Carbon Front Lip Project Diy From Scratch

[Pezhead]

Since I'm finally nearing the completion of this stage of my project I thought I'd post it up here.

PROJECT - Carbon 2 piece Front Lip / Part 1 (2nd piece yet to be built)

I noticed that the plastic lip on my GTR takes a real beating. My car isn't even that low but my driveway is hell. I decided to build a 2 piece lip. The first part (that goes on the bottom of the front bar) is about 2/3 the normal height of the stock plastic lip. I plan to make a second piece that goes on the bottom of that for show days that will go lower than stock.

I've been doing some researching around and decided I wanted to do this in fibreglass and then cover it in Carbon. There are a number of guys doing this on a few other forums with good success.

(PS - anyone wanting to see some really cool work look at these Forums. I've learned a lot and picked up a few tricks from those folks. You have to register to see the posts).

Anyone wanting to see the full build in pictures, I've uploaded them HERE.

The Plan: Build a full scale model of the lip in wood. Then cover in Fibreglass x 3 layers then 1 layer of Carbon Fibre.

Materials:

- 3 Yards of 6 Oz Fibreglass Cloth

- 3 Yards x 20 cm Carbon Cloth (MUST be a continuous piece)

- Epoxy Resin & Hardener

- PVA Mould Release (liquid that dries like a thin coat of cling wrap)

- Sand Paper

- lots of rubber gloves

- Auto Body Filler (Bog)

- Wood for construction

- Acetone (cleans the epoxy)

- plastic cups & popsicle sticks for mixing resin

Lots of various tools:

Jig Saw

Sander

Drill

Drum Sanders

Rotary Tool

paint brushes

Now, this actually took a lot longer than I thought it would to build. Most of the time goes into creating the model/mould. Also, in hindsight it was a bit ambitious to try a big part like this lip as my first carbon project, but I have done a little fibreglass work in my past so figured I'd give it a go.

On with the build...

[Pezhead]

First Step - The Template

First I had to make sure that this new LIP is going to fit my car perfectly. I made a template from cardboard that was rubbish. Wouldn't stay flat was a mess. So chucked that in the bin.

Here I bought a 3 mm thick piece of MDF board and made a template of the bottom on the front bar. I left it on the car because I wanted to ensure the shape doesn't get distorted.

Making a template

I then played around with a number of shapes I liked. I didn't take any pictures of that process so sorry. Once I got the shape done then I started building the parts.

Right away I noticed that this was going to be really big so I decided to do one layer in thick MDF and the other layer in 3 pieces. That allowed me to mate up to the bar easier as I wasn't always mucking about with a huge piece of wood.

Constructing mating pieces for front bar.

This is the basic shape and construction (cut larger than necessary to give extra material to "Play" with)

[N1GTR]

Awesome!

[Pezhead]

Next Step - Shaping

Working in 3D is a bit weird. Things that look good in your mind in 2D might not in 3D.

I used a drill motor and drum sanding bits to rough shape the wood.

Shaping the leading edge

A whole lot of sanding and wood dust everywhere... but this is the shape

Test Fit on Car

Shaping Center Piece

Mark & Cut to fit the bar

Test fit

[Pezhead]

Next step - molding and smoothing

So, next I used wood screws to fasten all of the parts together so they wouldn't move.

Time to break out the Bog (auto body filler) and start filling and smoothing the transitions between the parts.

Filling in gaps/transition points

I really didn't take that many pictures here because of all the dust. This step took me a whole day. In fact this is about 2 full working days worth of work to get to this point.

Wood is hard to see uneven spots, so I painted it gloss black (also cause I wanted to see the effect of the shape in dark color).

Results from a full day's work

Hard to see in this picture but there are lots of little imperfections that need to be fixed.

Only visible once the paint went on.

[Pezhead]

Awesome!

Thanks Mate! Lots of work, but I like seeing build posts like this. It's like time lapse photography seeing it all come together. That's why I've been snapping pics all along the build on this one.

Hope it inspires some of you to try it too.

