Congratulations! Your bending is about to get easier, cleaner, and less smelly. Blue Bend is a natural internal support material which is liquid at 300°F and solid at room temperature. It does not require freezing or a controlled ambient room temperature, is reusable, and cleans up with water.

The following is advice on using and preserving your Blue Bend. This is not a comprehensive document and is subject to change. Blue Bend was developed by me, Jacob Medlin, to use in my work building horns and was so good, it seemed irresponsible not to share. Technical advice on using Blue Bend comes from my personal experience as well as feedback from early adopters. There will be some trial and error for you to optimize your results for your application, but hopefully this will help you get there faster.

TLDR:

1. Blue Bend is HOT when in a liquid state. Don’t be dumb.

2. Overheating Blue Bend will ruin it. Develop your heating and pouring method mindfully.

3. The elapsed time from pouring to bending is key!

4. Blue Bend is removed with heat. Any remaining residue dissolves with water.

5. Blue Bend can be reused many times unless it overheats.

6. Store solid Blue Bend in an airtight container.

Warning!

This product is offered in its raw form. In an ideal world, it would be tested for safety and have MSDS sheets to comply with various regulations. Although this is not currently feasible, I take safety very seriously and will do my best to alert you of any dangers; common sense will be required to use this product. Use at your own risk!

Blue Bend is sugar based with natural, non-toxic additives to control the rate of crystallization. It produces very little smoke when heated properly and has almost no odor. However, as with any high temperature compound (even cooking dinner), proper ventilation is a good idea.

In its liquid form, Blue Bend is the consistency of syrup and is bloody hot. At 300°F, drips will cause burns and scarring (ask me how I know). At 300°F Blue Bend does not boil or smoke and so lacks the normal visual cues of high temperature. Use appropriate safety equipment!

Step 1- Heat Blue Bend to pouring temperature.

Heating method

Blue Bend begins to melt at around 250°F and is pourable between 300°F-320°F (hotter= less viscous). Look for a consistency similar to your favorite pancake syrup. The right consistency is important to let any bubbles or air pockets rise to the surface and avoid unsupported voids inside the tube. For smaller diameter tubes (less than half inch) use the higher end of the range. For larger diameters, it’s fine to use a lower temperature.

You can use any heating method and pouring vessel to melt Blue Bend to pouring temperature. My personal technique is to use a borosilicate glass beaker (with a handle) using a microwave.

An example (this is really what I do):

1. Place three 120g blocks into a 500mL beaker

2. Heat in the microwave for 5 minutes at 50% power

3. Check, heat for another 3-4 minutes at 50% power

4. Check, (it’s usually close at this point), stir, heat for 1-2 minutes at 50% power

5. Stir. If done, pour. If not, heat another 1 minute at 50% power

6. Fill tube and then pour the rest into a silicone mold. This is critical when using any glass container. Blue Bend shrinks very slightly when cooling and if a large amount cools in glass, it will break the container when it expands the next time it’s heated.

One customer heats in a pot on an induction plate and reports good success. Another heats in the microwave but with a silicone pot rather than a glass one. There are no wrong answers here.

HOWEVER…

Anyone developing a custom heating process must keep in mind that overheating the Blue Bend is non reversible. Your technique must be sensitive to hot spots and be incremental enough that you can identify the pourable range accurately. So, while heating in a pot on a good quality induction plate is fine, heating on a gas range will likely overheat the bottom layer of Blue Bend and ruin the batch. This is why I don’t recommend a microwave setting higher than 50%. It’s too easy to overshoot the temperature range or cause hot spots.

Overheating-

Blue Bend is a very resilient material and can be recovered and reused EXCEPT when overheated. Inside the stated pouring range, it appears that it can be reused indefinitely. However, once the temperature starts to climb beyond 320°F, the component molecules begin to change and the properties and support capabilities of the solid degrade. Blue Bend regularly overheated will begin to change color to a blue green and start to have a caramel smell. It may still work in this condition, but begins to get brittle and the crystallization timings become less predictable. This change starts around 350°F. If cooled Blue Bend does not harden and has a thick sticky layer on top, it’s ruined and can be safely discarded in the trash. Don’t attempt to salvage it or mix it with fresh Blue Bend, trust me….

Avoiding overheating-

There are two main methods of monitoring temperature during heating:

1. Use a probe thermometer (best)- A high quality probe thermometer can help make sure the Blue Bend stays in the pourable range with minimal overshoot. Make sure your probe is rated for at least 350 degrees. A candy thermometer is too slow to give accurate readings. Remember that heat moves slowly through Blue Bend, so always stir before taking a reading. NOTE: an IR or non contact thermometer will read low by about 10-20 degrees unless the emissivity is calibrated.

2. Visually- There are visual cues to let you know the temperature of Blue Bend. Obviously this is less precise and riskier, but honestly, I have enough experience with the material that I use this method regularly. You are looking for:

   1. Consistency- Pancake syrup. When stirring, the tool (I use a 1/4in wooden dowel) should move easily through the liquid with minimal drag.

