Would someone please descibe a "rosette weld"
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In my opinion, a very good book is sold at Lowes, in the tool department near the welding supplies: "Welder’s Handbook" by Richard Finch. The author seems to have significant experience with aircraft welding too. Jim Austin
I have not met Mr. Finch, but I have read his books. He has two, "Welder’s Handbook" and "Performance Welding." He has very strong opinions that are not shared by any of the good welders that I have known. I have seen a great deal of better welding information on this newsgroup. The best books on welding are probably the books that used to be put out by the suppliers of welding gases and equipment. Even those have to be taken with a grain of salt. For a homebuilder there is little reason to use anything but a simple oxy-acetylene setup. You can buy the small Smith torch with a good selection of tips for a little over $200 with gauges from Wicks, Aircraft Spruce, or Wag Aero. There is no better small torch for aircraft type welding of steel and aluminum. MIG welders cost about twice that and are NOT a good way to weld on aircraft unless you are a real master of the technology. It is real easy to lay down a beautiful looking weld bead with MIG that you can peel off the base metal with your fingernails! TIG welding works well on all aircraft applications. However, a suitable TIG welding setup will cost you in the neighborhood of $1000 or so. When I train a TIG welder I always start them with oxy-acetylene. The technique is the same, only the source of the heat is different. With the torch you control your heat by moving the torch closer or farther away. With the TIG you control your heat with a foot pedal. When you weld aluminum with a torch you use a flux to keep oxygen away from the weld. With TIG you purge the area with inert gas. Otherwise it is the same. If you are only going to build a few airplanes save a lot of trouble and learning time and just get a good OA torch like the little Smith. :-) There are only a couple of secrets to gas welding. The first is adjusting the torch. You want just four or five pounds of gas pressure. To adjust the flame you turn on the acetylene first and light it. Then you turn up the gas until the flame starts to lift away from the torch and turn it back down until it is just attached. Then slowly turn up the oxygen until the flame hardens up. You will see the flame turn light blue when there is enough oxygen to burn up all the gas. Look at the small darker blue to white cone that forms right on the opening in the welding tip. It will be a little feathery at the edge. Turn up the oxygen until the feather goes away and you have a clean sharp cone in the center of the flame. Then tweak the oxygen back down until you get just a tiny edge of feather. That is the ideal flame for welding both stainless steel or aluminum. For welding steel just tweak the feather barely away. The torch should be running at a quiet roar. If you do not have enough gas going through the torch it is prone to backfire. If it backfires and burns all the way back to the tanks it will ruin your whole day! 
The second secret of gas welding is the ‘puddle.’ When you apply the torch to the spot you are planning to weld it should be held just far enough away that the little inner cone you used to adjust the torch doesn’t touch the metal. Heat a spot until a small puddle forms. You can add a bit of filler rod to the puddle by holding the end of the rod in the flame above the puddle until a little bit melts off and falls into the puddle. Do not dunk the rod in the puddle, as that will chill your puddle. The puddle will "follow the heat." You can lead it around with the flame. You just lead the puddle along where you want to weld, keeping the puddle full by melting a little bit of filler rod into it once in a while. Just move the puddle evenly along the weld line. The slower you move the puddle the deeper the weld will penetrate. If you keep the puddle in one place for too long it will melt all the way through and make a hole! You don’t wanna do that! If you do make a hole, you can weld it closed. Just weld little pieces of your filler rod along the edges of the hole until it goes away. The best way to learn how to do all that is to take a torch and practice. Clip some coupons ( little squares of sheet metal ) and make a welding bench. I made mine with a frame of angle iron from old bed rails. Get a couple of dozen firebrick at the local brick store. Fit the firebrick into your frame to make a table. You can weld on that table and not stick to it or burn it up! First practice lighting the torch. When you get that down, start making a puddle in the middle of the coupon. Add a little filler to the puddle and move it around for a while. When you start to get some control over that process start welding. Place two coupons side by side and try welding them together. Flow the puddle along the seam. When you get two coupons welded together, put them in a vise and hammer them silly. Try to bend them or break them. If you can bend them and they don’t break you are starting to get this welding stuff down. When they look pretty, bend and don’t break, and you can do this consistently, you are ready to start welding tubing. Weld scraps at first. It is a little trickier when you are welding in a tight corner and everything isn’t flat on the bench. When you get that down to where the welds are pretty and don’t break when you flatten the tubing you are ready to start on