How To: Fiberglass Fabrication

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Broadfield
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I posted this in the car audio section, but it doesn't get much traffic. I didn't want to limit this to just car audio folk. I actually use fiberglass more for non audio stuff than audio installs. So on to the meat of it.

I don't usually take pictures of my work, but I thought I would in this case to help demonstrate the custom fabrication of pretty much anything you can dream up. I will show step-by-step process of fiberglass molded panels. From the skeleton beginnings to the final painted product. Keep in mind that a painted product is not always the route I take. Some customers want it vinyl wrapped, carpeted or wrapped in something else.... carbon, Kevlar etc. Using automotive paint as a finish is obviously the most time consuming, considering it has to be perfect. I will update this as I see fit. I am sure I left some things out that might help you. There is obviously a lot of things I purposely left out, but I wasn't going to go over EVERY step and detail. But fell free to ask if you have any questions.

The most important step is your frame work or "skeleton" as I like to call it. This is what you are going to stretch material over to get the shape you want. So you really have to plan out and envision how the material will stretch over it and what shape you are going to have once the material is stretched. You need points to staple or glue the material to and then stretch it to the other sides and staple or glue it over there. Lets start off with some pics so you get an idea and we'll dive in from there. By the way, this is going into a 2003 RX-8....... so it is very limited on trunk space. This customer wanted the sickest looking install in town, so that's what I gave her.

First off the skeleton:

This is mocked up outside the car after I made sure it fit in the trunk. She wanted (4) 8" sub woofers and 3 amplifiers. Give it a nice look without too much stuff crammed in there. This is just the beginning of the skeleton work. I still need to fasten on stretch points for the material.



This pic shows the pieces over the amplifiers which are my stretch points for the amp rack. Material will be stapled to the bottom side of those rectangular cutouts, then stretched to the outside edges of the amp rack.



Back in the trunk to make sure I like what I have so far.



Next I use speaker box carpet to stretch over the amp rack. It is very important to stretch it as tight as possible. This will give you consistent contours, and also prevent it from sagging too much once the resin is laid on. This pic is actually after I poured resin on it and trimmed the edges with a air sander.

So the steps would be:

1)Staple material(carpet, fleece, grill cloth etc.) on one side of skeleton.2)Stretch tight as you pull it to the other side and staple.3)Work your way around the skeleton stretching as you go and making sure it is tight every time you lay a staple. I use a staple every 1/2" or so. Or more where necessary. On this particular piece I actually stapled in the amplifier openings first, then stretched to the outer edges of the rack. You will quickly figure out the best way to stretch and attach your material once you mess with it a little. It will also depend on what type of setup you are stretching over.4)Once all of the material is tight and you are happy with the shape, it is time to resin.5)Mix up a batch of resin and use a cheapo brush to apply it onto your piece. It will soak up a lot, so don't be afraid to use a lot.6)Once it is rock hard and dry, you can use a air sander or grinder to trim the edges clean. I go right through the staples and all.







If needed, you can add fiberglass mat to the backside for extra strength. You will have to decide if your piece requires this or not. You can do as many layers as necessary. I added multiple layers of cloth on the exposed areas on the inside of the enclosures. You can also use this method to seal up gaps, holes etc.





For this install, I needed to get the amp rack to pretty much the final surface grade so I could figure out exactly where the sub enclosures would sit. They hang over the amp rack on each side, so I had to know my final thicknesses so I could continue.

So I sanded the rack down with 80 grit, then sprayed the entire thing with spray bondo. If you have never used spray bondo, it is "the bees knees". You simply spray it on with several coats and let it dry to a rock hard surface. The nice thing about it is that it maintains all of your contours on pieces that are like the ones in this install. If you use standard bondo with a spreader or even your fingers, you lose some of your perfect contours if you get it thicker in some spots etc.





These will come in handy for sanding and shaping. The more you can do with air tools, the better.



This is now sanded with 80 grit and test fit back into the trunk to start the sub enclosures.







