Single sheet TH challenge

oliver:
I've used sandeply -- the outside veneer is real thin. Your glue joint will fail easily when that thin veneer delam's. If you use it, you need to leave screws in place, and you need to use no larger than #8's because it splits easily when driving screws into end ply.

The thing I like about the arauco -- it's branded and it's the same. It only comes from one source, and I know what it is... It's the same year after year. The only issue I even see with it, is if it warps some due to humidity changes. Lay it flat and let it rest a bit in your shop before cutting/assembling usually helps.
 
""Also buy PL premium expanding polyurethane construction adhesive (in a tube) it's the best. "

PU glue has on average only 58% of the strength of ordinary PVA.

http://www.titebond.com/Dohttp://s6...lor.gifwnload/pdf/HowStrongisYourGlue_FWW.pdf

"The surprise of the test was this glue’s
poor showing. The snug joints were poor,
and the loose joints were unacceptable.
Polyurethane may be a tough finish, but it
isn’t a tough glue."
 
""Also buy PL premium expanding polyurethane construction adhesive (in a tube) it's the best. "

PU glue has on average only 58% of the strength of ordinary PVA.

http://www.titebond.com/Dohttp://s6...lor.gifwnload/pdf/HowStrongisYourGlue_FWW.pdf

"The surprise of the test was this glue’s
poor showing. The snug joints were poor,
and the loose joints were unacceptable.
Polyurethane may be a tough finish, but it
isn’t a tough glue."

What's the Difference: Glue - Fine Homebuilding Article

For a mortise-tenon, dovetail, or any other large surface area clamped joint -- I agree pva is the way to go.

However, you can't make these kind of joints with pva.
 

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The same principles apply though, only half of the area is end-grain and PU does not absorb into end-grain as well as PVA does.

On an uncontrolled test (run away cabinet going down two flights of stairs), a PVA cabinet required no repairs, a PU cabinet required extensive repairs. Cabinets were similar, but not identical (hence the term uncontrolled), and one took out a wall on the stair landing.

I tend to tack things with a brad nailer, and then use 8D galvanized casement nails to hold things until the glue sets up (blunt the tips of the nails to avoid splitting the wood).

I did use a tube of PU to repair the damaged cabinet, with a whole bunch of deck screws to pull it back together.

Maybe I just prefer PVA, it cleans up easier, and the fumes don't bother me (like PU does).

"However, you can't make these kind of joints with pva. "

And I wouldn't with PU either. I would wager that PVA with a sawdust filler might have more strength, but I generally cut angles where needed.
 
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The same principles apply though, only half of the area is end-grain and PU does not absorb into end-grain as well as PVA does.

On an uncontrolled test (run away cabinet going down two flights of stairs), a PVA cabinet required no repairs, a PU cabinet required extensive repairs. Cabinets were similar, but not identical (hence the term uncontrolled), and one took out a wall on the stair landing.

I tend to tack things with a brad nailer, and then use 8D galvanized casement nails to hold things until the glue sets up (blunt the tips of the nails to avoid splitting the wood).

I did use a tube of PU to repair the damaged cabinet, with a whole bunch of deck screws to pull it back together.

Maybe I just prefer PVA, it cleans up easier, and the fumes don't bother me (like PU does).

"However, you can't make these kind of joints with pva. "

And I wouldn't with PU either. I would wager that PVA with a sawdust filler might have more strength, but I generally cut angles where needed.

I completely agree with you in terms of cabinet building djk... I don't want you to think I'm arguing with you.

When I'm in 'cabinetry' mode -- everything fits within a whisker, and it's pva only.

When I'm building subs like this, it's all a matter of how fast and how well can I build.... speed is the name of the game, and expanding PL is part of what allows that speed. Torx head deck screws and pl allow me to build a quad of these in a day -- no clamps, no waiting for glue to dry, just go. When it's done it's air tight, square, and ready for finish and install.

So, I guess for my purposes, this is the way I choose to do subs. Pocket hole jig/screws and/or brad nailer with pva gets excessive use in other construction projects of mine -- but not subs.

BTW, what PU did you use? was it PL construction poly adhesive? or gorilla glue PU or something like that? The PL doesn't have any fume that bothers me.
 
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Hi Y'all,

Thanks for the additional information on the Sande and Arauco plywoods. I agree that Home Depot and Lowe's are not the most reliable sources, but difficult to get around.

As to the glues, I like Titebond II (or equivalent), and I agree that you should shoot for fitting joints. The proper way to prepare the wood is shown in the pictures of the DTS-10:

Danley DTS-10 "Super Spud" DIY kit - AVS Forum


Regards,
 
I used Home Despot Sande once, and I'll never use it again.
Had to strip worthless veneer and rough up every glue bond.
This veneer prevents glue penetration, far too paper thin to
sand, edges peel apart in a strong breeze. Forget routing a
quarter round to protect it, don't work...
 
