FIBERGLASS
A step by step guide to creating with
fiberglass
by: Drew Wilson
I am often asked where I learned to work with fiberglass, or where an individual can go for a
good write-up in order to learn how to fiberglass. I've never had a good answer until now.
I didn't "go" anywhere to learn other than the Internet and my
garage, and I can't recommend any of the Internet sites I'm familiar with as
each has distinct drawbacks. It seems that they are either corporate write-ups that are only out to promote their own
expensive products, amateur write-ups that are thrown together and may have
inaccuracies, or manufacturer's sites which simply show the steps taken in
great detail without the necessary background (Alpine's site for example). I am in no position to discount any of those
sources for information since they are basically all I have had in my personal fiberglassing education, but I hope to go beyond their usefulness to the every
day weekend customizer. I plan to do so by bringing the information from those sites together with my experience and
presenting the information as simply as possible. I will focus on keeping costs and the time involved down as much
as possible, but the advantages of using fiberglass will always come with an
added cost in both dollars and time when compared to "cookie-cutter" MDF, and
stock speaker location installations. Finally, although I have achieved some level of success and certainly a
ton of experience for an "amateur" I attribute most of that to the amount of
time I'm willing to spend redoing my own mistakes rather than to any talent or
special knowledge. If you think you know a better way to do something you should, obviously, do it your way.
There are a few basic concepts in fiberglassing, which a thorough understanding of
will allow you to create practically anything. What I mean is that the same basic skills that enable you to build a
kick panel or a
subwoofer enclosure can also be used to create a bumper. I've decided that the best way to present those underlying
concepts and to help people with their projects is to go through a couple of
ways to build shapes in fiberglass, then briefly present a third method. The idea is that the reader will be able to
just follow the instructions to do most typical projects or to use the concepts
in them as a springboard to creating virtually anything.
SPECIAL MATERIALS:
The materials you
will be working with are the most important determinant of the outcome of a
fiberglass project. They are also a
great place to save some money.
I'll not go into the normal tools such as an angle grinder or the wood saws that
you'll be using, but I'll make sure to point out the specific materials needed
You will need to
find a local distributor for fiberglass resin and mat. This may be difficult for many of you
due to geographical constraints, but if you're determined to find one you should
be able. I know it took me a year
of using the inferior "Home Depot" branded resin, before I got off my butt and
found a place locally to sell me the good stuff, mainly because I thought the
good stuff would cost more. The
truth is that I save about 35% by purchasing from my local distributor in 5
gallon pails (5 gallons is too much for virtually any single project), but even
if I weren't saving money it would save me a ton of time and improve the end
quality of my work to use the good resin.
When you buy from Home Depot or Walmart or any of those places you get resin
that is thicker, sets-up slower, and sets-up weaker than the better stuff out
there (you'll know if you have the better stuff if it is at least as fluid as
cooking oil, the bad stuff resembles molasses). Try calling around to local audio shops or marinas until you find what
you need. It is also possible to
mail order, but the cost seems prohibitive to me. Single gallons should be $25-30 and 5 gallon barrels should be around
$100-$120 with the necessary hardener.
Buy "chop mat" from
the same place you buy the resin.
I'm not going to go into the different weights of matting, but obviously
the heavier weights are "stronger" and the lighter are easier to use (forcing a
heavy mat over a curved surface without either cutting it up into tiny pieces or
creating air bubbles can be an impossible challenge). You won't need woven matting for most
projects. There is only one other
thing I would recommend purchasing from your fiberglass supply store and that is
a sprayable polyester body filler, or what Duratec calls their "base primer".
"Base primer" can either be sprayed through a primer gun or painted on with a
brush and can be applied very thick.
It is easy to sand and when you plan on painting your finished product it allows
you to jump ahead rapidly if you paint it on after initial sanding with 36 or 40
grit paper and then begin sanding it with 80 or 100 grit.
It is roughly $40-50 for a gallon, but if you build a large enclosure or a
fiberglass rollpan using it might save you many hours.
Fleece is necessary for most projects.
I most often just use whatever fleece is cheapest at Walmart. The fleece is basically only going to be
used to provide an initial backbone which the mat will add strength to, don't
fall into the trap of thinking that fleece and resin alone is rigid or durable
enough for much of anything. There
are "special" fleece's available from a few sources that claim to be thinner,
stronger, stretchier at a much greater cost, you will be able to make do with
the cheap stuff and any time you could have saved with the specialty fleece will
be more than made up for in savings. You are going to be looking at paying between $4 and $7 a yard for
fleece.
The only other "specialty" material that is universally needed is body filler. You will need to use some body filler to
smooth your fiberglass work even if you are going to cover the final product
with vinyl, and the brunt of your work will be at this stage if you are trying
to prep for paint. In keeping this
simple, I will break body fillers into those that have some ground up fiberglass
strands in them and are meant to be used to provide some strength and those that
do not and are exclusively designed for "finishing" and "feathering".
