glass dilemma
Printed From: the12volt.com
Forum Name: Fiberglass, Fabrication, and Interiors
Forum Discription: Fiberglass Kick Panels, Subwoofer Enclosures, Plexiglas, Fabrics, Materials, Finishes, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=48084
Printed Date: May 09, 2024 at 11:20 PM
Topic: glass dilemma
Posted By: doc t
Subject: glass dilemma
Date Posted: January 19, 2005 at 6:13 AM
I know there have been a lot of posts on this subject......but I need some help. I plan on building a box for a ford ranger with four(4) 12"dvc subs made be scosche the EFX line. the subs will be inverted for show. they will be powered by an EFX hd8001 class D monoblock. the airspace for each sub will be around 1.07cf per sub the top will be glassed with min 10 layers. The sides, bottom and internal braces/dividers will be 3/4 MDF . I've been told that the box will fail due to the serious pressure. the person that i'm getting this info from, has the same system and has hit 144db at a couple of competitions. should i be worried ? is 10 layers going to be enough or should i plan on more layers? I've built many boxes in the past and this will be my first using glass. and yes I will take pics for everyone.
Replies:
Posted By: doc t
Date Posted: January 19, 2005 at 6:24 AM
The sub amp is an Earthquake PH2 I believe and not the EFX HD8001.
Posted By: realitycheck
Date Posted: January 19, 2005 at 8:37 AM
I think 10 should be plent of layers I mean that getting like a 1/4 inch thick. Just make sure you test the flat areas for weakness, push on the area with your thumb and see if it moves. If it does just glass more on the inside in that specific area, I even glassed a piece of mdf on the flat areas inside my box. The way the thumb works is that with you pushing with the small area of your thumb you are putting way more pressure on that specific are compared to any sub putting pressure on it. So if it doesnt move then you should be good to go.
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Learning the trade one fiberglass creation at a time!
Posted By: doc t
Date Posted: January 19, 2005 at 8:59 AM
And if i'm reading the posts right, I glass the inside of the box and bondo the outside? or do i glass the outside as well. and is it nessasary to sand between layers to help eliminate air bubbles? I've made speaker pods two layers thick before but nothing this big. it will be covered in suede. the "peanut butter" thing sounds interesting, can you get the carbisol/areisol at homedepot or lowes or west marine?
Posted By: doc t
Date Posted: January 19, 2005 at 9:03 AM
aerosil-cabosil, sorry, had a brain fart!
Posted By: realitycheck
Date Posted: January 19, 2005 at 10:03 AM
You might be able to get it at west marine but I doubt it, but I would check and see. my link for it https://www.shopmaninc.com/fillers.html this stuff goes on the inside which will change your cubic feet, so you might want to consider that. No you should glass the outside and then sand and bondo, the glass. ------------- Learning the trade one fiberglass creation at a time!
Posted By: doc t
Date Posted: January 19, 2005 at 10:17 AM
what about sanding between layers of glass to smoth it out. to eliminate air bubbles.
Posted By: doc t
Date Posted: January 22, 2005 at 8:27 PM
ok this is what we've got done so far....tomorrow the fleece. the rings were a B@#$% went through two dremil bits. then had to finish with the jigsaw.
Posted By: doc t
Date Posted: January 22, 2005 at 8:49 PM
need to retake the pic before fleecing....figured out my camera.
Posted By: fexploder
Date Posted: January 23, 2005 at 5:24 AM
Ten layers of glass is overkill. if you have between 1\4 and 1\2 inch you will be perfectly fine. I also do recomend laying glass on the bottom and sides, but only one or at the most two layers. this will prevent the mdf from flexing at all and will also give you a box without any leaks ( meaning no sealing the box ). Cabosil is verry misunderstood. Cabosil ( a thickened version of "resin" ) only needs to be used to fill in holes in fiberglass, seal two peices of fiberglass togeather, waterproof a peice of exposed mdf, and so on. using cabosil to "fiberglass" wood is like building a car out bondo. NOTE: When it comes to resin and catalyst dont be cheap. ALWAYS use a good quality resin and ALWAYS use a liquid hardner.
Posted By: fexploder
Date Posted: January 23, 2005 at 5:31 AM
Between layers you should lightly sand off the burs ( sharp bumps ) then wipe the glass with acetone shortly before applying the next layer. REMEMBER to wipe the dust and dirt off before applying each layer. This will prevent air pockets which weaken fiberglass.
Posted By: doc t
Date Posted: January 23, 2005 at 6:08 PM
sorry if these are too small....still trying to figure out this new camera.
 Used the divider to strentghen the back side of the box. 
all the rings in place. 
this morning we streched the fleese....it was 30 deg's in sunny florida this morning....not as cold as you guys up north but for here it's butcold! 
this is another view the staples were used to keep the shape of the rings.....do i have to remove them? 
here it is with the first three coats of resin applied, you may ask why three?....well the first and second were applied with only half the needed hardner, the cold got to me and i miss calculated, once i warmed up i realized my error and we mixed up another batch with just a wee bit more hardener and the set in the sun to increase the heat and it hardened in a couple of hours.......man is it stiff...the glass not me. will let it set till next weekend and then we will start the layers of fiberglass. any comments or sugestions are appreciated. T
Posted By: PimpVan
Date Posted: January 24, 2005 at 6:54 AM
The pictures came out good.I think you got one big project on your hand though.Just next time try not to forget to put the right amount of hardner in.Or that will slow you down alot.Hope it comes out good for you.
Posted By: doc t
Date Posted: January 24, 2005 at 7:36 AM
It's amazing how attention to detail goes out the window when your cold.
Posted By: realitycheck
Date Posted: January 24, 2005 at 8:14 AM
Yeah thats why I rather not deal with it when its cold. I'm waiting to do my lil. bro's box when it gets warm. I'm not a fan of the cold and once my fingers start going numb I really really want to get back inside. Anyway, your box looks really good man, props on the design. Quick question, did you test all four of your subs to make sure they all fit in the box? and didnt touch on the rings, or the inside of the box?
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Learning the trade one fiberglass creation at a time!
Posted By: doc t
Date Posted: January 24, 2005 at 8:29 AM
It's going in to my son's ranger, he's the one who came up with the design...so it's his fault if they rub!!...HAHA LOL just kidding the subs will be inverted for show and the surround clears, no rub.....the cold makes you realize that men have nipples too!!
Posted By: bluetruck
Date Posted: January 24, 2005 at 9:43 AM
looks nice. i hope he isnt pushing the subs too hard w/ 4 in one common chamber though.
Posted By: doc t
Date Posted: January 24, 2005 at 10:17 AM
It is divided into two chambers. the amp is around 700-800 wrms @4ohms
Posted By: PimpVan
Date Posted: January 25, 2005 at 6:55 AM
Ya with an amp like that he is going to be quakeing.I guess thats why they call it and EarthQuake amp huh.I think your sonis going to need hearing aids with that much power behind his head.Ya better hope the subs clear or that means more work out in the cold.(Not a very good plan)
Posted By: doc t
Date Posted: January 25, 2005 at 9:15 AM
PimpVan wrote:
Ya with an amp like that he is going to be quakeing.I guess thats why they call it and EarthQuake amp huh.I think your sonis going to need hearing aids with that much power behind his head.Ya better hope the subs clear or that means more work out in the cold.(Not a very good plan)
WHAT?.... I CAN'T HEAR YOU!!! (bur!!)
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