Proof of bead penetration?

Hvacr · Sat Mar 28, 2015 8:16 pm

I cut out a cross section of a 3/16" plate i ran some 1/8" 7014 at about 135 amps DCEP. I CAN't tell if the beads actually penetrated the plate. I thought i was going to see grain changes in the heat effected zone, but i don't see anything, is this seen only through magnification or X-rays? I figured i must have had some penetration because the beads aren't crowned too much. But i am not sure. Does the pic of the back if the plate tell any story? Would it show those heat lines with or without penetration? Input appreciated!

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Sat Mar 28, 2015 8:32 pm

You have to etch it with some kind of acid. Naval jelly or rust converter. The steel must be polished to a mirror shine. Evidently it helps if it's a little warm. This takes time so be patient. At the end you must wash the acid off and if you want to keep the image, you need to paint it with some clear varnish.

Hvacr · Sat Mar 28, 2015 8:51 pm

weldin mike 27 wrote:You have to etch it with some kind of acid. Naval jelly or rust converter. The steel must be polished to a mirror shine. Evidently it helps if it's a little warm. This takes time so be patient. At the end you must wash the acid off and if you want to keep the image, you need to paint it with some clear varnish.

Mike, do you think the welding rod penetrated the steel based on your experience? The acid sounds doable. Thanks.

Sat Mar 28, 2015 9:06 pm

A flat bead on plate will penetrate. its a given because gravity aids the process. The only way you can not get fusion in that set up is if push a stick rod and really work the slag out in front, (then it will still proibably burn in. or on a mig bead with the wire turned way way up. ) 3/16 plate isn't going to be hard to melt. The problem comes when you move to a joint where your welding techniques have to make the weld burn in.

Hvacr · Sat Mar 28, 2015 9:46 pm

Yeah ok, good. Attempting joint welds is in my future

.

Sat Mar 28, 2015 9:55 pm

Keep up the good work.

dirtmidget33 · Mon Mar 30, 2015 11:31 pm

Jody did a good video on etching welds with household or easy accessible items. It is worth watching . . . . all Jody's videos are worth watching even for processes you might not use he always will prolly throw something in there that will help you down the road.

Here is the link to vid

http://www.weldingtipsandtricks.com/macro-etch.html

Hvacr · Tue Mar 31, 2015 8:28 am

Dirtmidget33, thanks for the link, watched the vid and will use to see what my practice welds are doing. Thank again! Saw the pics of you on another thread flying through the air in your machine

Tue Mar 31, 2015 6:52 pm

This etch on 304 stainless was done with a commercial acid-based toilet-bowl cleaner...

It took about 2 hours, and you need the light just right to get this image...

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Steve S

Hvacr · Tue Mar 31, 2015 7:48 pm

Steve, did you bathe the metal in the drain cleaner or just keep dabbing it on over two hours? BTW, that weld looks perfect, very even penetration.

Tue Mar 31, 2015 7:56 pm

I used a Q-tip, to dab the cleaner on periodically. I suppose soaking it would have worked just as well.

Thank you for the compliment; This was a part of our ASME "R" stamp certification, welding a process I'd never done before (spray-arc stainless with ceramic tape backing), and my job will never require again. Go figure.

To do this, polish your edge. After you cut it, sand it with progressive papers to at least 400 grit. This was 600 grit, because I had it available.

Steve S

dirtmidget33 · Fri Apr 03, 2015 3:24 am

Hvacr wrote:Dirtmidget33, thanks for the link, watched the vid and will use to see what my practice welds are doing. Thank again! Saw the pics of you on another thread flying through the air in your machine

Glad I could help. yeah with open wheel cars you learn to fly and go for a ride. I have flown and flipped down a track several times. Besides the broken parts on car the driver ends up with concussions and red eye (blood vessels break in eye from the g forces of impact)

Hvacr · Sun Apr 05, 2015 2:45 pm

Otto Nobedder wrote:This etch on 304 stainless was done with a commercial acid-based toilet-bowl cleaner...

It took about 2 hours, and you need the light just right to get this image...

The attachment GEDC1588.JPG is no longer available
Steve S

Steve, here is a pic of my flat plate bead penetration. I first placed the metal edge in a bath of loctite naval jelly overnight, i think i did not have the sutface smooth enough cause there was no etching i could discern. Then went through all the grits again up to 1000 grit and soaked the piece in Manitowos Ice Machine clearner, it has phosphoric and citric acid. This did much better. I did sand the metal with 320 and 600 after the soak.

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