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  #21  
Old 01-05-2012, 05:31 AM
donc donc is offline
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After finding Tig to finnicky for SS I used ss wire in my 110 mig and butt welded new 20 ga mirrored stainless together..ground and polished welds...peace of cake, I haven't tried that on old trim tho...
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  #22  
Old 01-06-2012, 01:59 AM
bentwings bentwings is offline
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Trim materials are typically in the .015-.019 thickness range SS and of unknows alloy. Often they are bent and distorted so getting any kind of good gap fit is nearly impossible. Most have paint and other contaminants down in the creases so they bubble out just when you think you have a good weld going. Once you have welded it and filed it you can creat very thin section so when you go to reweld there is nothing there and you blow a big hole. It is nearly impossible fill this if you have not had a lot of practice. this is where you find out how good the machine is and how well you can use it.

I recently spent a couple days down at Dan's shop TIG welding a bunch of trim for him. It was extemely tricky and tedious to say the least. Fortunately he is a lot of fun to be around and kept the spirits up. haha.

We used a copper backing on most parts and filler cut from old trim. this adds another complication as it is hard to cut a .015 sliver of metal from stainless that is even close to straight and the same width. We tried 308L from the spool gun but it leaves a discoloration when polished smooth.

I use the TIG at pretty low power around 10-15 amps sharp .040 cerated electrodes polished bright. I used a gas lens and around 15cfm gas flow. We really did not get too fussy on the visual of the weld, more on filling the holes and gaps and did not worry too much about the sugar on the back side either. The TIG does not leave a hardened weld in fact it is quite soft. Dan used a file to get the weld down to the base and smoothed. I had to add a little TIG "bondo" where there were a few dents that Dan couldn't pound out. He did an excellent job of polishing and finishing.

The TIG weld is not for the bull gang. You really have to finesse it. You really need steady hands and good vision and good workplace. My auto dark helmet is useless. I used an 8 lens in my old head shaker that I use only for this stuff. It's a bit hard on the eyes but just don't watch the arc directly.

I've also done this with DCEN and larger electrodes. It is tough to do this way too but it does work. The fit must be perfect and I mean absolutely 0 gap. Machined is best. Everything has to be spotless clean. Normally I back purge all stainless welds but for this the back side got ground anyway so we didn't bother. You use twice as much gas and you use more gas anyway as all the welds need pre flow and post flow.

I guess there are micro torches and special fluxes that can be used but they take a lot of skill too. I don't have enough life left to learn this so I'll stay with TIG. I'm not sure what gas would be used..probably hydrogen. I did some really small glass work at one time with a torch about the size of a wood pencil. The flame was like a needle. The process was done under a large magnifing glass in a cleanroom.
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  #23  
Old 01-10-2012, 01:51 PM
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Ok I got the tin man flux yesterday. It is a powder that I need to mix with alcohol or methanol. Methanol was preferred on the label.

I've done some old fashioned googleing and come up with methanol being the same as methyl alcohol and being available at paint stores or TCS.

I wanted to check here first before I ran out and bought anything. The other reason was even if I went with alcohol I didn't know if that plain rubbing alcohol or not.

Thanks.
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  #24  
Old 01-10-2012, 07:07 PM
Richard-S Richard-S is offline
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I use denatured alcohol from the hardware store in my Kent White stainless flux. It's ethyl alcohol (grain alcohol) with a little methyl added to poison it so the winos can't drink it. Most rubbing alcohol is isopropyl alcohol, but some is ethyl alcohol. Look on the label.

Down here in Mexico ethyl alcohol is sold in every grocery store and pharmacy, without the poison. It's dirt cheap. Good place to be a wino.

Richard
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  #25  
Old 01-10-2012, 08:04 PM
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Quote:
Originally Posted by Richard-S View Post
I use denatured alcohol from the hardware store in my Kent White stainless flux. It's ethyl alcohol (grain alcohol) with a little methyl added to poison it so the winos can't drink it. Most rubbing alcohol is isopropyl alcohol, but some is ethyl alcohol. Look on the label.
Down here in Mexico ethyl alcohol is sold in every grocery store and pharmacy, without the poison. It's dirt cheap. Good place to be a wino.
Richard
Haha darn I was hopin to get a cheap buzz. Just kidding. Thanks for the info. Ill look for denatured alcohol. I believe thats a little easier to find.

Also you said about annealing by heating to 1900F, I found out my infared thermometer only goes to 500F. So would it be safe to assume heating it cherry red evenly then quenching would be good enough?

