Fleece or Cotton?

what type of job are you doing???  will it be finished and seen? 

OKAY...seriously how many times does this have to be said....

using fleece is ridiculous...waste of money...

there are only two reasons someone builds a fiberglass box, 1. cool shapes, 2. less wieght...

first of all...a soaked piece of fleece has no strength at all...what because it is a quater inch thick and soaked up half a gallon of resin it is strong...think again...a fiberglass piece's strength comes from multiple layers of mat not gallons of resin...all that resin does is add weight and brittleness to the project...

you can take a cured piece of fleece and hit it with a hammer..it will punch a hole right through it not to mention crack the crap out of it...now take a piece of quarter inch fiberglass that has been made of 6 of 7 layers of mat and do the samethingnot only does it weigh a pound or two less (depending on the size of the piece it could be a considerable difference)...no crakcs no holes...most likely no blemish...

i wish people would understand that the whole strecthing "fleece" is just a way to obtain a fluid shape for your project, fleece has nothing to do with the strength of the project what-so-ever...it is strickly a way of getting a shape...it doesnt matter what faric you use as long as it will soak resin and not fall apart...i suggest panty hose for everything..it streches like crazy...requires next to no glue to hold it in place, you dont have to pull it stupid tight like you do fleece...and it is ten times thinner and ten times lighter...once it is cured it provides you with exactly what you wanted and needed a  relatively hard curvy surface....

to each his onw i suppose i prefer to save money  weight and time when i build my boxes...

yeah like nouseforaname said, this thread isn't about the strength of resin soaked fleece over resin soaked cotton.  Its about xlt_explorer trying to figure out whats the difference between the two and what will work best for him.  Any kind of sub box or interior piece i work on will be fleeced, because i like the fact that its fairly strong after the resin has cured and i can easily move it in and out of the car without worrying about knocking a hole in it or cracking it ( i dont have a whole lot of falling hammers in my car) The bottom line is that resin soaked fleece is stronger than resin soaked cotton, but both need to be reinforced with fiberglass mat if they will form any structural piece.  And like i said earlier, i would use cotton for something that wasn't structural and wasn't getting a layer of mat, where as i would use fleece for a sub box. 

nouseforaname wrote:

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you can also hit fiberglass mat with a hammer and knock a hole in it. fleece is a good first layer to use to form because of its stretchability. then you must layer mat to add strength. you can't stretch mat over a box to get a shape as you mentioned crazyoldcougar, so you are kinda disputing yourself. you have to start somewhere when getting a shape, which is the point of this whole thread i beleive, and fleece is better than cotton when it comes to that with box building. now small interior panels and what not, cotton is fine. no need to mat it or use fleece, unless its gonna get kicked or something like that. and if you've ever went to walmart in the baby section and looked at the fleece baby blankets, you'll see fleece isn't very hight at all.

oh yeah, and pantyhose? not my first choice for a box, buy hey, what ever floats your boat.

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i never said anywhere to stretch mat over the box!...that is clearly impossible..and good luck getting a hammer to go through a 1/4 inch of properly laid fiberglass espcially if it is curved...

first fleece ISNT "that" stretchable...there is plently of far more stretchy materials out there... fleece is fine to use if you want to completely nulify the fact you are building a lightweight fiberglass box.  Since you dont know...(most) fiberglass resin is a polyester based liquid, therefore a polyester based fabric is going to be best suited to applications....ALL fabrics will absorb resin...it is a liquid..it is like spilling water on it...if it will soak up water it will soak up resin... but once again the point of a fiberglass box is organic shapes and LIGHTWEIGHT....trust me the thinner and lighter the material used for stretching the better, because NOTHING soaked in resin, unless it is specifically designed for it will have ANY strength...so you are best to use the absolute thinnest and lightest material and spend your time and money adding fiberglass rather then gallons of resin to materials that have no strength..7 to 10 lyers of mat will be no stronger with fleece under it then it would be with panty hose under it...

i have seen far too many people lay up a 1/4 inch fleece and one or two layers of mat and call it a box...i guess that is fine if you want a heavy, weak, expensive, crappy sounding box..

