mirror welding and window welding

By pipewelder_1999 (****)

Date 09-01-2003 11:40

Heres my opinion

1) Your hands know how to weld on the backside of an object. Use the mirror to make sure you have the correct arc length and that you are getting proper fusion.

2) Make a couple of "Dry runs" 1st. When you do these concentrate on what your hands are doing not what you see in the mirror,

3) Place the mirror so you are welding into the mirror and not away from it.

4) DONT stack a clear lens on top of the mirror to protect it. The Ullman K-2 replacement mirrors are inexpensive and one puddle is always better than 2. When stick welding you may want to throw this suggestion out.

5) Up is up in a mirror and right and left are still right and left. Let your hands weld like they know how to.

6) When Tig welding you may want to reduce your amperage a little to give you more time to adjust. A remote amperage control is great with someone else running it. You can reduce the amperage way down if you get in a bind and reposistion as needed.

7) Practice. As with welding anything, the best thing you can do is practice. You cannot increase your skill by reading. You can only make it easier to increase your skill.

Theres much more to it but thats all I can think of to write down. The main thing is practice. Setup, do it, and repeat as needed.

Window welds are welded just like anything else. Rod angles are a little harder to keep "textbook" but that doesn't stop anything from having a good weld. You may have already seen the sketches but here they are anyway. http://www.weldinginspectionsvcs.com/WindowWelds.htm These are more often used in boilers but sometimes used in piping. The window dimensions can vary depending on the application. Remember to fit the window a little above flush since it will pull in a little.

PRACTICE

Gerald Austin
HTTP://www.weldinginspectionsvcs.com
Iuka Miss

By TRC

Date 09-01-2003 17:43

Window and mirrow (W/M) welding comes in handy when all else fails. Planning is just as important as W/M welding. If your in the building while the fitters are doing their thing talk to them and let them know you are available to bench weld the weld that you may have to W/M weld later. I have seen welders taken advantage of because they could W/M weld. Being able to W/M weld is like having an insurance plan, you have it but hope you never need it.
If this approch fails follow PW1999 instructions because as usual he did an excellent job explaining this difficult task.

See ya- Ted

P.S. my daughter can write backwards so when she has to do a mirrow weld she doesn't know what the fuss is all about- she didn't get that from me!

By JTMcC

Date 09-01-2003 18:57

I have used gold welding lenses as mirrors many times, the large size is neat, the smaller ones have to be used sometimes. You can attach them to a magnet, duct tape them wherever, put them on the end of a automotive style telescoping mirror handle, they are available in any little town with a welding supply, farm supply or parts house. Several large ones allow quite a range of motion before having to stop.
As was mentioned, this is last resort, and often encountered in repair work, but if you have to weld with a mirror on new construction then someone, somewhere, has probably messed up.

JTMcC.

By pipewelder_1999 (****)

Date 09-02-2003 01:19

Never tried that but I'll have to keep it in mind. Ullman devices makes a mag base mirror as seen at http://www.users.ntplx.net/~ullman/ull2.htm#mx that works pretty good.

I haven't mirror welded in a while. I may need to bookmark this page and see what I said :)

Thanks

G Austin

By aircraft (**)

Date 09-02-2003 15:36

I have a couple high polished chrome mirrors, no double image. They work great. They are not easy to find though. If somone knows where to get any I have friends who need to buy some.(they keep borrowing mine).

By FITA Marine Date 09-04-2003 00:06

Aircraft,

By FITA Marine Date 09-04-2003 00:09

Aircraft,
try looking for those mirrors at marine related store, they are often sold as signal mirrors for use in lifeboats, and rafts.
Jerry White

By aircraft (**)