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How does the PL Premium compare to the Gorilla Glue polyurethane glue used in the test? I've used PL several times where I'm looking to fill a gap such as a tapped horn when the second side goes on. These smallish gaps would never be perfectly filled by a standard PVA glue.
 
How does the PL Premium compare to the Gorilla Glue polyurethane glue used in the test? I've used PL several times where I'm looking to fill a gap such as a tapped horn when the second side goes on. These smallish gaps would never be perfectly filled by a standard PVA glue.

my 2c

PL and gorilla glue are 2 completely different animals. I'd never use gorilla glue for building a SS15, only the PL.

In fact due to the "loose fitting joints" in the ss15, if you don't have PL available to you, the next best thing is probably just general construction adhesive (like for subfloors) in a caulking style tube for all of the interior panel to interior panel connections.
 
my 2c

PL and gorilla glue are 2 completely different animals. I'd never use gorilla glue for building a SS15, only the PL.

In fact due to the "loose fitting joints" in the ss15, if you don't have PL available to you, the next best thing is probably just general construction adhesive (like for subfloors) in a caulking style tube for all of the interior panel to interior panel connections.
I used construction adhesive for four bass cabinets I later recycled (3/4" Baltic Birch).
Unlike cabinets built with yellow wood glue, when breaking down the cabinets the construction adhesive mostly split on the glue line, rather than tear off the wood. In that case, I was glad I used the easy break down stuff.

Considering your previous statement about the amount of deflection you noticed on the SS15 front panel using 1/2" wood, I would not feel confident with construction glue lasting well on 1/2" construction, unless lots of screws were used.
 
Construction vs regular PL

I have tried both. I screwed and glued, but the screws are only to keep everything aligned during building.


Construction glue bought locally

for building my T36 and first pair of Omnitop 15
(all 12 mm ply)


PL from Leland Crookes / Speakerhardware

for Stadium horns and 4 more Omnitops (btw. attempting to mod them in the style of Screamerusa)
(the Stadium horns are 19mm, the OT again 12)

The construction foam really expanded tremendously, must have tripled in volume. The PL expansion was less noticeable.
The construction foam dried to a hard yet elastic / rubbery finish.
The PL dried much harder and less flexible.

Both rip plywood layers off when I did my tests. Both were a bitch to get off my hands. Both did a good job. The PL from the USA was way cheaper (under half the price of the construction glue I found here), aside from that I struggle to declare a winner...

Regards, Ben

Edit: I call it construction foam, because, when cut with a stanley knife, it was full of tiny bubbles....
 
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HS12 top

Hi there i have been looking at this and other treads for a while now,i have fall in lov the SS15:) [i have pic of SS15]and HS12, i have suggestion for the HS12 were the components is concern the Selenium D2500Ti has a better sound than D220Ti and what about the B&C ME10 H90+V60 horn it seems to have very good dispersion and the Kappa lite 3012HO for a over all higher output enclosure (just my two cents):D

 
Hi there i have been looking at this and other treads for a while now,i have fall in lov the SS15:) [i have pic of SS15]and HS12, i have suggestion for the HS12 were the components is concern the Selenium D2500Ti has a better sound than D220Ti and what about the B&C ME10 H90+V60 horn it seems to have very good dispersion and the Kappa lite 3012HO for a over all higher output enclosure (just my two cents):D


Hey, thanks for the thoughts. The hs12 components were chosen primarily for cost reasons, and yes there are many good upgrades that work well in that cabinet.

The dayton pa310 driver is a great upgrade and provides more 80-100hz that the beta12a-2, and gives basically the same power handling as the 3012ho at half the price.

Yes the neo 2500ti sounds better in the typical 40x90 horn than the 220ti, but the low expansion dayton waveguide seems to mitigate that. The 220ti/dayton is a reasonably nice sound.

This being said, my 'upgraded' drivers that I like for the HS12 are the pa310/2500ti. (keeping in mind the 2500ti is a bit louder than the 220ti)

If you want to make these cabinets lighter DL2512/2500ti puts it on about a 6.5lb diet.
 
on subject of glue.
I use Titebond 2 and Liquid Nails. I bead out the TB and use a brush to get an even coating. Then use screws (or even brad nails) to hold it all together while drying.
The Liquid Nails is for any gaps AFTER the TB is used.

And example in the SS15 would be the corner reflector.
It is glued. Dried. Filled with expanding foam and then the gaps are filled with Liquid Nails.

Side note about Gorilla Glue.
It has to have wet surfaces in order to activated and adhere. It also expands a great deal. Enough to ware it can push pieces apart.