[Pezhead]

Next Step - MORE smoothing

The paint also helps you out in another way. Anyone that's done any dent fixing knows that when you sand a painted surface high spots go through the paint and low spots stay colored.

More Bog and sanding until surface is good and flat

Believe it or not there was a whole another day in here getting the surface all flat and painted again.

Looks good and smooth now

[Pezhead]

Next Step - Hard Coat

Since I will be fibreglassing over the top of the wood, I need to seal the wood up. I did this with a couple of coats of epoxy - the same epoxy I'm using for doing up the glass and carbon.

In hindsight I should have just used some fibreglass layup resin - it would have set and dried faster.

Apply several thick coats of epoxy

The epoxy sets in about 45 minutes (meaning just turns thick and sticky). Apply the second coat during this phase of the first. Then leave both to fully cure overnight.

Did a light wet sand the next day and a little polish to give a really smooth finish.

[Pezhead]

Finally - Laying fibreglass

To prep the surface I applied some release wax and several coats of the liquid PVA. This creates a layer that should release between the model and the layers of fibreglass over the top.

Need to cut some fibreglass cloth. A trick I learned from another site is to use masking tape on the cloth. This gives you a mark to cut on but more importantly keeps the cloth ends from coming undone. Be sure to leave enough extra width to lay over the boundaries of your part.

Cutting cloth with a straight edge razor

Next, put the first coat of resin directly on top of the PVA that has now dried. All this to cure until it is sticky and thick (Sorry, no pics of this).

Laying cloth

After the cloth is laid down on the resin, and is flat with no wrinkles or pulls start applying epoxy over the top with a brush. It will turn a bit translucent when the resin permeates the cloth. Some times a dabbing motion is better than brush stroke for getting the resin pushed into the cloth.

I then allowed this to cure for a bit. While it was curing, I used a straight edge razor to trim the excess. This is great on a couple of counts. First anything you trim now is something you don't have to cut or sand later. Anyone that has worked fibreglass will tell you it is messy and itchy. Much better to work it while it is still cloth before it turns hard. Second, it is really easy to trim the part to the desired shape. I found that trimming is best after the resin has set up quite a bit.

First Coat of Fibreglass done

Another layer going on

[Pezhead]

Prepping for Carbon - aka even more Smoothing

At this point I decided I better start trimming it up so that the edges are nice and clean. Mainly I had to trim off the excess bits. Most were only 1 layer or so as I tried to do most of the trimming while the glass was still wet.

Trimmed Part

With three layers of fibreglass there bound to be some small waves or areas where the glass lifted. On the areas that did, I used some very rough sandpaper to cut down the high spots.

BIG TIP: Fibreglass filings are just like little needles. When you sand they get stuck in your skin and itch like crazy. So, I used some disposable gloves (got a box of 100 from bunnings cheap) and wet sand down the fibreglass. The water turns milky because it catches all the fibreglass bits. Then just dump out the water. After days and days of fibreglass work I can say my skin hasn't been irritated at all.

So, now apply bog to low spots are areas that need it and smooth out some more (get the picture, I've used almost an entire container of bog on this one project!).

More Smoothing

[Pezhead]

Are we ready for Carbon yet? ... YES!

OK, so now the part is nice and smooth and all ready for carbon coating. I mixed some black dye into the resin for the first coat. This creates a dark coating under the carbon just in case you can see the layer under through the weave. Just like before allow this layer of epoxy to set up to thick and sticky.

Black dye epoxy coat

I used this time to cut the carbon cloth. I bought this fabric from the US. Was cheaper by the yard over there and I needed 3 continuous yards, the cost savings paid for the shipping and still had some savings. But this stuff is still not cheap! I ended up paying about $200 for 5 yards of fabric (bought some additional for other projects too).

So, like before use the masking tape to keep the fabric from fraying. This is even more important on the Carbon as the weave is much coarser. It is very easy for the fabric to come undone.

