First Box, First Mistake

so i started on my sub box for my 03 grand am this week, all was going good until about 10 minutes into fiberglassing my fleece.    pathetic i know.  i was using the bondo fiberglass resin, and i must have had a little too much hardener because about halfway through soaking my fleece, my resin started to turn to jelly.  well i panicked, figured i could still smear it around a bit and get it to soak in some.  nope.  it ended up chunky on the surface of my fleece.  should have stopped there, knocked the chunks off and fixed my mistake.  figured "hey, im puttin a few layers of fiberglass on here, this will be easy to cover up."   nope.  it was a dive for me from there on out, those chunks caused air bubbles, i was working with chunks of matt too large for the contours of my box, so they wouldnt press tight,  and i had air pockets everywhere.  should have stopped there and fixed my mistake.   nope.   kept goin.  finally tonight i came to realize i cant cover up this one.  so i started grinding off all the excess resin where there is air pockets.  which is pretty much everywhere.  lol.  its a proper mess alright.

so time for dave to ask for help.  when all you guys who have more experience/luck than dave, do your boxes,

do you put the resin on the surface,and then work the matt into it, or soak the matt and then lay it on,  or both.?
am i better off using long thin strips of matt?  do they have to be larger to make strength, or just overlap them?
how many layers of  matt should i be putting on in one go round?

box is for 2-10s and an amp, so its fairly straight forward.

btw, like i said this is my first serious attempt at fiberglass, and im basically going off what ive read on the internet.

Well good sir, I recommend,

1. If you did not spend too much money on the setup, to scrap the setup and start over.

2. When you lay down your fleece or absorber material.  Always lay down the resin first, to truly saturate your material first.  Double check the proportions of resin and hardner again before attempting it the second time.

3.  After your material is soaked up with resin, you can begin laying the fiberglass over it.  If you have a complex piece, it will help to pre-cut your fiberglass material to insure it curves or aligns with the area you are working on.

4.  When you are laying down the fiberglass, it helps to use a roller to even it out and eliminate air bubbles.

When you are putting resin on your fleece for the first time i would suggest going a bit less on the hardner because it take alot more resin to soak the fleece then it does to soak your mat. I made a similar mistake as you with my amp rack but wasn't to concerned since the rack won't be under pressure. Anyway use less hardner then recommended when applying to our fleece for the first time so you have plenty of time to soak it completely.

I am assuming your otehr question has to do with AFTER you have applied your layer of resin the first time on your fleece and after it has dried. I have seen it done both ways, applying mat first then soaking it and pre soaking the area with resin then adding the mat and soaking it again. I find that if you don't have a roller to smooth out the bubbles then your best bet is to wet the area first with resin and then lay the mat down and soak it with resin.

Smaller strips of mat are much better because it's easier to lay down. If you have a large very flat surface then a large peice is ok but you have a greater chance of bubbles.

Tearing the mat and overlap is the best choice by far.

aceracer and saw hit, well said.

One question I forgot to ask cruzKing, what type of weather are you working in? cold, hot, in between?

ive been using a small paint roller to try and get the bubbles out, but that hasnt been working so much.   i think i can save the project by grinding all of the "bad" fiberglass offl.  other than the chunks in the first batch, my fleece round went good.

how much of a difference does tearing it vs. cutting it really make, if im overlapping it?

as for weather, its pretty hot here in alberta, around 30*C

thanks for replies.

tearing makes a major difference..in strength and in workability...

overlapped cut edges will produce a hump, that will have to be ground off or filled (waste of time and money)

torn edges will fray, the frayed long strand edges will give you considerably better overlap and less chance for bubbles...the reason i say less bubbles is because the process of tearing the mat actually opens up the mat and breaks it appart for you therefore air doesnt get trapped and the loosened torn mat wil also conform to contours alot better..put it this way if your cutting your mat your doing the it wrong...mat should always be torn...and fiberglass cloth should not be used for sub boxes either..if you were wondering..

as for your project you are going to be hard pressed to grind that all back to fleece without burning through it...you have to decide if the effort justifys the time and cost of rebuilding it..

second...you should purchase a better quality resin...bondo brand produces a heavy wax when it cures...which means considerably more sanding for you...IE you will have to sand between each cured layer of fiberglass..

you have to allow the fleece to cure before laying up your mat, and i would say the best easiest and most convient sized pieces to work with are approximately 4" by 4" for curvy areas as small as 2.5" x2.5", and for larger flatter areas, you can go as large as you wantbut you should make sure only the frayed edges protrude past the curves or corners, otherwise you will get air trapped in there and it will lift on you...

if you insist on soaking the mat, then please purchase a fiberglass roller...you can get them on ebay for like 2 bucks...this will squeeze out all the extra resin as well as any trapped air...obviously a paint brush is the easiest way to lay up fiberglassyou want brushes with short stiff bristles (about 1.5" long)

personally i hold the mat in place with one hand and with the other stab it a couple times witha resin soaked brush..the piece is now stuck and i continue stabbing the piece until it has wet out...this way i get no air bubbles and no wasted resin...you have to remember that the strength of fiberglass does not come from how much resin you put into it it comes from multiple layers of properly wet out fiberglass...your brush should be pretty muh dry while you are applying the resin, trust me it doesnt take much to properly wet out a piece of mat...

if done perfectly with no waste you should be able to do an entire trunk with a litre or two of resin..

thanks for all the suggestions, ive finished grinding off all the bad parts, i didnt have to go all the way down to fleece all over.  as for the bondo, its all i can get around here.    after grinding down all the bad parts, my sides (largest unreinforced area) are still fairly strong.  i only hit mdf a couple of times around my sub rings.  other than that everything went good.  about 5 hours of my time spent grinding is cheaper than me buying materials again. 

now ive got everything flat again, there is pinholes in it, but i will just lay resin on before matt, and that will fill them in

go check www.westmarine.com and use to store locator to see if theres a store near you.  I've used their resin on many projects without any problems.  Its not the best stuff around, but it will work better than bondo and from the sound of it, it should do fine for your project. 

so everything took a turn for the better on this project, i got a couple more layers of fg where it needed to be, got it sanded, layed on a couple layers of body filler, spot putty, first layer of high build, sanded,  i had to spot putty a few more little spots, and tonight i will prime again, and maybe paint.

thanks for the replies, and the suggestions, they helped muchly

i only have pictures of the frame (before any fleece) and now with paint on it.  no inbetweeners.  my pictures wont upload onto here, so ill give you the site that i have them posted on

https://www.gaownersclub.com/forum/showthread.php?s=&postid=801259#post801259

dude!!!!!!!!!!

i did it too long time ago, all i did was grind down the lumps and went back to glassing.keep in mind the less hardner you use the more time you will have to work your magic,but  your project will still get hard