- Welding is one of those essential processes in the motorsport fabrication industry,
traditionally that's been either MIG or TIG.
However laser welding is becoming more and more prominent.
We're here with Evan from Serra Laser to talk a little bit about laser welding.
Now first of all, laser welding at the moment, it is still a reasonably expensive process compared
to enthusiast level TIG welders for example isn't it, quite an expensive unit?
- Yes that's true, the prices are quite a bit more than your garage level welding systems
but they're close to being on par with an industrial style system.
- That being said, these aren't currently being targeted at enthusiast level fabrication shops
are they?
This is a professional production level product?
- Yes that's true, there are quite a few people who are using them in their garages, few artists and
custom fabricators but a lot of times they're being targeted towards a production environment.
- Alright let's talk about the differences in terms of pros and cons between TIG welding
which is generally the go to if we want a lot of control over the weld, a lot of control about
the amount of heat that we're introducing into the parent metal, compare that to laser welding,
pros and cons.
- OK so we're introducing just enough heat that we need to weld the material effectively without
wasting energy going into the surrounding material so our energy is 200 times as energy
dense at the point of welding so our energy is just focused where we need it and not anywhere
else.
- So this means that there's less heat just being put into the material, the heat affected
zone is narrower?
- Yeah the heat affected zone is much smaller, you retain the material's natural properties
much better and that creates a stronger weld.
- So is this also useful for some of the materials that are very prone to being affected by heat
like chromoly, could you use laser welding for chromoly welding?
- Sure, yes you can.
- Now in terms of the actual technology itself, obviously the laser is being used to essentially
melt and fuse the parent material together but you do have a filler wire so when you
look at the actual unit, it almost looks like a mix between a TIG and a MIG welder, talk us
through how that works.
- Sure so the laser welder can be used as a fusion welding machine as well, if you have
perfect fit up, you can fuse the parts together, called an autogenous weld but if you want to
add a filler wire, you have small gaps to fill, you can add a filler wire and that filler wire
actually moves your welding gun along and it produces a perfectly consistent result,
that's my favourite way to use it.
- So the filler wire basically pushes the gun along the weld so your travel speed along
the weld is essentially controlled by that wire?
- Yes that's exactly right.
- In terms of the controls that the welder has access to, what knobs have we got to adjust here?
- So we have, we start most welds with a preset mode, there's some preset conditions that are
really well thought out that'll get us through most of our welding applications and from there
we can dial the power up and down to achieve more or less penetration and we can also do
some control of the width of the weld.
The laser wobbles side to side and we can control how wide it goes and how fast it wobbles side to
side also.
- OK so a reasonable amount of control in there, some of the demonstration pieces that you're
welding there are relatively thin pieces of stainless and the impressive part there is just
witnessing how little distortion there is of the material once it's been welded.
But on the flipside of this, how thick can we work with with these machines?
- So depending on the model we can get full penetration up to a quarter of an inch.
It's not limited to the material thickness but you can get a quarter of an inch penetration
into the material.
- Now normally if we were maybe MIG welding or even TIG welding quarter inch plate, it's going
to require quite a bit of prep work on the weld area, we're going to probably have to chamfer
or V out that weld so we can get that full penetration, what's the preparation required
with a laser welder?
- So with a laser welder, the best bet is to make the fit of the join as tight as possible.
We don't need a bevel and we don't need a gap, the laser has no problem penetrating
deeply into the material, that's what it specialises in and so we can just have a complete butted up
joint and get full penetration right through.
Even in the middle of a plate where there's no joint I can penetrate all the way through.
- Alright let's talk about shielding gas, I mean this is essential for MIG and TIG, no different
here with the laser, you're still essentially heating the base material up and to a point
where it would react with the atmospheric air, so what's the shielding gas you use?
- So the most common shielding gas that we're going to be using is nitrogen.
That's the optimal gas for steel, stainless, nickel alloys, copper, you can also use it for
aluminium but argon is recommended for aluminium and you will need to use argon
with titanium.
- OK so typically for TIG welding we would be using argon, is there a benefit in terms of
cost for nitrogen over argon?
- Of course yes, argon prices are rising, nitrogen is our most abundant gas in the
atmosphere and it's fairly easy to generate.
Many of our customers have nitrogen generators for their laser cutting machines
that they then use that nitrogen to use as a shielding gas for the laser.
- So again this works into the hands of those who are working at production levels, doing a
huge amount of welding.
In terms of the speed, once everything's prepped, in comparison to TIG and maybe even MIG, can you
let us know where laser welding lies in terms of outright speed?
- Sure, it's said to be twice as fast as MIG, I've seen it go quite a bit faster than that and
as far as TIG goes, if you're on a long linear application on thin materials, I've seen it go
up to 10 times as fast but on average, I would say it's four times faster than any other hand
weld welding process.
- OK that is a massive saving in terms of time, again at production levels.
Now you've got a couple of options here in terms of what the finished weld looks like and you've
got a pulse mode which almost replicates the look of a nice stacked dime weld that we're used
to seeing with TIG welding.
What are the two modes, does that stacked dime give us any benefit or is it a visual
thing only?
- So yes the typical weld is very smooth and high speed, the stacked dime look we actually found
out by accident that it has the benefit of allowing us to go slower.
So on really tricky applications such as rounding a pipe on a stainless steel exhaust, that pulse
mode allows us to slow down and get finer control and that's something that's been really
beneficial to us.
- Now in terms of fit up which you've mentioned, obviously again if we compare conventional welding
techniques, TIG welding does require a pretty good fit up, maybe not perfect but the better
the fit up, the better the result.
MIG welding, obviously you've got the benefit of being able to fill in some reasonable sized
gaps, this one, more in line with TIG welding or does the fit up need to be even better than
what we could get away with with TIG?
- So it's more in line with TIG welding, my rule of thumb is I try to keep the gap smaller than my
wire diameter which I typically use 045 wire.
You can definitely fill gaps that are slightly larger than that with some gun manipulation
but the tighter fit up the better and it's going to give you an easier result.
- Now coming back to the purging gas, you've mentioned there nitrogen, welding on some
of the more reactive materials like stainless steel, typically with a TIG we would back purge.
Safe to assume that that's still something that you'd recommend using laser welding?
- Yes definitely, we'll back purge with nitrogen and weld with nitrogen.
- And no differences in the techniques of how we actually go about the back purging?
- No same exact thing.
- Perfect now if someone wants to find out more about these products, and again I'll
reiterate they are definitely a little bit more pricey than your average TIG welder,
they're not really designed for the average home enthusiast, but if someone is in the
market for something like this, where are they best to go?
- Alright so you can search the internet, I work for a company called Serra Laser,
you can go to serralaser.com, that's S.E.R.R.A L.A.S.E.R.com and the product that we're using
in the IPG LightWELD 1500 laser welding system.
- Perfect and we'll put some links to those in the show notes as well.
Hey thanks for your time, really appreciate it.
- Thank you.
- If you liked that video make sure you give it a thumbs up
and if you're not already a subscriber, make sure you're subscribed.
We release a new video every week.
And if you like free stuff, we've got a great deal for you.
Click the link in the description to claim your free spot to our next live lesson.