How to bend aluminum tubing

[Mark W]

I am going to build a blind on the Lind Ducker. Last blind I built worked well but was a lot of work with a lot of moving parts. I want this one to be simple.

I have a tubing bender for the back part of the blind but the front part I want to follow the contour of the boat. How do I bend the tubing to follow the front contour?

Here is a picture of the boat for reference.

 

[Huntindave McCann]

I am going to build a blind on the Lind Ducker. Last blind I built worked well but was a lot of work with a lot of moving parts. I want this one to be simple.

I have a tubing bender for the back part of the blind but the front part I want to follow the contour of the boat. How do I bend the tubing to follow the front contour?

Here is a picture of the boat for reference.

Mark,
Square tubing or round tubing? Square can be rolled as well but takes a different set of dies. If you are bending round;
Better run out and pick up a tubing roller right now at this price, I'm not kidding. This is a heck of a deal. If you have no further use for it after you are done, I bet you could sell it and get 100% return on your cost.



I'm guessing you have a conduit bender? or do you actually have a tubing bender? Either one is a poor choice for creating a large radius bend. Rolling a bend is better suited for creating a large radius. Just an example,

Note the bend can be anywhere in the middle of a straight piece, you don't need to roll the bend in the entire length of said piece.

 

[Mark W]

Mark,
Square tubing or round tubing? Square can be rolled as well but takes a different set of dies. If you are bending round;
Better run out and pick up a tubing roller right now at this price, I'm not kidding. This is a heck of a deal. If you have no further use for it after you are done, I bet you could sell it and get 100% return on your cost.

View attachment 57452

I'm guessing you have a conduit bender? or do you actually have a tubing bender? Either one is a poor choice for creating a large radius bend. Rolling a bend is better suited for creating a large radius. Just an example,

Note the bend can be anywhere in the middle of a straight piece, you don't need to roll the bend in the entire length of said piece.

Round tubing and yes, I have a conduit bender. Thanks for the info.

 

[roy brewington]

I,ve made hoops/gentle curves in conduit for Dodger frames by bending 3/4" emt in a plywood jig. I thought there actually use to be a tutorial on here by someone. If it wasn,t here i,m sure I found it on line.

 

[Ed L.]

Steve Sanford has a tutorial on here somewhere showing his diy jig for bending aluminum hoops for his boats and coffin box.

 

[Mark W]

Steve Sanford has a tutorial on here somewhere showing his diy jig for bending aluminum hoops for his boats and coffin box.

I'll look for it. Thanks. Think if I had a person hold the 1/2" aluminum against the boat that I could stand at the other end I bend it by hand? I have heard of filling the tube with sand and doing so. I like Dave's idea and it is the best way. $150 to make one hoop isn't economical for us retired folks. Been seeing if there is any place around town to rent one.

 

[Steve Sanford]

Good morning, Mark~

Yes, I have bent both conduit and actual tubing made for boat canvas. Filling the tubing with coarse sand (playbox sand) prevents collapse and crimping. I tape the ends once filled.

For you project I would make a jig the follows the curve - but with a couple of inches of "overbend" built in. Lay out the actual curve on a piece of plywood. Then, using a "fair batten" - a length of clear wood or molding, etc - draw the curve nice and fair - which means no hard spots or hollows - but make the overall bend 2 or 3 inches tighter. Fasten blocks every 10 inches or so. I bevel my blocks on the table saw about 15 degrees so the longer edge overhangs the tubing and prevents it from popping up. Each block is about 6 inches long and should be a bit thicker than the tubing. A single deck screw on each block right through the plywood will suffice if the plywood is at least 1/2-inch.

Begin at the end with the tightest radius - which I am guessing is the bow - and work your way toward the straighter end. If you have extra length leave it hanging out on the forward end - and trim later. As I often work alone, I try to control the free end with a length of line, snugging it tighter as I move aft. If you have a helper available it makes the job much easier.

I use Jorgensen wooden clamps for this job - but if you have metal clamps be sure to put a 4-inch block of pine or the like between the clamp pad and the tubing.

If there is still too much "springback" (a little bit is fine) once you remove the tubing from the jig, you can simply move the blocks to get a tighter bend and give it another try.

Hope this helps!

SJS

 

[Dave Diefenderfer]

Similar to what Steve does, I made this jig. I was able to bend the conduit with it, aluminum likely would be easier.

 

[Huntindave McCann]

I was able to bend the conduit with it, aluminum likely would be easier.

Aluminum being easier to bend would be entirely dependent on the specific type (recipe)of aluminum that has been chosen.
Of the grades listed below, I suspect the material Mark is using to be one of these 3 choices; 6061, 6063, or 3003.

Grade 7075 is very common in small diameter tubing and is the hardest to bend for any given diameter.

Grade 6061 is the grade most commonly used and encountered by the home hobbyist/consumer. High strength & good welding. Not good formability - If formed, needs a very gradual radius. This is where the process of "rolling the bend" excels. When something is bent around a jig, the piece goes directly from a straight condition to a bent condition of the desired radius. When the same piece is "roll bent", the radius starts out as a very large radius, putting very little bend /stress into the tubing, during a single pass. Each subsequent time the tubing is passed thur the rollers, the bend radius is reduced, until the desired radius is reached. This process inherently is less stressful to the tubing, reducing the chance of the tube cracking or kinking during the process.

