Is it possible to use high density foam instead of mdf if you are fiberglassing over it anyway? I want to do a nice layout in my trunk but dont want the massive ammount of weight. Any thoughts?

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RIIIIIIIIIIIIIIIIIIIIIIIIIGHT
sorry...
You can always try, but foam will soak up the fiberglass and youll need to use a lot more of it, and it will not be a strong back to hold any subwoofers or any other item. You can try, but I would expect not so good results.


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The foam I would use is actually pretty rigid and with glass to support it it makes it very strong. They actually use foam with fiberglass to build race boats and they take more abuse in the ocean than a woofer could put on a box. I was just wondering if anyone has tried it??

best time so far 14.3 @ 101.1mph(no traction)
fastest 2GNT with a hitch! until proven wrong...

I think you should see how it works, I know about the foam they use on boats but i dont remember all the properties it possesses. There is a boat manufacturing facility in my town, ill see if one of my friends could bring me some of it. id still make sure that u mount your subwoofers into at least an mdf ring.

i asked my coworker about it (he used to work for that company), he says that it would work fine, possibly even better then wood. He is also emailing one of his buddies that works in management there to get his opinion on it, the name of the material and maybe getting me a sample.

Ill post when i get more information.

-Gabe-

Sounds good. Thanks for looking into it. This would save massive amounts of weight

best time so far 14.3 @ 101.1mph(no traction)
fastest 2GNT with a hitch! until proven wrong...

They don't use the foam to back the fiberglass in racing boats for structure, they use it for flotation. They build those hulls then fill the gaps with expanding foam which seals them off from all water and makes the boat virtually unsinkable.


If you lay fiberglass onto foam there's a big chance you are going to melt the foam during the curing process. Foam generally doesn't like any kind of chemical interaction. Hell spraypaint will melt styrofoam.

I say brush some resin onto the top of the foam and see if it will harden normally, if it does, it will be solid and a great alternate light weight base material.

a_miller you're wrong. They do use the foam as fillers and sealers as u said they did, BUT they also use types of foam for structural uses. I will get u the specs on it. My coworker designed boats for Cobalt Boats for 6 years. I think he would know what he is talking about. I will get the specs, I will get the proof, I promise this.

-Gabe-

edit: here is a list of suppliers listed on boat design forums. Ill still get the info on the stuff they use at Cobalt Boats.

http://boatdesign.net/forums/showthread.php?t=368&goto=nextnewest

Well i stand corrected :thumbsup

Aaron - sorry, didnt mean to sound like an ass bud.

I would really like to see this done. Hopefully by someone who has used mdf. That way we can have a comparison on ease of use, strength, weight savings, cost and so on. maybe when its all said and done maybe mdf is still the way to go.

-Gabe-

Well homedepot has pink foam that is used to insulate homes you can get a pretty large sheet for 14 bucks. As far as resin goes I will not be using polystyrene. I will use a 2 part epoxy. It is buch stronger and has almost no fumes. Foam is used on race bots for structual purposes. You could make a boat out of cement wiht no foam and it would float the foam has nothing to do with it.

best time so far 14.3 @ 101.1mph(no traction)
fastest 2GNT with a hitch! until proven wrong...

Originally posted by extreme97nt
You could make a boat out of cement wiht no foam and it would float the foam has nothing to do with it.

Wait now hold on there cowboy :) You can make a vessel with a diplacement of water greater than that of the sum weight of the vehicle out of ANY material and it will float, but flip it over and you're fucked. Get any of these modern fiberglass bass boats and the hull is 6-12 inches of foam injected into a fiberglass shell. And it's ADVERTISED for floatation so that it's impossible to sink the boat. And it's true. The total weight of the boat is like 1/20th of the amount of water it diplaces and there is no way shape or form that it can take on more water, therefore reducing it's natural mass to displacemt ratio and sinking.Even if you fill the passenger compartment of those boats with water you can't sink them.

I may be a dumbass sometimes but not all the time.

You are correct I was under the impression that you said boats needed foam to float.

best time so far 14.3 @ 101.1mph(no traction)
fastest 2GNT with a hitch! until proven wrong...

