DIY Kevlar Belly Pan Reinforcement

[PCHS4]

I decided to try out putting Kevlar fabric on the factory belly pan. I started this project because the factory pan is weak and easily
torn up (as many of us are well aware). I could not find any after-market products that addressed this problem. At a minimum it should
offer some additional protection for abrasion and help hold the thing together if it gets gashed on a sharp object.

I got the Kevlar from ACP Composites, http://www.acpsales.com/, the cost was about $75 for 2 yards.
It is type 49, 4HS (4 harness satin weave). The epoxy is from Aeropoxy ($50), make sure to use the 1 hour hardener.
A good website to learn about how to do this work is http://www.fibreglast.com/category/Learning_Center

I cut the fabric a little bigger than the belly pan, placed it over the pan then put the epoxy (Aeropoxy PR2032 + PH3660 hardener) on top,
worked it around with epoxy spreaders (Dynatron 358), and a radius roller from FiberGlass Coating Inc, model #129688. While it was
partially cured, I cut off the excess material. It is possible to put more layers on top for more strength and stiffness.

It is my first time working with Kevlar and there are some bubbles here and there. But I learned a lot and now know what not to do.
I could do a much better job next time, but it should get the job done for now. -Bruce

Before, factory belly pan, with light sanding for surface prep:
http://i.imgur.com/3QQko.jpg

Here is the finished part:
http://i.imgur.com/5Fv73.jpg

Close up:
http://i.imgur.com/7m1z7.jpg

This is what it looks like with the epoxy wet:
http://i.imgur.com/f9Gfr.jpg

[zamm3k]

talk about attention to detail. Well don sir, well done!

[richib86]

only thing that would make that an A+++ would be a trap door for oil changes

[staticuxo]

only thing that would make that an A+++ would be a trap door for oil changes

indeed. had cut hole on my B7 S4 for this :D

[QuattroRocket]

That looks great, I will pack mine up and send it to you this weekend [>_<]

[tchuck]

Looks great!

SfmDRuT2

[apexit1]

Damn that looks good. Inspired me to do some stuff

[NWS4Guy]

only thing that would make that an A+++ would be a trap door for oil changes

Just use an oil extractor from the fill tube up top [;)]

[PCHS4]

That looks great, I will pack mine up and send it to you this weekend [>_<]

It's not too hard, but rather time consuming process by hand. I would do it for you, but you probably wouldn't like the cost.[wrench]

[TofuShop]

bookmarking. great job!

[1auburn]

Cooooooool.

[PCHS4]

Finally got the belly pan installed. Now if wish I would have painted it. With the car on the ground the lips of the pan are visible near the wheels.
For now, I think I will just brush on some flat black enamel paint in that area and avoid removing it.

http://i.imgur.com/x4o0f.jpg

[ENV²]

Just spray it with Plastidip.

[nunonbreak]

How many layers are needed to be bulletproof? I want to do my front doors.

[ghst868]

You never know when a stray bullet might hit the belly pan [:D]

It must have been a lot of work. Well done.

Like mentioned previously you should plasti dip the pan.

[tchuck]

I'm totally doing this. Best diy I've seen in ages. :thumbup:

SfmDRuT2

[PaperishPlastic]

How many layers are needed to be bulletproof? I want to do my front doors.


thats not a bad idea at all.

[ENV²]

how much weight is added? LOL

[PCHS4]

how much weight is added? LOL

It takes a surprising amount of epoxy. I mixed up about 12 ounces. Make sure to have enough epoxy mixed and on hand, there is only about 1 - 1 1/2 hours of time to get it all applied. I then applied a second coat a couple of days later, but this time it was far less. So, the total weight is about 1 lb.

[PCHS4]

How many layers are needed to be bulletproof? I want to do my front doors.

I used Kevlar 49 (composites grade), not Kevlar 29 (ballistics grade) - supposedly there is a big difference in abrasion resistance and workability for the composites grade. I try to stay out of parts of town where my belly pan will get shot at. lol.

