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They look great Dave. Phil

David Carter wrote:I'm starting to burn out a bit. Need a vacation from building for a while (after finishing this build).
The stack...

Go ahead and take a well deserved break when you're done. I get tired just looking at this picture.

That stack is exactly what is on my wish list. Oh well, it will just have to do me for a couple of years, to look at your nice cab build. Cheers.

Got to do a little work yesterday and today. My sander died yesterday, so I had to spend some time this morning fixing it, but all is well now.

Getting ready to attach a horn sheath...


Spray painting reflectors...


I found that, due to the way I had stored them for the last several months, most of my reflectors would not spread wide enough without some help, so I ended up cutting small strips of 1/4" ply and fastening them in place with brads to force the reflectors to spread out. This actually made it a lot easier to ensure that the reflectors were placed correctly and helped them stay in place while I glued them. I will definitely adopt this practice on all future DR builds...


BTW, a little tidbit that I think has been added recently to the plans is the idea of chamfering the edges of the reflectors to act as a trough for the glue. I don't remember this being in the plans when I did my DR250's a while back, but it's a brilliant idea! It took some time to do all that sanding, but it made the gluing SO much easier! Thanks, Bill!

The stack...

David Carter wrote:

DaveK wrote:You're doing something interesting with the butt cheeks. Is that semi-circular cleat a recent change in the plans or an innovation of your own?

As Chris said, it's not in the plans, but it's been done before by others. I did one of my DR250's that way, and found it a little more difficult to get the curved back material in place, but it greatly simplifies things overall if you're doing a squared back.

Is this mod posted anywhere here? I looked in the tip and tricks section but could not find it. I am pretty sure I want to do the square back and if this makes that easier, then I'm all for it.

Also, my version of the panel jig plans don't have the jig for the melded array which I also think I want to attempt. It appears like a pretty simple 90 degree angle jig with a guide/stop along the bottom. Anything special about it? It seems like if you use this jig then you have to cut the 45 degree angle one at a time rather than gluing the tweeters together first and then cutting them all at 45 degrees in one pass.

Which approach is easier/better?

Thanks,

Doug

David Carter wrote:As Chris said, it's not in the plans, but it's been done before by others. I did one of my DR250's that way, and found it a little more difficult to get the curved back material in place, but it greatly simplifies things overall if you're doing a squared back.

DrDoug018 wrote:Is this mod posted anywhere here? I looked in the tip and tricks section but could not find it. I am pretty sure I want to do the square back and if this makes that easier, then I'm all for it.

I don't think it's described in great detail anywhere. I just picked up the idea from Stan's (SoundInMotionDJ) pictures of his DR200 build. It's pretty self-explanatory, but if you have specific questions, let me know, and I'll try to help.

DrDoug018 wrote:Also, my version of the panel jig plans don't have the jig for the melded array which I also think I want to attempt. It appears like a pretty simple 90 degree angle jig with a guide/stop along the bottom. Anything special about it? It seems like if you use this jig then you have to cut the 45 degree angle one at a time rather than gluing the tweeters together first and then cutting them all at 45 degrees in one pass.

I cut them all individually. It's probably easier to glue them then cut. The jig would still help for holding the two halves of the array in place when gluing them together. In fact, that's what I did. I cut them all individually, then glued together all the piezos for each side, then glued the two sides together on the jig. You should be able to get an updated version of your panel jig plans from Bill. The jig is pretty straight forward, but the plans give you measurements.

The last several days have been busy with other stuff, but I've got a little bit more done.

Got the port holes drilled and the PVC rings installed to enable the variable tuning. Also got the "wings" attached, bondo'd, and sanded. Applied black latex paint to the areas that will be hard to reach after attaching the butt cheeks...



Experimenting with the butt cheeks...





Instead of trying to cram a full height piece of steel in there, I decided to go with two overlapping sections per side. I trimmed the edges that touch the top and bottom panels in an arc so they are snug up against the cleats all the way around. The bottom halves went on first, and they were cut so that they are flush with the edge of the back braces (see pic above). The top halves overlap the bottom halves by about 1" and have plenty of PL in between them. Everything is PL'ed and stapled to the cleats and the back braces. I also put PL across the back of the steel sheets everywhere there is a staple to make sure there will be no air leaks through the staple holes. Finally, I put a fat bead of PL down the center line between the two butt cheeks and ran a long thin strip of ply across it to work it down into the gap.

Oh, and I almost forgot to mention that I spray painted the inside face of the steel sheets before attaching them, so they are already black. I'll probably squirt a little more paint in there later to mask the little bit of PL "squeeze out" that's inside, but, for the most part, the painting is already taken care of inside the curved back section. I've always used the cheapest no-name spray paint I could get my hands on in the past, but this time I'm trying Krylon black satin finish, and it's amazing the difference. It goes on much easier and more evenly with a lot less overspray than the no-name stuff from Wal-Mart.

The whole thing is in the garage drying as I speak. If it works well, I'll do the same with the other three tonight or tomorrow...

Hey David,

Looking good! I'm no paint expert- is their any problems with Duratex sticking to latex? I'm thinking of shooting my OT12's with Latex first, then doing Duratex over that. I was under the impression (probably wrong), that I wouldn't need to do any prep work in between the Latex and Duratex. Just my first initial sanding of the outside of the cab. (60 or 80 grit?)

djtecthreat wrote:I'm no paint expert- is their any problems with Duratex sticking to latex? I'm thinking of shooting my OT12's with Latex first, then doing Duratex over that. I was under the impression (probably wrong), that I wouldn't need to do any prep work in between the Latex and Duratex. Just my first initial sanding of the outside of the cab. (60 or 80 grit?)

You shouldn't have a problem going Duratex over latex. That's what I did on the T39's I recent built, and it worked beautifully. My other builds prior to that, I did 2-3 coats of Duratex without any other coatings under it. Having done both now, I much prefer the Duratex over flat black latex. Same nice finish but it uses a LOT less Duratex.

Here's the T39's with a coat of flat black latex before the Duratex...

Did you shoot the latex or roll it on?

bgavin wrote:Did you shoot the latex or roll it on?

Rolled. I don't have the tools for spraying.

I'm getting very close to prepping my new T48 for Duratex.
I want to also prime with a flat black Latex, and don't really want to shoot it, even though I can. Messy.

Did you thin the primer at all, or just roll it on and call it good?

bgavin wrote:I'm getting very close to prepping my new T48 for Duratex.
I want to also prime with a flat black Latex, and don't really want to shoot it, even though I can. Messy.

Did you thin the primer at all, or just roll it on and call it good?

Full strength brushed on for me.

WB wrote:

bgavin wrote:I'm getting very close to prepping my new T48 for Duratex.
I want to also prime with a flat black Latex, and don't really want to shoot it, even though I can. Messy.

Did you thin the primer at all, or just roll it on and call it good?

Full strength brushed on for me.

I rolled it on full strength using a foam brush to dab it into the corners where the roller wouldn't reach. Just thick enough to make sure that the whole thing was black so I wouldn't have to worry if my roller didn't reach every tiny little nook and cranny when applying the Duratex.

bgavin wrote:I'm getting very close to prepping my new T48 for Duratex.
I want to also prime with a flat black Latex, and don't really want to shoot it, even though I can. Messy.

Did you thin the primer at all, or just roll it on and call it good?

Bruce, remember that you can prime with a thinned(with water) coat of DuraTex, too. This is my preferred method.