# Subwoofer box - MDF vs other materials



## PrarieChicken10 (Jan 26, 2021)

I have been researching for the best material for a subwoofer box and MDF has been mentioned the most. I bought some MDF and put a Box together. My question is... is MDF suppose to be very fragile? The MDF I bought breaks very easy on the corners and splits like a bunch of stacked papers when I drill screws in. For as heavy as it weighs, I am disappoint that it isn’t holding up better. 

Is MDF truly the best material for subwoofer boxes? Is there a better material ?
Are there different grades of MDF ? Possible I could have gotten a crappy grade ? 

Thanks! 


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## krash (Jan 21, 2021)

Yes it is rather fragile as you describe... it is a good material mainly because its readily available, its cheap, its straight, and easy to work with... except for DIY's with simple tools.. if you have a table saw, router, and air nail gun its great, unless it gets wet in which case its like a sponge.


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## blammo585 (Feb 1, 2020)

PrarieChicken10 said:


> I have been researching for the best material for a subwoofer box and MDF has been mentioned the most. I bought some MDF and put a Box together. My question is... is MDF suppose to be very fragile? The MDF I bought breaks very easy on the corners and splits like a bunch of stacked papers when I drill screws in. For as heavy as it weighs, I am disappoint that it isn’t holding up better.
> 
> Is MDF truly the best material for subwoofer boxes? Is there a better material ?
> Are there different grades of MDF ? Possible I could have gotten a crappy grade ?
> ...


Make sure you pre-drill into the mdf. Don't just take a screw and start drilling it in or it will split.

There may be people who say otherwise, but there's nothing wrong with using some interior plyboard either.


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## llebcire (Nov 17, 2016)

It’s also very dense compared to other products in the same price range.

MDF is pieces of wood, ranging from sawdust to small chips, that is bound with a resin (glue) and formed using pressure.

While it’s easy to work with, it’s more prone to crumbling as you found. And as mentioned, it’s ruined by water.

It’s a great option if your enclosure will be finished.

-Eric 


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## DavidRam (Nov 2, 2014)

It's about the worst material to use, especially for the car environment... A bookshelf speaker box that never sees the elements, is about the only place I can see MDF being ok for any kind of a box.


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## platoon2063 (Apr 19, 2020)

blammo585 said:


> Make sure you pre-drill into the mdf. Don't just take a screw and start drilling it in or it will split.


Agree 100%

Personally, I don't care for mdf (used it many times) because it's heavy and doesn't stain.


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## miniSQ (Aug 4, 2009)

90% of all car audio sub boxes are built from MDF. The trend in the past 15 years or so has been that hobbyists are using Baltic Birch plywood. If you can source true 5x5 3/4" baltic birch or 4x8 Apple Ply, i would suggest you try it. If you can only find 4x8 birch ply from the big box stores i would suggest staying with MDF. Good quality MDF is not fragile and does not even need screws if you have an arsenal of clamps. ( or a brad nailer). I never use screws to assemble any box.
People say ( as noted above) that it is heavy and it does not do well with water. Its maybe 10% heavier than BB, so thats pretty much a non issue, and it should not be hard to keep water out of your car LOL.

But yes my preference is true Baltic Birch. MDF is second, and is perfectly fine to use. 

That being said i am working with a test box now that is made from the cheapest crapiest 3/4 inch ply that i bought from Home Depot to put some shelf's in my woodshop. And so far its fine. LOL> So what do i know, pretty much nothing.


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## DavidRam (Nov 2, 2014)

Mdf is used because it's cheap, readily available and easy to work with... there are no other benefits than that.


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## DaveG (Jul 24, 2019)

I’ll play devils advocate here. MDF is half the price of Baltic birch. It cuts and routers much cleaner than bb too. No tear out. Mdf also makes a tremendous amount of saw dust. It’s also heavier and doesn’t do well getting wet. Sound wise personally I can’t tell the difference.
If you have nice tools and are an experienced wood worker go for bb. Otherwise your mistakes will be much less expensive using mdf.


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## DavidRam (Nov 2, 2014)

Great info copied from another thread:

There has been a lot of talk recently about using birch ply to construct sub woofer boxes as an alternative to MDF.

But why bother? Birch ply is expensive…

Birch ply is a stronger and stiffer material than MDF. A birch ply box will flex less than a MDF constructed box. I’ll let someone else explain why box flex is undesirable.

There are many grades of birch ply and even more grades of plywood available. Far too many to be listed here. Care must be taken when purchasing your plywood.

