How I put together my Vac Formed Knees


Well-Known Hunter
The Styrene for the main body of the knee is 0.080 thick. That is the main section that needs to be able to move and flex. The sides are 0.060 thick. They do not need to move and need to have more detail. So, when I made my new ones, I wanted to make the stronger. I did have some webbing. So I just sanded it down before I started. I also used a heat gun to bend anything else that I did not like into the shape I wanted.

Here is how my kit started

Picture of the real thing and our goal of what the kit will look like when done.

1. I just took a normal pencil and marked a line all the way around. Next, I cut just above that line.


2. I notched the sides so that they will lay flush with the front of the knee.


3.Look at the spot in the circle. You will have to trim the bottom of the knee to make this match.

4. Test Fit. Make sure you sand everything before you glue it together. I mean everything.

5. I took some extra plastic to go behind to help hold it togher. You will want to make sure that you make this strip as long as you can. I cut this strip to short on my last set and that is where it broke.








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Seeing that I have not had time to totally finish them I am not sure. I know that my current ones that are .060 will flex. I just did to many photos on one knee with kids. Oh well. :D
Nice! Is it flexible? I've always been worried about breaking my fiberglass knees from bending my knees to far or too quickly.

I have vac-formed Boba knees similar in construction to these. I reinforced the joints with JB Weld and it would probably take a nuclear bomb to break 'em now. :)
Where did you get your knees? My JD knees were tacky when I got them over 6 months ago, and the gel coat still hasn't fully cured. Short of finding a way to cure them, I could use a new set of knees.
I updated the pics and there will be updates as I finish mine.
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Count me in for a set with knee darts as soon as you have a set ready for shipping.

Please PM for details on S&H, and paypal info.


Those look great!

I have found that with vac pulled knees they last a long time. They just don't have that much detail. Fiberglass has great detail, but they break to quickly. So, I am trying to get the best of both worlds.

I have found that the main body of the knee needs to be able to move and bend. So, making it out of 0.080 styrene works great. The sides do not need to flex and that is where we need the detail. So, here goes. I had some soft pulls to test on so, they are my test parts. :D

The side with the upside down "F" is cast in the same resin that just the "F"s where cast in. So, I put them together and made a new mold. Now you heat up the "tail" and use a clamp to hold it in place while it cools. Then just glue it in.

I have not found a way that I like to make the side with the darts in fiberglass. I can be done, I just don't like the way they come out. So, I am going to pull them out of 0.060 styrene to get better detail and not compromise strength.

What do you think?


I like it. As an owner of your knee armor, I think the one piece side with tab will increase ease of use and overall strenth to the build up. It looks nice and neat , and it cuts out "variables" that comes with fitting more pieces together. (y)
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I like what you are doing with the kit. I wish there was a way to make the whole thing out of one type of material for ease of production and assembly. Is there any way to reinforce fiberglass so that it wouldn't crack as easily? I thought maybe a layer of the metal window screen mesh embedded in the topcoats would add strength and would be thin enough to work with. What do you think?
i will tell you this...i have his kit and it was all styrene and i love them...easy to put together and they look great. I added some aluminum knee darts to mine and they really look great
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