Date 09-04-2003 00:39

thanks

By insp76

Date 09-06-2003 15:58

So you want to be a mirror welder ah, I have done this many times, on the bottom rows of convection boxes ,wall and roof tubes in the radiant sections in heaters and furnaces and weld after weld on boiler repair jobs. My suggestion is to first be a master of welding in the open right handed and left handed before atttempting to mirror weld (for rt quality production welds). I also recommend using gtaw for your process,better control and no speckling of the mirror. The practice method is the key, using a 2" or 3" coupon get use to runnig your root looking through the gap right hand and left hand from one focal point without the mirror.This is how your going to have to run your root in the field and is much easier once you learn how. When you master that it`s time to fill and cap. Start off not yet using the mirror but getting used to welding with the filler rod bent to the OD of the pipe laying in the groove and just walking over it. To further explain:( this is the trick of the trade that not too many welders know about) , bend your rod in a half circle making sure it is tight to the OD of the groove,this gives you one less thing to worry about(feeding rod), it also gets your rod feeding hand out of the way from your sight in the mirror. Practice this until you master it taking note on the heat your running and most important the timing of you movements from side to side and your travel speed. Then set up your coupons in a resritcted jig of some sort reletive to welding expected in the field. Non fusion and tungsten inclusion is your worst enemy. Check each pass before applying the next one and grind if you need to , just like you were in the field. My last suggestion is to not run your machine too cold, this will hirt you more than help you ( NON FUSION) run your normal heat. Gerald has already given you some excellent advice so I nead not go in to any more details. Let us know on your progress and if you need any help , just ask and someone will be glad to help you. Good luck and Have a good one!

By Ken Dougherty (**)

Date 09-09-2003 03:44

Really appreciate the info on this. I tried mirror welding once just to see what it was like. I concluded I would have to have my brain rewired but now I can see there are other alternatives!
Thanks
Ken

By billvanderhoof (****)

Date 09-09-2003 04:31

I had a dentist work on me once who was so used to working in a mirror that he did it even on things he could see directly.
Bill

By ssbn727 (*****)

Date 09-09-2003 23:33

Sometimes, I comb my hair without even using a mirror!!!
(I'm still an UGLY S.O.B.!!!)

To all of the posts regarding mirrors, Have any of you used more than one at the same time to weld? I ask this because, One mirror is a challenge but, two or three??? Well, that's a whole different ballgame!!!

To those of you who mentioned that mirrors are only used to fix mistakes, this is true!!! How else are you gonna fix it - by ripping everything out???? I Do'nt think so!!!! If you're that perfect then, my question to you is: are you human???

Anyway, Interesting thread!!!! Keep-em coming!!!

Respectfully,

SSBN727 Run Silent... Run Deep!!!

By MBlaha

Date 09-10-2003 11:41

Ahhh, yes, the old mirror welding trick. Been a while but have used it on many jobs. There are times when one just cannot get to the last bank of economizer or reheat tubes next to the waterwall. Welding up in the penthouse on headers next to the collector beams is another place. Welding dutchmans in generating banks. On one job in a paper mill on a recovery boiler, we had to take a test that was mirror welding our way out from the center of the generating bank. The contractor set up a replica of the bank by using an old scrapped section of steam and mud drum and we had to weld in 1 foot dutchmans using a mirror. The testing method was RT. I still think it would have been cheaper to just replace the sections of tubes, but the boilermakers came through and we had only 1 rejection on 250 welds. I like someone else in the thread posted, learned to weld these hard to get at places by looking though the root while welding the back side, then capping out with stick using the mirror. Try this on tubes when you have easy access to them. The hands on practice is invaluable and will make it easier when you need to do it. Make sure you have a clean sharp tungsten. Keeping a nice sliver gap helped imensly. Bending the wire to the circumference of the tube is an invaluable trick. Even when welding water wall tubes, I would bend the wire around the tube. I never really had a problem using the mirror to weld. The problem as goofy as this may sound, was getting my hands to move the correct way when not using the mirror after using it.

Good luck and practice, practice, practice

Mike

By ssbn727 (*****)

Date 09-10-2003 22:11

That's why I comb my hair and brush my teeth without a mirror, because I've got a reputation to keep up as being really UGLY!!!

After all. if I used a mirror then, I would lose my rep!

BTW, Mike! I remember those infamous locations that you mentioned, and you hit hit it right on the nail brother!!! Good to read from some other mirror welders!!!!

Respectfully,

SSBN727 Run Silent... Run Deep!!!