• 7075
  This alloy has a high strength-to-weight ratio and is resistant to corrosion. It's often used in aerospace applications because it can withstand cyclic loading.
  
  
• 6061
  This heat-treatable alloy is lightweight, weldable, and corrosion resistant. Not good formability - If formed, needs a very gradual radius. It's easy to work with and can be cut, bent, drilled, and more.
  
  
• 6063
  This alloy is often used for extrusion and can produce a high quality finish. It's used for structural pipes and tubes, seamless tubing, and heat-sinks.
  
  
• 3003
  This alloy contains a small amount of magnesium, making it up to 20% stronger than pure grade and 2011.
  
  
• 5052
  This alloy has a good strength-to-weight ratio and is easy to machine. It's often used for CNC.
  
  
• 1100
  This alloy is made of pure commercial aluminum and has good electrical and thermal conductivity. It's often used for heat sinks and heat exchange equipment.

Compared to aluminum, mild steels are very tolerant bending and forming. The various grades of aluminum can be a tricky animal.

 

[Mark W]

Thanks everyone for the comments. Hopefull get to this next week.

 

[Dave Diefenderfer]

Aluminum being easier to bend would be entirely dependent on the specific type (recipe)of aluminum that has been chosen.
Of the grades listed below, I suspect the material Mark is using to be one of these 3 choices; 6061, 6063, or 3003.

Grade 7075 is very common in small diameter tubing and is the hardest to bend for any given diameter.

Grade 6061 is the grade most commonly used and encountered by the home hobbyist/consumer. High strength & good welding. Not good formability - If formed, needs a very gradual radius. This is where the process of "rolling the bend" excels. When something is bent around a jig, the piece goes directly from a straight condition to a bent condition of the desired radius. When the same piece is "roll bent", the radius starts out as a very large radius, putting very little bend /stress into the tubing, during a single pass. Each subsequent time the tubing is passed thur the rollers, the bend radius is reduced, until the desired radius is reached. This process inherently is less stressful to the tubing, reducing the chance of the tube cracking or kinking during the process.

• 7075
  This alloy has a high strength-to-weight ratio and is resistant to corrosion. It's often used in aerospace applications because it can withstand cyclic loading.
  
  
• 6061
  This heat-treatable alloy is lightweight, weldable, and corrosion resistant. Not good formability - If formed, needs a very gradual radius. It's easy to work with and can be cut, bent, drilled, and more.
  
  
• 6063
  This alloy is often used for extrusion and can produce a high quality finish. It's used for structural pipes and tubes, seamless tubing, and heat-sinks.
  
  
• 3003
  This alloy contains a small amount of magnesium, making it up to 20% stronger than pure grade and 2011.
  
  
• 5052
  This alloy has a good strength-to-weight ratio and is easy to machine. It's often used for CNC.
  
  
• 1100
  This alloy is made of pure commercial aluminum and has good electrical and thermal conductivity. It's often used for heat sinks and heat exchange equipment.

Compared to aluminum, mild steels are very tolerant bending and forming. The various grades of aluminum can be a tricky animal.

I stand corrected! This site is always teaching me something new.

 

[Steve Sanford]

Aluminum being easier to bend would be entirely dependent on the specific type (recipe)of aluminum that has been chosen.
Of the grades listed below, I suspect the material Mark is using to be one of these 3 choices; 6061, 6063, or 3003.

Grade 7075 is very common in small diameter tubing and is the hardest to bend for any given diameter.

Grade 6061 is the grade most commonly used and encountered by the home hobbyist/consumer. High strength & good welding. Not good formability - If formed, needs a very gradual radius. This is where the process of "rolling the bend" excels. When something is bent around a jig, the piece goes directly from a straight condition to a bent condition of the desired radius. When the same piece is "roll bent", the radius starts out as a very large radius, putting very little bend /stress into the tubing, during a single pass. Each subsequent time the tubing is passed thur the rollers, the bend radius is reduced, until the desired radius is reached. This process inherently is less stressful to the tubing, reducing the chance of the tube cracking or kinking during the process.

• 7075
  This alloy has a high strength-to-weight ratio and is resistant to corrosion. It's often used in aerospace applications because it can withstand cyclic loading.
  
  
• 6061
  This heat-treatable alloy is lightweight, weldable, and corrosion resistant. Not good formability - If formed, needs a very gradual radius. It's easy to work with and can be cut, bent, drilled, and more.
  
  
• 6063
  This alloy is often used for extrusion and can produce a high quality finish. It's used for structural pipes and tubes, seamless tubing, and heat-sinks.
  
  
• 3003
  This alloy contains a small amount of magnesium, making it up to 20% stronger than pure grade and 2011.
  
  
• 5052
  This alloy has a good strength-to-weight ratio and is easy to machine. It's often used for CNC.
  
  
• 1100
  This alloy is made of pure commercial aluminum and has good electrical and thermal conductivity. It's often used for heat sinks and heat exchange equipment.

Compared to aluminum, mild steels are very tolerant bending and forming. The various grades of aluminum can be a tricky animal.

Dave M~

As Mr. Diefenderfer commented, I, too, appreciate the very helpful information in your post - one to print out for future reference!

Thanks very much!

SJS