[Moose201]

How did you cut and finish the various holes?

[PCHS4]

For the hole cutting and edge trimming, I waited until the epoxy was partially cured, very firm, but not hard. All the trimming can be done with an Xacto blade. Use a fresh blade and change it out when any cutting resistance is felt. It cuts like butter!

[amz]

Curious, how has this help up over 2 winters? This looks like a pretty easy and cost-effective mod that'll help with the ice chunks northern areas have to deal, along with other winter road hazards.

[PCHS4]

I am driving around in the southwest and have not encountered any snow or ice. But, I did break my first OEM pan without Kevlar due to other road hazards. This one is in good shape, no signs of de-lamination or cracking.

[A4 Centaur]

Great work!

[tchuck]

Bump for a long term update. How is it holding up?

[Joe85sti]

I'm curious as to how much protection this really provides. Kevlar provides protection against projectiles because it acts like a strong series of nets that gradually slow the object down. It doesn't do well against protruding objects because they have driving force that just pushes through the mesh. That's my understanding of Kevlar and maybe I'm wrong but just curious.

[Cooper993]

Looks good (and a lot of work).

How much does a new belly pan cost? Is it more than covering in Kevlar?

[Over9000]

Looks good (and a lot of work).

How much does a new belly pan cost? Is it more than covering in Kevlar?

I just replaced mine a few months back. I think it was around $215+shipping from genuineaudiparts. I wish I would have remembered this thread, or the new ECS pan had come out sooner...oh well.

[nefkntym]

Awesome. Just had to replace my belly pan as well. This would be pretty cool to try.

[salyaqout]

http://www.ecstuning.com/Audi-B8_S4-Quattro-3.0T/News/Audi_B8_S4_30T_Quattro_ECS_Tuning_Street_Shield_Al uminum_Skid_Plate_2010_2011_2012_2013_2014/

Aluminum anyone?

[cartersjc]

I'm coming late to this (sorry), but I love the idea - total kudos to you - and plan to try it, with the additional adaptation of metal reinforcement in some of the high risk (and easy to add) areas. I'm curious though why you did not clear out this cutout that is open in the OE version. Please explain if you are still following.
https://imgur.com/a/kuzcI

[PCHS4]

I'm coming late to this (sorry), but I love the idea - total kudos to you - and plan to try it, with the additional adaptation of metal reinforcement in some of the high risk (and easy to add) areas. I'm curious though why you did not clear out this cutout that is open in the OE version. Please explain if you are still following.
https://imgur.com/a/kuzcI

I couldn't link to you're picture, but I am assuming you're talking about the circular hole on the passenger side? I don't remember why I did it, it was 5 years ago, lol. But, 5 years later, it's still holding up great, no delamination of the kevlar or cracking.

[USAF_Danny]

I couldn't link to you're picture, but I am assuming you're talking about the circular hole on the passenger side? I don't remember why I didn't, it was 5 years ago, lol. But, 5 years later, it's still holding up great, no delamination of the kevlar or cracking.

The fact that you're the OP and you responded to a thread you created back in 2012 amazes me lol

[PCHS4]

The fact that you're the OP and you responded to a thread you created back in 2012 amazes me lol

Pretty easy, I was looking at my phone and I got a message that someone quoted my post. If I didn't still have the 11 S4 I might not have been subscribed and got the message. I have mostly moved on to modding my 14 Jeep Wrangler and don't spend much time on AZ these days.

[Pawan2013]

that's awesome but ecs does make the street shield

[MME1122]

I've seen the ECS part but I had always wondered about sound with it. The oem panel is plastic with some sound deadening in it. The ECS part being metal would just reflect all the sound instead of absorbing it. I like this idea better.
Has anyone tried the ECS shield? Any thoughts on noise?

[Krusty]

Dude,

How strong is this? Do you think if you hit something this mod will protect you from cracking your oil pan?

[PCHS4]

It's a belly pan, not a skid plate. Two different concepts.

[Krusty]

Understood, really wondering how strong this update made the pan.