Subwoofer box

[mf01]

I'm adding a Kicker 12" CVR to my SPN. I have built many car boxes, but this will be my first marine box. I'm thinking I should probably use a water seal on the box before I carpet it. What are others doing in their boats?

[mf01]

RE: Subwoofer box

I should have searched first, but I found that you need to fiberglass or line the box. Could I use this on the MDF: http://www.northerntool.com/webapp/w...70_47722_47722

[AuMDLST]

RE: Subwoofer box

just mix up resin for fiberglass work and paint it on.

[mf01]

RE: Subwoofer box

Just the resin part? You don't have to actually use the glass strands?

[MHayes]

Re: RE: Subwoofer box

Just the resin part? You don't have to actually use the glass strands?

Not if you're just trying to waterproof an MDF box. The fiberglass is for strength and not necessary in this situation.

[core-rider]

RE: Re: RE: Subwoofer box

I put fiberglass mat on mine just to make it a little stronger, but it was not needed and added to the mess I made while doing it. If waterproofing is all you want, got to Lowe's/Home Depot and pick up some fiberglass resin, mix in hardner, and paint it on.

[mf01]

RE: Re: RE: Subwoofer box

Doesn't sound too bad. I used the fiberglass kit to make a rear bumper on my Ninja years ago and it was not fun molding it. Just the resin sounds pretty easy. I'll have to coat the inside too.

[core-rider]

RE: Re: RE: Subwoofer box

I guess you don't have too, but make sure you get the outside very well. Any exposed MDF will blow up like a balloon once it starts to get wet.

[mf01]

RE: Re: RE: Subwoofer box

It'll be a ported box, so i probably should do the inside. I wonder if it will affect the sound on the inside.

[EarmarkMarine]

RE: Re: RE: Subwoofer box

Coating an MDF box with fiberglass resin will provide some resistance to water… but is not waterproof.

Resin is porous. It’s actually the gelcoat that seals a fiberglass hull.

For most applications where the box is exposed to a little spray and drips, resin will be adequate.

But if you set the resin-coated box directly on the deck carpet it will wick up the trapped moisture through the resin and eventually swell up causing the seams to fail.

To avoid this elevate the enclosure off the sole with polymer mounting pads. Half-inch ABS, King Starboard or any other polymer will do.

David E. M.


MF101,
Yes, in a ported box you should coat the interior also, including the edge of the woofer opening.

[TravisFling]

RE: Re: RE: Subwoofer box

I used rubber bumpers from my local hardware store and then drilled a screw right through the middle into the box, with the sub firing down and it sounds fan-tastic.

[mf01]

RE: Re: RE: Subwoofer box

I plan to put it under the passenger seat. It rarely gets wet under there, but I still want to take precautions.

[mf01]

RE: Re: RE: Subwoofer box

I started working on the box on Thursday night. I finished it Saturday. It took the resin a long time to dry. I put it on Friday night around 7pm and it still wasn't dry Saturday at noon. I ended up carpeting it while it was slightly tacky. Here are the pics: http://s30.photobucket.com/albums/c3...oofer/?start=0

[OHLNautique]

RE: Re: RE: Subwoofer box

Good job on the box. You were right on to resin the inside. It would have cured faster if you had used more hardener in the resin. Do you mind if I ask why you did not build a slot port into the box? A slot port produces a lot less port noise plus it re-inforces the box. That probably doen't matter in a boat though.

[mf01]

RE: Re: RE: Subwoofer box

I was going to use a flared port I have, but realized it was out of the question half through the build. It was 4" and I needed a 3" to tune the box. Truthfully I don't hear any port noise right now.