In general:-

Birch faced ply: -
This is plywood faced with a birch wood veneer. The internal laminates are minimum grade spruce and birch in alternate layers.

Birch ply:-
All laminates are birch. Face layers are also birch. Standard number of plies for 18mm thickness = 13

MDF:-
Chips about 20mm in length from either softwoods or hardwoods are thermally softened before being past through a machine which mechanically refines the chips into bundles of fibres or individual fibres. These fibres are mixed with a synthetic resin then pressed into a sheet. The fibres are randomly arranged within the material. This mat is then pressed again whilst subjected to elevated temperatures and pressures to cure the resin and produce a sheet of the desired thickness.


Mechanical properties:-
In laymen’s terms, strength is an indication of how much load a material will withstand before failure and stiffness is how much the material will flex, or deform, when subjected to a given load.

We are not really interested in the ultimate strength of our sub boxes as they seldom fail, so the material strength is of little use. However, we are interested in how much a box will flex. Therefore, we will concentrate on the stiffness of sub box materials.

Eb = Modulus of elasticity in bending.
Eb describes how stiff a material is under bending. The higher the number, the stiffer the material is and the less it will flex. It allows us to easily compare the stiffness of different materials.

The following properties are all based on 18mm sheet materials:

Birch faced ply:-
Eb = 2700 N/mm^2 perpendicular to grain
4600 N/mm^2 parallel to grain
Density = 11.6 kg/m^2

Birch ply:-
Eb = 3400 N/mm^2 perpendicular to grain
4600 N/mm^2 parallel to grain
Density = 12.4 kg/m^2

MDF:-
Eb = 2200 N/mm^2
Density = 10.8 kg/m^2

It can be seen from the above, that the plywood properties are directional depending on the orientation of the grain. For the purposes of this analysis, we can assume the stiffest properties as sub box panels are generally supported on all four edges. MDF is a homgeneous material and the mechanical properties are identical in any direction.

Comparing the Eb values given above it can be seen that the birch based plywood is over twice as stiff as the MDF. Therefore, if two identically sized sub boxes were fabricated, one from 18mm MDF and the other from 18mm birch ply, the MDF box would flex twice as much as the birch ply box.

That’s quite an improvement from simply using a different material for your enclosure.

Thickness vs. Material stiffness:-

Birch ply is expensive and MDF is relatively cheap.

It’s often asked, ‘Do I use 18mm Birch ply or 25mm MDF for my new sub box?’

As discussed above, birch ply is a stiffer material than MDF. It’s just over twice as stiff. However, the thickness of the material has a far greater effect on the overall stiffness than the actual material stiffness.

Example:-

It is common to ‘double up’ on the baffle thickness of a sub box from 18mm to 36mm.

You’d imagine that by doubling the thickness, you’d double the stiffness and effectively half the flex of the baffle. However, this couldn’t be further from the truth…

By doubling the thickness from 18mm to 36mm you in fact increase the stiffness by a factor of 8. The 36mm baffle will be 8 times stiffer than the single 18mm baffle.

This is derived from the second moment of area of the section given by Ixx = (bd^3)/12

Where d is the depth, or thickness in this example. The thickness value is cubed to arrive at the section stiffness.

For the full increase in stiffness to be exploited, the baffles should be glued together so the two layers act together in unison under load.

A double 18mm baffle is 8 times stiffer than a single 18mm baffle.

A triple 18mm baffle is 27 times stiffer than a single 18mm baffle.

A quadruple 18mm baffle is 64 times stiffer than a single 18mm baffle.

And so on….

By simply increasing the thickness of the material the stiffness overall is increased dramatically. Remember that birch ply is twice as stiff as MDF. However, the original question was ‘Do I use 25mm MDF or 18mm birch ply for my box?’

In this case, the increased thickness of the 25mm MDF will far outweigh the increased material stiffness of the 18mm birch ply. The panels of the 25mm MDF box will be 28% stiffer overall than the 18mm birch ply box.

In general, the thickness of the material is king to minimize flex. The thickness will increase the stiffness far more than a stiffer material would. However, by doubling the thickness you also double the weight of the box.

For ultimate performance, the stiffer birch material should be used in multiple layers. You will then get the best of both worlds. But it is worth keeping in mind that double the layers of material and the weight of the box will also double.

As always in car audio we are faced with a compromise. Box stiffness vs. weight vs. cost.

The choice is yours.

But for someone constructing a simple 18mm thick enclosure, Birch ply will be twice as stiff and only a fraction heavier than MDF. I know which one I’d go for and I'd double the baffle too whilst I was at it.