Thanks again for the help.
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  #26  
Old 01-11-2012, 03:40 PM
crystallographic crystallographic is offline
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Yes, you are correct about the alcohol. 70% Isopropyl is fine, or the good methanols. Stay away from the aromatic rubbing alcohols, as the eucalyptus, mentholated, witchazel or whatever is of no help for your welds.

re: heat color on steels:
Remember that when you are using color to indicate heat levels, your room should be dimly lit - bright lights cancel the true colors and can make your temps several hundred degrees Higher. The old blacksmiths shops had floors of black cinders mixed with dirt, and the walls were old brown boards or stone that were coated with soot. Lighting was the forge with maybe a kerosene lamp, and you went to the open door to get a good look at your part. Within that dim environment you saw the heat colors on steels accurately. Try to duplicate that and you will see your colors accurately - and then see the color disappear when you turn your overhead lights on.

Kent White
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  #27  
Old 01-11-2012, 06:54 PM
Richard-S Richard-S is offline
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Stainless doesn't have the same colors as steel. It's more orange. Your annealing temperature is not critical for what you want to do. I heat it to a point where the orange starts turning a little yellow, and then quench it. Be careful not to melt it. The melting point is considerably higher than 1900 but a momentary lack of attention and an acetylene torch can melt almost anything.

To completely anneal stainless, it needs to be held at heat for an hour in a heat treating oven and then quenched, but that's not necessary here—probably not even desirable.
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  #28  
Old 01-11-2012, 07:24 PM
hotrodder hotrodder is offline
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I know this thread is really concerning oxyfuel but as TIG has been mentioned i thought i'd just add my 2p worth as i did this job a few months ago, well the welding part at least.

This sort of trim is usually a ferritic stainless, my guess is probably 430. We gave up trying to cut filler from the parent material as cutting it fine enough to work was a proper ball ache. I ended up using 308L 0.8mm MIG wire, we knew the colour match would be off but couldn't justify buying wire for the job and it's not like the mismatch is 'in your face'. Personally i never bother with tungstens smaller than 1.6mm, just grind 'em with a longer taper. I initally settled on 14A when playing with some offcuts and then tried pulsing @ around 175Hz which made it easier. With pulse ended up at something like 18A peak, 11A background, 50% peak time.

The thing that bit us in a couple of spots was trim that looked and felt clean/straight ended up less than stellar once the polishing was finished. Next time we do it we're going to pre-polish the trim rather than just carefully selecting pieces.

FWIW the 'pegs' in the pics are 1.6mm TIG wire

P8150515.jpg

P8160522.jpg
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  #29  
Old 01-11-2012, 09:09 PM
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Quote:
Originally Posted by crystallographic View Post
Yes, you are correct about the alcohol. 70% Isopropyl is fine, or the good methanols. Stay away from the aromatic rubbing alcohols, as the eucalyptus, mentholated, witchazel or whatever is of no help for your welds.
re: heat color on steels:
Remember that when you are using color to indicate heat levels, your room should be dimly lit - bright lights cancel the true colors and can make your temps several hundred degrees Higher. The old blacksmiths shops had floors of black cinders mixed with dirt, and the walls were old brown boards or stone that were coated with soot. Lighting was the forge with maybe a kerosene lamp, and you went to the open door to get a good look at your part. Within that dim environment you saw the heat colors on steels accurately. Try to duplicate that and you will see your colors accurately - and then see the color disappear when you turn your overhead lights on.
Kent White
Thats very interesting to know and makes sense. I got some denatured alcohol from Home Depot today but didn't have time to play with welding at all.
Thanks for the info.

Quote:
Originally Posted by Richard-S View Post
Stainless doesn't have the same colors as steel. It's more orange. Your annealing temperature is not critical for what you want to do. I heat it to a point where the orange starts turning a little yellow, and then quench it. Be careful not to melt it. The melting point is considerably higher than 1900 but a momentary lack of attention and an acetylene torch can melt almost anything.
To completely anneal stainless, it needs to be held at heat for an hour in a heat treating oven and then quenched, but that's not necessary here—probably not even desirable.
After I read what you wrote I remember it being more of a deep orange when I was heating the pieces the other day. But you obviously got what I meant.
I will see how it goes when I get to that point. Thanks again.
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  #30  
Old 01-13-2012, 10:09 AM
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MAX MAX is offline
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I'm the one that posted that thread on the H.A.M.B. I have been chopping, modifying, and shaping stainless for many chopped custom cars. This type of work is very tedious and expensive, but for those individuals that care about the appearence of such pieces, it's worth the extra expense. I don't care for doing this type of work, but I can honestly tell you from experience and from my research of previous cars built, there are only a handful of guys that can do this type of work and make it look like it never happened, and that's rare.
I have seen many done with the silver, as a matter of fact, I've had customers that thought my pricing was too high, go to another and silver solder, and end up coming back for me to redo the job. One of the things that most people don't realize is that you have to bend the crap out of these trim pieces to fit them back on the car, so your welds better be strong, and you had better not file, grind, or sand too much around the weld areas or it will buckle, or worse crack, and you will see it on polished stainless, you can't hide any blemishs.
I look forward to your success with the torch, good luck my friend!
Max
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