your actual airplane! The old pipefitters welding certification test required him to take a length of steel pipe and cut it into segments. Then the segments were welded together into a ball. A hole was drilled and tapped into the ball and a fitting was installed. The ball was pressurized and had to hold pressure for 24 hours. Then the ball was flattened and pressureized again. It had to still hold pressure. Then you were a welder. I took about two days of directed practice before I had my Grandson, who had never welded anything before in his life, doing aircraft quality welding. The tricky part of welding is selecting the rod for the particular metals you are welding. For aluminum use plain soft aluminum rod or wire. For aircraft tubing use a good low spatter mild steel rod. You do not need 4130 rod because the molten metal will pick up enough carbon from the flame to harden. If you use 4130 rod it is easy to get too much carbon into the weld site and embrittle it. Bruce Frank often posts good suggestions here on which rod to use and where to get it. By the way, I am a believer in ‘normalizing’ welds after welding them. 4130 steel is a hardening steel. A draft can cause the area near the weld to harden to the point where it is brittle. "Normalizing" is a process similiar to "tempering" of steel. Heat the entire area affected by the welding heat to a real dull red. You should be just able to see a soft red glow in a rather dark shop. Then let it cool down slowly. That will draw some of the hardness from the area affected by the weld and leave it strong but not brittle. A steel spring is hardened to where it is brittle and then "tempered" down to a "spring temper" so it Practice is the key. Directed practice with someone who KNOWS how is best. — Highflyer Highflight Aviation Services
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To All: Highflyer provided us with a good post on basic welding. We owe him a vote of thanks. In his message he pointed out that the key factor was control of the puddle. Left unspoken was the fact the puddle’s size is a reflection of the metal thickness and the size of your torch, while the color of the molton pool reflects its temperature. (Unspoken because you’ll find that out for yourself quick enough Most of my recent welding students have been geezers like me. A significant difference between geezers and kids just outta boot camp is that most geezers need corrective lenses in their welding goggles in order to see the details of the welding pool. Welding .035 tubing, you’re dealing with a small torch and a tiny pool… you’ve got to get your nose right into it. But a lot of geezers simply can’t see that close-up unless they use corrective lenses. Once they can see what the hell they’re doing, they pick it up as fast as anyone else. Your welding equipment supplier carries a range of corrective lenses that fit all common welding hoods & goggles. If you’ve tried welding and come away with the impression you can’t do it, put on your reading glasses and try it again — ANYONE can learn to weld. -R.S.Hoover
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Good tips. I have used oxy-acetylene since 1970. Their is a MFG, of snowmobile engine tuned exhaust pipes, in Kenosha since 1975. They build them, from making them up with sheet metal by the thousands of pipes a year. Olav, said to me, we have welding salesmen come in here all the time, to give us a demo and try to sell their units. We still use oxy-acetylene, Its still the best. The Smiths units are one of the best. My tip is to buy a unit for your shop. You will be using it for your project and many side jobs, the rest of your life. The only Caution, When you buy it from a private person. Make sure you get his sales papers from him. Many units are stolen. Larry Fitzgerald
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Pete, Your pictures represent the weld very well, but I’ll pick a little nit. A rosette weld gets its name because of its resemblance to the overlapping petals of a rose created by the welding of a fillet around the edge of the hole. The center area of the inner tube may not be covered by the weld. A weld that fuses with the inner tube, fills the hole in the outer tube while incorporating the edges of the outer tube is more accurately called a "plug" weld. A rosette weld is usually done in a larger hole so there is actually room enough to weld a fillet around the circumference. Plug welds are smaller and fill the hole. True rosette fillet welds are stronger but are overkill and plug welds are fully up to the job. Rosette and plug have become completely interchangeable with few but the oldest books making a distinction. I am not giving you a hard time…just one of the pieces of trivia I have accumulated over the years. Bruce A. Frank – Hide quoted text — Show quoted text – or point me to an illustration – Mike Mike, a rosette weld is nothing more than an imitation spot weld. Essentially, instead of using a spot welder, you drill holes in the outer layer and fill it with weld. The illustration shows a rosette joining 2 different diameter pipes on an airframe. http://www.bradroberson.com/images/skybolt/buildpic/splice.html Here’s a better photo – http://users.rcn.com/iclark/images/Jan27_01%207.jpg Good luck. Peter
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Rosette and plug have become completely interchangeable with few but the oldest books making a distinction. I am not giving you a hard time…just one of the pieces of trivia I have accumulated over the years.