Originally posted by extreme97nt
You are correct I was under the impression that you said boats needed foam to float.

Nah, i used to work on a cruise ship, no foam there LOL

thats how they make surfboards too. :cheers should work well.

At home depot, they have stuff called "great stuff". I used it to keep the shape of the footwell when making a box for it. This stuff works very well, very lightweight, but it's VERY messy and you DO NOT want to get it on fabric, it doesn't come off vry well. But it is very lightweight, hardens strong and you can glass over it. If ya have any questions about how to use it or anything, PM me or somethin, i've been through the process with it a few times and know how to use it.

interesting. just make a cube of foam, coat it with resin, poke a hole in it and pour gasoline in there. voila!!! LOL.

anyways, we may have a new sub box standard, yes?

Originally posted by 420AYE
interesting. just make a cube of foam, coat it with resin, poke a hole in it and pour gasoline in there. voila!!! LOL. anyways, we may have a new sub box standard, yes?

Uhm, no :wary

dude... i was TOTALLY serious. jesus.

my god is this ghetto


It will work but the density will be oh lets say not dense. The sound will suck and you will need 1/2 to 3/4 inch thick fiberglass for strength. the woofer will crack anythinf smaller and the foam wont hold up. now if you need 1/2-3/4 fiberglass them why have the foam in there at all? Its a question of density not will it work.

Terry

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Originally posted by Star Turbo Talon
my god is this ghetto It will work but the density will be oh lets say not dense. The sound will suck and you will need 1/2 to 3/4 inch thick fiberglass for strength. the woofer will crack anythinf smaller and the foam wont hold up. now if you need 1/2-3/4 fiberglass them why have the foam in there at all? Its a question of density not will it work. Terry 96 Eagle talon ESI Star Stage II - Boost/oil/EGT gauges 97 Eclipse Greddy header/evo exhaust - SFMU/return line - Stage 2 6 puck Sprung hub MIBA clutch - Shortened shifter - Koni Yellows w/eibach prokit - Stillen Fr/Rr swaybars - ceramic intake - DEI Keyless entry alarm - Niche 17" Shoks Waiting to be installed: Apexi AFC, HKS EVC IV, 450 Turbo injectors, GSX Front brakes (need rotors)

nooo...it was a question of weight dude....shutup. let them experiment. what do you care anyways? :thumbsup

remember? the first post asked:

"Is it possible to use high density foam instead of mdf "

High density. HIGH FUGGIN DENSITY.jebus.


AND, THIS IS STRUCTURAL FOAM! NOT packing foam dude. figure out whats going on b4 u even post.

EDIT: Might i add, its posts like these that discourages a lot of fabricators for making things for our cars as well. be positive eh?

^^^^dude, why are you so angry recently. what you just said didnt make sense, "high density foam" is still FOAM. not everything labled "high density" is riged, which is the main concern here.

with enough structural bracing and a small enclosure, this is a great idea. its been used for ages in making kickpanels and other small 'glass pieces.

Originally posted by SPL_Eclipse
^^^^dude, why are you so angry recently. what you just said didnt make sense, "high density foam" is still FOAM. not everything labled "high density" is riged, which is the main concern here. with enough structural bracing and a small enclosure, this is a great idea. its been used for ages in making kickpanels and other small 'glass pieces.

He's so angry cuz he's constantly posting worthless crap and the wrong answers to everything.

ok. ur right. i am a little pissy recently. And i post a lot because all i do at work is sit around. But as far as giving the wrong answers? just show me where i've been giving wrong answers and i will gladly take them back. If i EVER give a opinion on anything important, i always say, "don't quote me" or something like that. BUT. if these guys wanna try something let them. I see you guys getting on other people's cases for dumber stuff than this.

sorry. im just stickin up for this thread.

If im not mistaken, your the one giving wrong advise.

"They don't use the foam to back the fiberglass in racing boats for structure"

:rolleyes

"I may be a dumbass sometimes but not all the time."

maybe so. im a dumbass most of the time though. :bash

"EDIT: Might i add, its posts like these that discourages a lot of fabricators for making things for our cars as well. be positive eh?"

