2 Jack 112s

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88h88
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Re: 2 Jack 112s

#16 Post by 88h88 »

I used similar stuff (though less bubbly it appears) for subs and made double-triple sure everything was airtight before putting the side on. This process involved running over joints 2-3 times more until we were happy it was all sealed. The cab is more adhesive than wood and that's purely because I didn't trust the adhesive enough. It can be done but it's too much of a complete ballache and if you screw up then you've screwed up bigtime as once that last side is on it won't come off easily.
4xOT12s, 2xT39s@22", TTLS@18", 2xT60@18"

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Harley
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Location: Christchurch, New Zealand - Authorised BFM Cab Builder

Re: 2 Jack 112s

#17 Post by Harley »

The problem with stuff like this http://www.titebond.com/ProductLineTB.a ... prodline=6 is that it's like treacle and easily dribbles away from the joint if the surface is not completely level. Like PL, it relies on compression and moisture for cure, but even with compression it can still seep away from the joint.

That's why a gelled 100% exp polyurethane ( in a tube ) works better. It stays there.

A couple of years ago I did extensive experiments with all sorts of glues and spoke with the rocket scientists that produced the stuff. The titebond is actually as strong as the gelled polyurethane BUT under the right application conditions and cabs are NOT the right application conditions.

In fact talking of glue strengths, I had a hot melt glue that was quickly clamped under intense pressure and let settle for 24 hrs yield as much tear strength on the ply joints as PL BUT, again, it's totally impractical for cab building.
ImageSemi-retired: Former Australia and New Zealand Authorised BFM cab builder.

TwoTone
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Joined: Fri Jul 01, 2011 7:07 am
Location: Australia

Re: 2 Jack 112s

#18 Post by TwoTone »

As I said, too late. I've used this on my 2 Jack 12s.

tcorder
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Joined: Sun Mar 01, 2009 7:02 pm

Re: 2 Jack 112s

#19 Post by tcorder »

Unfortunately, PL is not available in the UK and at $30 or more a tube to ship, it's a bit expensive to ship here.

Bruce Weldy
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Re: 2 Jack 112s

#20 Post by Bruce Weldy »

tcorder wrote:Unfortunately, PL is not available in the UK and at $30 or more a tube to ship, it's a bit expensive to ship here.
If Two Tone had put his location in his name info - he might have gotten a better response that would be applicable to his situation. There a lot of builders in the UK that probably would have chimed in with suggestions.

Bill, you should make location a required field in the setup for the forum. It would save a lot of unnecessary keystrokes and misunderstandings.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


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Bill Fitzmaurice
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Re: 2 Jack 112s

#21 Post by Bill Fitzmaurice »

Bruce Weldy wrote: Bill, you should make location a required field in the setup for the forum. It would save a lot of unnecessary keystrokes and misunderstandings.
The software decides that, not me. It's up to the user to put in their profile their location so we know, or leave it out and let us ask 30 questions to figure it out.

TwoTone
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Location: Australia

Re: 2 Jack 112s

#22 Post by TwoTone »

I really appreciate all the help guys. I'm actually from Australia and did some research to try to find PL before I started but couldn't.

So my plan of attack now is to get the back on, run a tone through them and see how I'm doing for leaks. All my joints were pretty much spot on with no gaps so I'm hopeful. If they do whistle and leak I'm thinking I'll attack it on the inside with some sikaflex or similar heavy duty sealant around the joints. If that's no dice then I guess I just have to start again :(

lincsoldbird
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Location: Lincs UK

Re: 2 Jack 112s

#23 Post by lincsoldbird »

tcorder wrote:Unfortunately, PL is not available in the UK and at $30 or more a tube to ship, it's a bit expensive to ship here.
Try toolstation.com Lumberjack 5 min pu in a tube about £6.
built 4 T30 24in BP102 now sold 2 DR280
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88h88
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Re: 2 Jack 112s

#24 Post by 88h88 »

lincsoldbird wrote:
tcorder wrote:Unfortunately, PL is not available in the UK and at $30 or more a tube to ship, it's a bit expensive to ship here.
Try toolstation.com Lumberjack 5 min pu in a tube about £6.
This is the stuff we used on ours, it works really really well but we used multiple applications on the panels and then pretty much drowned the edges before putting the final side on and weighting it for 12 hours.

