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Old 26th February 2011, 05:09 PM   #481
jbell is offline jbell  United States
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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.
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Old 26th February 2011, 09:11 PM   #482
oublie is offline oublie  United Kingdom
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hi quick slightly unrelated question.

What would the uk equivalent of pl premium glue be?
different project but i need good glue.

tks
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Old 27th February 2011, 12:03 AM   #483
djk is offline djk
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""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....urGlue_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."
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Old 27th February 2011, 01:42 AM   #484
jbell is offline jbell  United States
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Quote:
Originally Posted by djk View Post
""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....urGlue_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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Old 27th February 2011, 02:30 AM   #485
djk is offline djk
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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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Last edited by djk; 27th February 2011 at 02:36 AM.
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Old 27th February 2011, 03:12 AM   #486
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The cured strength of polyurethane glue is slightly less than that of PVA—generally around 3000 psi—but still plenty strong for most any home-building application.
From the link, but who cares.

djk; In your "uncontrolled test" The one that broke probly would have broke no matter what glue was used. The other one probly fell on it.
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Old 27th February 2011, 03:37 AM   #487
jbell is offline jbell  United States
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Quote:
Originally Posted by djk View Post
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.

Last edited by jbell; 27th February 2011 at 03:40 AM.
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Old 27th February 2011, 04:45 AM   #488
tb46 is offline tb46  United States
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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,
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Old 27th February 2011, 04:56 AM   #489
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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...

Last edited by kenpeter; 27th February 2011 at 05:08 AM.
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Old 27th February 2011, 07:01 AM   #490
djk is offline djk
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"From the link, but who cares."

The link assumes you have a tight fit, and you know that (or you should).
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