To All: It is more than trivia. When associated with a splice it has to do with load distribution. Which is also why the fish-mouth is often curved instead of straight and the rosette is often located asymmetrically. On the original blupe there’s usually a NOTE associated with the joint, "Position As Shown" or whatever. Fifty years later someone does a repair, sticks it together willy-nilly, throws in a couple of plug welds and you end up with a joint that is weaker than the original The point here is that rosette and plug welds ARE different. And for a reason. -R.S.Hoover
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Point well taken! Thanks Bruce. My only real experience with "rosettes" are with non-critical sheet metal work. All I can say at this point is, Michael (original post) is getting his ‘plug’ nickel’s worth. <g – Hide quoted text — Show quoted text – Pete, Your pictures represent the weld very well, but I’ll pick a little nit. A rosette weld gets its name because of its resemblance to the overlapping petals of a rose created by the welding of a fillet around the edge of the hole. The center area of the inner tube may not be covered by the weld. A weld that fuses with the inner tube, fills the hole in the outer tube while incorporating the edges of the outer tube is more accurately called a "plug" weld. A rosette weld is usually done in a larger hole so there is actually room enough to weld a fillet around the circumference. Plug welds are smaller and fill the hole. True rosette fillet welds are stronger but are overkill and plug welds are fully up to the job. Rosette and plug have become completely interchangeable with few but the oldest books making a distinction. I am not giving you a hard time…just one of the pieces of trivia I have accumulated over the years. Bruce A. Frank
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In my opinion, a very good book is sold at Lowes, in the tool department near the welding supplies: "Welder’s Handbook" by Richard Finch. The author seems to have significant experience with aircraft welding too. Jim Austin
Just remember to take Mr Finch with a pinch of salt and you are OK. Some of what he says is "arcane theory" – and a lot is left unsaid. – Hide quoted text — Show quoted text – I certainly am! Care to reference a good bok on oxy welding? – MIke Don’t have any. (don’t have any books on driving either) Any welding supply outlet should have books on basic gas welding techniques and this page will get you in enough trouble to start… http://pratt.edu/~jlee4/classes/OA_Welding_1.htm Peter
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I thought a "rosette" weld was any weld done by a transvestite formerly named
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Ummm…well, I am not sure I would recommend that one as a good teacher. The EAA has some good books on oxy/acet. A really old book that I like is "Metals and How to Weld Them". It was once the standby for welding schools and some military classes. It is primarily aimed at arc welding but gives you a real understanding of what is happening in the welding process. – Hide quoted text — Show quoted text – In my opinion, a very good book is sold at Lowes, in the tool department near the welding supplies: "Welder’s Handbook" by Richard Finch. The author seems to have significant experience with aircraft welding too. Jim Austin I certainly am! Care to reference a good bok on oxy welding? – MIke Don’t have any. (don’t have any books on driving either) Any welding supply outlet should have books on basic gas welding techniques and this page will get you in enough trouble to start… http://pratt.edu/~jlee4/classes/OA_Welding_1.htm Peter
– Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL | Publishing interesting material| | on all aspects of alternative | | engines and homebuilt aircraft.| (-o-)/ AIRCRAFT PROJECTS CO. ___/ Manufacturing parts & pieces / for homebuilt aircraft, 0 0 TIG welding While trying to find the time to finish mine.
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I certainly am! Care to reference a good bok on oxy welding? – MIke
The Oxy-Acetylene Welding Handbook, I think it was put out by Linde Gas. — Highflyer Highflight Aviation Services
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I certainly am! Care to reference a good bok on oxy welding? – MIke – Hide quoted text — Show quoted text – Point well taken! Thanks Bruce. My only real experience with "rosettes" are with non-critical sheet metal work. All I can say at this point is, Michael (original post) is getting his ‘plug’ nickel’s worth. <g
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I certainly am! Care to reference a good bok on oxy welding? – MIke
Don’t have any. (don’t have any books on driving either) Any welding supply outlet should have books on basic gas welding techniques and this page will get you in enough trouble to start… http://pratt.edu/~jlee4/classes/OA_Welding_1.htm Peter
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In my opinion, a very good book is sold at Lowes, in the tool department near the welding supplies: "Welder’s Handbook" by Richard Finch. The author seems to have significant experience with aircraft welding too. Jim Austin – Hide quoted text — Show quoted text – I certainly am! Care to reference a good bok on oxy welding? – MIke Don’t have any. (don’t have any books on driving either) Any welding supply outlet should have books on basic gas welding techniques and this page will get you in enough trouble to start… http://pratt.edu/~jlee4/classes/OA_Welding_1.htm Peter
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In my opinion, a very good book is sold at Lowes, in the tool department near the welding supplies: "Welder’s Handbook" by Richard Finch. The author seems to have significant experience with aircraft welding too.
I bought that book and didn’t think it was worth the paper it was printed on. It doesn’t give enough specifics to be useful to a welder, although it might be good for a newbie who wants to learn the differences between the processes and types of equipment. Finch has a much better book out there called "Performance Welding" in which he goes into enough detail to be really useful and it is my recommendation that you skip over "Welder’s Handbook" and buy "Performance Welding" instead. The EAA also puts out a very informative publication on oxy-acetylene aircraft welding. Del Rawlins- Unofficial Bearhawk FAQ website: http://www.rawlinsbrothers.org/bhfaq/
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or point me to an illustration – Mike
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or point me to an illustration – Mike
Mike, a rosette weld is nothing more than an imitation spot weld. Essentially, instead of using a spot welder, you drill holes in the outer layer and fill it with weld. The illustration shows a rosette joining 2 different diameter pipes on an airframe. http://www.bradroberson.com/images/skybolt/buildpic/splice.html Good luck. Peter
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or point me to an illustration – Mike Mike, a rosette weld is nothing more than an imitation spot weld. Essentially, instead of using a spot welder, you drill holes in the outer layer and fill it with weld. The illustration shows a rosette joining 2 different diameter pipes on an airframe. http://www.bradroberson.com/images/skybolt/buildpic/splice.html
Here’s a better photo – http://users.rcn.com/iclark/images/Jan27_01%207.jpg Good luck. Peter
