Another aluminum mig welding question

[WCAMARANO]

Happy Easter Everyone !
I want to pick your guys' brains some more.. Was told to use 5356 , ,,only found 4043 or 4047 at Lowes yesterday ..Welderbob or Kmorin you out there ? Whats' the different between spools of superglaze and just regular aluminum welding wire.. ? Can i use 4043 or 4047 or do i need that higher alloy ,magnesum content... Can't get to welding center "airgas" before they close on weekdays ,might have to take a day off .. Found a page about different wire alloys awhile ago ,but can't remember where. Thanks Wayne

[welderbob]

4043 wire doesn't have the weld strength when welded on 5000 series aluminum . It will also be softer and harder to feed. Buy a roll on line,100's of web sites or send me a PM and I'll get some to you.

Bob

[kmorin]

WCAMARANO,
Bob has given the main reason but there are a few others- all in the vein.

I'd add that the break bend tests of 4043 show the final weld to be brittle, crack prone and not up to the bending strength of the 50 series alloys. Why this matters is that the filler looks like it produces a 'good' MIG welds -leading folks to rely on it. But when the welds are bent for testing the flaws show up. I've seen articles online by folks who rely on the looks to determine if their welds are reliable- not weld destructive testing as they should.

I don't know the name or brand name 'superglaze' I just buy by alloy, sorry can't help there.

http://www.lincolnelectric.com/knowledg ... umwire.asp

Cheers,
Kevin Morin

[kmorin]

WCAMARANO

http://content.lincolnelectric.com/pdfs ... e/c805.pdf

it looks like the brand name superglaze from Lincoln to emphasize the wire feed improvements from their wire's smoohter surface finish- I guess the 'off brands' feed well enough and I've not used Lincoln consumables?

Cheers,
Kevin Morin

[keith]

Kevin,
What is the proper way to break bend test welds in aluminum plate? Is there a specific radius that it should be bent to? I would think that the thicker the plate the larger the radius? I have bent my TIG welds in .120 5052 with 4043 and been able to flaten them in the vise without them breaking.

[kmorin]

keith, butt welds should be bent to a 4T radius die in a press or bent over that die/ or near sized pipe with clamps and if dressed flat/smoothed you'd only bend the first time or press a U. Then look at the two root edges and the face and back for cracks. If you left the bead crown you can give it the reverse bend as well, to see what you get for malleability, but a lot depends on one sided or double sided bevel and welds?

The T or fillet would bend grabbing the vertical leg up four thicknesses; then and laying it to the flat/touching, both face and back/root bends as separate tests; next bend back to vertical and if possible over the opposite way. Usually the parent metal will strain harden after the first bend movement and fail along the edge of the HAZ or heat affected zone.

5052 and 4043 are a 'livable' match, for content and alloy, the resulting mixed tensile (pull apart in-line) is much lower than 5356 but they will flex, together, one way because the 5052 is so soft to begin, just take the 5052 and bend it in a vise- then do the same with 5086 or 5083..... that difference is why all quality welded hulls are the stronger materials- excluding production and formed boats.

Also it makes a difference how wide a bead or fillet face and root you use in your bead for the test. A weld should be about 1.10X to 1.15X the thickness on the root face and a fillet face of the same (rough) dimension in this case. So if your test is in 1/8" parent material the face should be roughly 0.130" or just under 5/32" -otherwise the weld is 'bigger' than the parent metal, softening, annealing and not being tested in the bend break. Wide TIG in 5052 removes the last of very little temper or hardening native to 5052 sheet for a wide path making the material very nicely softened and malleable, but if you can "crush" the weld and parent without failure, then the weld should hold in a similar real world crushed condition?

Where 4043 is not good practice is with 60 series of 5086/5083 or the other stronger hull alloys.

Cheers,
Kevin Morin

[WCAMARANO]

Hi Guys, picked up my .035 1 lb spool of 5356 . with some new tips.Made it to Airgas , Salesmen said going thicker would help with pushing wire through . I believe one of you guys said to go thicker also. I will get back with results soon ,hopefully this weekend i'll get some free time to mess around with boat and welder. Interesting about testing welds ,,,, Thanks again for all the answers..!! Wayne

[keith]

Thanks for your reply Kevin. When I read your posts I get the feeling that you have forgotten more about welding than I ever knew.

[kmorin]

keith, operative word: forgotten; being an old welder isn't for the faint of heart especially loosing most of the 'stuff' you thought you'd stored in the 'hard disc between the ears' is a pain.

WCAMARANO, 0.035" 5356 seems like it will be pretty flexible in a 10' stretch out, but the power supply may not burn the 0.045"-0.047" wire that would be stiffer yet?

Cheers,
Kevin Morin

[WCAMARANO]

Hi Kevin,, Do YOU think my power supply [ sp-130t ] 220 unit is not going to be enough to heat? Should i preheat the aluminum [ 18 gauge some is a little thicker] . And should i also clean with acetone after SS wire brushing area to be welded ? ... It's over cast now , maybe should wait for sunny day .Let the sun heat up boat for a few hours before , what do ya think. ? Wayne

[kmorin]

Wayne, first, I would be welding on test pieces on the bench before the boat!

I don't know the power supply well enough to say what it will output, I'd want about 18-22 volts welding for 0.035" wire and depending on your wire feed speed control 300 (and up) inches per minute of wire- but depending on how the wire feeds, which you know I'm a little skeptical about, you may need higher feed rates to keep wire feeding.

I'd clean all weld areas with acetone BEFORE cleaning with the brush, and I'd use a 4" power brush first, to get the most cleaning- this brush should have soft bristles- 0.012" to 0.015" wires MAX or you'll gouge the metal or cut it. Then I'd use a tooth brush immediately before the weld.

Degrease, wire brush, tack, tooth brush each weld zone just before welding that area.

If the power supply were maxed and the puddle beads up or curls under at the toe and top ( these beads form rounded beads 'laying' on the parent metal)- showing you don't have the heat of fusion of the parent material, then preheating will help by adding a background or base temperature to the parent material. Make sure you tooth brush after preheating and make sure any preheat 'runs' the dew off the material. Propane burning makes a by product of water, that collects as dew on the heated surface- heat till that 'runs' or drys off the surface, then tooth brush and weld.

I wouldn't preheat if I didn't have too, and the telling point is if the edges of the bead fuse at the 12:00 and 6:00 O'clock regions of the weld zone.

cheers,
Kevin Morin

[WCAMARANO]

Kevin ,, first clean with water, boats a bit dusty from sitting.Or should i just blow off Then Acetone then wire wheel with fine bristles.. so your saying tooth brush without out acetone ,Just dry ? Rite before i start welding ? Wayne

[kmorin]

wayne, yes car wash if the boat is dusty, then when its time to really clean, clean- then acetone first, power brush the areas to remove long term oxide and any real junk- tooth brush to disturb the oxide immediately before MIG or TIG, not as critical with TIG.

if you have used SS tooth brush for ANYTHING else, rinse in acetone prior to use on alloy.

Cheers,
Kevin Morin

[ZanderJay]

I've tried to have a split twist test of 4043 into the final weld. I found that it was not up to the twisting strong point of the series alloy. For that matter, we can use and produces a MIG welder to rely on it.

[kmorin]

ZanderJay,
sorry to be dense but I'm not clear on your post's terms. In general if you don't state all the W's then its not as clear what's being asked, stated or discussed? [Who What Where When Why.....]

Without the following information alloy, thickness, filler alloy, welding power supply, wire feed, weld position, all weld settings like wire speed, amperage, voltage, mode and several other items; its hard to see context for the post?

Cheers,
Kevin Morin