There are times when you want the body filler to "hide" your errors earlier in
the project and you need to put it on somewhat thick.
Whenever you need to add any thickness of filler use one of the products that
provides strength (also note what you did wrong and correct it the next time- you don't want to ever be in that
situation if you can help it). The
"finishing" filler always follows the other or in cases where the shape is
correct from the beginning it is all you would use.
I personally use Duraglass and Rage Gold respectively. I have found that it is distinctly not worth trying to save
money by using inferior products when it comes to body filler. You should pay just less than $30
a gallon for either of those. Everything
else you will need you either already have or probably wouldn't appreciate my
advice in purchasing.
Basic
Stand Alone Subwoofer Enclosure
Here are two examples (Thanks to my
brother Ryan and friend Pierre):
In
order to build a box like this you start with an MDF frame. You can choose to make as many sides of the
frame as you wish MDF. Here are a
couple of shots of frames from my friend Pierre's Explorer's box and my
brother's Escape's box -
The key is to get
a feel for what your frame will look like once you have stretched fleece over
it. At first you will likely end up
with nothing close to what you were expecting for your final shape. Be certain that you take your time creating
your frame because if it isn't square you will waste a ton of time making the
final product square later. Make sure
you plan out where any LCD screens, amplifer(s), ports etc. will be going at
this stage and remember to think about where any wires will run. At times you have to be very creative in how
wires will get from one place to another inside a box (ex. the wires going to
the 13" screen in the Escape's box above).
Once you are happy with your frame you will drape the fleece over it making sure
that you have plenty overhanging all sides. Start in the middle stapling the fleece to your frame stretching it hard
and working outward in an even radial manner. You need to be certain that you start in the middle and stretch out in
each direction from there evenly. Upon completion, place your work on a drop cloth, put on some latex gloves, and mix
your resin. I recommend using a flexible Tupperware type bowl (approximately 40 oz size). With Tupperware after any unused resin
hardens you can flex the bowl and crack the resin out so you can recycle the bowl for quite a while. Be sure to follow the directions for mixing the
accurate amount of hardener. Finally, "paint" the resin onto the fleece. The tendency is to not apply enough resin and there is no real
drawback to applying too much so be aggressive. After that stage your enclosure will look something like this-
That is my little brother Ryan's
current box in his Escape. Hopefully,
your garage will look a bit better. You'll have an hour or two to go watch TV or whatever while the resin
hardens. When you come back use a
Rotozip or something similar to cut out the holes where the subs go and any
other holes that are supposed to be in the box. Use a flap wheel on a grinder to clean up the edges (the bottom
edge above had a big lip on it where the resin and fleece had built up).
At
this stage the enclosure is flexible and weak. The mat is used to add strength. You are going to have to make a determination based on the size of the
enclosure and the output of the subs you will be using how many layers of mat
you will need, but it will be at least three and probably not more than ten. The size and shape of the pieces
of mat you will use will be up to you in each situation. I would recommend starting with 4"x6"
pieces." Paint" some resin onto the
surface of the fleece, place the 4"x6" piece of mat on the fleece and then
paint over the top of the mat to completely soak it with resin. Move quickly until the entire surface has
been covered, slightly overlapping each neighboring piece of mat. Use whatever method of dabbing or brushing
enables you to avoid air bubbles to the fullest extent. A trick to help avoid bubbles around curves
and edges is to tear the mat rather than cut it with a scissor. The torn ends are much easier to force into
a shape of your choosing. Take care
around the edges where the fleece meets the MDF. The mat and resin will stick and seal to the MDF as well as they will to the fleece and you
want to take full advantage of that fact to be certain the edges are
sealed. Repeat this process as many
times as is necessary in order to achieve the level of strength you need. With enough properly applied layers
fiberglass can withstand incredible abuse.
One
way to possibly save yourself a lot of time is to apply the mat and resin to
the non-cosmetic inner surface of your work. When you apply the mat on the side you are planning on eventually
painting, no matter how carefully, it will result in you having to add some
Duraglass in order to smooth out some high and low spots. If you can get away with leaving the bare
hardened fleece on the cosmetic side you may only have to use the finishing
body filler and can save a ton of time sanding. I did this with my current box in my explorer. It requires leaving one side of the box
"open"
so that you can reach in and apply the resin and mat like this-
In most situations doing it that
way would have been more trouble than it was worth, you have to make the
decision on the basis of each project.
