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Baltic Birch Expansion
Baltic Birch Expansion
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Old 17th December 2017, 10:48 AM   #21
robert1111 is offline robert1111
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Every joint has expanded. But can not be seen on the sides, probably because the veneer stripes run parallel, with the expanded panels.

Not sure where the plywood is made.

You guys have been helpful, next time I know how to make better. I'll probably wait and see how the speakers act. They sound creat, and maybe in the correct place and lighting, this little error can not be seen. If it still annoys me I have to do the veneering again.

I quess the first speakers most likely wont be 100% successful anyway.
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Old 17th December 2017, 01:21 PM   #22
straight8s is offline straight8s  Canada
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I see what you mean, some of the tiny veneer edge is visible. You can get felt furniture markers that have stain in them. Colour the edges and they are hardly noticeable.
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Old 17th December 2017, 01:22 PM   #23
simon7000 is offline simon7000  United States
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In days past you would have just left a record stack or even just a cover to hide it. Perhaps a doily or some such and claim it improves the sound.

BTY it is a reasonably nice start effort.
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Old 17th December 2017, 01:29 PM   #24
straight8s is offline straight8s  Canada
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Wood is unnatural, imperfect. I agree you did a pretty good job by the looks of it. Try one of the markers if it bothers you that much. I use them sometimes on say an antique piece of furniture thats opened up here or there, and an inner edje becomes slighly visible. or a situation like yours. The edge will virtually disappear.
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Old 17th December 2017, 01:34 PM   #25
DonVK is online now DonVK  Canada
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If you reapply veneer without correcting the problem, you will get the same outcome.

One way of preventing the edge from telegraphing is to use thicker (1/8"-1/4") single wood sheet veneer across the entire surface to cover the joints. Often you can buy this in the wood species of your choice. Alternatively, you could add a thin sheet of underlay (1/4 sureply) to cover the surface and edges (used under vinyl flooring) before applying extremely thin veneers.

I suspect all side panels lengths are not equal (ie. front=back, and left=right but front<>side). The panel widths (front-back, and left-right) are probably the same from top to bottom so expansion/contraction happens at the same rate along the entire side but not the top-bottom. This is why its showing on the top first, but it can telegraph along any edge.
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Old 17th December 2017, 01:44 PM   #26
kevinahcc20 is online now kevinahcc20  United States
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Generally speaking 13 ply BB should be quite stable in its length and width as the plies oriented with alternating grain direction restrain this movement. It will undergo a modest amount of movement across the thickness axis as the thickness of the plies are radial to the orientation of the wood in the tree. I can see the marks in your top two pix but the third one doesn't show at all and the construction of your box is unclear. If the box under the veneer has exposed BB edge plies glued to the veneer in the areas showing the marks it may be differential movement between the edge plies and the veneer.
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Old 17th December 2017, 01:51 PM   #27
scottjoplin is offline scottjoplin  Wales
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Quote:
Originally Posted by kevinahcc20 View Post
I can see the marks in your top two pix but the third one doesn't show at all
Yes, I couldn't see what he was getting at in the third picture, which has disappeared by the way
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Old 17th December 2017, 04:24 PM   #28
phase is offline phase  United States
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Screws wonít effect the expansion of the entire panel, but if the boxes have been in the environment that they will be used in, they are not going to change unless the humidity or temperature changes. I use a flush trim router if I can, otherwise sanding works too.

I would re-do it since I know I could fix it, as opposed to factory made stuff, where you donít know what you are getting into. The re-application of the lacquer would be a bit of a drag though, so I understand just leaving it and enjoying the speakers, which look great btw.

I have a few smaller dents in my car, which read differently depending on the temperature, so every time that happens, they catch my eye, as theyíve changed slightly. Between seasonal changes, I hardly notice as Iíve become used to how they appear...
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Old 17th December 2017, 04:46 PM   #29
Pano is offline Pano  United States
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Baltic Birch Expansion
Quote:
Originally Posted by paul burchell View Post
This reminds me of a earlier project done here where a tall multi driver speaker was constructed using stacks of ply laminated together, then steel rods where added down through the laminations and glued with apoxy. Soon after the stack cracked near the center of the stack.
Right here. Bad news plywood.
The making of: The Two Towers (a 25 driver Full Range line array)
Starting at post 113.
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Old 17th December 2017, 06:03 PM   #30
phase is offline phase  United States
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I think I would have ran the plies in the opposite direction, or used a series of ribs, with a dado groove for each one if it just had to be like that for aesthetics. Can’t blame the wood really when used like that...

Last edited by phase; 17th December 2017 at 06:05 PM.
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