fleece seems to be the "in" thing for box's, everyone has seen it on alpine's site and thinks that is the way to go....LOL it is funny....cars built strictly for show...that cant even be driven (legally) have become the status-quo for box building...fleece is cheap and strong enough for a show.... i am willing to bet the actuall custom installs done for customers are done differently, and they definately dont show everything on the website...still everyone swears by fleece having tried few other more suitable materials

and if your concerned about the strength of the pantyhose..dont be.. take your time, do the job right and start with one layer of mat over it first, after that has cured it will most likely be just as strong as your 1/4 of fleece but at one tenth the weight and cost of resin used...LOL i could build a incredibly solid box out of pantyhose mat and with the same amount or less resin as you would use just to soak your fleece.  if you charge your customers out the butt for resin then all the power to you, i just hope they arent dissapointed with a 50-75 pound fiberglass box that could have been 25 pounds...

and one other thing...if you build any fiberglass project..the point is to actually put fiberglass in it...cotton panels soaked in resin will crack regardless of how much filler and resin you put on it, and regarless if they get kicked or not...you have to remember that temperature greatly affects a products performance hot and cold (100* to AC) or freeze thaw will crack the crap out of your non-matted fiberglass projects. so please dont give out advice like that to someone..

there again cotton can be used, is it the best, not likely, but like i said, ANY fabric will absorb resin, some will completely fall appart, most will not..look for the cheapest lightest thinest most stretchy (polyester) based fabric you can find that will be your best fabric...what do you know that is pantyhose...and stay away from spandex materials...the rubber doesnt hold well against the resin and that material doesnt cure all that well either...

sawhit4 wrote:

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On and one more thing, the main purpose of fleece is to get the correct shape you're after, like crazyoldcougar said, but you also need a sturdy first layer to apply mat to.  I've never tried panty hose, but i cant see it holding in much resin at all.  It seems to me that it would have trouble supporting the weight of resin soaked mat when you started to fiberglass the box, but like i said i've never tried it. 

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LOL there is no reason what so ever to ever soak your mat in resin.....a simple brushed on stroke or two of resin...add your mat to it, squeeze out the excess resin from your brush then begin to poke the piece of mat in place...stronger, lighter, less expensive and less messy then soaking the mat with resin...once the first layer of mat has cured there will be no strength issues at all...you could apply later layers with a roller if you so chose...i do it all the time...well i never use a roller cause the "brush and poke" method pretty much eliminates excess resin and air bubbles...

I never said i was presoaking my resin in little pans overnight like you would marinade a steak.  When you apply fiberglass mat, it needs to soak up the resin, otherwise you'll get air bubbles.  Fiberglass mat and resin have to work together.  Neither one byitself will be worth anything.  Its obvious you're just taking what everyone else says and basically attacking it, for what reason i'm not sure, i guess you get some kind of fix off of it.  I see no reason to counterpoint everything you wrote in that post, because theres a pretty good chance the guy that started this post doesn't even look at it anymore, and the point of which fabric to use has been beaten to death.  "To each his own" 

sorry but NO mat does not need to sit in resin and soak it up...it is much, much, much stronger if applied with a little tiny bit of resin...by soaking a piece of mat in resin you stand a better chance of bubbles, as when you apply the now soaked piece it doesnt breath all that well, and like applying a vinyl sticker you get tiny little bubbles under it..

and i am not attacking anyone...i am just trying to make what is clearly a misunderstood art a little more clear...

if people want to run around making 100 pound fiberglass boxes for one and other i couldnt care less....i just find it funny that no one is willing to try a better proven technique and make their boxes that much better while saving boat loads of money, time and weight...

Where can I get the material that you use? I mean enough to do sub enclosure?  I would like to try your method. I am very interested in saving weight. and I would like to do a new enclosure for my subs.  I like the " build from behind method. Where you make your shape then build it up from the back to save on time and effort to finish the box.

Ravendarat wrote:

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For what its worth, I use grill cloth for my first base then build on that using matting. The grill cloth takes the resin just fine and give me a good platform to build off of, as well as its light as hell

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