#1
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OA advice
Installing an new shaped panel on rear corner of 38 panel truck
Original sheet metal is lightly rust pitted on inside and also thinner than 19ga, repair piece , Going to media blast and wire brush area to be butt weld panel n ew panel too . Should add new panel is large aprox 20x 16 . Open for suggestions / advice !!!! Thanks Larry |
#2
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Larry,
Instead of media blasting, try phosphate prep first. Media blasting will stretch the surface and ruin the shape. After using phosphate you can wire brush the iron phosphate away and a little local sanding will make it good to go. Mike |
#3
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hmmmm,
no media for me, either - embeds surface with hooligans, makes weird welds. Me? solvent wash and 25% phosphoric acid wipe - Must for Rust / Ospho / etc. No rinse - wipe up excess and leave the powder. ( + Media blast leaves the fresh bright area Rust Prone to the max.) "Better metal resto through Chemistry."
__________________
Kent http://www.tinmantech.com "All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919. |
#4
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OA welding advice
I always try and get away from pitted rust areas for welding , not possible in this case though,
Will try phosphate cleaning the edges thanks kent / mike ,Heres a shot of the panel need to get edges trimed and filed , Vert weld going to be a challenge oh boy ! IMG_0929.jpg |
#5
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Quote:
You need to tack this thing where you can, first. ("look" at the weld line with the torch heat, and when the sides agree, tack there. ) After you tack where you can, then you tack where you have to. Hammer out the tacks to line it up again. Remember that chemistry wins - set a small tip - #0 - with a slightly carburizing/reducing flame (sumpin' tiggies cannot do). This balances the oxidized nature of one side of the seam. Flame is good when no fizz happens in the pitted weld area. Try welding downhill between two tacks. Then try uphill. Tacks should be 1-1.5 in apart. You can lay the rod on and just melt it in (one technique for pitted-to-good weld seams, but there are others.) Oh, are you using the torch? I assumed so because of the nature of the job .... - right?
__________________
Kent http://www.tinmantech.com "All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919. |
#6
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OA welding advice
Quote
You need to tack this thing where you can, first. ("look" at the weld line with the torch heat, and when the sides agree, tack there. ) After you tack where you can, then you tack where you have to. Hammer out the tacks to line it up again. Remember that chemistry wins - set a small tip - #0 - with a slightly carburizing/reducing flame (sumpin' tiggies cannot do). This balances the oxidized nature of one side of the seam. Flame is good when no fizz happens in the pitted weld area. Try welding downhill between two tacks. Then try uphill. Tacks should be 1-1.5 in apart. You can lay the rod on and just melt it in (one technique for pitted-to-good weld seams, but there are others.) Oh, are you using the torch? I assumed so because of the nature of the job .... - right? __________________ Kent Yes using torch! after tacking start at one end and weld complete seam ? Larry |
#7
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Quote:
Thusly: Go to one end, and step back 2 inches then weld that two inch run, to the end. Step back 2 and weld to the previous weld. Repeat to finish.
__________________
Kent http://www.tinmantech.com "All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919. |
#8
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OA welding advice
Kent
Do you use gas rod most of the time for your torch welding ? Thanks Larry |
#9
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Quote:
If I am welding 4130 then I use the rod recommended for either ductility or for heat treat, since they are different beasts, altogether. When I was a pup metalboy I used to think "gas rod" and "tig rod" but over the years I learned that filler was filler, no matter the method - (95% of the time.) The torch can weld steels, aluminums, copper, stainless, bronze, gold, iron, magnesium, etc and usually with the same rod a tig guy would use. But most folks don't think of the torch as that versatile. It took me a number of years to get onto the torch, as I was trained as a tig-boy, and maybe that limited my thinking ...?
__________________
Kent http://www.tinmantech.com "All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919. |
#10
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Quote:
I was under the impression that if you didn't rinse MFR, it'd just keep eating through the metal.
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Drew Schumann |
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