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## miniSQ (Aug 4, 2009)

DavidRam said:


> Mdf is used because it's cheap, readily available and easy to work with... there are no other benefits than that.


When i buy MDF in 2x4 sheets i pay $20 a sheet, and $50 a sheet when i buy it in 4x8 sheets. I pay $60 a sheet for 5x5 Baltic Birch. I live in the smallest of towns in Vermont and both are readily available. BB is 8 minutes away and can be delivered. MDF is 30 minutes away.

I know you are not one to change your mind about anything, and that is fine. But just because you have discovered BB in the last couple years does not make MDF the devil. The number one reason and probably the BEST reason not to use MDF is the dust it creates during cutting is nasty ****!!

But it makes perfectly fine sub boxes.


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## platoon2063 (Apr 19, 2020)

miniSQ said:


> Good quality MDF is not fragile and does not even need screws if you have an arsenal of clamps. ( or a brad nailer). I never use screws to assemble any box.
> People say ( as noted above) that it is heavy and it does not do well with water. Its maybe 10% heavier than BB, so thats pretty much a non issue,


Agree with the first statement.
Not to argue but mdf is approx. 30% heavier than BB according to my bro-in-law who has been a trim carpenter for 20+ years. So i agree it's a non-issue probably in the car audio world. But, I've constructed 8 cuft sub enclosures for my HT room out of mdf and BB and I can tell you that damn that mdf is heavy.



DaveG said:


> I’ll play devils advocate here. MDF is half the price of Baltic birch. It cuts and routers much cleaner than bb too.


Top 2 advantages to using mdf for sure.


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## DavidRam (Nov 2, 2014)

miniSQ said:


> When i buy MDF in 2x4 sheets i pay $20 a sheet, and $50 a sheet when i buy it in 4x8 sheets. I pay $60 a sheet for 5x5 Baltic Birch. I live in the smallest of towns in Vermont and both are readily available. BB is 8 minutes away and can be delivered. MDF is 30 minutes away.
> 
> I know you are not one to change your mind about anything, and that is fine. But just because you have discovered BB in the last couple years does not make MDF the devil. The number one reason and probably the BEST reason not to use MDF is the dust it creates during cutting is nasty ****!!
> 
> But it makes perfectly fine sub boxes.


I typically don't look for justifications to do things the easiest way with the cheapest materials possible. Again, cost, availability, and ease of use, are the ONLY reasons to use mdf. There are NO acoustic, quality, or longevity benefits to mdf at all.

So it the question is "what is the cheapest material I can use for a sub box?" than the answer is mdf. If the question is "what is better, or the best material to use?" than the answer can not include mdf.

Btw, I have been in the furniture industry for 25 years, and that includes custom furniture design, one-off fabrication and large scale manufacturing, which includes the choice of materials and construction techniques... I might be new-ish to subwoofer boxes compared to some of you, but I am not new to wood and fabrication.


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## Chris12 (Sep 20, 2018)

Plywood (BB plywood in particular) is lighter than MDF. Plywood is also stronger than MDF. Plywood does better in wet environments. MDF doesn't do well in wet environments. MDF sawdust is very toxic to breathe.

MDF is more dense than plywood, BUT for resonances, I'd guess that some combination of plywood and CLD would be lighter and perform better than MDF.

If you want something cheap and readily available, get MDF. If you want something that will last and that will also be stronger and lighter (than MDF), get BB Plywood.


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## miniSQ (Aug 4, 2009)

DavidRam said:


> I typically don't look for justifications to do things the easiest way with the cheapest materials possible. Again, cost, availability, and ease of use, are the ONLY reasons to use mdf. There are NO acoustic, quality, or longevity benefits to mdf at all.
> So it the question is "what is the cheapest material I can use for a sub box?" than the answer is mdf. If the question is "what is better, or the best material to use?" than the answer can not include mdf.
> 
> Btw, I have been in the furniture industry for 25 years, and that includes custom furniture design, one-off fabrication and large scale manufacturing, which includes the choice of materials and construction techniques... I might be new-ish to subwoofer boxes compared to some of you, but I am not new to wood and fabrication.


But what you always fail to understand, is that while BB is "better", MDF does not suck. As in ferrari is better, but a mercedes does not suck.


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## couchflambeau (Apr 18, 2006)

DavidRam said:


> Great info copied from another thread:
> 
> There has been a lot of talk recently about using birch ply to construct sub woofer boxes as an alternative to MDF.
> 
> ...