Image
4xOT12s, 2xT39s@22", TTLS@18", 2xT60@18"

TwoTone
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Location: Australia

Re: 2 Jack 112s

#25 Post by TwoTone »

Ok, so after a brief hiatus where I was so peeved with myself for using the wrong glue, I'm back into it. I've sealed the joints that I can reach with a polyurethane flexible filler and added my drivers and back panel. One of the cabs is all good, no leaks apart from a small leak where I've mounted the connector tray on the rear panel, which I haven't siliconed yet. The other one is not right, there's a popping noise coming from it when I turn up my test signal (30 Hz) to a reasonable level. If I run the test signal at 50 or 80 Hz then the noise does not become apparent until higher levels.

I remembered reading this post http://billfitzmaurice.info/forum/viewt ... ug#p151568 about a similar problem so pulled the driver, but the dust cap looks fine, no dents or marks where it might have been hitting. At the levels I tried it at I could hear no leaks (using the flexible hose as stethoscope method).

I'm about to go away for the week for work, but hoped maybe some people might have some suggestions for me. Should I try swapping the drivers in the two cabinets? They are both brand new Deltalite 2512s. Could it be that a leak in the dodgy one is cause the driver? The same signal was run into the two drivers giving the two different results.

I'm feeling pretty good about the whole glue issue and the predicted leaks have not eventuated. All my panels were cut true and exact so I think that's helped a lot. I just need to get to the bottom of this problem now, can't wait to try these cabs at rehearsals and gigs.

I've included some pics for interest, one where you can see the sealant I've used.

thanks for all the comments everyone.
Attachments
Sealed.JPG
Front.JPG
BackPanel.JPG

petegt
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Re: 2 Jack 112s

#26 Post by petegt »

88h88 wrote:
lincsoldbird wrote:
tcorder wrote:Unfortunately, PL is not available in the UK and at $30 or more a tube to ship, it's a bit expensive to ship here.
Try toolstation.com Lumberjack 5 min pu in a tube about £6.
This is the stuff we used on ours, it works really really well but we used multiple applications on the panels and then pretty much drowned the edges before putting the final side on and weighting it for 12 hours.

Image
I just bought 2 tubes of the 30min lumberjack gel, I hope I chose well because gripfill didnt work out so well last time :(
2 TAT 16" loaded with JBL GTO 804 + V plate
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Dave Non-Zero
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Re: 2 Jack 112s

#27 Post by Dave Non-Zero »

I've just used the B&Q PU glue for all my cabs,
http://m.diy.com/mt/www.diy.com/diy/jsp ... t_redirect

I couldprobably get cheaper stuff online, but I always need 'one more tube' in the middle of a project.

Not had a leak yet.... :fingers:
-1 for thought terminating cliches.

Built and/or own:
8 x T48 24" 3015LF
6 x DR280
2 x DR250 old style beta10
2 x T36s 20" delta15L
1 x TAT
1 x dual Lab12 30" T60

In Progress:
2 x DR280

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Tom Smit
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Re: 2 Jack 112s

#28 Post by Tom Smit »

TwoTone wrote:
I've included some pics for interest, one where you can see the sealant I've used.

thanks for all the comments everyone.
Can't see the pics .....and the links were no good :cry:
TomS

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Bill Fitzmaurice
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Re: 2 Jack 112s

#29 Post by Bill Fitzmaurice »

TwoTone wrote:there's a popping noise coming from it when I turn up my test signal (30 Hz) to a reasonable level. If I run the test signal at 50 or 80 Hz then the noise does not become apparent until higher levels.
That usually indicates the driver exceeding xmax, usually the result of a leak. But be very aware of what a 'reasonable level' is at 30Hz. J112 will reach xmax at 30Hz with 16v input. Output will be around 100dB, but 100dB at 30Hz isn't as loud as you'd think, being only as audible as 70dB at 200Hz.

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Chris_Allen
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Re: 2 Jack 112s

#30 Post by Chris_Allen »

Bill Fitzmaurice wrote:but 100dB at 30Hz isn't as loud as you'd think, being only as audible as 70dB at 200Hz.
Is that the old Fletcher-Munsen [sic?] curve?
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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