Once
you are comfortable with the number of layers you have applied and the strength
of your enclosure it is time for body filler. You will have to use your own judgment in deciding with which type of
body filler to start with. In the most
extreme cases you will have to do multiple coats with Duraglass just to get the
shape and curves under control. I like
to sand the early coats with a 40 or 60 grit flap wheel on a grinder focusing
on the general curves. Whether you are
painting, or covering the enclosure with some sort of fabric you need to get it
completely finished to the 36 or 40 grit sandpaper stage. Once again focus on the general shapes and
curves being certain they are as you want them. When you are at that stage you could wrap the enclosure with
vinyl or another fabric and call it quits. I may do an addendum later describing that procedure and the products
I've found that are easiest to use to that end. If you are planning on painting the finished project you are now
ready to apply the base primer if you have it. Brushing or spraying the base primer on will basically allow you to skip
from 36 or 40 grit all the way to 80 or 100 grit sandpaper. Once you have used it I assure you that you
will never go back to working your tail off applying coat after coat of
"finishing" filler and sanding with 60 or 80 grit (but if you don't have base
primer you'll have to do exactly that). Once you get to 100 grit you can use regular sand-able primer rather
than body filler between bouts with the sandpaper. I don't do my own finish paint work, but in general I try to
finish everything to 220 grit before turning it over to whoever is doing the
painting.
A
SLIGHT MODIFICATION- SPARE TIRE ENCLOSURE
You can use the
same skills to create another type of enclosure with just a couple of changes
in how you set-up the "frame". First
here are two examples of "spare tire enclosures" that I've done recently-
�
That is a true
example of a "spare tire enclosure" in that it uses that space and no other
space at all. Those are pictures of my
Audi A6 Avant. The following pictures of my friend Rhys' J-spec Toyota Supra
also show an enclosure I would consider a "spare tire enclosure" although it has
sort of grown out of that space a bit-
The key common
denominator between those two enclosures is the need to use as much of the
airspace available as was possible. The
spare tires from both cars were removed in order to gain space leaving me with
a very uneven surface that would have precluded any efforts to make an MDF frame
that used all of the space available. The "frame" in this case actually becomes
the car itself. With a few layers of aluminum foil and masking tape carefully
protecting the surface you are "molding" or "framing" off of you can skip
straight to adding mat in order to create a piece of fiberglass fit perfectly to
the space available-
On the left is the
Supra (I used fleece rather than mat in order to save as much mat as
possible-I think we had purchased all
the mat on Grand Cayman for our projects at that point and I was afraid of
running out), and on the right is the Audi. You will notice the MDF ring that was placed around the top of the space
I was molding in the A6.That ring gave
me a base to build more MDF off in order to make the top of the enclosure. Here is an inside peak at the MDF
framing that occurred in the Supra-
There was still
more MDF added later in order to house the Memphis Belle amplifier (and its
wiring) and the plexi window into the sub (which was finished on the inside
with brushed aluminum) but that gives the general idea of what you are trying
to do. Once you are at that stage in
the process it is no different than making a "normal" fiberglass
enclosure.
FOAM
MOLDING/FRAMING:
The third method of making a frame
I often use is with foam. The advantage
of foam is that you can literally cut or shape it by sanding to make any
shape. That is how I made my bumper,
side skirts, rollpan, grille, and hood on the Explorer.
I use the green foam available at
most craft stores and Walmart which is primarily intended for making fake
flower presentations. It is widely
available in 2"x12"x36" pieces that can be glued together with liquid nails. I've seen Chip Foose using
suspiciously similar looking foam in huge blocks, but I haven't yet figured out
where to purchase those. The beauty of
this foam is that you can cut it with a knife blade or sand it with 36/40 grit
sanding paper into any shape you choose. Once you have made the desired shape in foam you can then either lay mat
directly onto the foam (mix the resin a little cold or else as the resin's
exothermic reaction takes place as it hardens the foam will literally melt
away) or you can devise a way to wrap the foam with fleece. You can use liquid nails to attach the foam
to just about anything, such as the bottom of the stock bumper or the side
skirts to which you're trying to add some depth and shape.
CONCLUSION:
I could go into a
lot more detail about exactly how to do a lot of the details such as how the
Audiocontrol EQX was sunk into the enclosure in my A6 or where the wires for
that screen in the Escape do go. However, I think its better that each prospective hobbyist figures those
types of things out on their own project by project. I know I hate just "copying" someone else's design or ideas.
I don't know any other major techniques
other than what I've presented here and I have been able to make a ton of other
parts that I never would have though possible before I started working with
fiberglass such as the dash in my Explorer.
Which reminds me
how far behind I am with taking pictures (it does have a finished fiberglass
center console too).
I hope that this
gets people started in the right direction for their initial forays into
working with fiberglass, and that it might provide some new ideas to people
with experience. Anyone can feel free
to email me on AOL instant messenger at wattsupcustoms or at
wattsupcustoms@hotmail.com with
any questions or comments. I wish I had
more complete pictures of the procedures outlined, and for that manner more
completed projects.
|