   2. Homogeny- One benefit to using glass to melt Blue Bend is the ability to see the point at which the liquid is uniformly melted. There should be no solids below the liquid line.

   3. Surface activity- The surface should not boil, not even close. At 320°F, you will see a line of tiny bubbles (almost more like foam) start to rise around the edges of the liquid line. You will also see the color of the Blue Bend shimmer in spots if you look carefully. At not point in the pourable range will the material create substantial bubbles.

   4. Smell- In the pourable range, the Blue Bend should have very little smell and produce minimal smoke. A significant amount of white smoke or a caramel smell signals overheating. I realize this is not a visual cue.

Step 2- Pour

Stop one end of the tube with anything that is temperature rated for 350°F or so. Some of my favorites are vinyl tube caps, rubber stoppers, and the tops of silicone ice molds for water bottles.

Pour Blue Bend with whatever suits you, either the vessel you heated in, or something else. Always be aware however that as you move Blue Bend around, it will start to cool rapidly. Monitor the temperature as you pour and reheat if necessary to maintain the right pouring consistency.

Blue Bend shrinks very slightly as it cools, anyone familiar with bending using pitch knows this phenomenon. So, while you may fill a tube to the top, if you come back in 10 minutes, you’ll see the level of the material is lower than when you left it. Fill the space with more Blue Bend to the top if desired. At this point in the pour, temperature is not important. As long as the Blue Bend has enough heat to flow, you’re fine to top off a tube.

Step 3- Wait

Any bending support material must hold its shape but break in a controlled, ordered way in order for the tube to bend and maintain roundness. Achieving this balance is key to predicting successful bending and is the main advantage of Blue Bend. Since the crystal matrix develops very slowly, you have control over how much support or how much flex your need to created your desired geometry.

While Blue Bend cools in a few hours, the crystal structure takes much longer. For your first bends, I recommend waiting 8-12 hours for a half inch diameter tube, 12-18 hours for something larger like a trumpet bell.

Once you have a feel for how these initial timing works, you can modify the timing to suit your individual needs. The basic rule is that a longer wait results in a stiffer material.

Some examples:

1. After 8 hours, you bend a tube and notice that the cross section is not as round as you would like. Next time, try adding 2-4 hours to the rest period.

2. You forget about a tube you filled and realize that it’s been 24 hours. You decide to bend anyway and find that the tube is hard to bend and the outside surface finish is very segmented. Next time, reduce the rest period to get more flex in the material.

CAVEAT!

These timings are based on my and others’ observations bending thin wall (.015-.025) brass and nickel silver tube with a soft or mostly soft temper. Your timings will likely need to be adjusted based on your tube parameters (alloy, thickness, temper, etc), as well as your bending technique and tools.

This can be a fiddly thing to have to deal with, but it opens up a lot of possibilities previously not available. I often adjust my timings based on the part I am creating. Large bends need less cross sectional support and I can create bends with good roundness and fantastic surfaces. For tight, technical bending, I use a timing which produces a stiffer bend which may require some extra finish work, but holds a roundness tolerance that wasn’t possible before. Keep an open mind, a good logbook, and your world may open up in ways you didn’t expect!

Step 4- Post bending processing

After bending, Blue Bend comes out easily with heat. As with pouring, the exact technique isn’t critical beyond a few key points.

1. Avoid lingering flames- I melt out Blue Bend with a large soft flame torch and I notice that it takes a while for the material to start moving. I stay patient, move the flame constantly, and occasionally pause with the flame away from the tube to let the heat soak towards the middle of the Blue Bend plug.

2. Heat guns are a pain- A paint strip or heat gun works, but it takes a frustratingly long time. If you are unfamiliar with other bending support fillers like pitch, you might think about using a heat gun for the first few times just to get some experience.

3. Empty onto a mat- Use a silicone baking mat or parchment paper on top of the surface you are emptying onto. This will allow you to easily recover the melted out Blue Bend plug and reuse it.

4. Store recovered Blue Bend in an airtight container. Blue Bend can absorb moisture from the air and cause excess bubbles to form when heating. Don’t spend too much time worrying about this, it’s fairly stable, but don’t store in high humidity areas like the refrigerator, or outside in the Southern summers.

5. Dissolve any residue with water. Soak the tube in water for around 15 minutes to remove any residue left from the heating step. For a faster removal, use warm soapy water. You can also easily clean heating containers, stirring implements, and spills.

Step 5- High five your nearest colleague.

After using Blue Bend, your bent part looks amazing and is perfectly round. Your shop area isn’t covered in spills and it isn’t filled with smoke. Your lungs thank you and you’re happy knowing you won’t be spending the next 3 hours banging out lumps and ripples or using a bunch of rounding rings. So, take a minute to do a dance and have a snack before you move on to the next task.

I hope Blue Bend positively affects your work like it does mine and please let me know of your great success! If you have any trouble, let me know that too, I’m always happy to troubleshoot. I want your bending to be easier and healthier and I’m here to help make that your reality!