My first box log. *pics*

[coolahan 10+ year member]

I know you won't believe me, but putting more screws in there actually LOWERS the structural integrity of the enclosure. Even pre-drilled holes reduce it. Will the enclosure fail? No; I doubt it. Is it weaker than maybe 1 or two screws per side? Yes.

proove it

 

[lilmaniac2 5,000+ posts]

[sarcasm]

Yea since screws are what holds the box together. more really hurt

[/sarcasm]

 

[Immacomputer 10+ year member]

[sarcasm]
Yea since screws are what holds the box together. more really hurt

[/sarcasm]

I hope you don't use screws to hold your enclosures together (as in, if you take the screws out, the enclosure will fall apart). That's just poor craftsmanship there.

proove it

Phil at http://www.woodlawncabinetry.com did a test using a compressor and measured at what pressure enclosures failed. If I remember correctly, he used multiple enclosures that he built and tested for their breaking points. I'm pretty sure that he found the weakest link of the enclosures to be the MDF and not the glue joint.

I took an old enclosure and pulled out every single screw from it and tried to break it. After playing it very hard and dropping it off my roof, it was still solid. I went at it with a bat and when the enclosure broke, it separated from the wood and not the joint. The sad part is that I used plumbers caulk to glue the enclosure together because it was just a ghetto quick-fix box and that's all I had.

Like I said before, you won't notice a difference and you probably won't have a failure but you are wasting screws and your time (even though it's very little) on something that is only making things worse. But either way, you won't believe me and will go on doing what you're doing. If you haven't had any trouble, why change, right?

 

[ultimate157 5,000+ posts]

I hope you don't use screws to hold your enclosures together (as in, if you take the screws out, the enclosure will fall apart). That's just poor craftsmanship there.

Phil at http://www.woodlawncabinetry.com did a test using a compressor and measured at what pressure enclosures failed. If I remember correctly, he used multiple enclosures that he built and tested for their breaking points. I'm pretty sure that he found the weakest link of the enclosures to be the MDF and not the glue joint.

I took an old enclosure and pulled out every single screw from it and tried to break it. After playing it very hard and dropping it off my roof, it was still solid. I went at it with a bat and when the enclosure broke, it separated from the wood and not the joint. The sad part is that I used plumbers caulk to glue the enclosure together because it was just a ghetto quick-fix box and that's all I had.

Like I said before, you won't notice a difference and you probably won't have a failure but you are wasting screws and your time (even though it's very little) on something that is only making things worse. But either way, you won't believe me and will go on doing what you're doing. If you haven't had any trouble, why change, right?

Even though what you said may be true, all it does is prove how strong the glue is used to hold the MDF walls together. You have two sides to a proof. Just because you proved how strong the glue is, it doesn't mean the converse is true. The converse being that screws are weakening the structure.

 

[Immacomputer 10+ year member]

Even though what you said may be true, all it does is prove how strong the glue is used to hold the MDF walls together. You have two sides to a proof. Just because you proved how strong the glue is, it doesn't mean the converse is true. The converse being that screws are weakening the structure.

More screws = less surface area for glue to cover and also may pull the wood in too close causing a good amount of glue to leak out the sides instead of being absorbed. Also, even if you pre-drill the holes, the screws will make the wood split easier and this is how my enclosure failed. Have you ever separated MDF before? I recently had to do this for an amp rack and do you know how I did it? I drilled in three screws across a 12" section of MDF. This caused a mild crack that was easily exploited and I was able to make two bases using the split piece of wood.

 

[reneeb7363 10+ year member]

a few screws in the box does assist you in making sure the seals/edges are glued together tightly ... similiar, if you will, to putting a mess of clamps on the box until the glue has had time to cure... Any good cabinet and/or furniture maker will instruct you in such. The glue will absorb into a particle or fiberboard and create a better hold in the long run but it is really all about establishing a solid bond in the first place...Extremely VITAL to the quality of the cabinet/box/enclosure...what have you.

.............that's just my opinion---I could be wrong! At least I am woman enough to admit it! LOL !!!!