Now it's time for the enclosures. We need to work on strecth points around the edges of the enclosure. You will notice the one on the bottom which has a nice flowing radius. I also had to add ones on both sides. The side that meets the amp rack is just a straight up and down piece. The side that meets the back trunk panel needed a step in it. These don't have to be 100% perfect since you are going to be stretching fairly thick material over it. Also, you can add to it later if it doesn't fit exactly the way you want it...... which I will touch on that later.





Now it's time to stretch the enclosure. However, this one is much more difficult. Part of it has to be stretched to the vehicle itself for that perfect fit. So I staple to the bottom and up both sides since those are all stretch points on the enclosure. I then take the material that is left up top and sandwich the rubber boot over the top of it pinching it into the trim. I then slit the carpet over the sub cutouts and stretch it down into the hole as I staple it around my trim ring.

I also had to make a temporary stretch point on the underside of the trunk ledge. I used it to take out the slack between the sub enclosure and the rubber trunk gasket. This is a pic on the passenger side for reference.





Next step is to resin that and trim it so it fits the way you need it to.



All trimmed and back in the car for a test fit.





It had come to my attention that I didn't get both sides stretched exactly alike. I had a bulge in one area that I didn't on the other enclosure. That's the nice thing about working with fiberglass. I just cut it out and put a patch in to get the contour that I wanted.







Next up is the rear trunk panel. It is plastic, so resin will not stick to it.... which is good in this instance. I glued carpet onto it then did the resin trick on it. It had some dips in it because of the huge cavity that was in the panel for the jack etc. So where the carpet dipped down after the resin, I had to add a bunch of bondo to get it nice and level. I then popped it off the original for a perfect duplicate of the original. In some cases, depending on your job, you will leave your original plastic piece in there and not separate them.









Next up, sanding the sub enclosures. I also used a nice ring of bondo around the mounting rings to insure I had a perfect contour around the subs. These had to be sanded with basically one finger.





All that bondo just to fill in these little areas,





Now I pre-fit every thing again. Now we are starting to see what this thing is going to look like.





I also decided that it would be stupid to leave the carpeted trunk lid cover original. Couldn't see opening the trunk to see a bunch of gloss black fiberglass work, only to have a carpet piece overlooking it all. So I decided to use the resin over carpet method on the trunk lid panel. Simply resin it to get it hard, then the usual bondo and sanding to get it ready for the same black paint. Note: As you can see in the pic, I took the trunk lid off the car and then did the resin job. This way the piece wouldn't warp on me if I took it off the trunk 1st. Once the resin starts to set up it will get very warm. So the piece will actually distort as it sets up if it's just a free floating, thin part. The sub enclosures and the like are fine since they are stretched tight and bound by the skeleton.



Now it's time to get the enclosures to fit perfectly up against the rear panel. Sometimes it's impossible to get your piece, in this case the enclosures, to fit perfectly just from the initial stretch. So you can go back in and fill or take away material. In these pics you can see the gaps or where it was impossible to have a smooth transition when I stretched from the rubber trim to the skeleton of the enclosure. I used a product called Kitty Hair to fill in the gaps. It is bondo with fiberglass strands mixed in. So the outcome is whatever shape you want, but with a lot better strength than regular bondo.













Once that dries, you will obviously sand and shape the Kitty Hair to the exact shape you need. Once everything is sanded down to 80 grit and there isn't any huge gouges etc., it's time to spray bondo the rest of the pieces.

Trunk lid panel prepped with 80 grit, then spray bondo. Keep in mind that since this piece is out in the sun, it is getting warm. So once the bondo is dry, you would want to take it back inside and fasten it to the trunk lid before it cools off. This will insure it retains the proper shape.





The rear panel and the enclosures after spray bondo.







After the bondo it's time to sand all of it down to 80 grit again. You also want to make sure that as you sand you rub your bare hand across the surfaces to make sure there are no minor waves. You won't be able to see them, but you will be able to feel them. Because once it is painted with base coat/clear coat, you will see every little wave etc.

At this time I sealed up the back side of the enclosures using a combination of MDF and more fiberglass cloth and resin. They need to be 100% sealed. I also used just straight resin to poor into gaps etc.



