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Up Topic Welding Industry / General Welding Discussion / underwater (non-hyperbaric) welding
- - By curtis73 Date 09-09-2005 07:07
My apologies for the amateur post but I need some help. I am a welder, (primarily MIG and arc) an electrician, and a SCUBA diver and someone requested me for a commercial to do underwater welding. The commercial pays well and I haven't given them an answer yet, but thought I would ask first.

The commercial briefly shows someone welding a ship's hull, so accuracy and quality aren't an issue. They just basically need to see someone (me, I guess) striking an arc for the commercial.

Can someone give me enough quick education to strike an arc, or is it way more involved? I know very little about it, but if its something I can strike an ugly arc with your help I'll tell them yes. Thank you for your time.
Parent - - By backpurge (*) Date 09-09-2005 13:14
It ain't quite as simple as just taking the welding kit into the water and striking up.
Used to work at a "wet stick" welding school and the procedure was as follows
Firstly you use suitable electrodes
Welding current is turned off until you have end of rod touching workpiece
You give command to "make it hot" to controller top side who then turns on current, you then strike arc and weld until the electrode is burnt down or you want to stop.
You then give commend to "make it cold" and controller turns off the juice
Parent - - By TimGary (****) Date 09-09-2005 13:33
What happens if you touch the weldment or the rod while it's hot?
Parent - By curtis73 Date 09-09-2005 17:19
My guess is you get a zap.

Thank you very much for the response. Sounds like a little more involved that I can just throw together, huh? Maybe we can do an underwater flare or something.
Parent - - By medicinehawk (**) Date 09-10-2005 08:09
Fair warning: There is a 25% mortality rate for under water welders.....guess that is why it pays so well.
Parent - - By backpurge (*) Date 09-10-2005 09:32
Curtis
You've got it just about right, water and elecrticity don't mix too well. There are also concerns about weld defects at the start if you fire up in the conventional way.
Regarding pay for diver welders, I don't know about your side of the pond but in the UK rates for wet stick welders diving on compressed air are very poor especially when you consider how much it costs to qualify. If you are reasonably skilled you can easily earn more keeping dry.
Parent - By RonG (****) Date 09-11-2005 15:04
Using a DC current at roughly 17- 19 volts.

If you were totally submerged in the water and have a hot stinger in your hand, would you not be only one side of the circuit? And would not the water be a better conductor than your body?

By comparison, standing knee deep in the water with a hot stinger in your hand you would be completing a circuit through your body which by design has to much resistance to push a dangerous amount of current through it.

The results would be shocking to say the least but not deadly. When you establish an Arc and then it all goes away for as long as you maintain the arc.

Been there! Done that many times! Not saying its not dangerous here, but sometimes the danger lies somewhere other than principle. Like driving an automobile at 70 MPH. “Speed Kills” but in truth its recklessness that makes the final stroke.
Parent - By Josephp (**) Date 10-09-2005 11:52
User medicinehawk wrote and posted on 10-Sep-05 at 04:09

"Fair warning: There is a 25% mortality rate for under water welders.....guess that is why it pays so well."

medicinehawk where did You get this figure of 25%?

As wet welding is and has been performed everday by several thousands of people and the "mortality rate" is less than surface dry welding.

"guess that is why it pays so well."

The wage is NOT well, surface dry welding wages are more.

If a Diver/Welder in the GOM{Gulf of Mexico] is making $25.00 per hour, that person is on the high end of the pay scale.

Regards

Joseph

a diver, dockbuilder, rigger and welder

"Equipment Should Never be an Excuse for Poor Performance. If You are Going to be a Professional, You Get the Correct Equipment, then the Only Excuse is Your Ability to Perform." ℠ © ® ™

Parent - - By gndchuck (**) Date 09-25-2005 16:23
For welding underwater if you don't have access to any commercial underwater electrodes, you can use 7014, coat them with beeswax or spray paint. Beeswax works the best, but you'll have to melt the wax and dip the rod in it. Also, you'll want a DC welding machine, straight polarity, set at about 160 amps. Welding progression is downhill. Be sure to put your ground lug on the ships deck and you're in business. We use a 400 amp knife switch, make contact with the metal and call for make it hot, but if you are on scuba, have a rope or cord tied to your BC and use 1 tug for make it "hot" and 2 tugs for make it "cold". Wear rubber dish washer gloves if you're concerned about getting shocked.
Hope this helps and good luck.

Charles Welch
Parent - By gndchuck (**) Date 09-25-2005 16:28
oh, I forgot to mention, you'll want to go about 4 to 8 inches per rod. The best stinger you can use is get a stinger that has a top that you screw down to hold the rod, this will minimize shock. And be sure that if there is any splices in the welding lead to tape them very good with electrical tape. Be safe in your endeaver.

Charles Welch
Parent - By billvanderhoof (****) Date 11-23-2005 06:18
I don't know if you still come by but I stumbled on this which might be helpful.
http://www.thermadyne.com/newsNewProductDetail.asp?div=ta&id=192
Bill
Up Topic Welding Industry / General Welding Discussion / underwater (non-hyperbaric) welding

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