Now that's about as close to a scientific discussion on the subject as I've seen. I was already leaning towards BB for the hydrophilic properties of MDF but overall it looks like BB beats it in a variety of aspects. Great (re-)post.


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## DavidRam (Nov 2, 2014)

miniSQ said:


> But what you always fail to understand, is that while BB is "better", MDF does not suck. As in ferrari is better, but a mercedes does not suck.


A Mercedes does not swell up when it gets wet, nor does it split on the edges when you barely brush up against it... A Mercedes does not flex more than a Ferrari, therefor needing more bracing.


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## DavidRam (Nov 2, 2014)

miniSQ said:


> But what you always fail to understand, is that while BB is "better", MDF does not suck. As in ferrari is better, but a mercedes does not suck.


I think we have different definitions of what "sucks." But we're still friends.


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## Anu2g (Nov 4, 2020)

DavidRam said:


> A Mercedes does not swell up when it gets wet, nor does it split on the edges when you barely brush up against it... A Mercedes does not flex more than a Ferrari, therefor needing more bracing.


Haha. A Mercedes probably does flex a bit more than a Ferrari.


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## miniSQ (Aug 4, 2009)

DavidRam said:


> I think we have different definitions of what "sucks." But we're still friends.


I would like to look back and see when the first time i used used BB in my car. I know i have been using BB in my HT boxes for 20 years. I suspect its been close to that for my car. But i am not not so anti MDF i would say it sucks.
PS. a 12 cuft HT sub built from BB cannot be moved with 1 person.


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## Chris12 (Sep 20, 2018)

My local Home Depot has "Swaner Hardwood Prefinished Birch Plywood" and they have it listed as 13-Ply. Its $66 for a 4x8 sheet.








Swaner Hardwood Prefinished Birch Plywood (Common: 3/4 in. x 4 ft. x 8 ft.; Actual: 0.703 in. x 48 in. x 96 in.) 971080 - The Home Depot


This hardwood plywood is perfect for interior use from a practical as well as an aesthetic point of view nothing else has such timeless good looks or provides such a sense of well-being. This fine hardwood



www.homedepot.com





Is this "Baltic Birch"? No, it is not. But for those that can't find Baltic Birch local to them, it may be a good substitute. Ive also seen Appleply listed as a substitute, but its very hard to find in stores (except online ).


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## krash (Jan 21, 2021)

blammo585 said:


> Make sure you pre-drill into the mdf. Don't just take a screw and start drilling it in or it will split.


And if hoping to countersink your screw heads flush, (many try to use drywall screws), pre countersink your holes.

Use some scrap and test drill/screw a few holes, then set the clutch on your cordless drill so it slips when tight..
And don't forget wood glue.


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## dgage (Oct 1, 2013)

krash said:


> And don't forget wood glue.


This is the most important part as for our commercial subs, we don’t actually use fasteners, only glue. We use PL 3X a lot of times for sub boxes as it will also seal a box air tight. For regular glues, we use Titebond 3 though 1 or 2 work just fine for interior work.


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## Fish Chris 2 (Dec 18, 2019)

DavidRam said:


> Mdf is used because it's cheap, readily available and easy to work with... there are no other benefits than that.


But those are all big benefits. And btw, it can be finished a million ways. I was thinking about adding a veneer to mine, of something with a really strong grain pattern, then using some bright orange or green wood dye on it 🙂 Maybe this Summer 👍
Currently, it's covered with bed liner. But I can still cover it with anything I want to.
Oh, and I always paint the inside of my mdf boxes with a sloppy thick coat of semi gloss lacquer, to seal it.


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## Fish Chris 2 (Dec 18, 2019)

Chris12 said:


> My local Home Depot has "Swaner Hardwood Prefinished Birch Plywood" and they have it listed as 13-Ply. Its $66 for a 4x8 sheet.
> http://[URL]https://www.homedepot.c...ual-0-703-in-x-48-in-x-96-in-971080/203005208[/URL]
> 
> Is this "Baltic Birch"? No, it is not. But for those that can't find Baltic Birch local to them, it may be a good substitute. Ive also seen Appleply listed as a substitute, but its very hard to find in stores (except online ).


