MDF vs. Ply

[audiohonic65]

One point to sonsider here is that wood is cheaper and easier to work with as compared to metal. Also, MDF is engineered to be effectively flat on it's surfaces. Plyw is genearlly not flat. Last, MDF machines are very nice and gives a uniform look.

 

[lsiberian]

One point to sonsider here is that wood is cheaper and easier to work with as compared to metal. Also, MDF is engineered to be effectively flat on it's surfaces. Plyw is genearlly not flat. Last, MDF machines are very nice and gives a uniform look.

The ply I've used is flat enough for speaker building. The key to good machining is having good bits and blades. Whiteside or Lee Valley bits have been shown to work great with mdf and ply. The Forrest blade looks very nice. Once the rain stop I plan to give it a try.

 

[highfigh]

The ply I've used is flat enough for speaker building. The key to good machining is having good bits and blades. Whiteside or Lee Valley bits have been shown to work great with mdf and ply. The Forrest blade looks very nice. Once the rain stop I plan to give it a try.

Give it a coat of paste wax before you use it- the wood resin (in actual lumber) will have a harder time sticking to it.

 

[Alex2507]

Give it a coat of paste wax before you use it- the wood resin (in actual lumber) will have a harder time sticking to it.

Now you tell me.

Actually I knew that but I forgot which reminds me of the saying 'I forgot more than you'll ever know" but I was milling up some 100+ year old Southern Yellow Pine to use as speaker bracing and the sap had to be cleaned off the blade repeatedly.

Wax on DIYers!

 

[lsiberian]

I've never waxed a saw blade before.

I had no idea

 

[Chopper Greg]

I went to the local lumber yard, and the only MDF they had was 1/2" for 4x8 sheets or 3/4" shelving material.

OTOH, as far as 3/4" ply, all they had was the type made with thicker verniers - perhaps 7 layers, is this stuff ok?

 

[lsiberian]

I went to the local lumber yard, and the only MDF they had was 1/2" for 4x8 sheets or 3/4" shelving material.

OTOH, as far as 3/4" ply, all they had was the type made with thicker verniers - perhaps 7 layers, is this stuff ok?

For subs it would probably be fine, but for loudspeaker enclosures you want 13 ply. Home depot does carry 13 ply.

 

[Chopper Greg]

What is the reason behind wanting more layers?

 

[Rickster71]

I've never waxed a saw blade before.

I had no idea

The blade, and the table too; everything slides nice and no rust on a cast table.

 

[sawzalot]

What is the reason behind wanting more layers?

Strength , multiple layers laminated together with the grains running at 90 degrees to the layer before it amounts to the strongest design possible, also these multi layered products will stay true and straight better than a solid and or minimal layered product. Most multi ply 13 or more, would be used in custom cabinet making , where strength and durability are a must.

 

[lsiberian]

What is the reason behind wanting more layers?

For encolsure design it reduces cabinet resonances. Not as much as bracing and dampening though.

 

[highfigh]

Now you tell me.

Actually I knew that but I forgot which reminds me of the saying 'I forgot more than you'll ever know" but I was milling up some 100+ year old Southern Yellow Pine to use as speaker bracing and the sap had to be cleaned off the blade repeatedly.

Wax on DIYers!

How do you like those yellow pine splinters? Kinda burns, eh? I used Southern Yellow Pine for the baffles in the first speaker cabinets I ever made.

Try citrus-based cleaner for saw blades.

 

[highfigh]

I went to the local lumber yard, and the only MDF they had was 1/2" for 4x8 sheets or 3/4" shelving material.

OTOH, as far as 3/4" ply, all they had was the type made with thicker verniers - perhaps 7 layers, is this stuff ok?

Cabinet grade plywood doesn't have voids in it like regular plywood, which makes it usable with exposed edges like drawer boxes and dividers. The layers are always laid perpendicular to each other and that adds a lot of stiffness, too.

Home Depot and Lowes carry 13 layer but after the experiences I have had with plywood from big box stores, I won't buy it from them again. If you go to a woodworking store like Rockler or WoodCraft, they can tell you where to get the best lumber and sheet goods.

One thing about cabinet grade plywood- its dimensions are usually metric. 3/4" is usually called 19mm.

 

[Chopper Greg]

I was thing about ordering marine ply ( and it can be obtained in 4x10 and 4x12 sheets if you want it that big ) - it too has to be void free, and uses a waterproof adhesive - not water resistant adhesive that exterior grade uses.

 

[sawzalot]

I was thing about ordering marine ply ( and it can be obtained in 4x10 and 4x12 sheets if you want it that big ) - it too has to be void free, and uses a waterproof adhesive - not water resistant adhesive that exterior grade uses.

Why? are you putting these subs on your boat? J/K of course but really there is no logical reason to use that ply unless it is more readily available or free, as I know it costs quite a bit more than Birch or MDF.

 

[lsiberian]

Why? are you putting these subs on your boat? J/K of course but really there is no logical reason to use that ply unless it is more readily available or free, as I know it costs quite a bit more than Birch or MDF.

What if he's flooding prone. It would save him from diving into the rising waters to save his precious subwoofer.

 

[Chopper Greg]

Why? are you putting these subs on your boat? J/K of course but really there is no logical reason to use that ply unless it is more readily available or free, as I know it costs quite a bit more than Birch or MDF.

After having dropped by a couple of cabinet shops, it ends up costing about the same per sq/ft - the local shops appear to be very reluctant to part with some of theirs.

 

[lsiberian]

After having dropped by a couple of cabinet shops, it ends up costing about the same per sq/ft - the local shops appear to be very reluctant to part with some of theirs.

I know it's sinful to suggest using the big box stuff, but with some bondo I think it would be just fine for a sub. In fact my Home Depot bondo's pieces before putting them up for sell.

No point in you paying an arm and a leg. I've used 5-ply and gotten decent results before. Folks here talk in ideals. But life is about compromise.

 

[WmAx]

Standard cabinet grade hard wood ply is sufficient for subwoofer boxes, and still superior to MDF. You do not need 13 ply for subwoofers.

-Chris

 

[highfigh]

I was thing about ordering marine ply ( and it can be obtained in 4x10 and 4x12 sheets if you want it that big ) - it too has to be void free, and uses a waterproof adhesive - not water resistant adhesive that exterior grade uses.

What kind of glue will you be using? Wood glue won't work because it's water-based.