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Bein' as the three of us do a lot of stuff with torches, I gotta questionYou know I heat shrink a lot. But I think I have met my match.My little rosebud is whimpy whimpy whimpy compared to what I have to doI had some clown hang his tractor off the back end of my hay trailer by putting too much down pressure on his loader while loading hay. (First time anyone other than myself has ever loaded this trailer, and consequently why it's as good as the day I bought it, or was) The dumbazz actually had the front of the tractor off the ground, and lifted the rear of the truck the trailer was attached to with the leverageTo make a long story short, the back 10 feet of the trailer was bent downwards around 3", maybe less, maybe more, haven't had time to measure the damage.The main frame of the trailer is either 10 or 12" schedule 40 pipe. Didn't get around to measuring it either, but it looks around that dia.The plan is to lift the rear of the trailer to put upward stress on the pipe, and heat shrink the top portion of the pipe to bring it back into line.I've looked at some of the high BTU propane burner/torches like you built a while back. Will something like this put out enough heat to do the job? I'm looking at heating a 3" wide band across the top half of the diameter of the pipe, then either letting it air cool, or misting it.THIS ISN'T SOMETHING MOST FOLKS SHOULD TRY UNLESS YOU'RE FAMILIAR WITH HEAT SHRINKING. DISASTER CAN RESULTThe mission, should you accept it, is to make an educated guess at the BTU output required for the job.Heat reqirements...............By my reckoning, I want to heat to the crossover point from bluish white to red (in the shade, or with good cutting glasses on). I don't want bright red, or even get close to plastic form. Just enough to get good shrinkage when cooled. The idea ain't to melt it, just get it to the point where I can smoodgie it (high tech metalworking terminology). I think you understand what I'm talking about better than most. Don't wanna melt it, just gently heat it to the right temp.I figure either you, or JS oughta know(sorry, it is definitely not a plasmatic thing)"Any day above ground is a good day"http://www.farmersamm.com/
Reply:I just strainghtened the front tilt arm off a 624 JD loader yesterday, 1 1/8" plate that I had to heat to a dull red so we could pull it back into place. Took me 20 minutes to heat a 3" x 16" area using a large propane rosebud. Not sure of the size as I've never had a reason to look but the head is roughly 1 1/4" diameter. Used over 1/2 a bottle of oxygen, never made a dent in a 100lb bottle of propane......Mike
Reply:Sounds like it's bent too far for shrink alone to pull it back far enough.Also, I think you'll have to heat with Oxy-fuel to get the needed concentrated heat input.Good Luck
Reply:Why not take a slicer wheel in a grinder and cut the pipe from the bottom up untill they will bend back a little past straight then reweld the pipes? If I understand right every thing that is welded will be in compression when the trailer is loaded.
Reply:Samm, if it's only 3" down over ten feet, it should come back, assuming it is a gradual bend.Put the trailer frame on blocks, if you can add a little fire-proof weight, all the better.I'd eyeball the trailer, first picking out the center of the bent area, mark it, then the very beginning and ends of the bent area. Mark off equal segments, for places to heat, how many places to heat is kind of a judgement call. When you heat, only a strip maybe one or two inches wide, across the pipe, starting on top, working down on both sides to about the halfway point. Ideally, your heat band, should be slightly wider on top, tapering down as you go down the sides. Dull red is good enough. I generally start on the ends, working to the middle, switching from side to side. DON'T go back and reheat a part you've already done. Let everything completely cool, eyeball it again. Note the difference between what you had at the start, and what you have now. Again, if it needs more, it's a judgement call, you start a new round of heating, between your original spots.You are not trying to treat the whole bent section of pipe, you are only shrinking small sections, maybe one or two feet apart, the end result will be a straight-appearing pipe. Also realize, straightening pipe is considerably more difficult than doing I-beams or something, due to the shape. As you start heating, the arch will actually start getting worse, because the initial heating expands the metal where you heat, shrinkage only happens as it starts cooling off.Oxy-acetylene or oxy-propane will be needed.Before using the heat, since this is gradual enough of a bend, consider flipping the trailer over, block it up in the center, park your truck or a tractor on the tongue (to hold it down), and push down on the back end, very carefully, with your loader bucket. Move the blocks in the center, as necessary, where they need to be in order to put the force where you want it. It's worth trying, and it will be cheaper and faster if it works.Last edited by jsfab; 11-24-2009 at 10:31 AM.
Reply:Big or small rosebud doesn't matter, all heat spots don't have to be red at the same time. EACH, individual, heat spot should shrink several thousandths of an inch, the cumulative result should be a straight appearing pipe. If you need more movement, you heat more spots, not more heat on the same spot.I can put a two inch arch, into a decent 28 1/2 foot flatbed trailer (size they use for doubles), only having to heat the bottom flange three places on each side, and end up with no discernable kinks.Big rosebud, will just make the job go faster.
Reply:SammI read your first post too quick, didn't catch the bit about 10" or 12" pipe. For some reason, I was thinking two rails, 4" pipe or so. It's still doable, just harder than I made it sound, and yes, you might need a bigger rosebud.I know you've posted up pics of that trailer before, can you post up again?