I also had the issue of my rear piece flexing out in the sun when it was drying. So it didn't clip to the back edge of the trunk around the latch area like it originally did. So I decided to kill to birds with one stone. I mixed up a really "hot" batch or resin...... so lots of hardener. I used fiberglass cloth to add strength 1st of all. And since the resin gets really hot, it would allow me to bend the piece back to the exact shape I needed. The nice thing is that the resin gets non-tacky to the touch, but is still really hot. So at that time I installed it back into the trunk and temporarily held it in place with whatever means possible. I just had to make sure it was exactly where I wanted it as far as shape and placement. Once the resin fully cures, you can pull it out and it will now keep the shape you want.







Up next, the final piece to the puzzle...... the center section that connects the enclosures. Keep in mind that all of these pieces are separate just so you can get them in and out of the trunk. There is no way in this install that this could of been done in one huge fiberglass monstrosity. I used a thin piece of 1/8" hardboard as a starting point. It's strong and flexible. That way it will bend around the front of the trunk opening and follow that contour.





Making this piece had to be last because I needed the enclosures to be at their final finish grade. This piece is going to lip over the front edges of the enclosures. So I want a perfect seam there.... no gaps. I applied masking tape around the area where I would be spreading in Kitty Hair. It won't stick to the tape, so it works great and has a really minute thickness. So it won't throw off the gap between where the center section meets the enclosure.









After I rough sanded the Kitty Hair down, I took one solid piece of fiberglass cloth and laid it over the center section. Resin this and now you have a really strong piece. The back sections of the Kitty Hair are the only things that really had to stay the way they were. This is the only part that touches the enclosure and had to retain perfect gap tolerances.



Sand and trim the edges for a nice finished piece. This piece was simple enough that spray bondo was not required.



Once you are 100% happy with the way everything fits, it's time for primer. If you are working on little projects, like gauge panels etc, then I would just use spray can primer. In this case, spray gun is the only way to fly. You can also get a lot higher build out of it and it will easily fill pin holes etc.



Now it's time for sanding that down with 240 grit. A really cool trick, no matter how big or small your piece is, is to use a guide coat. Simply take black can spray paint and pepper it over the eniter piece you are sanding. As you sand it will take off the black. It's not good enough until the black is all gone. This way you can identify minor low spots because there will still be black left in there. You will also not keep sanding in the area once the black is gone. You have to try it to see how well it works. If you find any little imperfections or pin holes, now is the time to fill those with thin bondo and sand with 240 grit.







After that I used spray primer again then wet sanded it with 400. You want to make sure you don't break through the primer. It can cause goofy things to happen with the base coat once it is sprayed on.

I used the same technique of the guide coat again. After this is all done, it's time for your final paint. Note: You need to make sure the piece is absolutely perfect





I had my friend paint it since I don't have a ultra low dust free environment. He runs a body shop, so it was just too easy to take it to him.



This is where all of your hard work pays off...... finally assembling it all in the trunk for the finished product. Unfortunately it's black, so it's hard to pick up all the details in pics...... but you get the idea.



























Modified by Broadfield at 9:41 PM 8/26/2008
Modified by Broadfield at 9:43 PM 8/26/2008


94_240sx
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One word "Sick."I wish you are close by, so you can fabricate this tonneau cover for my s13.


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Broadfield
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Now that looks fun! I love fabricating stuff that is a little out of the ordinary.

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Vicious176
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Cleanest looking sound system I've ever seen. Kudos.

94_240sx
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Broadfield wrote:Now that looks fun! I love fabricating stuff that is a little out of the ordinary.
Me too!! I might have to jump on it and start the project. My problem is I want end product to be perfect like yours. I doubt that I can make it that way.

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srpowered240sx
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simply awesome write up. inspiring. im speechless.

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S13xCrazy
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how much do you charge for something of that nature?Maybe when my vert is done I can bring it down to your shop for a week or so to get something like that vert' tonneau cover for mine. I'm not to far away

psmith
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Broadfield =

Once my car is the way I want it, I'm road tripping to Normal and turning you loose!

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maxima0-60
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that looks freakin sweet as ****

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keith0486
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thats wicked sick but do those boxes have enough air space they look kinda small for those subs.

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Brandon93240
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Hey 94 240 where in texas are you?

