The sounds of imploding plywood......
My vacuum pump is your vacuum pump......with all of this post action I guess I'm going to have to build something.
And one that your loyal friends might have to sneak the occasional usage on
My vacuum pump is your vacuum pump......with all of this post action I guess I'm going to have to build something.
2 things to remember
- As Evan says the form for vacuum pressing curved laminations needs to be very sturdy - even at only standard air pressure of 15lb PSI, the total surface area means a substantial amount of pressure, and the materials can easily buckle. We use at least 2 layers of 1/4" ply or MDF nailed to a framework of 3/4" MDF ribs on not more than 2" c-t-c spacing for our forms. There's far more time and material involved in fabricating the jig than in the actual layup of a couple of panels.
- Vacuum bagging of an elliptical shape as shown in your original photo would probably be easier to fabricate as 2 separate pieces joined with a rear spine of solid wood . The fully cured curved panels will have virtually no flex, and you'll have a "bit of trouble" getting this shape off a form sturdy enough to withstand the vacuum process.
Several years ago I attempted my first build of a very similar shaped enclosure the "easy" way -as in your early photos with ribs and studs with several layers of timber-flex kerfcore, etc. It was certainly sturdy enough for acoustic purposes, but not so successful aesthetically. - and after attempting several different combinations of multi-way drivers and XO, etc, it was "permanently retired"
- As Evan says the form for vacuum pressing curved laminations needs to be very sturdy - even at only standard air pressure of 15lb PSI, the total surface area means a substantial amount of pressure, and the materials can easily buckle. We use at least 2 layers of 1/4" ply or MDF nailed to a framework of 3/4" MDF ribs on not more than 2" c-t-c spacing for our forms. There's far more time and material involved in fabricating the jig than in the actual layup of a couple of panels.
- Vacuum bagging of an elliptical shape as shown in your original photo would probably be easier to fabricate as 2 separate pieces joined with a rear spine of solid wood . The fully cured curved panels will have virtually no flex, and you'll have a "bit of trouble" getting this shape off a form sturdy enough to withstand the vacuum process.
Several years ago I attempted my first build of a very similar shaped enclosure the "easy" way -as in your early photos with ribs and studs with several layers of timber-flex kerfcore, etc. It was certainly sturdy enough for acoustic purposes, but not so successful aesthetically. - and after attempting several different combinations of multi-way drivers and XO, etc, it was "permanently retired"
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A friend makes Kayak canoes by glueing 1/8 in thick 2 inch wide strips of veneer over a former. Three diagonal layers (in alternative directions) are used, each fastened in place while the glue sets by paper staples, which are then removed. The appearance is stunning, and the finished product very light but extremely strong.
One thing to note, the hull is banana shaped one way after two layers, and after three very slightly the other way, which can be an advantage in canoeing. Four layers makes it straight.
The former is removed for reuse.
I think four layers would be fine for smaller cabinets, six layers would be ideal for large cabinets.
One thing to note, the hull is banana shaped one way after two layers, and after three very slightly the other way, which can be an advantage in canoeing. Four layers makes it straight.
The former is removed for reuse.
I think four layers would be fine for smaller cabinets, six layers would be ideal for large cabinets.
I´d recommend building the speakers in strip planking in stead of or in addition to veneer.
Boatbuilding Methods: strip planking
You have a shape that curves in one plane only. It is super for this technique, and you can build a lot of thickness quickly. Strip planking gives you some new options for wood patterns as well.
Boatbuilding Methods: strip planking
You have a shape that curves in one plane only. It is super for this technique, and you can build a lot of thickness quickly. Strip planking gives you some new options for wood patterns as well.
An externally hosted image should be here but it was not working when we last tested it.
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