 

[LeofromtheH 10+ year member]

a few screws in the box does assist you in making sure the seals/edges are glued together tightly ... similiar, if you will, to putting a mess of clamps on the box until the glue has had time to cure... Any good cabinet and/or furniture maker will instruct you in such. The glue will absorb into a particle or fiberboard and create a better hold in the long run but it is really all about establishing a solid bond in the first place...Extremely VITAL to the quality of the cabinet/box/enclosure...what have you.


.............that's just my opinion---I could be wrong! At least I am woman enough to admit it! LOL !!!!

//content.invisioncic.com/y282845/emoticons/iagree.gif.15d6c075ee8d3913ba26866d06993068.gif

nice box btw, but i honestly don't think you need that many screws

 

[ultimate157 5,000+ posts]

More screws = less surface area for glue to cover and also may pull the wood in too close causing a good amount of glue to leak out the sides instead of being absorbed. Also, even if you pre-drill the holes, the screws will make the wood split easier and this is how my enclosure failed. Have you ever separated MDF before? I recently had to do this for an amp rack and do you know how I did it? I drilled in three screws across a 12" section of MDF. This caused a mild crack that was easily exploited and I was able to make two bases using the split piece of wood.

You're also talking about putting perfect cut boards together. My boards weren't perfectly straight, therefor they needed to be tighter anyways. and a 3/32 pin-hole ain't exactly a noticable difference when talking a 36" long 3/4" wide glueing face.

 

[Immacomputer 10+ year member]

You're also talking about putting perfect cut boards together. My boards weren't perfectly straight, therefor they needed to be tighter anyways. and a 3/32 pin-hole ain't exactly a noticable difference when talking a 36" long 3/4" wide glueing face.

Don't take what I'm saying personally and also don't misinterpret me either. If you need the screws to fix a bad cut (I would really suggest a re-cut if you have the wood) then so be it. What I'm saying is that all those extra screws will lower the integrity of the enclosure. It's not a big deal but I don't want people thinking it's the other way around and worrying about putting tons of screws into their enclosure when it is not needed.

I use screws to hold the pieces square and together while the glue cures. I usually only use 1 screw if under 12" and two if over 12" and I have never had a problem.

 

[ultimate157 5,000+ posts]

Heh, didn't mean to sound personal. I just like a good, thoughtful argument every-so-often.

 

[MrSwiss 10+ year member]

agreed screws and pretty friggin awesome + titebond.

 

[PowerNaudio 10+ year member]

i agree with the use of screws. i have found out that the closes you want to have them using 3/4"mdf is 6" that keeps the mdf safe from any spliting even if pre-drilling and it does actualy add to the strength of the enclosure. if using brad nails. every 4" work great. i have been able to separate two pieces of wood that had just been glued together with tightbond II. with my bare hands. but with screws on it it was almost imposible. had to use a hammer. but any ways lots of people will argue this issue im just giving you my two cents.

and for turning your sealed enclosure into a ported enclosure here are some nice apps that can help you make it happen.

i have been using this nice software thats free along with winISD is box notes.

here is what you get out of it.

#

Take into account the extra volume taken up by your ports, bracing and driver

#

Check the minimum dimensions required to house your driver

#

Quickly see the effect of changing port parameters

#

Spot problem resonances and adjust your dimensions to minimise their impact

#

Print your cutting list, including optional allowance for trimming with router

#

Save your work in boxnotes project files, including comments

#

Supports both Imperial and metric measurements

#

Generate a text based report containing your choice of information

great looking enclosure you built there. let us know how it sounds once you get runing.

laters

 

[ultimate157 5,000+ posts]

great looking enclosure you built there. let us know how it sounds once you get runing.

laters

I think I'm going to throw the sub back in it tomorrow and tell you guys how it sounds on music. I played test tones with it before @ 20hz and was bouncing quarters. I know I keep saying it but i've never heard of a sealed doing that kind of pressure @ 20hz. I'd like to get it metered ...

 

[Bake 10+ year member]

That is a nice looking box. It doesn't look like your cuts were too far off.

The less is more take on the screws is right. Too many and the MDF can split. I bought a brad nailer when I first started building boxes and it has been worth every penny of whatever I paid for it back then.

Oh yeah,,I would use some bracing in a box that big.