<p>I am looking to fabricate an acrylic/plexiglass bonnet with an open top and outside dimensions of 20&quot; x 20&quot; x 36&quot; with 1/4&quot; wall thickness. Essentially the bonnet pictured below, but with no top:</p>
<p><a href="https://i.sstatic.net/38j3N.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/38j3N.jpg" alt="enter image description here" /></a>
<a href="https://i.sstatic.net/Yiqk5.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Yiqk5.jpg" alt="enter image description here" /></a>
<a href="https://i.sstatic.net/qYrSw.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/qYrSw.jpg" alt="enter image description here" /></a></p>
<p>It seems easy enough by gluing two 20&quot; x 36&quot; pieces to two 19.5&quot; x 36&quot; pieces. But I don't understand how to get the really smooth and seamless-looking edges that are pictured here? Did they use a heat gun to do this? Or is there a particular type of adhesive or polishing process I need to use?</p>

CC BY-SA 4.0
2023-04-30T16:40:01.210Z
I don't have enough signal to research a proper answer, but when I've worked with acrylic, heat has only been for forming (e.g. bending); clear joints can be made by solvent welding.
Chris H
CC BY-SA 4.0
2023-05-10T12:40:17.390Z
@ChrisH: I think OP refer to the cuts - they look shiny ans transparent, not opaque - as they result after immediately after saw- or disk-cutting.
virolino
CC BY-SA 4.0
2023-05-10T12:59:58.080Z
@virolino That may be true.  Heat polishing after cutting and before bonding may be one option, but mechanical polishing could also be used. Heat polishing is tricky to get right  (too hot and the material scorches, too slow and it deforms). The key is to keep the joint dead straight as solvent bonding has no gap-filling power, so I'd (lap and) polish mechanically.  Solvent bonding can however smooth slightly rough surfaces, but that's only useful on the inside of a join
Chris H
<acrylic-glass>
How to Make a Plexiglass Bonnet with Seamless Edges?
Emmett Palaima
# How to Make a Plexiglass Bonnet with Seamless Edges?

(Asked by: username_0 on 2023-04-29)

I am looking to fabricate an acrylic/plexiglass bonnet with an open top and outside dimensions of 20" x 20" x 36" with 1/4" wall thickness. Essentially the bonnet pictured below, but with no top:

[![enter image description here](https://i.sstatic.net/38j3N.jpg)](https://i.sstatic.net/38j3N.jpg)
[![enter image description here](https://i.sstatic.net/Yiqk5.jpg)](https://i.sstatic.net/Yiqk5.jpg)
[![enter image description here](https://i.sstatic.net/qYrSw.jpg)](https://i.sstatic.net/qYrSw.jpg)

It seems easy enough by gluing two 20" x 36" pieces to two 19.5" x 36" pieces. But I don't understand how to get the really smooth and seamless-looking edges that are pictured here? Did they use a heat gun to do this? Or is there a particular type of adhesive or polishing process I need to use?

**Tags:** acrylic-glass

> **Comments:**
> **username_1**: I don't have enough signal to research a proper answer, but when I've worked with acrylic, heat has only been for forming (e.g. bending); clear joints can be made by solvent welding.  
> **username_2**: @username_1: I think OP refer to the cuts - they look shiny ans transparent, not opaque - as they result after immediately after saw- or disk-cutting.  
> **username_1**: @username_2 That may be true.  Heat polishing after cutting and before bonding may be one option, but mechanical polishing could also be used. Heat polishing is tricky to get right  (too hot and the material scorches, too slow and it deforms). The key is to keep the joint dead straight as solvent bonding has no gap-filling power, so I'd (lap and) polish mechanically.  Solvent bonding can however smooth slightly rough surfaces, but that's only useful on the inside of a join  

---

## 0 answers