MastaYu
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very awesome write up

gregfarz78
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wow that is sick I've done some glassing like that on a much smaller scale, fiberglass isnt as bad as it looks its just time consuming to get it perfect....I'm guessing thats at least 2k in just fabrication/paint alone

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VirginiaPS13
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Toby you are the man! Everything you do is so clean..Props to you for taking so much pride in your work!

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Broadfield
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keith0486 wrote:thats wicked sick but do those boxes have enough air space they look kinda small for those subs.
They are exactly .6 cubic foot per box. Each sub requires .3 per....... they are only 8's. I'm sorta of insulted that you wouldn't just assume that I made them the proper size. I've only been doing it for 16 years.
gregfarz78 wrote:wow that is sick I've done some glassing like that on a much smaller scale, fiberglass isnt as bad as it looks its just time consuming to get it perfect....I'm guessing thats at least 2k in just fabrication/paint alone
Thanks man! Labor came out to $3000 on my end. Of course that is also installing the rest of the system, dynamatting etc.

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slyedog240sx
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amazing fabrication. I can tell by the way you post that you are a hell of an installer. My only dislike is i am not a fan of jl audio. I had 3 10w6 back in the day and they just didn't cut it for me.But hey i am an idiot that uses eclipse (except front and rear stage) so what do i know.

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Broadfield
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I'm kind of surprised. These 8's absolutely blew me away! I could not believe how hard they hit and how deep in the spectrum they played. One of my friends in town has been an IASCA finalist numerous times and even a judge in the early 90's. He thought they were the most impressive setup using 8's that he's ever heard. I have been having tremendous luck with small JL subs lately. 8w7's, 6w3's and 8w3's have been REALLY nice to me lately..... and I usually don't like anything under a 12".

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S13xCrazy
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Man, I defiantly want to check out your shop sometime.

Where about is the shop? How big of a place are you?

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Broadfield
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There really isn't much to check out. We are a really small operation, we just focus on quality. There is me, my partner, installer and salesman....... that's it!

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slyedog240sx
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i was running 4 ohm with my old xtr 2250 and only hit 134db. Hell of a sound but not worth $750 for subs and $1500 for amp.Subs died long ago.Amp was worth every penny though. I'm sad thinking about this cause i sold the orion on ebay about a year ago cause i had 2 kids in two years. Stupidest thing i ever did (not the kids).

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nismoracingsx
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i think its good i don't live near you, you would have all my damn money, wow thats hella good quality work, toby

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Bumnah
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1 fish tank away from being Michael Fishman.

Great stuff.

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Warped161
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Just WOW hmmm now figure out a small enclose that will take the space where my rear seats use to be...and i'll drive the car to you.

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keith0486
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Broadfield wrote:
They are exactly .6 cubic foot per box. Each sub requires .3 per....... they are only 8's. I'm sorta of insulted that you wouldn't just assume that I made them the proper size. I've only been doing it for 16 years.
ahh ok they look bigger then 8's in the pics ok never but it came out pretty damn clean nice work

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Team_Undisputed
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Broadfield wrote:

does anyone else see the resemblence lmao

all jokes aside man broadfield you did an AMAZING job man everything is soooo clean good job man! oh and for having one of the cleanest 240s ever! inside and out i envy your car man

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Broadfield
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Warped161 wrote:Just WOW hmmm now figure out a small enclose that will take the space where my rear seats use to be...and i'll drive the car to you.
You bring me the car, then I'll figure it out!

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ca18detgabby
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SIMPLY AWESOME

vancouverbc
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Impressive. I've added this to my tutorial list because it might help people doing minor repairs. Look under F.

Index of all Tutorials

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Broadfield
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ca18detgabby wrote:

SIMPLY AWESOME
Thanks Gabby!
vancouverbc wrote:Impressive. I've added this to my tutorial list because it might help people doing minor repairs. Look under F.

Index of all Tutorials
Thank you sir, I appreciate it.

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sviellvoicae
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Bumnah wrote:1 fish tank away from being Michael Fishman.

Great stuff.
Ha i have never understood what exactly people see in his work. I find him to be kind of an *** hole, but thats just me.

Anyways I have been a car audio installer for 5 years now and damn, I will just never understand how some of you guys get this amazing. Very nice work man!


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