OTOP 12 JARRAY PROJECT.

[cave]

Thanks Grant Bunter. I live in Ghana in West Africa. The recomended PL Primeum is not available here . The 5min Lumberjack is a one part moisture curing Polyurethane wood adhersive which sets hard in five mins. It is resistant to most chemicals and is 100% seawater proof. The product foams slightly on application to fill small gaps. I guess it being a Polyurethane Glue is cool and does the job. I will definately fill the gaps with auto filler before sanding and pay attention to air leaks in the boxes. thanks for your advice.

[Chris_Allen]

I would be rather concerned about the T-Nuts having a raised profile behind the spacer which would create a gap all the way round. That's a big area to fill with glue.

As Phatman rightly pointed out, you are only really securing your driver to the spacer then gluing that down.

The phase domes look really cool - how much clearance do you have from the dome to the back of the Compression driver?

[cave]

I would be rather concerned about the T-Nuts having a raised profile behind the spacer which would create a gap all the way round. That's a big area to fill with glue.

As Phatman rightly pointed out, you are only really securing your driver to the spacer then gluing that down.

The phase domes look really cool - how much clearance do you have from the dome to the back of the Compression driver?

The T-Nuts were nailed to flush with the spacer. The spacer was then heavily glued to the baffle and nailed to secure them in place while the glue cured.

The clearance on the domes to compression driver is about 1/8 of an inch.

[escapemcp]

The 5min Lumberjack

This:


Yeah? If so, then good as that's the stuff I use.

EDIT: Just saw the pic of the Lumberjack glue on previous page. Looking at Everbuild's web page, they say that the tube is 'gel' and the bottle is 'liquid'. They both use the same spec sheet, but I cannot seem to see if the liquid stuff foams up or not.

[Chris_Allen]

but I cannot seem to see if the liquid stuff foams up or not.

You can tell by some of the pictures that is does indeed foam but I can also see a number of gaps on the surface, so it's hard to tell if an air tight seal has been achieved.

I must say though, I do like the look of the JArray OT12's.

What is the planned colour scheme?

[Tom Smit]

Looking at the pics, and zooming in, it appears that there is squeeze-out for the most part. As long as there is a good bead between the joints, then all is well. Perhaps you might a bead along the horn sheaths, and trim before a full cure, to make sure that it is air-tight.

[DJPhatman]

The T-Nuts were nailed to flush with the spacer. The spacer was then heavily glued to the baffle and nailed to secure them in place while the glue cured.

And this leaves no hole in the woofer baffle for the threaded part of the driver mounting bolt to go through as you are tightening down the driver. Also, this only leaves the glue joint strength and 1/2" (12mm) of wood to hold the driver, which is the very heavy Delta Pro 12A. This mistake puts your cabs at high risk of failure. You are now too far to correct your mistake. The only fix I see, without scrapping the cabs and starting over, is to mount the drivers in different holes in the spacer and baffle with lag bolts or Recex style screws.

[rogerc]

The T-Nuts were nailed to flush with the spacer. The spacer was then heavily glued to the baffle and nailed to secure them in place while the glue cured.

And this leaves no hole in the woofer baffle for the threaded part of the driver mounting bolt to go through as you are tightening down the driver. Also, this only leaves the glue joint strength and 1/2" (12mm) of wood to hold the driver, which is the very heavy Delta Pro 12A. This mistake puts your cabs at high risk of failure. You are now too far to correct your mistake. The only fix I see, without scrapping the cabs and starting over, is to mount the drivers in different holes in the spacer and baffle with lag bolts or Recex style screws.

Some screws through the spacer, if need be from both sides, to reinforce the adhesive and careful trimming to length of the driver mounting bolts will sort this.

[Tom Smit]

One could drill through the T-nuts (without gouging out the threads) and into the wood behind. This would allow the bolt to bite into the wood also, after it goes through the nut.

[DavidMW]

One could drill through the T-nuts (without gouging out the threads) and into the wood behind. This would allow the bolt to bite into the wood also, after it goes through the nut.

I'm seeing a small piece of pipe placed inside the T-nuts to protect the threads with a smaller bit in the drill to drill out the center of the wood.

[cave]

One could drill through the T-nuts (without gouging out the threads) and into the wood behind. This would allow the bolt to bite into the wood also, after it goes through the nut.

Hi guys, we are now at the stage of filling all the possible leak points in the boxes and will take all your suggestions into consideration. Thanks so Much. As usual, pix will follow soon.

[cave]

To strengthen the spacer I intend to put drywall screws through the spacer into the baffle after filling the gaps with glue.

[bmf]

You could always drill through the nuts completely and install new ones to the baffle letting you bolt through the spacer and baffle. This will give you a better mounting surface and secure the bond between both pieces. You would need to do this in steps and not try to remove to much of the original at a time.

[cave]

Get ready for our next phase

[cave]

Hi folks,

We took some time off to attend to a few other things but still managed in between time to fill the potential leak points on the boxes with a mix of very fine saw dust and white carpenters glue. This mix bonds so well to the joints and seals all the leaks. We then sanded it smooth and test fitted the compression horns. We are working on the flying rig design and will post pix on thoses soon.