any first-hand experience with underwater welding?
406320
most underwater welding is a patch type repair..you use electric arc welding but it cools too quickly and is not as strong as a surface weld. i attended "the ocean corpation"\ncommerical diving school in houston in 1976. underwater cutting is much easier...experience is the best teacher. all these schools do is acquait you will enough info to keep you alive until you learn...
555540
Not sure about using "welding rod", but I know you can spot weld and ultrasonically weld Polystyrene to Polystyrene quite well.  There is "General Purpose" and "Rubber Modified" Polystyrene.  The rubber modified is easier for spot welding, swaging and staking, so I'd assume is easier for other methods of welding.  If you use welding rod, it would need to be Polystyrene (You may get some bonding with Polycarbonate as well).  Haven't seen welding rod in either of these materials though....  maybe someone else has??
832984
Open it fully (not hard) and back off 1/4 to 1/2 half turn. No more or you may cause turbulence in the 1 st stage (heat it doesn't need) and potentially causing condensation in there. Not a good thing for the reg and definitely bad news if you're diving a normal reg and even an environmental, in freezing conditions. It can also cause a possible a supply issue at depth, when you need it most. Leaving it fully open, could cause the valve to stick, making detaching the 1 st stage a vexing experience to say the least.\n It is part of the course, you may have just missed it. I've seen Instructors whip through that part mumbling.\n\nEdit: I disagree with Don on the fully open part regarding overheads etc. So NOT true nor taught in any wreck course or technical diving course. You ARE taught to know your manifold without the need to think. If indeed you do start to turn it the wrong way, the little it has been shut is an immediate indicator. Also, when it's backed off just that little bit from open full, it has NO impact on supply or smoothness of flow to the 1st stage.\n\n Edit: Yup, ask your buddies, they'll agree. As for the fella that answered last...well I guess he's never seen one occur nor read even the OW manual from PADI ( I dug it out, it's in there.). It DOES happen. Just like that outdoor tap that you opened too far and need a wrench to close.\n Due to the amount of dive related questions that are popping up, this evening during a social at the local pub, I asked a pal of mine that owns a 5 star Padi to join under his shop's name. A number of years ago, this man saved my life on a wreck dive, and he's about to become a PADI Director. That's about as high as you get in that particular org as well as standing in my book. I'm not an instructor ( I got bugged again to do the course tonight for free), hence my reluctance to put the word of "god" into some of my answers here. Mine is strictly advice and experience.\n He can. Hopefully he'll join.\n If you're curious, his shop's web site is www.coltcreekdiving.com\n heck, I think there may be a pic or two of me in there too.
708172
I have suffered a lot of red-eyes and watery-eyes days during my technical training period while practicing 'Electric Arc Welding' exercises. Although our Swiss instructors adequately informed about the danger of even few seconds of 'accidental' exposure to the sparks from the welding with back up theoretical details, more than half of the students had to suffer anyway! We later saw the same thing repeating in almost all the following batch of trainees and thought that this may be the price you pay for learning this typical task (LOL). However, please read the following excerpt: \n\nAlthough UV and IR light is invisible to the human eye, it nonetheless can have dangerous effects. UV light can damage the eyes in several ways. Excessive exposure to the lowest wavelengths of UV light, also called UV-C (180-290 nm), can cause damage to the cornea as well as the lens. These wavelengths are not common in nature, since they are absorbed by the atmosphere, but are present in some industrial environments, such as electric arc welding. \n\nWelding shades: There are a number of options for welding applications, all of which require shaded lenses to match with the intensity of the electric arc current in use. Attention must be paid to the welding equipment manufacturer's recommendation for weld shade and level of protection required. Welding without the proper precautions can be hazardous, so special care must be given to the type of coverage selected, ranging from safety glasses to face shields to welding hoods and full suits. \n\nBe sure not only to choose the right equipment for a specific application, but also pay close attention to fit as well as function. The right equipment poorly fitted is a significant cause of eye injuries.
1123131
There is NO WAY you can do an adequate repair in the water...and you are in immanent danger of having the whole deal come off if you can feel cavitation. I'm surprised you don't mention leaking around the bolts as well.\n\nI just finished doing keel boat replacements on a Columbia 50 and it was a bear.........bolts rusted off inside, rusted solid outside.......torches, wrenches, drill bits, sweat blood and tears...ballast keel had flange at the top that the bolts passed through...we needed to take the keel off after we got the old bolts out and re-bed it before putting new bolts in.....but you have to do it cause you may lose the whole boat in heartbeat..\n\nThe u-channel inside idea is almost right...you'd have to drill down into the ballast keel, tap the hole, and then try drawing several thousand pounds up tight with machine screws ( lags are too coarse threaded to work)....this would be a lot easier with the boat out of the water and sitting on the keel and the ocean not pouring in.\n\nWhile you're at it with Columbia, check the mast step and see whats holding it...and the mast and the whole rig....in place. Be prepared to be shocked and amazed.......
