HELP! J-rail tipping

Thanks for advice. Holes are already pre-drilled. I think he needs to shape it first before he puts it on the trailer. Will try that. I wondered if he had the wrong size/style of screws or was tightening screws too tight. Just brain storming.
What exactly are the stretchers? Thanks again!
Erin

Another thing that helps (but is a huge PAIN) is heating or 'annealing' the aluminum. I've not had as much luck with new J rail sold in RV shops. We straighten the old and re-use it. Most can be made to look like new. From what I understand, the teardrop place sells softer J rail. They call it drip rail.

www.socalteardrops.com/parts.php?cid=2&pid=28

Great tip N2hicky!

Nicky
Thanks so much! Great tip

YES!!!!!  

Somebody finely gets it!  It's called "metal shaping".

First, Rain Rail, "J" rail, and Drip Rail is all exactly the same thing with different names.  It might look different if it's made by different companies.  It's just soft aluminum that has been formed to shape.  It comes in 16' sections, and is NOT cheap to ship due to the size.  It sells for about $2/foot, or $25 to $30 a stick.  Any "local" RV parts store can obtain it from their normal wholesale suppliers, but they choose to not stock it because it's very easily damaged and would be hard to make a profit.  You do not want to order it "on line" because it has to be cut down to 96" to comply with UPS and FedEx shipping sizes.  You want to have long smooth pieces (easier to bend), NOT a bunch of extra end seams.  It usually takes three, 16' pieces to do a small canned ham trailer.  Two to do the left side, and one (with a awning rail" to do the right side.  It's much easier to use new soft, not old oxidized metal, and to polish it "before" you shape it to your trailer.  Use 1" #8 Pan Head "stainless screws" to attach.  Do not use the self taping flat head sheet metal screws in the above photos.  They are not long enough, and do not have a nice deep thread.  Buy you screws by the hundred.  You usually get a bulk discount, and they run about 9 cents each.   

Note: You can buy rain rail when you place your RV skin order from my sponsor at Hemet Valley RV.  Steve sells rain rail, but no longer sells awning rail.  The biggest advantage is "will calling" or "shipping" the rails when you obtain you new skins for freight savings.

Since the rail is made of very thin, and very soft aluminum you will find that it tears "if you use the internet method, of Screw, Bend, Screw, Bend.......".  In my annual VCT Boot Camp class on Metal Shaping, I teach the method of pre-bending the rails using wood templets.  One property you have to understand about bending metal is called "spring back".  I would guess the percentage of spring back on aluminum is close to 15-20%.  Because the metal springs back, you cannot just cut out a single templet the shape of the trailer to bend your rails.  All you need is some different radius bends, start at the top, make some reference points on the trailer and the rail so you come back to the same point each time.  Then work your way down.  Hold the radius up to the curve, mark what part of the radius you want, then bring it down to the work table and make that part of the bend.   It's easier to demonstrate, harder to explain the method.  You can shape the rain rails down to about a 12" radius (without tears) with this templet method.

Shrinkers/Stretchers.  I use the Lancaster (USA made) brand in my class.  They are the original quality made product that Harbor Freight copied.  You do not need to buy these advanced metal shaping tools to just shape soft rain rail.   I use them to show how my students can form 3/4", 1", and 1 1/2" by 1/16" aluminum angle into curved shapes like is used on round window and fender lip trims. 

Annealing is very easy to do, you can find lots of information on the net.  First, it's not needed to bend rain rail, if you use the templet method.  I teach annealing mainly for bending extruded awning rail.  The thicker extrusion is "much more difficult" to shape and it helps to soften the metal hardness before you begin.  I use an acetylene torch.  I first coat the working piece with carbon soot (you could use a candle, or even the felt marker ink), then I slowly heat the metal to burn off the soot.  At precisely the point the soot burns off, the metal is hot enough to change hardness, and you have to STOP heating the metal because it will melt.  Again, this is necessary for bending new/or re-bending old extruded awning rails.  Not necessary for bending rain rails unless they are really old.

Work Hardening.......Have you ever tried to bend a new 3/8" copper tube, and tried to bend a fifty year old 3/8" copper tube?  BIG difference correct.  The new tube is soft and easy to bend, the old tubing is very hard and stiff to bend.  The inside diameter, the outside, and the wall thickness are all  exactly the same.  So what's the difference?  Metal work hardens, the metal becomes harder.  This can happen in fifty years of heating/cooling cycles.  It can also happen due to shaping like happens during the extrusion process.  You can reverse the hardening by using the annealing step.  You will know when it's needed because the metal will not easily bend.

Class over, 
John