Reply:I've loaded a few bales of hay. We've always used flatbeds, but uh... please tell me this was just a case of an inexperianced operator. A really inexperianced operator.Had a neighbor that straightened the tailgate on his pickup by driving his tractor over it!Ranger 250 GXTSmith Gas Axe
Reply:JS, Unloaded the trailer, and took it back for another load, and the guy saw the bend immediateley. We came to an agreement. I jumped off the deep end initially, which I have a bad tendancy to do. He was decent, and concerned about the damage. And he saw the bend without getting off his gator. Guy is up in his 70's and doesn't get around too good. I gotta quit runnin' people down before I give them a chance.I'll do the work, and he'll pay for larger heating equipment, if it's reasonable. Otherwise we bid it out to a shop.I fogot about spot heating Used it to my advantage when I built my loader, and had to shrink large areas of 3/16 plate. Heat dots around 2-3" apart over the width of the plate (12" wide at places)We sighted the bend, and put a straight edge on it, and it is gradual. Definite starting point just behind the axles, and sloping towards the rear. What you'd expect. I own a 125cf Acetylene bottle, and a larger rosebud than what I have (about 3/4" dia, 5 holes) would probably draw more gas than the bottle can handle. So I'm thinking propane?Trailer weighs around 3500 empty, and I figure lifting at the rear will put enough force on the pipe to do something when the bent areas are heated and cooled. If not, I can load the front portion of the trailer to give more ballast when it's lifted. The design of the trailer concentrates the load over a very small area (see pics)I think, as you do, gentle movement is the thing. Don't try to do it all at once. Been there, done that, and overbent stuff.Your sorely missed at the home 20. NOthing is not doable, it's just a matter of coming up with a plan.Pic one...........the main structural member is pipePic two........how it's loaded (me loading it), It is a good design, but has it's weak points. The trailer will take a heavy load of hay, but it isn't designed like a flatbed trailer. You have to be careful when loading in order not to put excessive down pressure on it(like the full weight of the front end of a 7000lb tractor). It's a compromise, but one helluva good working design. We, here in the good ol' USA, do have good minds!! Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Mike...........the propane thing.......what's involved to set up regulators, tips, and mixer, to handle propane?"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Samm; I've known people who have made air-aspirated weed burners and used a large needle valve to control the propane flow. The pressure-stability thing isn't a problem with propane, just uniform delivery. Using it fast will tend to cool the cylinder and reduce the pressure but that isn't exactly critical. Scrounge a fitting for the propane tank from a discarded barbecue and drill out the tiny hole in it somewhat, to where it serves as a flow-restrictor to give you the flame you want.
Reply:Mike...........the propane thing.......what's involved to set up regulators, tips, and mixer, to handle propane?
Reply:Originally Posted by farmersammI fogot about spot heating
Reply:can you put blocks under the rear and a forward point and use a loader to apply down pressure in the middle ?
Reply:Thanks Joe.I've been doing stingers for years, but on TOP of the steel. I never thought to grind a groove/bevelIt worked, but had to do about a million passes, grind them off , and do it all over again to get the right shrinkage.You guys that do this part time, myself included..........YOU JUST GOT AN EYE OPENER. I KNOW I DID!!!!!!!!!!I got a lifetime worth of experience in a few short simple sentences. It makes sense, and you know it if you've been around the iron for any time at all. I couldn't see the forest for the trees.This could of all been PM'd, but it wasn't. Y'all got some very serious discussion, and thought out advice. Read it!!Joe, Mike.................. THANKS.I wouldn't have put this crap up if I didn't need help.Still in the middle of the hay haul, and have some other crap to do, but the work will be posted for everybody to see.Side note...............Wayne, down at the supply, is gonna put together a heating torch (propane) with a new tip, and a used handle, to keep the cost around 100 bucks, and he's gonna loan me (forever) a 30lb propane bottle. The only issue is the valve on the bottle, and whether it can be legally refilled, but we are gonna work that out. Wayne is a good dude too.This being the begining of the holidays, and me being a sort of grouchy SOB, I feel really good about people right now. Very unusual for me."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Happy thanksgiving axxholes"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by farmersammHappy thanksgiving axxholes
Reply:You too Sandy"Any day above ground is a good day"http://www.farmersamm.com/
Reply:....and me being a sort of grouchy SOB
Reply:I've never done any heat shrinking(besides the plastic stuff over electrical connections, not quit the same!) but I think it's cool that you can use welding to "bend" metal. Might have to get some scrap metal and try some things out. I know I get worpage when welding but must be a great skill to be able to control the heat and warp the metal how you want to! Good post Sam and glad it worked out.
Reply:Sam Is that a red rhino trailer? i just got one this summer and love it> I will have to watch my loaders carefully though. thanks for the heads up
Reply:Originally Posted by retiredIWSam Is that a red rhino trailer? i just got one this summer and love it> I will have to watch my loaders carefully though. thanks for the heads up
Reply:Supper waiting to be cooked.Couple of pics..................the offending tractorand gotta 590,000 BTU propane rosebud in the little fat brown truck headed this way. So anyway that's what they tell me. Probably melt the whole stinkin' trailer Never used one like it, so it ought to be a hoot Attached Images"Any day above ground is a good day"http://www.farmersamm.com/ |
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发表于 2021-9-1 00:02:06