Aha! Thanks for another wake up call Steve! I wouldn't make any progress without you!
I hope I am not a pest, love a great experiment/work.
You're intuition must be itchy cuz I'm actually already working on it today. I'm regluing the T nuts with CA glue because the PL construction adhesive that I used before is very strong and tough, but it doesn't wick under the TNuts to make a good enough joint. It's more like taping them on from above. I could only glue one side of the TNuts with PL while the drivers screwed down to hold the nuts in place, so some of the TNuts could rock a little on the other, loose side. The CA seeps under and glues it tight. I'm using Bob Smith medium viscosity 15 second cure, but on the rough side of the masonite it cures very slowly, but it's solid after 10 minutes. Luckily I haven't glued any fingers together yet, but there's still one baffle left. I like the first wiff of CA, reminds me of happy days in my previous stress free hobby of model airplane building. But after a few minutes the smell gets old fast.
Also today I will drill 4 small holes in each of the 64 divider panels that go between each driver, holes to allow the hookup wires to pass through. Some of the panels need less holes, according to the wiring schematic, but the most holes any panel needs is 4, so I'm drilling 4 in all of them, then I'll fill the unused holes after the hookup is done. That's easier than gluing each divider panel in a "correct" position, and messing it up. Also allows changing the wiring schematic if I already messed that up but don't know it yet. Since all the drivers move the same, in same volume chambers, there shouldn't be any air movement through the holes, but I'll seal them up anyway, and the wires through the holes. Once the holes are drilled I can start the sexy job of gluing up the boxes.
Edit: My wife wants me to finish these so she can hear what all this work is for. So I am motivated to show it off for my biggest fan and that should accelerate my progress. Just don't hold your breath!
That is one phase I don't like thinking about, making sure the nuts stay in place. I have not had any experience to see how long CA will work with wood. Will you need a combo of CA and CL to prevent nuts from falling after decades would work or just CA alone?? Using any washers, on either side??
Cheers and keep up the good work Rich.
Steve
I have used CA since the 80s and never had a failure even after repeated speaker R&R. I always use Baltic birch as one of the front baffle layers to get a final baffle thickness of at lease 1". Considerably thicker baffles for larger drivers. Normally I'll use 1/4" -1/2"MDF, Medex or tempered Masonite for the external layer just to make it easier to finish.
ALWAYS use machine screws at least as long as the baffle thickness and use a lock washer under the screw head on drivers bigger than 7 inches.
Small drivers I drill the screw holes 1 size under the tap drill size for the screw being used. Run a tap through the hole. The tap will it and compress the BB fibers which increases the fiber density. Apply Scotch tape to one side of the hole and fill the hole with thin CA and let it penetrate the wood for a couple of minutes. Which the CA out with a pipe cleaner and let it cure naturally for 30 minutes. Remove the cello tape and then spray CA accelerator in the hole and wait 5 minutes. Then re-tap the hole. I use this method on drivers up to 8". Like I said - no failures.
Larger drivers I normall use threaded inserts, but these need to be installed before routing the driver holes. Drill the smaller hole first, then counter bore for the threaded insert. Install the threaded insert and then run the tap through from the insert side. Here is where disaster can happen. Here is where disaster an happen. Stand the baffle board on one side and slowly, carefully saturate the wood (MDF, whatever) with thinCA. Some fill flow underneath the insert. Let it cure and then re-tap one more time.
Bullet-proof.
Sounds like a lot of work, but after you do it a few times it is faster than one would think and is way quicker than having to fix a bad hole.