Bending plastic for trim curves

[NOBLNG]

On 4/30/2021 at 7:50 AM, Len Woodruff said:

The problem is I need to use 1/2 round and the curve has to follow the body. What I might so is tape it to the resin body then use the solvent glue to break the bend tension. 

That is when it usually snaps for me. What size half round and what radius are you using? Any pics of what you are trying to do?

Edited May 1, 2021 by NOBLNG

[NOBLNG]

I just tried an experiment. I heated the two plates clamped in the vise slightly. Then put the .060” half round in and bent it around the .030” spacer. It stayed very nearly flat.

Edited May 1, 2021 by NOBLNG

[TooOld]

I think you may be over thinking this  . Small half round strip bends easily using the thumb and forefinger of both hands , just work it a little at a time until it's bent where you need and then over bend it so that it holds it shape . I just did this convertible boot trim using .060" half round , it took less than a minute .

To glue it to the body I used medium CA glue . Start at one end , position it in place and let it dry , then continue along the length of the trim . When everything is completely dry then I go back along the edge with some Tamiya Liquid Glue to make sure it is completely secured .

[Rick L]

The options are not ideal. But they are options.

[Len Woodruff]

Thanks guys for all of the input. The heated plates are nice. What I did with some success is to put the ca on the .040 flat side 1/2 round. Then stick it to the straight roof of the body. After the glue was dry I slowly used a thin wire to add more ca as  I bent the rod around the roof to the side then cut it of.

Here are some of the results.

 

[Rick L]

LOL! 🙃 I totally misunderstood which way you were bending. You’ve got this.

[Len Woodruff]

23 minutes ago, Rick L said:

LOL! 🙃 I totally misunderstood which way you were bending. You’ve got this.

No worries. I should have supplied the pic when I originally posted the question. But lots of good discussion on this subject.

[Chariots of Fire]

Len:  Can you give us a look at what you are trying to do?  That would help.  There are several alternatives to trying to bend plastic that do not end in the plastic being in a stressed condition.

[Len Woodruff]

1 hour ago, Chariots of Fire said:

Len:  Can you give us a look at what you are trying to do?  That would help.  There are several alternatives to trying to bend plastic that do not end in the plastic being in a stressed condition.

Charles if you scroll up a couple of posts you can see the picture with the trim. Basically I am putting the trim across the roof and down the sides of the window area.

While the rear piece is straight down the front piece has a angle to it.

Edited May 2, 2021 by Len Woodruff

[NOBLNG]

On a related note, I just tried another test with 1/16” round. The Tamiya QS cement made the bend snap. The Plastruct did not. I got the Plastruct on my last trip to the hobby shop cause it was on sale. I can see why because it sure doesn’t weld styrene together the way the Tamiya does!🤨 

Edited May 2, 2021 by NOBLNG

[Len Woodruff]

1 hour ago, NOBLNG said:

On a related note, I just tried another test with 1/16” round. The Tamiya QS cement made the bend snap. The Plastruct did not. I got the Plastruct on my last trip to the hobby shop cause it was on sale. I can see why because it sure doesn’t weld styrene together the way the Tamiya does!🤨 

I tried the Plastruct but it didn't really soften the plastic like I thought it would.

[Chariots of Fire]

Len:  Can you give us a look at what you are trying to do?  That would help.  There are several alternatives to trying to bend plastic that do not end in the plastic being in a stressed condition.

Ok.  Now I see.  I have done similar things but I first try and take some of the stiffness out of the plastic by dragging the plastic over something round roughly where I want the bend to go.  I do this several times until it becomes more pliable.  Then I glue that portion of the strip that is the straightest first and then a little at a time wrap the strip in the direction I want it to go.  Looks like you accomplished that.

[Len Woodruff]

46 minutes ago, Chariots of Fire said:

Len:  Can you give us a look at what you are trying to do?  That would help.  There are several alternatives to trying to bend plastic that do not end in the plastic being in a stressed condition.

Ok.  Now I see.  I have done similar things but I first try and take some of the stiffness out of the plastic by dragging the plastic over something round roughly where I want the bend to go.  I do this several times until it becomes more pliable.  Then I glue that portion of the strip that is the straightest first and then a little at a time wrap the strip in the direction I want it to go.  Looks like you accomplished that.

Thanks Charles. I will try that. I have to redo the strips since one is not straight and the other I missed the line up with the tape on the side.

[Len Woodruff]

On 5/1/2021 at 10:32 AM, TooOld said:

I think you may be over thinking this  . Small half round strip bends easily using the thumb and forefinger of both hands , just work it a little at a time until it's bent where you need and then over bend it so that it holds it shape . I just did this convertible boot trim using .060" half round , it took less than a minute .

To glue it to the body I used medium CA glue . Start at one end , position it in place and let it dry , then continue along the length of the trim . When everything is completely dry then I go back along the edge with some Tamiya Liquid Glue to make sure it is completely secured .

Thanks for this tip. I need to bend the rear window trim like you did the above trim. I tried it and it will be the solution for the rear trim.