A little veneer work

M

MrBoat

Audioholic Ninja
5/8" isn't a bad thickness for these but I still like 3/4. Thicker with bracing should dampen these noticeably. I was able to salvage the ports once I cut the baffles from the speakers and they are nice, IMO, and the crossover looks to have decent quality parts as well. I was able to save the baffles. I started to toss them but they are of a good quality MDF.

I can reuse the front baffles if I pad them with a piece of 1/4" ply that I have. The cabinets will be expanded slightly to account for the mass of the bracing and even with expanding the baffles, it will be easier than laying out and doing all of this otherwise, non-typical router work, that makes special accommodations for the waveguide that couples the mid and tweeter.

Being that I can pad the inside of the baffles with a layer of 1/4", this will leave a land for any side or end extensions I glue to the edges. I can trim a bit of all 4 sides on the table saw so that I am not just gluing slivers on. It's overkill from a construction standpoint, but makes keeping things flush (or proud enough to sand some off, ideally) easier. I could just make them slightly deeper and not mess with the overall dimension much. It's not going to take much added volume to make up for a single, central brace, so that'd likely be the best option here. Only difference is from the thicker panels and in this case would just be .125 on all sides.

I would likely settle for solid wood picture frame around the baffle and veneer over that so that any further edge treatments (bevel or round-over) could be integrated without much contrast or at least within stain blending range.


Baffles are MDF while the casework is particle board. Here is the "budget" part of this build.


 
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M

MrBoat

Audioholic Ninja


Perhaps this weekend I can get a good start on these. Just add some rabbets and assemble. Still need to modify the baffles to fit the now larger OD.
 
M

MrBoat

Audioholic Ninja
Progress. Corners are half depth rabbets. Baffles rabbets are 5/16" deep taken from the original baffles and am reusing the baffles so made those the same. I have to rebuild and fit the baffles first before figuring out where the braces can fit. Much of the baffle is otherwise used up so it's going to be tight.

 
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isolar8001

isolar8001

Audioholic General
I'm not as sharp as I used to be, but I find all of this very baffling. :)
(and excuse me, beautiful work by the way!! )
 
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M

MrBoat

Audioholic Ninja
I was able to cut the old rabbets off of the baffles and add some stabilized (cactus juice/vacuum) cherry blanks to the edges with epoxy thickened with fumed silica and also filled screw holes and sealed the cabinets. I flow epoxy on the ends that have the rabbet engrains and then sand flat. This helps keep these joints from telegraphing through the veneer years on down the road. I typically use multiple coats of lacquer and let it cure for months and then block sand the whole affair so any minor telegraphing that may occur due to shrinkage later on, is leveled out in the final sanding.

There only needs to be enough cherry for round-over or chamfered edges so there won't be any issue with the hardwood moving differently than the MDF. These epoxy joints are just clamped tight enough for a bond but enough epoxy is left in the joint which is what the thickener helps maintain. Epoxy relies on film strength and you don't want to clamp it as tight as wood glue. Since it is vacuum/resin stabilized, glued with epoxy and then sealed very well after, I expect no issues from it. Cherry is pretty stable on it's own once dry anyway. The resin used to stabilize it is then heat cured in an oven afterwards, and any movement will surely show then. It's the same resin I use to stabilize my wood knife handles.





It's a lot of extra work but I live in Florida and these methods have proven pretty reliable with my wood boat building projects so it's pretty much overkill here and is what I have the most supplies for.
 
M

MrBoat

Audioholic Ninja
Looking good man!
Everything is well oversize on the baffles and most of that bulk gets machined off.

lol. . . See what you started, William?

Meanwhile, I am listening to your ex's while waiting for epoxy to dry on these. I only had enough clamps to do one baffle at a time and I swore to not rush these like everything else I get into. Having the second set to listen to during, helps.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
Everything is well oversize on the baffles and most of that bulk gets machined off.

lol. . . See what you started, William?

Meanwhile, I am listening to your ex's while waiting for epoxy to dry on these. I only had enough clamps to do one baffle at a time and I swore to not rush these like everything else I get into. Having the second set to listen to during, helps.
Ok. I’ll except that it’s my fault! Can’t wait to see em.
 
M

MrBoat

Audioholic Ninja
Slow progress during the work week. I did manage to get one box sanded and trued and the back panels fit. I wait until the boxes are assembled and cut the back panels more precisely to size because I use those to square the cases before fitting the baffles. Cases were true within a 16th but the back panels fine tune them more perfectly after the fact.

I use the RO to take the tacky gloss from the epoxy and use the misery whip to flatten/read the flat areas and to really crisp up the corners which makes for a better overall veneer job. The idea behind the epoxy barrier coat is to seal the end grains and basically homogenize everything so that the contact cement doesn't cure differently in the more absorptive end grain. The end grain will cause the contact adhesive to shrink more than the flat areas, otherwise, causing those areas to show thru the veneer, months down the road.

Also, unsealed MDF and plywood takes two coats of contact cement or there will be starved areas when applying it by hand. It's overkill to be sure but I hate applying contact cement to an otherwise wooden sponge.



The RO sander alone, causes dish-outs on the flat panels when trying to concentrate on just the putty spots. Not really a big deal but I notice it when blocking the final finish coats. This step just makes everything ultra flat. A bit looney, probably, but just the way I was taught.
 
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M

MrBoat

Audioholic Ninja
I got the baffles fit. Can't trim the edges until the veneer is on the cases. I started to go for it and decided against it with trying to take my time instead of getting into that habitual production rush job I always get into like it's my real job, or something. I can tinker with the braces during the week and do the veneer next weekend.

Machining the cherry edges flush with the baffle faces was a tedious affair. All the grain was going the wrong way with regard to the direction I had to flush trim it. I am somewhat surprised at myself for not catching that ahead of time when I installed it. All but one edge was arranged the wrong way, which made me really have to be careful of tear out. Basically had to nibble away at it, which took awhile.

 
M

MrBoat

Audioholic Ninja
I'm making progress. Some design changes have caused me to need more steps in between. Example being, The originals have a small chamfer on 3 baffle edges. After I got the cabinets routed for the same reveal the stockers have, I didn't like it, so I padded it out some, roughly .125" thicker. This way I can try a decent round-over first, and if it doesn't look like I want, I can change to a bevel like the originals. Anyhow, this caused me a whole other step that set me back a week. I just keep reminding myself I am in no rush.

Today, I started applying veneer to the backs and then quit after that. Wanted just to take it easy and relax the rest of the weekend away with some music listening.

Got the braces done as well. Huge difference with the tone of the rap test after adding the brace. These speakers could likely get away without braces, especially with 18mm MDF, but wth.





I used a spreader clamp to push the box sides apart when I put the brace in so all of the glue doesn't get rubbed off. From there it's just a matter of releasing the clamp and letting glue squeeze out normally. I meant to put rabbets for the braces and forgot. That and I could not be sure exactly where to put them until the baffle fitment/port tube clearance/location was set in stone.
 
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