Mebbe that wasn't very positive...and i now stand corrected for everything i was wrong about...happy?

Also, "what you just said didnt make sense, "high density foam" is still FOAM."

I have actually no clue what this stuff is he is talking about. but he seems pretty positive he knows what he's talking about. He works with it or something, and if he thinks he knows what he's talking about, i won't question him.

"He's so angry cuz he's constantly posting worthless crap and the wrong answers to everything"

That of all things doesn't make sense man.

Jesus dude, don't bring up the boat thing again.


When they make a fiberglass boat the make a shell in a vacuum mold then they lay the inner and outer shell together. Once they are in place they pour that foam in the shell for boyancy and to make it impossible to sink them. It has NOTHING to do with structure, and the fact that they pour it in after the boat is together, they don't lay the glass on top of foam.

THIS IS WHAT I'M FUCKING TALKING ABOUT.

Originally posted by a_miller_76
Jesus dude, don't bring up the boat thing again. When they make a fiberglass boat the make a shell in a vacuum mold then they lay the inner and outer shell together. Once they are in place they pour that foam in the shell for boyancy and to make it impossible to sink them. It has NOTHING to do with structure, and the fact that they pour it in after the boat is together, they don't lay the glass on top of foam. THIS IS WHAT I'M FUCKING TALKING ABOUT.

Im bringing it up one last time before you come beat my scrawny ass.


I don't really care how they make boats float mang, NOR do i see how its even relevant to topic. Im just saying that you apparently misunderstood, and gave slightly wrong info.
Its just you were acusing me of something. You acuse me of this while in the same thread you made a mistake/misinterpretation/WRONGINFO. I just don't see the logic.

Originally posted by a_miller_76

Originally posted by extreme97nt You could make a boat out of cement wiht no foam and it would float the foam has nothing to do with it.

Wait now hold on there cowboy :) You can make a vessel with a diplacement of water greater than that of the sum weight of the vehicle out of ANY material and it will float, but flip it over and you're fucked. Get any of these modern fiberglass bass boats and the hull is 6-12 inches of foam injected into a fiberglass shell. And it's ADVERTISED for floatation so that it's impossible to sink the boat. And it's true. The total weight of the boat is like 1/20th of the amount of water it diplaces and there is no way shape or form that it can take on more water, therefore reducing it's natural mass to displacemt ratio and sinking.Even if you fill the passenger compartment of those boats with water you can't sink them. I may be a dumbass sometimes but not all the time.

You know? i really doubt if he cares if you know how boats work, or if you know how to use google. I pump gas for boaters all day long. I see more bass/crapie/catfish boats in one week than you do. I know what a boat is made of and what they look like fyi. You can use numbers all you want, and people will beleive you 99% of the time because they are too lazy to check.....Did you beleive that?

im done.

Originally posted by a_miller_76
Jesus dude, don't bring up the boat thing again. When they make a fiberglass boat the make a shell in a vacuum mold then they lay the inner and outer shell together. Once they are in place they pour that foam in the shell for boyancy and to make it impossible to sink them. It has NOTHING to do with structure, and the fact that they pour it in after the boat is together, they don't lay the glass on top of foam. THIS IS WHAT I'M FUCKING TALKING ABOUT.

OK, maybe that is how they make bass boats, however the foam will not give it any boyancy unless the fucker sinks. Also the vacuum mold is used to get all the bubles of air out of the fiberglass. It also allows the builder to use the correct amount of resin. Anyway I am not talking about little 20' bassboats that never see big waves. I am talking about offshore race boats which my father used to build. Yes they do use foam for strenght. On older boats they used strips of foam maybe 3/4 inch thick by 6inches wide down the sides and bottom for strenght. On newer boats they make the whole sides of the boat out of foam vacuum bagged in between fiberglass. This allows the boat builder to make the boat lighter without sacrificing weight. There is also things called stringers and bulkheads which I am not going to get into. For the record. I built a box with foam and glass and it works great. the glass is about 1/4 in thick if that and I had no problems with it cracking and the soud was awsome.
SO YES IT WORKS...