I actually get my mdf from a specialty hard wood place. A few dollars more than a big box store, but I also bring a cut sheet, and their saws, plus their workers do an excellent job 😉
They also have a fantastic selection of hardwoods. I'm sure I could get 3/4" baltic birch or anything else you could imagine. But instead, I'm going to get some 1/8" of something really pretty, and just put a nice veneer on my current mdf box 😉👍


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## DavidRam (Nov 2, 2014)

Fish Chris 2 said:


> But those are all big benefits. And btw, it can be finished a million ways. I was thinking about adding a veneer to mine, of something with a really strong grain pattern, then using some bright orange or green wood dye on it 🙂 Maybe this Summer 👍
> Currently, it's covered with bed liner. But I can still cover it with anything I want to.
> Oh, and I always paint the inside of my mdf boxes with a sloppy thick coat of semi gloss lacquer, to seal it.


They are benefits to the build process, but not to the end result...


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## Fish Chris 2 (Dec 18, 2019)

DavidRam said:


> They are benefits to the build process, but not to the end result...


I think the benefits of specialty woods are questionable. As was already stated, a 10% weight savings means almost nothing. Not to mention, plywood can split too, if not properly dealt with, and is also subject to water damage.... If that really matters. I might use something else in a boat 😀 lol


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## miniSQ (Aug 4, 2009)

Fish Chris 2 said:


> I think the benefits of specialty woods are questionable. As was already stated, a 10% weight savings means almost nothing. Not to mention, plywood can split too, if not properly dealt with, and is also subject to water damage.... If that really matters. I might use something else in a boat 😀 lol


Anyone that thinks they could hear the differnce between a proper MDF box and a proper BB box is smoking crack.


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## diy.phil (May 23, 2011)

Usually the old school thought is MDF is a dead or low/non-resonant material and this can be a suitable material for a speaker box.
Particle board is awful... sometimes it's for cabinets (inside) or low cost furniture and nobody will see it (inside/back pieces). Or they'll laminate it until it looks pretty or presentable for the outside pieces.
Between baltic birch and MDF boards... everyone's been arguing both ways about it since the beginning of time. People each know which one one prefers.
Metal has lots of resonant... they make lots of trumpets with it.
Regular wood resonates too... it's a great material for an acoustic guitar, piano, percussion instruments, etc.
Wind instruments uses wood too. Low-end ones are made of plastic.
I'm thinking nobody makes an acoustic piano out of MDF even if no one's using it and it's purely for home decoration only!!


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## dobslob (Sep 19, 2011)

MDF is fine in many cases, but it is never great except for machining. It is easy to get a great finish with very little work. But don't use the crap from Home Depot or Lowes. Find an actual lumber company who can choose what MDF they purchase. Then it will likely be more dense and won't flake away. You will still need to pre-drill if using screws for assembly. I prefer brads to hold things together while the glue dries, they cause way less damage than a screw.


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## DavidRam (Nov 2, 2014)

dobslob said:


> MDF is fine in many cases, but it is never great except for machining. It is easy to get a great finish with very little work. But don't use the crap from Home Depot or Lowes. Find an actual lumber company who can choose what MDF they purchase. Then it will likely be more dense and won't flake away. You will still need to pre-drill if using screws for assembly. I prefer brads to hold things together while the glue dries, they cause way less damage than a screw.


I kinda cringe when I see screws in a sub box...


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## DaveG (Jul 24, 2019)

DavidRam said:


> I kinda cringe when I see screws in a sub box...


We all know you like to save your drywall screws for mounting speakers! LOL!


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## DavidRam (Nov 2, 2014)

I never said you can "hear" the difference between mdf and BB. You WILL get a much stiffer box with less flex which DOES affect the sub's performance. AND you get longevity and moisture/elements resistance with the BB that you do not get with mdf. 
Don't get me started on using drywall screws to mount the sub to the mdf baffle (which is a one time use scenario at best).


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## DavidRam (Nov 2, 2014)

DaveG said:


> We all know you like to save your drywall screws for mounting speakers! LOL!


Lol! In that post I was referring to assembling the box using screws... But I do get the joke!


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## blammo585 (Feb 1, 2020)

dobslob said:


> MDF is fine in many cases, but it is never great except for machining. It is easy to get a great finish with very little work. But don't use the crap from Home Depot or Lowes. Find an actual lumber company who can choose what MDF they purchase. Then it will likely be more dense and won't flake away. You will still need to pre-drill if using screws for assembly. I prefer brads to hold things together while the glue dries, they cause way less damage than a screw.


I only recently found out what "brads" are. I have been using screws myself. But my father helped me with a box a few weeks ago and because of the angle where the boards met we couldn't use screws. So my dad used his nail gun with these little nails. Then the other day I asked him what were brad nails and he said "Those nails we used in the gun." I might start using those from now on.


