AIRCRAFT QUALITY BOLTS

No orange flair, for one.

Cobalt Gold - not cobalt actually (better for the eyes) - or better yet the TM2000 from Tinmantech.com. They are an emerald green. And expensive. The Cobalt lens is not effective against ultraviolet, so if you are doing a lot of welding the TinMan lens is worth while (won't give you cataracts)

Reply to
clare
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I never noticed an orange flare when gas welding aluminium using ordinary OA welding googles anyway so maybe it's a flux thing.

Reply to
David Billington

Are you talking about some sort of flair from the flux that I hear people talking about so much? I can only assume that it is some sort of new fangled stuff that we didn't have back in the early '50's when I learned the technique, because I never noticed any "flair" using plain old green welding goggles.

Somehow I get the feeling that you've lost the thread. You tell me that some sort of fancy glasses let you see the heat when you weld aluminum; I ask you how that works, and now you are off and running with non-UV lens.

But how does all this let you see the heat of aluminum when you are gas welding it?

Reply to
John B.

I had a little look on the topic of aluminium welding and one UK forum mentioned GWF (Gas Welding with Flux) rated filters. I can't find mine now so can't check but at least one local welding supply lists them in various styles and shades so maybe that's what I had all along. Found this also

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and good to see mentioned the comparison to expensive ones being made, maybe the TM2000s?

I had a chuckle when I read the TM2000 page

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with his bad science analogy of how sodium gets in glass from glass = silica sand = seabeds = salt . As I'm involved involved in glass blowing I know that the source of sodium in soda lime glass is from sodium carbonate, not sodium chloride, which is added to help bring the melting point of the glass down to a workable temperature along with other things. In the heating process carbon dioxide is liberated leaving sodium oxide in the glass. Also glass sand as supplied is quite pure silicon dioxide.

Reply to
David Billington

I think it is because the flux has sodium in it and when heated gives that yellow sodium vapor light. Cobalt lenses filter out the yellow sodium ligh t and lets you see the aluminum clearly. So it is no miracle cure for weld ing, but it does let you see.

When you heat the aluminum, the outside oxidizes and the oxide covers the shiny melted aluminum. So you just keep poking at the aluminum with the ro d and when you get some melted aluminum the rod pushes the oxide to one sid e and lets you see the melted aluminum.

Dan

Reply to
dcaster

Hi - I just copied this from a Hobart Welding Guide.

"Aluminum does not exhibit color as it approaches its melting temperature. Aluminum will show color above the melting point, at which time it will glow a dull red.

When soldering or brazing aluminum with a torch, flux is used and the flux will melt at the temperature of the base metal approaches the temperature required. The flux first dries out and then melts as the base metal reaches the correct working temperature.

When torch welding with oxyacetylene or oxy-hydrogen the surface of the flux will melt first and assume a characteristic wet and shiny appearance. (This aids in knowing when welding temperatures are reached.)

When welding with gas tungsten arc or gas metal arc, color is not too important because the weld is quickly completed before the adjoining area would melt.

When the factors above are taken into consideration it will allow making welded joints in aluminum with little or no more trouble than when welding steels."

I assume that this may be correct but maybe an over simplification of things. I notice how it jumps from start to finish in 5 short paragraphs with (...no more trouble than welding steels).

Based on other things that I have read, rather than just relying on this 'wet and shiny appearance', with certain types of goggle lens and different fluxes a color change can help judge this ideal temperature range more easily, (before it falls on the floor). Is this a fair assessment? If this can be accepted then it appears to me that the idea of lens types and fluxes can be a 'fast-track' to the better aluminum weld with a standard oxyacetylene welder. Do you aluminum welders out there agree with this? If so, it sounds like maybe one can make this a big step in getting that better aluminum weld more sooner than later without the investment of an expensive welder for the casual odd job aluminum welding.

Bob Lowe

Reply to
Bob Lowe

It allows you to see that very subtle change that happens just before it flows away - which you can NOT see if you are blinded by flare.

Reply to
clare

The "wet and shiny" appearance is typical of any process that uses flux. Brass/bronze brazing, or even silver brazing. Just before the parent material reaches the temperature at which the brazing material melts the flux melts. But it hardly requires cobalt, or whatever, goggles. In fact I habitually silver braze with just my bifocals :-)

But the color change of aluminum that is mentioned is interesting. I've made some small aluminum castings and as I remember the liquid aluminum simply looked silver, not "red hot".

Reply to
John B.

I can only say that when I learned the technique, in about 1951, we used green goggles and paint on flux and the entire class learned to gas weld aluminum sufficiently well to be certified by the U.S. Government.... and not a one of them complained about flare.

Reply to
John B.

The green goggles are pretty effective at killing the flare. But not the UltraViolet.

Reply to
clare

Gee, the green goggles have been pretty well standardized in the gas welding/cutting business for what? 60 - 70 years? Longer? Now we got UV?

Reply to
John B.

Hi - I was just watching an aluminum welding tutorial and it made an interesting point...don't put all of your of your practice into making good looking welds. Make sure you practice in making 'bad' welds...this way one sees what is not good and what not to do. Just like the old adage, "One learns more from their mistakes than from their successes." And another point, like the extreme practice idea - If one is just starting out in learning to weld, start with welding aluminum and then welding steel will come much easier. Any takers on this? It sounds okay to me. I have always believed in the mistake philosophy.

Bob Lowe

Reply to
Bob Lowe

Why "practice making bad welds". You'll don't have to practice to do that and will make plenty of them in the normal course of learning how.

Reply to
John B.

Hello moderator - I hope you don't mind this thread morphing into another topic. John, I think the mistake philosophy in this aluminum welding has a definite dividing line with the difference being if you make a mistake while trying to do good, one may not know what caused it. If one is trying to make some bad welds on purpose and sees the results, this may help them to learn just what causes these bad looking welds when trying not too. Just a fine point. I can think of many applications. But this is not to say that all will think this way.

This video that I was watching was way better than most where most are out of focus and show just a ball of meaningless light. His was so well done and showed the fine detail of the puddle and with perfect focus and camera filters...Definitely a case of a picture being worth a thousand words. I will try to find the link again if anyone is interested.

Bob Lowe

Reply to
Bob Lowe

I'm not sure whether we are using TIG or gas for this exercise :-) but the problem with trying to do it wrong is that there are so many things that you can do wrong.... Wrong polarity with your DC machine; trying to weld aluminum with DC; Wrong filler rod; Wrong TIG electrode; Grinding electrode incorrectly; Striking a TIG arc with the gas turned off; and on and on. There are so many wrong things to do that it seems impossible to practice all of them.

It just seems like a better scheme to try to do all the right things.

Reply to
John B.

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