best time so far 14.3 @ 101.1mph(no traction)
fastest 2GNT with a hitch! until proven wrong...
www.cnnmotorsports.com

please, post some pics for the non beleviers. i was with ya the whole way. hit me up on aim or email me at: imlazy@gmail.com

SWEEET! How much does it weight? and how much power were u puttin to it.

i would reply with the reason it will not work as well as MDF but after your ingnorant reply 420aye i wont bother...what the hell do know i hit 135 DB with 2 10's and 300w 10years ago when i ran competition. Do what you want and give it a try.....while your at it try using a fuggin bucket and some liquid nails i bet that is one hell of an idea too.

God your a a$$ lately, get a hooker and get a piece already.

Terry
96 Eagle talon ESI
Star Stage II - Boost/oil/EGT gauges

97 Eclipse
Greddy header/evo exhaust - SFMU/return line - Stage 2 6 puck Sprung hub MIBA clutch - Shortened shifter - Koni Yellows w/eibach prokit - Stillen Fr/Rr swaybars - ceramic intake - DEI Keyless entry alarm - Niche 17" Shoks

Waiting to be installed: Apexi AFC, HKS EVC IV, 450 Turbo injectors, GSX Front brakes (need rotors)

Wanna save weight? Don't put ghey shit in your car. ;) :+

Originally posted by etx
Wanna save weight? Don't put ghey shit in your car. ;) :+

ill assume ur not talking to me. i don't have anything on my car. :shrug

Originally posted by Star Turbo Talon
i would reply with the reason it will not work as well as MDF but after your ingnorant reply 420aye i wont bother...what the hell do know i hit 135 DB with 2 10's and 300w 10years ago when i ran competition. Do what you want and give it a try.....while your at it try using a fuggin bucket and some liquid nails i bet that is one hell of an idea too. God your a a$$ lately, get a hooker and get a piece already.

ok. i'll use a bucket. thats exactly like fiberglass and foam. :rolleyes Apparently you know a bucket and liquid nails doesn't work. was that your pic i saw a while back? (I, AM, KIDDING.)

SERIOUSLY. I'm sorry if im hurting all your feelers, but EVERYONE knows MDF is proven. Here is a god damn tissue. But why would you try to prove it to me again? Personally, i'll be buying an MDF bandpassbox here shortly. Whats your point? Please, i'd like to know. NOONE knew for sure what some foam and mdf could do, and refused to give it a chance. Call me an ass, cuz I tend to be one when people are completely out of context(AKA BLONDE). Ask yourinmymirror95gs. We are nothing but assholes to eachother, yet we are pretty much best friends even though he doesn't live near me anymore. Either don't let it bother you or hate me, I don't really care. Its the internet, and I don't need, "e-buddies" like you to approve anything I do. I have my own, REAL friends, as I'm sure you do too. I just don't see why everyone is so determined to prove that peoples ideas won't work, BEFORE EVEN SEEING ANY FACTS, and STILL are ignorant to the fact that it works, AFTER it has been proven. There are pictures on this forum. Why don't you help out for a change?

Everyone else knows so much more than me. Maybe its true, I am not an audio expert, nor an expert in anything related to cars. While we are showing off with numbers and such, I honestly could go down the road, go to my dad's local hardware store, pick up a bunch of MDF for cheaper than you ever could get it(next to nothing if not free) and build a box that would be just as good as yours, if not better. This topic isn't about how much you know about MDF. The topic is: "Foam instead of MDF". Not why MDF is better and how stupid of an idea it is. When a post is made in efforts to explore new ideas and possibilites, there is no need for you to give any negative remarks or alternatives. This reminds me of the catholics and galileo. Stereotype anyone? Again, MDF is proven, and im sure if he wanted to he could make a box out of one. He made it already with a FOAM FRONT on his fiberglass enclosure and it works. Yes, I said foam, and yes, it works. I won't throw any insults. Doesn't belong here. Lots of people on this board, even myself have a tendency to reverse engineer the problem instead of solving it. But, it just isn't relevant. nuff said.