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## EricTundra (Feb 19, 2021)

Whatever you decide, maintain a social distance from the wood and wear a mask 😎 Ok, the social distance may be a bit overkill, but not the mask. The fine dust and heated by the saw blade glue is seriously bad for your lungs. I have a mask and a fan going when cutting MDF, plus the vacuum attached to the saw. Bad juju!


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## miniSQ (Aug 4, 2009)

DavidRam said:


> I kinda cringe when I see screws in a sub box...


100% agree on this one. Glue and clamps ONLY. Unless its a box i don't really care about and i will sometimes use brads.


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## DavidRam (Nov 2, 2014)

miniSQ said:


> 100% agree on this one. Glue and clamps ONLY. Unless its a box i don't really care about and i will sometimes use brads.


I use brads sometimes and strategically, just to keep the joints from moving around when clamping... I'm ocd and I'll freak out if the boards are off by even a 1/32 of an inch... Lol


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## miniSQ (Aug 4, 2009)

DavidRam said:


> I use brads sometimes and strategically, just to keep the joints from moving around when clamping... I'm ocd and I'll freak out if the boards are off by even a 1/32 of an inch... Lol


That is true, especially for the first couple glue ups. Why is it so satisfying to get a perfectly flush edge/corner?


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## diy.phil (May 23, 2011)

1/32" is terrible David!! You've got to improve to 1/100" with a Shaper Origin cutter!!


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## Mad Scientist (Feb 12, 2017)

DavidRam said:


> I use brads sometimes and strategically, just to keep the joints from moving around when clamping


Use salt. It acts as an abrasive to prevent the slipping of joints during glue ups, and it dissolves within the glue as it dries.


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## seafish (Aug 1, 2012)

Mad Scientist said:


> Use salt. It acts as an abrasive to prevent the slipping of joints during glue ups, and it dissolves within the glue as it dries.


Dam, you ARE a mad scientist ... I like it !!!


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## LBaudio (Jan 9, 2009)

there is also one aspect that nobody mentioned so far - Own Resonant freq of given materials MDF vs BB.

Since majority of us who build enclosures spend time on adequate bracing and enclosure damping, the vibration of the enclosure sides should not be a problem with any of before mentioned materials.
MDF of suitable thicknes (1") is strong enough for majority of SW aplications. There might also be option of double walled of double baffled enclosures.

Best IMHO would be to combine both materialswhen building a box.


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## Holmz (Jul 12, 2017)

Mad Scientist said:


> Use salt. It acts as an abrasive to prevent the slipping of joints during glue ups, and it dissolves within the glue as it dries.


rock salt?


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## Mad Scientist (Feb 12, 2017)

Rock salt would be far too large for this application because it wouldn't be able to dissolve fast enough before the glue begins to set, and it would push the workpieces you're trying to glue up too far apart due to its large size. Instead, you want to use the smallest grain salt you can (such as standard cheap table salt). 

As far as applying it during glue ups, you only need to sprinkle a small amount - just enough so the pieces don't slip apart as you clamp down. This is one of those cases where less is more. For a 90 degree corner glue up, it will likely be easier to use a 90 degree clamp instead of salt and clamps for a perfect OCD corner. For your classic box construction, 90 degree clamps like the one below are perfect for giving you the additional set of hands to help you. 

However, where table salt really shines is in larger pieces that need to be glued together and you don't want them to slip (like a layered / stacked sub box for example). Or, if you have other woodworking projects (like a 5" tapered table leg) that you can't easily purchase but need to make. Another is a stacked wood bowl where you use alternating types of wood and need to align them perfectly. In woodworking, there are many cases where a slipping glue up is more than just an annoyance - it can ruin the appearance of a project especially if you need alternating species of woods in layers to align correctly.


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## DavidRam (Nov 2, 2014)

Mad Scientist said:


> Use salt. It acts as an abrasive to prevent the slipping of joints during glue ups, and it dissolves within the glue as it dries.


Yep, that works too. As does sugar! Lol


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## diy.phil (May 23, 2011)

uh. they said no sugar 








Should I use salt in my glue to prevent slipping?


While I was gluing up four boards, my neighbor noticed how the boards slipped around. He sprinkling a little salt onto the glue before sandwiching the boards together. Is that a good idea?




www.woodmagazine.com


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## Holmz (Jul 12, 2017)

Mad Scientist said:


> Rock salt would be far too large for this application because ...


Thank for the detailed response.
I was thinking if one is playing Rock Music then should they be using rock salt? 

Maybe I should use this:


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