What's to chat about?

[Seth]

PL is so awesome because it can create a strong bond even when the pieces being joined don't fit perfectly, which for our DIY speaker cabs I absolutely understand why Bill mandates using it. Otherwise there'd probably be a lot of unhappy customers because they couldn't cut straight, their cabs fall apart, and they unjustly blame Bill. Wood glue like Titebond (I, II or III) will make a bond stronger than the wood itself, but the joint fit has to be spot on. I still use it for many projects (and gorilla glue, too), but if I am working on anything where the connection is even a bit off, PL is the way to go.

I totally agree. That's the same experience I've had with PL. However, the question that remains is; what's the next best thing for those that don't have any PL or equivalent polyurethane construction adhesive available to them?

[Seth]

Seth,
I've gone with the cheapest ply option I could find all the way, and don't regret any of my builds for any reason.
Driver selection, sometimes, builds, no.
Don't sweat ply type for goodness sake. The entire ethos of DIY is to save as much as possible, yet, ideally, end up with something much more valuable than the best out there in the retail market (pssst, that's part of why I keep on harping on about driver choices ), and every dollar you save makes that more awesome.

Heck, build a 20" wide BP loaded T39.
I know they work really well!
It's fun doing something a little different, but, if you use a 12" driver, and build to 28" for this one cab, you get an opportunity to evaluate the strength of a wider build. That might end up being gold...

That's great feedback Grant! Thanks for that. I was stressing about it a little. Then I realized that the Douglas Fir option is cost effective at +/- $20/sheet, weight conscious at about 40lb per 4x8 sheet, and readily available. It's what I built my TAT out of. I don't know why I wasn't considering it as an option for the Titan build. Guess I got a little caught up in cabinet grade ply (it is beautiful, and flat, and...). I have zero issue putting a skim coat of Bondo to fill any blemishes in the woods surface prior to DuraTex.

Gonna rent a truck and drag a pile of ply home this week. Finally get this project out of my head and into reality.

[Grant Bunter]

However, the question that remains is; what's the next best thing for those that don't have any PL or equivalent polyurethane construction adhesive available to them?

Seth,
It's no biggie.
The answer is for those of us who can't get PL to find a suitable substitute, or buy PL from the USA and have it shipped.
World markets don't mean every brand of anything is available right around the world anyway...

[Bruce Weldy]

Guess I got a little caught up in cabinet grade ply (it is beautiful, and flat,

Remember, cabinet grade is never suitable as it has a thin veneer on each side whether you can afford it or not.

As a reminder to those reading this who are still a little confused about plywood.....Birch ply is NOT the same as Baltic Birch/Finnish Birch/Russian Birch.......and Chinese birch is trash is case you are thinking that having a another country name in front makes it all the same.

[Seth]

Remember, cabinet grade is never suitable as it has a thin veneer on each side whether you can afford it or not.

When I say cabinet grade, I'm referring to 9 ply Baltic Birch, White Italian Poplar Ply, and/or Arauco Ply.

Perhaps cabinet grade isn't the correct term to use. What would you refer to these types of ply as?

[Bruce Weldy]

Remember, cabinet grade is never suitable as it has a thin veneer on each side whether you can afford it or not.

When I say cabinet grade, I'm referring to 9 ply Baltic Birch, White Italian Poplar Ply, and/or Arauco Ply.

Perhaps cabinet grade isn't the correct term to use. What would you refer to these types of ply as?

Honestly couldn't tell you if there's a group name for those....I think that's why it's always necessary to refer to each by it's actual name. I only brought it up because it's a question that gets asked over and over by new people on the forum.....and has for years. Sometimes someone will say birch when they mean BB and then there is confusion. It was more of a PSA for any folks that are new and/or just lurking.

[Seth]

A little woody wood wood story...

I put dimensions for one 16" T39 and four 30" T39's in the cut optimizer program and it boiled it down to 9 sheets needed. Yes, 28" instead of 30" saves one sheet per four count of cabs. But, I'm not too worried about the cost of an extra sheet. Anyway, I ran the optimization for both, lengthwise first cut and crosscut first cut. Lengthwise would have made fewer cuts necessary at the store, only one cut per sheet resulting in 18 pieces to transport home, but more cuts at home. The opposite true for crosscut first, about 2-4 cuts per sheet on the panel saw and a lot more time at the store resulting in about 33 pieces to be further processed at home.

