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Welding like soldering but bigger?
saahild - 27/10/10 at 08:44 AM

Been thinking about this, what do you welders reckon to the concept that welding is similar in concept to soldering?

I mean you put on the heat, add the metal, take off the metal, take off the heat.

Things can go more wrong in welding if you turn it up too high or what not but do the skills transfer?

balidey - 27/10/10 at 08:47 AM

I think brazing is more like soldering. Welding is more like when you undo your alternator and the spanner shorts out and melts something.... not that I've ever done that.

Bluemoon - 27/10/10 at 08:48 AM

In a word no, you melt the metal (of the work peice...

[Edited on 27/10/10 by Bluemoon]

saahild - 27/10/10 at 08:50 AM

Shows how good a start I am making in this Locost business .

So you melt the actual metals you are trying to join together, and add extra metal in there as well. I always thought you just added the extra metal to join stuff together.

I need me a welding course I reckon

nick205 - 27/10/10 at 09:10 AM

With soldering (and braizing) the parts to be joined remain intact and you use heat to melt a filler material to join the parts. Typically you can re-melt the filler material and remove it to recover the parts intact. It's more complex in reality as the parts and filler materials must be suitably matched so that the molten filler material properly "wets" the parts to achieve a good joint. Soldering and braizing differ in the fact that braizing is generally used as a structural joint (e.g. bike frame) and soldering is generally used as an electrical joint to achieve conduction.

Welding (Arc, Mig, Tig etc.) by contrast uses heat to melt the parts to be joined and the filler material to create what should be a homogenous joint - i.e. the same as the surrounding material. As with soldering and braizing, the technique and filler material should be properly matched to the parts to be joined to achieve a good joint.

Good welding IMHO is an artform and a pleasure to see

mookaloid - 27/10/10 at 09:13 AM

with soldering or brazing you need to add extra material to stick the work pieces together.

With welding as said you melt the material to make it into a continuous piece. sometimes you need to add more filler sometimes you don't. depends on the type of welding.

eg electrical spot welding doesn't use or need any filler. MIG welding does.

Cheers

Mooky

edit: too slow as usual

[Edited on 27/10/10 by mookaloid]

NigeEss - 27/10/10 at 09:18 AM

Soldering is a low temperature process effectively gluing the two components together
with a lead/tin based "glue". Brazing is a high temperature and stronger version of soldering
using siver or bronze based glue.
Welding involves melting the components to be joined adding extra material as needed.

02GF74 - 27/10/10 at 10:35 AM

I'm no expert but the two are not really the same.

soldering is using a different metal that fills in the gap between two pieces of metal in close contact, a bit like using a glue.

welding uses a metal that actually melts into the metal you are joining together.

blakep82 - 27/10/10 at 10:45 AM

solder is like gluing
welding is like, er, dunno, but you melt all the metals and mix them together before they cool down and solidify into one piece.

mcerd1 - 27/10/10 at 10:50 AM

^^ what they said - welding makes 2 parts into one, soldering/brazing just sticks them together

the filler material for welding is normaly similar to the parts your welding, but higher grade/quality to get around some of the problems with strength, brittleness, etc...

you can actually weld things without filler, normaly by heating them up and battering them together one way or another...


http://en.wikipedia.org/wiki/Welding

http://en.wikipedia.org/wiki/Brazing

http://en.wikipedia.org/wiki/Soldering

[Edited on 27/10/2010 by mcerd1]

omega0684 - 27/10/10 at 11:13 AM

quote:
Originally posted by nick205
With soldering (and braizing) the parts to be joined remain intact and you use heat to melt a filler material to join the parts. Typically you can re-melt the filler material and remove it to recover the parts intact. It's more complex in reality as the parts and filler materials must be suitably matched so that the molten filler material properly "wets" the parts to achieve a good joint. Soldering and braizing differ in the fact that braizing is generally used as a structural joint (e.g. bike frame) and soldering is generally used as an electrical joint to achieve conduction.

Welding (Arc, Mig, Tig etc.) by contrast uses heat to melt the parts to be joined and the filler material to create what should be a homogenous joint - i.e. the same as the surrounding material. As with soldering and braizing, the technique and filler material should be properly matched to the parts to be joined to achieve a good joint.

Good welding IMHO is an artform and a pleasure to see


very well put and even i understood it!

saahild - 27/10/10 at 11:16 AM

Ah I get it now, I was just thinking if it would be like soldering, I wouldn't want to get into a car with bits "glued" together so how come people put massive engines in them.

But I get it now.

So if I were to join to bits of metal rod together in middle to make 1 long rod the welded rod would be "almost" as strong as a piece that was long to begin with.

blakep82 - 27/10/10 at 11:27 AM

quote:
Originally posted by saahild
So if I were to join to bits of metal rod together in middle to make 1 long rod the welded rod would be "almost" as strong as a piece that was long to begin with.


er, in theory yes, but it will never be as strong as a peice that was 1 piece to start with.

mcerd1 - 27/10/10 at 12:20 PM

quote:
Originally posted by saahild
So if I were to join to bits of metal rod together in middle to make 1 long rod the welded rod would be "almost" as strong as a piece that was long to begin with.

actually in theory the weld should be slightly stronger than the parts, when they fail it tends to be where the weld metal meets the part



with normal steels most welds will tend to be harder/ more brittle than the parts so you get a stiff point on the part which can concentrate the stresses
I think TIG is better for this and I know friction welding gives good results

but in aluminium the heat welds can affect heat treated alloys and soften them near to the weld

and in stainless over heating it (welding to much in one place) can cause it to corrode next to the weld

there are hundreds of problems/ limitations for each type of material or welding process - but luckily MIG'ing mild steel is fairly strait forward
if you've never done any welding before you should think about doing a course, most colleges run fairlt cheap evening classes

saahild - 27/10/10 at 02:58 PM

Very much so a course is on the cards.

I was suggested onto here by a chap that made an indy when he was about my age (he's only a bit older then me mind )

At the moment I am right at the very beginning of the process. Reading lots, and designing a chassis.

After that comes balsa wood modeling and modifications to suit.

Then taking to boffins who tell me I've done it all wrong and to go change x y and z.

Then we source funds and sheds/tools.

If I haven't killed myself from frustration or blown up in a big ball of welding gas I should be at the actual welding stage some time this millennium...

Realistic time frame for the design and book learnings is roughly 5 years.

I want to be road worthy for me 35th Birthday in fully complete high spec trim. But it will be built to last generations with nought more then regular maintenance.