Mixing fiberglass and MDF... need help.

[Poseur]

Okay, so once again, I'm taking my sweet ass time to get it done, but now I've gotten to the rings. I was about to trim my box to shape, but it was late and that thing acts like a speaker as it sits, so the sounds of the dremel got neighborhood piercing-loud... So a couple notes on rings. 1st, That is my spendy ($25) circle cutter jig that I'mgoin to tryto take back and say sucks. it's flexy and crappy. I had to work over the rings with a dremel pretty heavily to get them down to somwhat round (fortuantely I was overly conservative with very circle and needed to lose some material anyway)

I used t-nuts which actually turned out to be easier than i'd imagined. I used #8 nuts with allenhead bots. Was thinking of going bigger, but figured that the holes would wind up overlapping the cutout hole ALOT. as-is they just barely get into the cutout, but not enough to hit the speaker. I used a bit of glue on them as well t tomake surethey won't pop out easily..

 

[sndsgood]

yeah, i'd even suggest fiberglassing those little buggers in. noting worse then having one pop out on you and not being able to get your speaker out, i ended up having to cut a hole in the side of one of my boxes to get behind there to hold the t-nut while i unscrewed it. those things are great but if not in securely while your screwing the allen head in they can come loose and start spinning and the little prongs can flatten out wich is what happened to me. so make sure they are in there good.

 

[chuyler1]

Man, that must have sucked. Did you try to drill the head of the bolt down?

 

[sam1]

im glad i never bought one of those tools. i saw them, but i just stuck with my good ol jig saw. works every time. i think im gonna use t nuts with my boxes too. ive always just used wood screws, but if im going to all this work for a box, im getting some good bolts too. im gonna put a drop of glue or liquid nails to hold the nut tho, like sndsgood suggested. especially since ive already got my rings glassed in before i made any holes. ive worked with them a couple times making other things and they can come loose and spin sometimes if theyre not seated properly. but anyways, almost ready to fleece then huh. shouldnt be long now before its finished.

 

[sndsgood]

i thought about it, but it was an allen head and pretty thick. i just said screw it, cut a hole in the box, fixed the problem then sealed it back up.

 

[Poseur]

I actually already had one dothat. I was setting them all in with gorillaglue, andapparantly some of the glue form one of them got into the threads... prettymuch just had to dremel that one off, and yank it out... hopefully I don't have problems, but *shrug* my sub mounts up REALLY nice... I was gonna glass them into place, as well as bond my rings together thaway, but but then again there's the issue of getting resin in the threads... ohwell, gorillaglue hasn't let me down yet. I've got a buddy who glued a bowling ball to the ceiling of his apt. still uptehre 6months later... not to say I don't get nervous walking under it...

 

[chuyler1]

Interesting. What kind of glue did he use? ...and how long was he standing there holding it while it dried?

 

[Poseur]

Gorilla glue. He held it in place with large PVC pipe that he wedged underneath it. IT's a blue marbled shin one too. Pretty freaky, eH? *L*

 

[Poseur]

So I've been way toobusy fixing up friends' bikes to get any work done on my own things, but I DID manage to borrow the compressor and airtools while I was down at my buddy's bike company... DAMN those things are nice. Took me 15min to do what would take an hour and a TON of busted cutoff wheels on a dremel. Only crappy part is that thing threw fiberglass dust EVERYWHERE... But atleast with compressors you can alsow blow said dust off of everything (I was outside mind you) forunately he had little paper-respirators around. But I still had to come home and take a shower to get the itching off... Atleast it's finally gota real shape to it now...

oh, yes and on the inside-car pic, this is the reason why I need a glassed-in compact box. My hatch looks like this all too often. It got to be quite a pain with my old clunky wood box. I'm enjoying the extra space already!

If I can find the time tomorrow, I REALLY wanna bare minimum get my rings braced into place (I'm gonna make atleast some of the braces structural just to help hold my #30 of sub) and MAYBE just maybe I'll atleast stretch my fleece ifnot actually get some resin on it.. we'll just have to wait and see on that.

