nouseforaname wrote:
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...
Fiberglass Guru.