From small acorns...

Not knowing much about metal treatments, I assume one could produce a stamp (for metal) out of low carbon mild steel, & harden it after, to see if it's feasible?

If using mild steel moulds...
Tip-dip or anti spatter as a releasing agent?

Which ever base metal is used for the mould; suggested settings/processes would be?

• (MIG) MAG process (ability to weld onto it's own bead)
• pull torch technique (less penetration)
• 0.6 wire (less heat input)
• torch travel speed to keep ark at front of weld (to allow metal to form in depressions)
• wire feed quite fast
• amps only adequate to melt the wire
• voltage set low (less penetration)
• arc length (adjust as necessary)
• Torch angle - low

...anything else that would offer an advantage?

I don't make any claims to this concept, but if it's do-able, it's worth a good go. All input welcome...

 

[PTvor]

All you know so far is what Keith19 and WelderPaul have said. Experienced welders with industrial machines can produce cosmetically good but unreliable welds when it pays them and there's no QC. They turn up the wire speed and turn down the juice. It sometimes takes just vibration and sometimes a biff through a blunt chisel to break the weld. Presumably quite a few don't come apart so easily. No clue as to what the shielding gas was, but probably Argoshield or Ar/CO2 mix.

You want almost none of the welds to take, and that includes when laying down a pad of weld. You're not interested in the cosmetic appearance of the weld. You are interested in welding over complicated shapes. The welds in question were simple welds.

I can see a world of wonder in experimenting with this, using nitrogen as a shielding gas and using stainless wire and all sorts of daft things, because you don't want a good weld. What about cooling the piece which forms the mould with water?

As far as I know the extent to which steel can be heat treated depends mainly on the carbon content and mild steel can't be heat treated, that's why it's called mild steel. You can increase the surface carbon content with casenit and case harden it.

All this is sounding a bit like something needing a metallurgy lab to look into. I'd do a good search on Google to see if anyone or any company has been working on these lines before. It might save a lot of time. As I said before, metal spraying comes to mind when talking about this.

 

[KennyC]

i have one of those hope the brace stops that happening

A fair few have been wrote off with the new brace fitted and the welds held, the frames were badly dented in the crashes but otherwise fine. I wouldn't worry about it. It didn't really tarnish their reputation/ resale value either

 

[Wedg1e]

on a good note if they were done properly u would be out of a job just the same as me the amount of callouts i get through botched workmanship from so called tradesmen is unreal

I've seen two vans around the area with your name on, although one spelled 'Brite...' rather than 'Bright...'

Any relation?

 

[Engineer]

A fair few have been wrote off with the new brace fitted and the welds held, the frames were badly dented in the crashes but otherwise fine. I wouldn't worry about it. It didn't really tarnish their reputation/ resale value either

The fact that the damage shown in your earlier pic only occurred as a result of severe crashes, is something that maybe needs a mention?

 

[Wozzaaah]

...and the welds were probably done using shoddily made diy machines with aluminium windings....

 

[Robotstar5]

...and the welds were probably done using shoddily made diy machines with aluminium windings....

but could be repaired with a used professional machine with copper windings from ebay.....

 

[Wozzaaah]

...and the welds were probably done using shoddily made diy machines with aluminium windings....

but could be repaired with a used professional machine with copper windings from ebay.....

...that can be bought for about the same price.

 

[KennyC]

The fact that the damage shown in your earlier pic only occurred as a result of severe crashes, is something that maybe needs a mention?

No because it simply isn't true. Several have cracked with no crashes (like the ones in the links below, you'll notice the fairings in mint condition) and some were only discovered when the bikes were being washed. The k7/8's have been known to crack when crashed and no recalls there....

Besides, crashing doesn't reduce the penetration of a weld.

http://www.gixxernation.com/forums/...what-has-Happend-to-those-whos-frame-cracked&

http://www.gixerboyz.co.uk/forum/viewtopic.php?t=7799