363584
Most US Navy subs can do at least 40 MPH submerged. I don't think you could hang on, even if you could survive the impact. And they have a little thing called sonar which keeps people from being able to sneak up on them unobserved. The sonar puts out pulses that can travel a hundred miles and return, they are pretty powerful. Used in 'antipersonnel mode', it would be like getting hit with a sledgehammer.\n\nWhat you need is a 'density shunt', a powered suit of armor of material MUCH denser than water (and you), like osmium. It is a rare metal, so this would be expensive. But in theory, with an osmium diving suit, the sonar pulses would travel through the suit, around you,and would affect you much less than if you were in contact with the water. \n\nTo get hold of the sub, instead of suction cups, I'd recommend a grappling hook with a cable, loop the cable around the conning tower. They'd have to have guys come out and physically cut the cable before they could get rid of you. \n\nWatch out for those SEALS, though. You might need to use some exploding harpoons from a CO2 powered spear gun to keep them from stopping you.... uh, just what is it you were planning anyhow...? Nothing bad, right, I mean, you're a loyal American, aren't you...? I hope I didn't just give away the weaknesses of the Navy. Listen, don't tell this to anybody else, OK?
1012954
Attach the earth cable of the welding machine to the ship's hull, and attach the job you are welding also to the ship's hull. The current will flow through the steel structure of the hull.\nOtherwise you can attach the earth cable of the welding machine directly to the job you are welding, if they are close together.
369019
You can check your local welding supplier, or check online for welding supplies.  eBay might even have them available.
251057
My crawl is not that well, so I use that technique all the time. If you are well trained in it it is as easy as any other technique. I used it in open sea and have no problem with it. Ofcourse in a rough sea any technique is harder. Good luck.
353821
Hi - I came across your insurance question and tried to email you.....also about the diving but they said your email has been 'unconfirmed' so my email wouldn't go through....you may want to check this out.  You may have to go into the email address you generated for this and acknowledge their link to confirm it so you can get emails.\n\nSo...I'm copying the email here:\n\nI don't know if this will help you at all....but at least you will have coverage...if it works.\n\n\nMy idea....if the house hasn't sold yet.  Tell the insurance company that you moved and that it is being rented.  If they need a copy of a lease... you can pick them up at any office max for $10.00.  Fake a signature...or better yet..if you have family or friends still by your old house see if they will sign the lease..just in case they need id's.  Had to do this after father-in-law passed away.  It worked.\n\nGood luck...I know it's a pain in the butt.\n\np.s.  I'm a scuba diver....but never been to N.C. to dive.  My favorite place is Curacao.  If you ever go there diving....let me know and I will tell you the best spot to stay...where you just walk down 27 steps with your gear straight into the ocean...great for new and experienced divers.  Gradually slopes from 5 feet to 200 feet.  Has overhanding cliffs to dive under and excellent for underwater photos.  Happy bubbles!!
300753
Aircraft structure requires a fail-safe approach to design which is difficult to obtain using fusion welding however welding is used in certain areas such as ducting.\nBest I can do with one sentence.
7409
Hi my freund.\nTIG is one of the method of fusion arc welding which its exat name is GTAW(Gas Tungestan Arc Welding)and contain a tungestune electrode and some sheilding gas such as Argon and Helium .\nI dont know how much information do you want.If you need more you cam mail to me by this address:\nmostafahedayati@yahoo.com to answer more accurately.\nGood luck
1157570
Welding rods are usually sold in air tight containers. Once they are open, the coating will tend to absorb moisture. Any procedure that will exclude atomspheric moisture is okay. \n\nI have seen jobs where they used an old refrigerator with a couple of 100 watts light bulbs inside to maintain some warmth.
8554
Well stillerfanz,\nAs an ex welder/HVAC tech and now an Inspector, I don't trust the Victaulic. Even though you groove properly and torque per procedure I would say:\n1) Victaulic quick, easy, and cheap Install or Fix.\nQuick if future change or repair needed,\nBelieve continuous torque should be rechecked because of machinery vibrations. \nMight lose the competitive edge because of rework. Leaks always possible.\n2) Weld more permanent and stable in regard to environment and conditions.\nDoesn't need continuous Inspection. \nLeaks unlikely\nHarder to perform change or rework.\nRegardless, both should recieve Base Line Inspection and Periodic Review.\nI am assuming you mean strictly Commercial/Industrial Installations.
647325
self contained underwater breathing apparatus
295433
Not sure if this is what you're looking for.\n\nhttp://www.weldracing.com
1163179
Sorry to answer your question with a question, but are you designing a submersible pump?  And if so, what have you done so far?