why aren't my SS TIG welds shiny?

greets all,
just a quick question.. subject line says it all.
i'm not talking about the backside, either.. the top.. i can
get nice solid weld beads down (stainless is a dream to tig) but
i can't get the weld bead / zone as shiny as the parent metal.
using straight argon and both 308L and 316L filler.
(what does the L stand for?)
thanks,
-tony
Reply to
tony
Loading thread data ...
OK my psychic powers just aren't what they used to be.
What torch, collet-body type, cupsize, tungsten, gas, gas flow rate, amperage, angle of torch, tungsten stick-out, size of filler rod, thickness of base metal do you have?
OK we know you are using pure argon and not a argon/helium mix.
The L stands for Low Carbon. The reduced carbon content reduces the chance of Chromium Carbides forming in the weld. Chromium carbides lead to rust spots and fractures.
Now fill in the rest and I will help as best I can.
Reply to
Ernie Leimkuhler
Hi Tony, Could be just as simple as giving it a light buff. We use plastic wheels on a drill for polishing all our stainless welding, but its mostly mig. They generally only pull out the tig for food grade, and when they do it I've found it doesnt look quite as good as the polished mig....
Reply to
Shaun
plastic wheels?, can you elaborate? i,ve been farting around at work with 10 ga. stainless making little art pieces tig welded with silicon bronze fill rod. i would like to experiment with different polishing tools. cj
Shaun wrote:
Reply to
cj
Hi CJ, I guess I should state first of all that we weld sheet bent into trays and then welded together around a spinning rotary platform to make a continuous feeding tray for dairy cows. The joins are all lap and we have really good and easy access to the flat welded surface. I wouldnt use this med for things where the access was tricky or mitred joins/pipe/bent items.
The polishing disks we use are for a drill and it's a bit hard to describe them, I could check who makes them and get back to you. They basically have heaps of plastic 'feelers' facing downwards - in the same direction of the drill and each one is maybe about 1mm in diameter and about 25mm long. They work well and are light on the metal. With a weld length of about 1.2 meters we go through 1 of these about every 25 welds. I dont think they're too expensive ($4 or $5).
In the past we used a sort of pickle paste, you apply and hose off 15 minutes later but we stopped using it since clients complained of the marks it left on their concrete, especially if it was painted. It gave nice results but left the stainless slightly whitish where it was applied.
I have also had success with buffing wheels on grinders; go with a medium to tough wheel like a the yellow calico or sisal, but stay away from the resin impregnated green ones. Use the darker compound too, probably the green or maybe even the dark grey. Use the dry compound blocks rather than liquid ones.
Apply a little compound to the spinning wheel and then apply heavy consistent pressure over a 2 to 3 minute period. Dont stop or keep applying compund, you'll never build up enough heat/friction to get a polish going. This works better with the mitred joints or weirder pieces.
Hope it helps. Shaun
Reply to
Shaun
That sounds rather like some "wheels" I got from Princess Auto. Abrasive filled nylon bristles, one type like a cup wheel and one with radial bristles. I have found these things the best yet for cleaning aluminum prior to TIG welding.
Ted
Reply to
Ted Edwards
Tony,
Get yourself some SS toothbrushes from your welding supplier. Make sure they are SS, Carbon will cause a thin layer of rust on the SS. It is usually best to brush with the grain of the metal, keeps the scratches from showing up so bad. It is also usually best to brush the weld right after you finish welding, the rainbow seems to come off best when it is hot.
If you are wanting to make the bead really shine I have a list and a brief explanation of the process I used a few years ago on some #8 finished SS. I would be happy to e-mail it to you or re-post it here.
Regards, Jim C Roberts
Reply to
Jim C Roberts
Jim, yes, if you could... i'd appreciate it.
i have stainless brushes but reserve them for aluminum. when i've got alot to do i fire up the wirewheel on the angle grinder. sure everything looks clean, but i can't get that shine back. i was hoping i could get shiny beads as-welded. wire brushing (or scotchbrite pads) leave a dull (noticeable) finish.
i'm getting what seems to be an inordinate amount of oxides (or really fine scale) on the bead. not sure if this is normal. should the TIG welds be dull/dark and subsequently require polishing?
sort of like aluminum. when i weld it, everything is nice and shiny.. to clean up the HAZ (usually white oxides), i run the wire brush across. this dulls everything down.
-tony
Reply to
tony
Tony, You asked for it;
Here is a brief summary of the products we used for the polished SS oven we just built. I had planned on posting this to the previous discussion on polishing, but figured it has gotten buried beneath the discussion on recent events.
First I need to say that all of the Norton products can be purchased either from MSC or by calling Norton for your local distributor. The Walter products were ordered straight from Walter, but I do remember our tool supply guy saying that MSC carried some similar products also.
I mentioned little gray wheels, which we used mostly as the primary weld remover. The official name is Norton Bear-Tex deburring wheels, #52200. We used the 2"x1/4" size with a 1/4" arbor hole. The finer gray wheel we used was also Norton's, Bear-Tex Unified wheel, #58773,(662610) both of these numbers were on the tags, not sure why it had 2 numbers. We used these wheel in the 3"x3/4" size with 1/4" arbor holes also.
The rouges that we used were Walter Quick Step products, the white(07-T 901) was used first, it does a fairly good job of polishing, leaving a slight "haze" that is easily finished with the blue(07-T 905). After the blue is applied and worked in, we usually went back over the area with a clean wheel, the same wheels we used to apply the rouges. These were 4" cushion sewn wheels with 3/8" faces, #528-41-4 but I couldn't find a brand name on them.
Hope this helps,
Try hitting the beads with a toothbrush or your grinder while it is still hot. If that doesn't get them as shiny as you would like you will probably have to use some sort of polish/rouge. As I mentioned with the toothbrush, be sure you are grind/polish with the grain.
Are you grinding any of your weld away Tony, or just wanting to brighten the weld as is? If you are not grinding them then you would not need the Bear Tex wheels I mentioned above.
The best you can hope for is a gold sheen over the weld(I honestly hate to have to do anything to a weld when I get that, it looks so damn nice!) A rainbow effect(dark blue/reddish coloring) is also a good thing, brown or black is a bad thing. It seems like my welds go to the dark side when I let my tungsten get too dull and can't keep a very fine puddle.
I know what you mean, I have been welding up a bunch of .120 Al boxes here lately. The corners are folded over to make a lap weld seam. When I can get my feces coagulated($hit together) and get the proper rhythm with the filler metal the welds come out nice and shiny, looks just like the base metal, with just a thin line of oxidation down both sides. Getting the oxidation off means using a toothbrush and that takes all of the shine out of the welds. :( I have some Alumiprep 33(?) that I have been tempted to use, but the directions make it sound like it would dull the finish even more. Oh well, the customer is happy with the looks of it even if I'm not.
Hope some of this helps, Jim C Roberts
Reply to
Jim C Roberts

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