I chose to have them do as much of the cutting as possible on their panel saw, leaving less to do at home.


OH MAN! I'm going to have my work cut out for me! (no pun intended) This 15/32 5 ply CDX is about as flat as a Pringles chip. Some of them so much so, that even the panel saw was making crooked cuts. Out of the 9 needed sheets I brought the equivalent of 11 home. 5 at full price, 4 at 70% off, and 2 for free, discounted due to their special potato chip qualities.

Looks like I'm in for a good bit of practice in working with warped ply.

[Grant Bunter]

You will be absolutely amazed at what some hardwood boards somewhere around 4" wide ripped in half will do to the bent ply, and use the dewarpers as 2"ish wide.
Drill some slightly oversized pilots for 3" screws (look out for the sharp ends in the panels), leave the dewarpers there until they absolutely have to be removed, and you'll be fine...

[Bryan Cox]

A little woody wood wood story...

I put dimensions for one 16" T39 and four 30" T39's in the cut optimizer program and it boiled it down to 9 sheets needed. Yes, 28" instead of 30" saves one sheet per four count of cabs. But, I'm not too worried about the cost of an extra sheet. Anyway, I ran the optimization for both, lengthwise first cut and crosscut first cut. Lengthwise would have made fewer cuts necessary at the store, only one cut per sheet resulting in 18 pieces to transport home, but more cuts at home. The opposite true for crosscut first, about 2-4 cuts per sheet on the panel saw and a lot more time at the store resulting in about 33 pieces to be further processed at home.

I chose to have them do as much of the cutting as possible on their panel saw, leaving less to do at home.


OH MAN! I'm going to have my work cut out for me! (no pun intended) This 15/32 5 ply CDX is about as flat as a Pringles chip. Some of them so much so, that even the panel saw was making crooked cuts. Out of the 9 needed sheets I brought the equivalent of 11 home. 5 at full price, 4 at 70% off, and 2 for free, discounted due to their special potato chip qualities.

Looks like I'm in for a good bit of practice in working with warped ply.

Man oh man you have your work cut out for you. I used ACX and it was pretty warped. I was able to remove most of it with some water on the concave side and pressure. Then of course I had to clamp everything like crazy. I sure hope it isn't this bad for you, but it probably doubled my T39 build time. CDX is a few steps down from ACX so I'm hoping for the best.

If I had to do it all over again, and since BB isn't available to me ATM, I'd have went with ABX. More costly but so worth it in the warp department.

[Tom Smit]

I, absolutely, do not envy you with those potato chips.

[Bruce Weldy]

Have I ever mentioned why I love BB and build everything out of it? Oh, I have? .......never mind....

[Seth]

Well, I'll let you guys know how it goes.

Grant, thanks for the tips

I'll get my chops up and build the thin 16" wide one for the rehearsal space first.

Cut 2 sides and panel's 1 & 2 today. Wont be back at it until next week. It feels good to have made some progress anyway.

Decided I'm just going to order the router circle jig instead of making my own.

[Tom Smit]

Seth, you know what? You, sir, are going to be a master of bent-panel-to-straight-panel installs.

[Grant Bunter]

Grant, thanks for the tips

In case it wasn't clear 4-5" wide x say 3/4", ripped in half.
Drill the holes from one 3/4" side. to the other...

[himhimself]

Seth, once you start cutting panels, if you don't assemble in short order, stack them up and drop some heavy cinderblocks or bags of concrete on them to keep them from warping even more. I've found once cut, they keep tacoing up even worse. Maybe a mist with some water or IPA before sandwiching them with weight to help assist in getting the bends out. BB is the bomb! My Menards has a bunch of those 20"x20" 1/2"BB panels again for cheap, so I'm planning to grab a stack. They were just big enough for me to get my T30 inner panels out of last time, and I plan to build two more this spring.