Welding Tips and Tricks

Looks like I got some 2G and 5G butts coming up soon that will require mirror welding due to limited access and other pipes frustrating the location.
I'm interested to see what mirror set up you guys prefer that do this kind of welding please.

Pics or your mirror set up would be great.
If you have part numbers would be helpful too.

I'm thinking of a 3" mirror on a goose neck attached to a magnetic earth clamp. What do you think?

I hate doing this & am useless at thinking backwards while welding but the few times I had to I got a cheap mirror from poundland as you will break several or cover them in splatter / smoke etc in no time - the sort I had best luck with was about 5" round & sold for birds to do makeup - it magnifies quite a bit so is tricky to position but gives a better view - never made it a mount - used a variety of redneck duct tape / vise grips etc to hold - I like your idea of a magnetic stand - maybe glue it to a short length of " lokline " machine coolant pipe - that works well for positioning thinks - I have led lights on it on a milling machine - probably not permitted for you application but over here it's not uncommon to need to repair pipes on board ship & rather than try almost impossible access mirror welds you cut a window out of the front where you can see - do all the difficult area welded from the inside then weld the window back in - normally on carbon steel with stick though - I have heard of it being done with Tig pencil torch but not done it myself.

I've seen photos of "window welds" in boiler water wall(?) pipes where you cant access the back. (never in real life, though)

Yer I've actually done a couple of window welds on boiler tubes. Tubes are thin walled and only require one pass.
I'll be on sched 40 3&4" with proper vee butt prep and three passes. The root I can get from inside the gap no worries but the fill and cap passes will be mirror. I've used my wife's makeup powder mirror in the past. She thought she left it at the mall. Worked ok but as she's not with us anymore I have to try something else. There will be more room than boiler work maybe 1/3 of the pipe will be mirror work.


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I use a 1 inch and a 3 inch on goose knecks. I clamp or zip tie or tack the handle in place. I also have a SS mirror that's 3x5inches. I did borrow a 3 inch one on a goose kneck that was a magnifying mirror that was really effective.

It's really worth getting the magnifying sort even if your not over 50 & half blind ! kinda like the first time someone lends you a hood with a cheater lens & you think - wow I can see the puddle like you can on You Tube !

I tried to weld a broken mirror once but didn't have any luck so we bought a new one.

electrode wrote:I tried to weld a broken mirror once but didn't have any luck so we bought a new one.

that was baaaddd...no soup for you!

I do a load of mirror welds, and I do not have a "standard" setup. Every situation presents it's own unique challenge. I use bunches of the 3" rounds from the craft store, sometimes put in place with two-side tape, sometimes on a magnet with the same tape, sometimes on a gooseneck. Often I can't use magnets (stainless and aluminum), so I rig clamps. I have an inspection mirror (3") with an extension handle I can sometimes clamp in the right area and adjust the u-joint for the right view. I also have a 4" X 6" generic replacement truck mirror with a ball joint on the back I can bolt to magnets or brackets with a 1/4-20.

There is no "one way" to do this.

The one thing I have found, is when I come out of the mirror and can see it straight again, I have to tail off, and walk away for five minutes, because I can't instantly switch back into "normal" mode. Steve S

I also use a 2"-3" inspection mirror on a teliscopic handle or tape it in place....Most of mine are done on stainless. I've also use mirrors lexan in a pinch.

Thanks guys,
you've been very helpful.

Sounds like a good Youtube video opportunity

tried mirror welding on my bench yesterday, no obstacles or obstructions just
a mirror and two pieces of clean metal butted. just about wore out my tungsten
grinder..... hope i never have to do it for real..
you guys that master this procedure ROCK!
craig

If someone else is paying and the job you need it for isn't stainless ?

http://www.mscdirect.com/product/details/03854148

motox wrote:tried mirror welding on my bench yesterday, no obstacles or obstructions just
a mirror and two pieces of clean metal butted. just about wore out my tungsten
grinder..... hope i never have to do it for real..
you guys that master this procedure ROCK!
craig

LOL....yeah it takes some time to master. Once I start in the mirror and get my brain thinking backwards I have to take a little time before I can weld the front. I just watch the weld, if you start to think about your hands, your done and will mess up...just have to do it, not think.

My last one was 3" off the ground laying sideways on my back over another pipe putting in a steam valve...fun, fun, fun

Rick_H wrote:

motox wrote:tried mirror welding on my bench yesterday, no obstacles or obstructions just
a mirror and two pieces of clean metal butted. just about wore out my tungsten
grinder..... hope i never have to do it for real..
you guys that master this procedure ROCK!
craig

LOL....yeah it takes some time to master. Once I start in the mirror and get my brain thinking backwards I have to take a little time before I can weld the front. I just watch the weld, if you start to think about your hands, your done and will mess up...just have to do it, not think.

My last one was 3" off the ground laying sideways on my back over another pipe putting in a steam valve...fun, fun, fun

I tried it once, I tried figuring it out, thinking of my hands and all that and messed it up royally.

Still haven't tried it for real, hope I never will have to

I would rather weld underwater

ok next challenge "razor blade mirror welding".
of course I'm only the author not a participant.....
craig

I've not done this for welding, but I've used my action camera and wireless connection to my smartphone to work in an area I couldn't see. The action camera is small (I have a sony), so I set it back in some spot that can see the work area, then my smartphone is connected by wireless to the camera, so I can put my smartphone anywhere I want and watch the image while I'm working. The nice thing about a camera is that things aren't backwards, and in fact with most smartphones and cameras you can flip the image upside down or left to right, so it doesn't matter what orientation you're in. I'm not sure how much the emf from the welding would affect the image, and you'd probably need to put a colored lens in front of the camera to reduce the quantity of light. This is one of those things on my list of things to try when I'm out of other projects.

I've also wondered why they don't just have a video camera on our welding helmets so we're really watching an image of what's going on instead of looking directly at things. It would be so easy to magnify things, change the lighting, etc. Doctors use this kind of technique to do surgery, doesn't seem like it would be that hard to implement the same idea for welding.

When I decided to get more serious with my racecar and add the full cage, I already had a rollbar that was very well made and the hoop fit quite tightly to the body. The prospect of cutting it out, cutting out the thick base plates, then trying to fit it back in and patch it up was daunting so I got a CK microtorch and crossed my fingers. Worst case I decided I'll cut holes in the roof and patch them after. But the microtorch had just enough access. I ripped the mirror off an inspection wand and used a rare earth magnet to pin it against the roof. This was all very McGyver impromptu stuff, if I had to do it again I'd glue the magnet to the back. I eventually got the hang of it pretty well but initially it definitely involved a lot of tungsten grinding when I zigged instead of zagging in the mirror. But, job done is job done.