Glassing Joint?

[philrev]

Thats a question from a newbie.
I like PL Premium for simplicity and effectiveness. But due to cost its cheaper for me to Glass the joint of the Titan 39 speaker chamber than importing PL. I know this is much work involve but the reward is high.
If this work and eliminates leaks in speaker chamber. Is it sufficient that i will only apply epoxy minus glass to the rest of the joint. Will my speaker got damage if there is a leak somewhere but not the speaker chamber? Say for example from the horn path. Advice pls..

[Gregory East]

People have built DR cabs from composite so it can be done. You don't want leaks anywhere along the horn path.

[Bill Fitzmaurice]

Will my speaker got damage if there is a leak somewhere but not the speaker chamber?.

It will. PL, or the equivalent, is not optional, it's mandatory.

[philrev]

Thanks Bill, I will make it sure that i will put glass on every joints to seal every leak to avoid speaker damage.

[bassmonster]

10.6oz of PL Premium at speaker hardware for 4 bucks, at least in the US. Don't know how much it is elsewhere. If you can't afford PL Premium and you bust a driver by not having the cab sealed correctly, how will you buy a new driver?

As DJPhatman's signature says, "Accept the fact that airtight and well-braced are more important than pretty on the inside.
If you can't find the time and money to do it right the first time, how will you find the time and money to do it right a second time?"

[philrev]

I will try to apply composite on cabinet joints, lets see if it will plug the leak. but if it wont, i had no choice but the PL. is there any method for air tight cabinet? I will start building this coming November.

[Gregory East]

Where are you "importing" to?

PL is the best stuff in USA. Other countries also build houses out of wood and use similar expanding polyurethane glue to stick down floor panels etc. You just have to find the local equivalent product.

[Doug Hart]

It will work fine until you get to the part about installing the second side.
There is no way to get to the joints to glass them... no way... at all... none.

Get the PL or equivalent... find a way.

[Rune Bivrin]

Where are you "importing" to?

PL is the best stuff in USA. Other countries also build houses out of wood and use similar expanding polyurethane glue to stick down floor panels etc. You just have to find the local equivalent product.

I think that's not necessarily correct. I find a lot of filling, flexible glues that are used for these purposes. It's the "expanding" bit that's pretty unique to PL Premium. Certainly the degree of expansion. And the fact that it's not available in large parts of the world even if other Loctite products are readily available says something about it's general superiority over other glues.

While there's no argument that it's a superior glue for speaker builders where air-tight is paramount, that's a fairly small fraction of the world usage of glue...

[Gregory East]

Just the other day some guy in Macedonia got recommended some "Bison" brand stuff with the necessary amount of expansion.

Downunder we use a GorillaGrip brand from HoldFast. It doesn't foam and ooze as madly as PL, going by the photos, but it does foam up a little and does the trick. We may not be able to get away with bodgy work the same as a bodger with PL but that's ok.

[Rune Bivrin]

There's stuff out there that works, certainly. But very few products actually specify expansion as a feature. So there's a fair amount of trial and error to be done.

As hard as I've looked, there's nothing available in Sweden that boasts expansion. There are a few PU-based glues but if they expand is more than I can tell.

Then again, in Sweden very few floors are glued. The most prevalent floors these days are click lock faux parquetry laminates, and they are usually laid floating on a layer of foam for sound absorption.

For massive wood floors they are most often nailed to the structure invisibly in the grove of one plank before laying the next. No glue is used as the planks will need to shrink and expand a bit with the humidity.

[Bill Fitzmaurice]

No glue is used as the planks will need to shrink and expand a bit with the humidity.

That expansion and contraction is what causes the fasteners to eventually loosen and the floors to squeek. With PL that doesn't happen. PL Premium is intended primarily for floors. I discovered that it's the best adhesive available for speakers, I don't know if PL (Loctite Corp) is aware of it. (I may not have been the first to use it but I was the first to publish its use).

[Rune Bivrin]

That expansion and contraction is what causes the fasteners to eventually loosen and the floors to squeek. With PL that doesn't happen. PL Premium is intended primarily for floors. I discovered that it's the best adhesive available for speakers, I don't know if PL (Loctite Corp) is aware of it. (I may not have been the first to use it but I was the first to publish its use).

Quite possibly, although our floor is pretty squeak free after eleven years. if the planks are only nailed on one side the movement should be on the other side. And if you choose a solid wooden floor that squeakiness is to some degree part of the charm because that reminds us of our childhood years in the squeaky summer house...

But what I'm getting at is that different parts of the world uses different methods, and what's available in local stores reflect that. At some point we have to accept that and work with what we have. I ordered PL Premium from Leland for my DR250:s and used that for some parts. For the T39:s I'm going all in with PL. I clearly see the benefit, but I could have managed with any other filling glue. I honestly feel the brad nailer, the large square and the Makita sink saw are much more of enablers for avoiding large gaps and non-square cuts.

[horst]

No glue is used as the planks will need to shrink and expand a bit with the humidity.

That expansion and contraction is what causes the fasteners to eventually loosen and the floors to squeek. With PL that doesn't happen. PL Premium is intended primarily for floors. I discovered that it's the best adhesive available for speakers, I don't know if PL (Loctite Corp) is aware of it. (I may not have been the first to use it but I was the first to publish its use).

I think there's a bit of cognitive dissonance going on, I proclaimed the magic of PU construction glue on a local woodworker forum which even has a subforum only discussing glue, but there was absolutely no resonance from anybody, they are happy to wax lyrically about the runny PU glue from the squeeze bottle, but it must be that using a glue for wood that comes out of the same package shape as silicone is somehow not right.

[Rick Lee]

I think there's a bit of cognitive dissonance going on

Hey now we'll have none of that around here!!! ... That's nice- sounds like something you could use in a speaker ad.

If the OP is comfortable with fiberglass and epoxy there's no reason not to use it. Just use an appropriate filler like Cabosil to thicken it up and it should fill the gaps nicely. PL or equivalent is definitely ideal because it expands but there's many a wooden boat floating out there that use fiberglass and epoxy to keep things watertight.