 

[sam1]

looks good. but yea, id put some serious bracing in there for the ring. i used four 1inch wide pieces of wood and glassed them in to place for mine. that sucker is never moving. and once the fleece is on you can really get an idea of what your box is going to look like finished. it should look tight. just remember to stretch the fleece really tight and glue it really good. i used a hot glue gun and glued it every 2inches or so. that way the glue doesnt pull loose when you stretch the other sides. and stretch it as tight as you can, because it will sag if you dont. mine saged just a little and i pulled pretty damn hard on it.

 

[Poseur]

Yea, I'vr got alot of wood scraps still lying around and such, Just gonna start cuting them til they fit and everythign situates itself somewhere mildly pleasing. ANd yes I'lll be glassing into place once I have it all int place. For the fleecing, I'm gonna do hotglue and then staples wherever I can... GOnna be weird, though because some of the areas of the ring are gonna be "recessed" meaning it'll be pulling the fleece instead of pushing it out, so I gotta secure it good. I figure staples there would be good.

 

[sam1]

ive seen on some sites where they use the piece they cut out of the middle of the ring to hold down the fleece. they just put the fleece on, then put the cutout back in the middle of the ring and put a couple screws in it. i think that would work best for this kind of application. ill try to find a site that shows it incase im not explaining it right.

 

[sam1]

just like theyre doing on this car
http://www.hzemall.com/Future_shop_installs_folder/future_shop_1990_honda_civic_system2.htm
and with the amp racks on this car
http://www.hzemall.com/Future_shop_installs_folder/future_shop_1997_honda_civic.htm

 

[Poseur]

Yea, that's exactly the idea I had, but my only real concern is being able to get the "cap" piece off. I know how well the resin likes to suck into wood. I was considering maybe using waxpaper between my circular "cap" piece and the fleece to keep them from sticking to eachother... Anyone have any input there?

 

[sam1]

that may work. if anything, just use your trusty tinfoil.

 

[fLyPiNoY7]

currently on this same type of project...but some advice is to use as much fiberglass as possible when making the front...if u skimp out on it, the fiberglass will be weak enough to rattle like hell at each bass hit...crappy ass sounding sub at that point...now i have to go back and reinforce the back of the fleecing like crazy with fiberglass...

 

[Poseur]

Hmm, thanks for the head's up. I'm pushing a pretty hefty driver so I'm a little paranoid about the possibilities for that exact thing happening. I've been trying to figure how much is truely warranted, and what's just rediculous overkill. Hence the reason that instead of getting anything else done I generally just wind up glassing another layer. My current plan for the front is to fleece it, then do atleast 3layers of glass, then sand it smooth, and possibly fleece again (or alteast pull some sort of fabric across it then resin to aide in smoothing and keep my bondo to a minimum as well) hmm... box's over at a friend's garage, and I'm pondering driving back across town right now to put down a couple more layers... I'm up to about a dozen... I think I need to get over it and call it good. I mean, really if it winds up being too flexy for my sub, I've got 3 friends locally with 5's who all want it. I can just take my experience and do me a beefier one... so FWIW, no further progress really today. There's like 3 different bike races this weekend which makes me a freelance bikewrench a busy guy.

 

[chuyler1]

You want to aim for about 3/4" thickness when you are done. This will be more than one layer of fleece and a few layers of glass.

 

[Poseur]

a couplefew layers of glass in a fleece sandwich it is then... 3/4" of fiberglass and fleece, though? really? sounds stout, but if it's necessary, I'll do it. Though I might need a new gallon of resin before I'm done... asfor the back of my mold, it's sitting at about 15layers mixed mat and cloth now, and I think I'm comfy with that. I can support my full weight without a front on even, and pushing on it I can't get anywhere to budge. I was looking at my old 3/4" MDF box, though and realizing exaclty how burly that stuff is... *sigh* ohwell. off to try to accomplish something....

 

[Poseur]

ring in place ready to fleece

Okay, so I found some time today, and managed to get my ring sticked into place. First I used hotglue, which seriously impressed me with it's strength, Nonetheless I also glassed the ends of the sticks to make sure they don't come out. (that's the wetspots) hopefully it'll dry nice and solid. I figure some of the crossbraces might actually strengthen the box itself, but it'll hopefully be negligeable.