Replies

1. 
   xcutsaw | Oct 30, 2007 07:34pm | #1

   You could try clamping the bent piece between two straight cauls.

   I once fixed a bent bicycle wheel rim this way using popsicle sticks and vise-grips :-)

   [Avoid schadenfreude]

2. 
   notatexan | Oct 30, 2007 07:47pm | #2

   For lightweight stuff use your drill press.  Put a couple of blocks on the table and space about the width of the bent area.  Chuck up a big drill bit and put another block between the drill and the bent piece (bend up).  Don't turn on the drill press!!!! (duh)  and gently push down to bend the piece. Trial and error, eyeballing, and spacing the blocks to the bend and you can get pretty close.   For steel you can buy a bottle jack 1.5-20 tons and bend almost anything if you have something to push against.

   Jim  

3. 
   saschafer | Oct 30, 2007 08:06pm | #3

   You generally don't want to use heat to bend aluminum, anyway, as it tends to go from solid to liquid all at once, rather than softening gradually the way that steel does. The good news is that aluminum's relatively low plastic deformation threshold means that it can usually be bent back into place without using heat.

   Can you post a photo of the piece? That may help people come up with ideas.

   -Steve

    

1. 
   forestgirl | Oct 30, 2007 08:30pm | #4

   "You generally don't want to use heat to bend aluminum, ...."  Not trying to bend aluminum, trying to bend steel!  My point was, with the aluminum bracket stuck onto the steel rod, I'd be nervous about applying heat to the steel during a straightening attempt.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

1. 
   saschafer | Oct 30, 2007 08:44pm | #6

   "Not trying to bend aluminum, trying to bend steel!"

   Oh, in that case, don't even think about it. Aluminum melts at a dull red glow (almost invisible in normal lighting conditions). Steel has to be heated to cherry red before it sgnificantly begins to soften. By that time, the aluminum would be long gone.

   -Steve

    

2. 
   forestgirl | Oct 30, 2007 08:31pm | #5

   Will post photo later if need be.  Gotta run to appt. at the moment.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

4. 
   RickL | Oct 30, 2007 08:54pm | #7

   You need to  put a straight edge to see if it's a  slight bend (gradual bow) or a sharp bend. On a gradual bow support it at the ends and push it slightly past being straight and that should get it there. There will be a slight amount of springback. For  a kink or sharp bend it would be supported just before the bend  and again slightly over bent. No heat is necessary.

5. 
   JohnWW | Oct 31, 2007 04:38pm | #8

   Forestgirl,

   RickL's suggestions cover the answer perfectly, heat should not be needed.

   John W.

1. 
   Y1RET | Oct 31, 2007 05:49pm | #10

   Are the two pieces intentionally attached or are they corroded together? We play with cars and bikes when not playing in the wood shop and have discovered when aluminum parts are bolted to steel the will corrode and stick together. It can be very difficult to separate them. Two good examples are aluminum wheels on steel hubs, especially European style wheels with flat hubs and steel spark plugs in aluminum heads. I have bent wheels trying to get them off and ruined a head trying to get the plugs out. Point is once you straighten the steel part you may want to put a dab of anti-seize between the parts before re-reassembling them. You can get a tube of it for a buck or two and any auto parts store. May save you some trouble down the road when you need to take them apart again.    

   <!----><!----> <!---->

   Bob T.

1. 
   forestgirl | Oct 31, 2007 06:04pm | #12

   The are intentionally attached.  There are two pieces, one on the end that's supposed to "stay stuck" and a sliding piece that will only slide as far as the bend, and then stops.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

2. 
   WillGeorge | Nov 02, 2007 05:29pm | #19

   Great post.. Reminds me of me and my wife.. I'd bet she had a tube of that stuff you mentioned!Or was that ...I'd bet she WISHED she had a tube of that stuff you mentioned!

   Edited 11/2/2007 10:30 am by WillGeorge

2. 
   forestgirl | Oct 31, 2007 06:12pm | #13

   Hi, John.  Tried the drill press approach last night, but my DP too whimpy, despite the fact that I only need to move the bar a small fraction.  It appears that the bar is bent in two directions (very, very, very slight in the 2nd direction).  I want to unbend the biggest bend first and see if it is enough to allow full siding of that one part.

   If I could find two heavy pieces of steel (heavy relative to the task at hand) to put this little bar between, could I use a pipe clamp placed right over the bend to squeeze the sandwich and make the bent bar conform to the straight pieces of bread???forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

1. 
   JohnWW | Oct 31, 2007 06:41pm | #14

   Usually all that is needed is to clamp the bar in a sturdy vice and then to gently work it into alignment with a mallet.  You may have to move it to different positions in the vice's jaws to get the bending force in the right place as you go.

   John W.

6. 
   bigfootnampa | Oct 31, 2007 05:22pm | #9

   Your blacksmith's would handle it with ease.  There is no need for any heat for slight restraightening like you are needing.  A couple of swats against the anvil (cold) will get it done.  Even without the aluminum to consider you wouldn't use heat for a job like this... it would lead to over adjustment and you'd have to clean it up again cold anyway.

1. 
   RickL | Oct 31, 2007 05:50pm | #11

   "Turns out one of the bars is bent slightly such that the aluminum bracket is restricted in its adjustment, and thereby prevented from being removed from the square rod."

   If you read the post correctly it calls for finesse instead of brute force. Smacking it on an anvil can distort the bar and it would be even worse off then being bent.

1. 
   bigfootnampa | Nov 01, 2007 03:30pm | #16

   Obviously you are not a blacksmith Rick.  I am.  Your "finesse" is likely to be too wimpy to accomplish the job at hand.  Any decent blacksmith will know just how much force to apply and where and how to apply it.  This is a one minute job, in all likelihood.

1. 
   RickL | Nov 01, 2007 04:28pm | #17

   I do have a  metalsmith  background though. More in the fabrication, machining, casting aspect and have done plenty of metal straightening.

   Edited 11/1/2007 10:34 am ET by RickL

7. 
   WillGeorge | Oct 31, 2007 06:53pm | #15

   I could just tag one of the blacksmiths who do shoeing out at the barn and ask them to fix it, but I'm concerned they wouldn't be careful enough about heating the aluminum.

   I'm MORE THAN SURE that you could sweet talk one of your blacksmiths into being extra careful! I'd assume a good blacksmith knows what aluminum is and be extra careful anyway.

8. 
   Steinmetz | Nov 02, 2007 07:18am | #18

   Those Guys out back are farriers They shoe Horses

   A REAL blacksmith would use a brass or lead hammer to strike the bent areas while positioning the rod (Bar?)over a flat tree stump A little at a time east to west then a little north to south

   He'll check his progress for straightness with a flat straight edge and may have to file off any bumps in the way. (No heat required.) If you liberally apply red or black magic marker to the bent area and slide the aluminum bracket over the bent area, it'll show exactly where to file away the offending high spots. Steinmetz.