Bending Acrylic

[Soren Christensen]

Hi Guys,

So currently due to Corona, my business havent been able to off its feet (startup), so I have been working on ideas for future projects and prototypes. This has sparked a fire in my girl, who has been spewing out ideas after ideas. However, im a little lost when it comes to bending and forming acrylic.

So without having a huge oven to heat it up, is the next thing a heat gun?

- How do I prevent it to "bend" back?
- How well does acrylic do, as lamp shades?
- How do I join 2 pieces, without getting visible lines in the joints?

last but not least. How do you prevent a cut pattern in acrylic, not to deform when the sheet is heated and bent?


Looking forward to hearing some advice from you pros in here. :)

[Roger Feeley]

Bending: depends on the type of bend. If you just want a right angle, look for a strip heater which is basically a straight heating element mounted in something heat proof. If you want to curve it, you need an oven.
Lamp Shade: fine with leds that don’t make much heat.
Bonding without lines: start with straight polished edges and solvent weld. People do this for aquariums.
Bend back: it’s just a thing. Experiment to find out how much past 90 degrees you have to bend.

[Ian Stewart-Koster]

99% of acrylic work is experience: trial and error and try again. It's cheap enough that you can afford to experiment. A lot!

[Keith Outten]

Be aware that the cost of acrylic has gone up due to the massive numbers of sneeze guards that are being fabricated. My local supplier let me know about the cost increases and lower availability just a couple weeks ago.

[Soren Christensen]

Bending: depends on the type of bend. If you just want a right angle, look for a strip heater which is basically a straight heating element mounted in something heat proof. If you want to curve it, you need an oven.
Lamp Shade: fine with leds that don’t make much heat.
Bonding without lines: start with straight polished edges and solvent weld. People do this for aquariums.
Bend back: it’s just a thing. Experiment to find out how much past 90 degrees you have to bend.

Then I might have to get an oven, just have to find a big enough one, since the normal household ovens arent big enough to fit a a quarter sheet, nor a full sheet of acrylic :(

Any thoughts about the cut out and maintaining the pattern, without it being distorted?

Also another thing.

If I wanted to make a "mold", to curve the acrylic around, after its been heated. Which material, would then be the easiest to make it with?

[Roger Feeley]

remember that acrylic has a memory. Yo can form it and then heat it and it will flatten back out.

it’s been so long for me.. is a sheet 4x8? To heat 2x4’ you would need a metal box with heaters. For just a few parts, you could line up infra-red radiant heaters like they use in hog houses.

I don’t understand your question about cut out.

for just a few parts, you could sculpt plaster. For many parts maybe wood. Are you pressing the plastic over the form by hand?

[Soren Christensen]

remember that acrylic has a memory. Yo can form it and then heat it and it will flatten back out.

it’s been so long for me.. is a sheet 4x8? To heat 2x4’ you would need a metal box with heaters. For just a few parts, you could line up infra-red radiant heaters like they use in hog houses.

I don’t understand your question about cut out.

for just a few parts, you could sculpt plaster. For many parts maybe wood. Are you pressing the plastic over the form by hand?

The sheets im able to get, is 2x4'. :)

Im guessing the way I explain it, it seems like i would need some of machine the press it over the form, but thats way out of my league. It could possible be done with a heatgun perhaps :)

[ChrisA Edwards]

I used to make visors for Honda Goldwings to shade the GPS screen.

I used 1/8" (3mm) thick acrylic. I made a wooden jig for the shape needed before I would bend it.

I rough cut the shape on a bandsaw with a metal work fine blade. I then routed my blanks to the final shape.

I used heat gun to warm the Acrylic before bending. I found it became pliable around 325F.

Once it cooled, it held it's shape.

https://hosting.photobucket.com/images/i452/cedwards874/DSC_9894_700x464.jpg

[Keith Outten]

Occasionally I thermally bend medium size long radius half inch thick solid surface material and once in a blue moon I bend small acrylic jobs. Solid surface material is heated with a heat press. Ninety degree bends in acrylic are a pretty simple process as described above using heat guns and benders. Large curved surfaces require an oven and a male/female mold. Norva Plastics has a commercial bending system large enough to make custom hot tubs and I have spent some time with the owner checking out his system. He owns a truck load of wooden forms and make new ones when the job requires something that is custom. Its a very expensive process.

[Soren Christensen]

Looks nice.

Seems like i need to aquire myself, a heatgun and start testing out :)