Bending acrylic...

[matta757]

Hey all,

I am about to go show some acrylic sheets who's boss with a heat gun and was wondering if anyone has any last tips? I read jack's topic about it, but had a few questions I wanted to ask:

Keep in mind, I have my acrylic sheets screwed onto my molds at one end to start.

1) When the sheets are warm enough to start bending, should I be using some sort of tool to form them to my mold or can I just use my hands to bend them? Will they be too hot for me to touch?

2) Is it best to warm the whole sheet then bend or should I be warming bit by bit while working my way up?

Any last minute advice would be great!

Regards,
Matt

[shaneb]

Hey Matt,

You will need gloves to protect from heat at a minimum.  I bent a piece of plexi recently and was able to bend and shape with my hands . .keep in mind this was a  3 1/2 in x 7 inch piece of plexi and was simply bending it over a piece of 3 inch pvc pipe to get a contour.   I worked slowly from side to side to get to the correct shape.  Also watch the amount of heat,  plexi will develop bubbles in the surface, not sure if arcrylic will do the same.    Hope this helps, maybe someone else will have more experience with arcrylic.

[matta757]

Hey Shane,

Thanks for the tip. What type of gloves did you use? Also, and correct me if I am wrong anyone, but I believe that Plexiglass is a brand name and that it is the same thing as acrylic, so your tips should be great!

Thanks,

Matt

[autocadplease]

These videos might be helpful http://www.tapplastics.com/info/video.php

[shaneb]

Hey Matt,

I think you are right . . just different types such as extruded or cast.  I used welding gloves that I had laying around.  I used a heat gun to heat the piece I was working with . . of course it was a smaller piece.   

[jackpilot]

The key is going real slow and keeping the heat gun at a distance .
I would avoid gloves contact and use a clean block of wood
Go slow, takes time.
Try on a sample first

Fun to do anyway...
Jack

[shaneb]

Hey Matt,

Jack mentioned a good point and my post after reading would lead you to think I "molded by hand"  I used the gloves to protect from heat generated to the round pvc I was using as a form.   I heated the plexi while it was secured to the pvc pipe, after heating, I gently and slowly bent the plexi by pushing down on the edges , then rolled the pvc pipe over a smooth metal surface . . slowly the plexi bent to the contour of the pvc pipe.

[matta757]

Hey guys,

Thanks for all the tips. Been working on and off all day, and needless to say, skinning the beast (as jack would say) is certainly a labor of love. Man this takes time and my shoulder is sore! Back to the grind either tonight or tomorrow morning. Despite all the intense labor, I am LOVING what I am seeing thus far. Updates to come.

Pics to follow...

Matt

[matta757]

Alright all... need some council...

how hot should my heat gun be able to get? I have been using my grandpa's old one, which only reaches 700F, but i see that new ones reach upwards of 1000F... should i be using a hotter gun?

i ask because it feels like this is taking forever and a day...

advice?

thanks,
matt

[phil744]

Hey Matt the hot air gun I use goes up to 700 degrees C about 1300 degrees F

One thing I do is boil whatever you plan on bending in water first this gets the bulk of the heating work done first and means its heated more uniformly, quick wipe dry then blast with hot air gun only for a minuet or two per side then bend.

One thing to bear in mind most guns have thermal overloads built into them, u get the nozzle to close and the gun thinks its overheating so shuts off the heating elements, but you would never know, still feels like its blasting hot air when really your cooling the job down, mine do that

For making curved lightplates i use something called an HFJ tool, stands for "happy face jig " (yes i have to keep myself amused somehow)basically slide it open, drop in the hot but still straight lightplate close it up quickley that formes it straight, shove a screwdriver through the hole in the middle to lock it into place, once cooled u have curved lightplate that one does the 767 flaps lightplate, i have different ones per TQ

Smile 

[matta757]

phil,

thanks for the GREAT info... i love the boiling water idea, now just gotta find a pan big enough!

also, i GOTTA GET ME one of the HFJs! what an amazing idea... that's been the hardest part... getting it to bend and stay night and straight. but given how important the TQ is to my 757/767 setup, I need to find a way and this might be it!

btw... when am i gonna be able to get a 767 MCP from you?!

Matt

[ETomlin]

Hey Matt the hot air gun I use goes up to 700 degrees C about 1300 degrees F

One thing I do is boil whatever you plan on bending in water first this gets the bulk of the heating work done first and means its heated more uniformly, quick wipe dry then blast with hot air gun only for a minuet or two per side then bend.

One thing to bear in mind most guns have thermal overloads built into them, u get the nozzle to close and the gun thinks its overheating so shuts off the heating elements, but you would never know, still feels like its blasting hot air when really your cooling the job down, mine do that

For making curved lightplates i use something called an HFJ tool, stands for "happy face jig " (yes i have to keep myself amused somehow)basically slide it open, drop in the hot but still straight lightplate close it up quickley that formes it straight, shove a screwdriver through the hole in the middle to lock it into place, once cooled u have curved lightplate that one does the 767 flaps lightplate, i have different ones per TQ

Smile 

Incredible tool there Phil. I love the idea and will probably build myself one for a similar part I need. I was staring intently at this photo and realized that your image of taking the photo was in the reflection of the part.