Cutting the Carbon Cloth

(at this point I just had to sit and stare at how gorgeous the carbon looks)

When the epoxy was ready I carefully laid on the carbon cloth. The trick is to take your time. Work a small area at a time so you don't get wrinkles in it. Oh, and this is very sticky! The rubber gloves get covered with epoxy that seeps through the fabric weave. Before long your fingers stick to everything. I found that I had to lay down the carbon, but then switch to a new pair of gloves so that I didn't get epoxy all over everything I was working with.

Carbon - even at this stage looks so good

I then put a coat of epoxy over the top and make sure that it impregnates the Carbon Fabric.

Epoxy impregnation

Once that coat set up, on for two more full coats. Gloss over the top really starts to look good.

Flow Coats

This is pretty much how it looks now - finishing to come

[ylwgtr2]

not trying to rubbish your job dude but why didnt you use sandwich foam to make the shape?Or better still(what i thought when i saw you using wood) Make a plug out of wood and bog,then mould it?That thing you got would be awfully heavy....maybe even start cracking under its own weight?I hope you take this as constructive criticism!Anyway massive amount of work you have done!Ive just bought an autoclave so keep an eye on this section as i will most likely post up some of our products

[Pezhead]

not trying to rubbish your job dude but why didnt you use sandwich foam to make the shape?Or better still(what i thought when i saw you using wood) Make a plug out of wood and bog,then mould it?That thing you got would be awfully heavy....maybe even start cracking under its own weight?I hope you take this as constructive criticism!Anyway massive amount of work you have done!Ive just bought an autoclave so keep an eye on this section as i will most likely post up some of our products

The wood model isn't going to stay in the finish product. will separate the fibreglass from the wood model. Will probably put some more FG layers inside for strength.

The main reason I didn't create a mold is that you can see the part is very slender at the end. I wasn't sure I would be able to keep the profile in a mold.

[Craved]

Nice work eric - looking forward to seeing the final product installed

and how you tackled the rough cuts where the bar jumps in under the Intercooler

[ylwgtr2]

oh ok i just read the part where you waxed and put on mold release....it would have been hard to keep the material in the mold without vac bagging it....ive had success with sharp area's without bagging by shoving an internal mold in tight areas ...you still get some shallow bubbles but ive filled them up with resin...i dont want to put the moz on you but it just seems like a lot of work then one clip of the kerb and whammo she's shagged!

Edited May 25, 2010 by ylwgtr2

[Sean W]

ace job Eric, look forward to seeing it sunday!

[sheepus]

looks cool, always wondered what was involved in making parts like this

[SS8_Gohan]

Ive just bought an autoclave so keep an eye on this section as i will most likely post up some of our products

^ this

dry carbon bonnet please

looking the goods mate, nice design, but with still enough aggressiveness to it.

[Pezhead]

So I was in a hurry today on a schedule so no build pictures.

Basically, I had to wet sand, polish and clear coat the lip. Had to clear coat because the epoxy resin got a bunch of tiny air bubbles in it that made it haze up every time I tried to polish it - seemed like the tiny pits from the air bubbles fill up with polish making spots everywhere. So hours of wet sanding to get it all smooth and then a single coat of clear paint.

All up, it didn't turn out too bad. There are a few things I learned that will definitely make the next project turn out better. I plan to use a vacuum bag technique on the next project that should really improve the finish.

Then I had to break the part free of the mold. Good think I used that PVA cause was harder than I thought to remove the fibreglass that exactly fits on top of the model. Also glad I used wood cause foam would have just broken apart. I could pry against the wood with a putty scraper and didn't damage the wood at all.

Last was mounting it on the car. It turned out exactly the shape I wanted. Before someone asks the obvious - I meant it to have lots of clearance as I still only have about 20 mm clearance when I pull out of my driveway. This lip was meant to be a full road driven part. One good hit on a curb or bottoming out and then it's all over. Also very happy with the fitment as it fits the lines and shape (in my opinion) of the aggressive GTR bar.

The finish is only ok - but I know what I need to fix for next time.

What do you folks think?

[RusH_]

that looks awesome man, you gotta be pleased with that. Congrats on a top DIY!