View Full Version : Few quick questions about my fiberglass project...

09-07-2006, 01:40 PM
Well, tomorrow after work i'm diving into my first fiberglassing project.

As a preliminary project, before i build my speaker pods, i'm building simple flush covers for the rear doors, where nasty huge chunks of the door were cut out to fit my type-r's, so the entire door pocket and speaker area are gong to be fleeced, and i'm gonna make a nice cover, which will be finished with bedliner for a nice black rubberized finish, as well as underlay the entire back of the door once the covers are installed to make the doors watertight, as well as quiet as possible.

Seems like an easy 1st project, but i had a few quick questions before i go to the store after work.

I've noticed there's a lot of different types of fiberglass mat. There's LOTS of different weights of woven mat, there's 'chopped' mat, there's woven roving (which looks like carbon-fiber) unidirectional woven mat, and a few others i couldn't keep track of.

Which type of mat do i want for both my projects? I'm guessing the woven stuff, but what weight? I don't even know the difference. I'm guessing heavier is harder to work with, but needs less plys, and lighter conforms to curves better, but requires lots and lots of plys..... What mat, exactly, have some of you used with good results?

Also, i had a question about fleecing. What is the main purpose for fleecing? If you had thin enough fiberglass, couldn't you just use a solid sheet of fiberglass for the skeleton, and then fiberglass on top of that? Or does the fleece retain it's rigidity when re-wet better than the cloth itself?

Just curious, it would save me a second trip to jo-ann's.

Thanks, i'll be checking back.

09-07-2006, 01:45 PM
hahaha, oh ya, flexibility, it didn't even occur to me that the mat itself isn't going to be flexible, i've never even seen the stuff in person :uhoh:

good deal, i'll just go middle of the road with the weight, and buy a few yards of fleece while i'm out.

I guess if the mat i get is too hard to work with, i can get some lighter stuff for my actual doorpod install in a few weeks.


09-07-2006, 02:09 PM
Shouldn't need to heavy of a mat for cosmetic work like the panels . The 5oz stuff they sell at lowes and auto stores will suffice . Not hard to work with if you take your time , and be patient . Don't mix the resin hot your first time . Follow the directions exactly . Be precise with your mekp . It will give you time to sufficiently wet out what you can with the amount of resin you mixed up. Nothing worse than a bunch of hardened resin in the bucket . That chit's too expensive for that :) As for the mat , just cut it into pieces you can lay smoothly. Overlap is alright. When you add one layer on top of the other , turn the bias 45 degrees with each successive layer. Makes the final product stronger . work out all the air bubbles , bubbles = weak spots . You can use a squeegee , or a roller . Some people just use a stiff bristle brush and poke the bubbles out . Try what works for you :)

09-07-2006, 05:47 PM
How much mat does it usually take to do doorpods?

I figure this is only 1/2 a doorpod, since it's only the top piece, with no depth (enclosure) behind it. I need to go back to the store tonight to get a few tubes of silicone, and some epoxy, so i could pick up more if i need. I ended up going with the braded mat, since it'll most likely save me some sanding time, and since this isn't a true enclosure, it doesn't need to be SUPER strong.

Here's what i've got so far:

-1 gallon elmer's resin w/ hardner
-4 packs of braided fiberglass mat (9ft^2 each)
-2 1.5" brushes
-10 measuring/mixing cups (the clear $.79 ones)
-handful of mixing sticks
-1 quart of acetone
-1 pack 80 grit sand paper
-1 pack 150 grit sand paper
-1 pack 220 grit sand paper
-4 cans of spray-on asphalt undercoat (for the back of the doors)
-2 cans of spray-on bedliner (for the front of my pseudo-enclosures)
-3 yards of sweatshirt-fleece from joanne's fabric (the real thin stuff)

i need to get a few tubes of silicone, because i'm making the door completely sealed, and an epoxy set for the fiberglass panels.

So far my total is $150, all included. Not bad, but i don't know if that's enough mat. What do you guys think?

09-07-2006, 06:01 PM
Also, here's a pic of what my doors looked like, with the hackjob type-r install:


now that the type-r's are gone, there's a nasty hole in my door, since the installers couldn't get the speakers IN my doors, and decided just to cut the crap out of my doors.

The red part is going to be completely cut out, and covered with the fiberglass panel, doorpocket and all. Do you guys think it would look better if i left the bedliner black? Or if i painted it to match another color on my door?

My only fear is that if i try and colormatch, and i'm off by a bit, it would look worse than if i just left it black. But the bedliner does say specifically that it IS paintable, so it's an option.

09-07-2006, 07:44 PM
Go to a CarQuest auto finishing store or the like. They can computer match your color and mix it up and even put it in a rattle can for you. About $12 for all that.

Should be more than enough mat BTW.

09-08-2006, 12:06 PM
It looks as if that spot where the speaker was mounted would come off seperate.
If it does, scuff the backside of it with the roughest sandpaper you have or can get. Tape the front of it all off with a couple extra layers over the hole.
Lay some resin and mat on the backside of the hole on the tape and overlapping the edges about an inch or more. 3 - 4 layers.
After that dries, remove the tape, sand the fiberglass and the front lip and use some duraglass to smooth it together. The some quality filler and then paint it the color of the upper door part. Car Quest is who I use also and they can color match anything.

If that piece does not come off seperate, then remove the whole map pocket and you can do what I described above.
If you want to shave the pocket also, then wrap the whole thing with the fleece and glue it on the backside with Super 99 or something similar. Try not to get resin on the glue as it will release.
Resin the whole thing and let it dry. Add mat to the backside of the fleece where the hole is that you want to repair to make it stronger. Also to the pocket hole if access is available.
Sand the fleece down with 80 grit. Body filler it and sandsmooth. Paint.

EDIT If the piece is not very sturdy off the door, then it may warp and not fit back tight. If that is the case, then take it off the door and do everything as above. BEFORE you resin though, tape the door panel off real good. A couple layers. After you resin the piece, put it back on the door to allow it to dry to the shape of the door to prevent warping.

Sorry for the novel, but I hope it was helpful.

09-08-2006, 05:36 PM
ok, i've already got another problem.

I don't know what to do about filling this recess while fiberglassing....


i want the panel to be flush all the way across where the recess was, since the door pocket will no longer be there, and my fleece wants to twist and wrinkle if i just stretch it over where the recess was, so i need to fill it, or cover it with something....

Anyone know what i could use? I'd use a piece of wood or something, but i want it to be as flush with the door as possible.

09-09-2006, 01:08 AM

i got one of my doors glassed tonight, and i love this stuff! haha, it's so cool how it turns clear when you get it nice and saturated with the resin.

I used an entire 9 square foot pack of fiberglass cloth and 16oz. of resin on one door! It should definitely be strong tomorrow!

as i sort of expected, the hardest part was getting started. Once i got my door taped off, and got my gloves strapped on, and my resin mixed up, it was on, baby :)

i got the above mentioned recess coverd up by going nuts with masking tape, and ended up not even needing to fleece the door, i taped off the entire gap, and glassed right on the masking tape. Very excited to see the results tomorrow!