Anyone have any links to fibreglass construction techniques, fibreglass orientated projects(doesn't have to loudspeakers) and such like. Really anything to do with fibreglass would be good.
I'm cooking something up but its really just a bunch of ideas in my head at the moment. Don't have a clue how to go about transferring them into reality.
I've got this idea of creating a skeleton frame covering it in cloth and slapping the fibreglass over that then sanding to the shape I want but that's just something I've pulled out the air and vaguely remember seeing years and years ago on the car audio side of things.
Thanks
I'm cooking something up but its really just a bunch of ideas in my head at the moment. Don't have a clue how to go about transferring them into reality.
I've got this idea of creating a skeleton frame covering it in cloth and slapping the fibreglass over that then sanding to the shape I want but that's just something I've pulled out the air and vaguely remember seeing years and years ago on the car audio side of things.
Thanks
Should be a whole ship load of boat building info out there.
Fiberglass hulls are build in molds though. You might want to think about doing it the same way. The biggest advantage is a uniform, thick "gel coat". This is sprayed inside the mold before the fiberglass goes in and provides the ultrasmooth ouside layer.
No more worries with the MDF movement.
Fiberglass hulls are build in molds though. You might want to think about doing it the same way. The biggest advantage is a uniform, thick "gel coat". This is sprayed inside the mold before the fiberglass goes in and provides the ultrasmooth ouside layer.
No more worries with the MDF movement.
el`Ol said:
Wouldn't you need a mold to create the styrofoam mold? Modelling clay or similar might be better since you could shape this by hand, templates and basic tools.
This is what I'm looking at building, its a rough and incomplete sketch so you'll have to use your imagination a little
An externally hosted image should be here but it was not working when we last tested it.
Plaster is a pretty workable material - both for carving/shaping a rough piece, and for use on molds. Its messy, and takes some learning, but is a great medium. If you embed cloth or wire in it, it can have quite a bit of structural strength. I once built a large bed in the shape of a shell out of plaster..
Hello Shin,
You could make a mould out of expanda foam .Make a rough skeleton out of chicken wire spray expanda foam over and use
a rasp file to shape it ,use car body filler to smooth it out .
Then use a fibreglass chopper gun to make a female mould .
Either hand lay it or use a chopper gun to make the positive shape .
Boat builders and surf board makers would be able to help .
Cheers .
You could make a mould out of expanda foam .Make a rough skeleton out of chicken wire spray expanda foam over and use
a rasp file to shape it ,use car body filler to smooth it out .
Then use a fibreglass chopper gun to make a female mould .
Either hand lay it or use a chopper gun to make the positive shape .
Boat builders and surf board makers would be able to help .
Cheers .
I second the idea of making a buck first, then a mold from the buck. I have made race-car body panels this exact way with good success. The advantage for you, as mentioned before, is the ability to use a thick gel coat at the surface layer. Your design looks like it is thicker in the middle of the part than at the baffle, this means you will have to use a two piece mold if you chose this method.
I have made free hand bucks using the wire and expanded foam method, it is very challenging to make a symmetric part this way.
The method which worked best for me follows:
If you have access to a large format printer, you can divide the solid model into evenly spaced slices and print of the cross sections. If you really need to save paper, you can print all of the cross sections concentrically on one piece of paper and trim off each cross section as you work your way down to the smallest one.
Standard builders insulation foam (the blue or pink stuff) can be easily cut with a hot-wire or sharp razor knife, and can be stacked ala trans-lam style enclosures to form the basic shape of the part. From here, there is the matter of filling in the steps between layers of foam with auto body filler or plaster and smoothing the shape to your finished part.
Now, here is a little trick I have used to make parts that were not weight sensitive and going on a race car. I have never used it on the scale which you are building and am not sure how well it would work.
You can make a "lost foam" mold by dissolving the foam out from underneath a finished fiberglass layer. With this method you make the buck as described above, then vacuum bag the fiberglass directly to the buck. When the fiberglass sets up, the foam inside can be easily dissolved using common solvents (acetone, lacquer thinner), leaving the shell behind.
I found a pdf that describes this method here: http://www.westsystem.com/ewmag/23/pdf/03-Lost_foam.pdf
The disadvantage with that method is that you will be making two mirror image parts and would have to make two separate bucks, rather than use the same mold for two parts. This makes having symmetric parts more challenging. However, making a mold takes a very long time, so you would not necessarily save time by making a mold. In fact, you would probably spend a lot more money and time making a buck and mold than any other method mentioned so far, but potentially have the best results, and the ability to make duplicates with just a little more effort.
Just some ideas to throw into the fray.
Regards,
David
I have made free hand bucks using the wire and expanded foam method, it is very challenging to make a symmetric part this way.
The method which worked best for me follows:
If you have access to a large format printer, you can divide the solid model into evenly spaced slices and print of the cross sections. If you really need to save paper, you can print all of the cross sections concentrically on one piece of paper and trim off each cross section as you work your way down to the smallest one.
Standard builders insulation foam (the blue or pink stuff) can be easily cut with a hot-wire or sharp razor knife, and can be stacked ala trans-lam style enclosures to form the basic shape of the part. From here, there is the matter of filling in the steps between layers of foam with auto body filler or plaster and smoothing the shape to your finished part.
Now, here is a little trick I have used to make parts that were not weight sensitive and going on a race car. I have never used it on the scale which you are building and am not sure how well it would work.
You can make a "lost foam" mold by dissolving the foam out from underneath a finished fiberglass layer. With this method you make the buck as described above, then vacuum bag the fiberglass directly to the buck. When the fiberglass sets up, the foam inside can be easily dissolved using common solvents (acetone, lacquer thinner), leaving the shell behind.
I found a pdf that describes this method here: http://www.westsystem.com/ewmag/23/pdf/03-Lost_foam.pdf
The disadvantage with that method is that you will be making two mirror image parts and would have to make two separate bucks, rather than use the same mold for two parts. This makes having symmetric parts more challenging. However, making a mold takes a very long time, so you would not necessarily save time by making a mold. In fact, you would probably spend a lot more money and time making a buck and mold than any other method mentioned so far, but potentially have the best results, and the ability to make duplicates with just a little more effort.
Just some ideas to throw into the fray.
Regards,
David
gtforme00 said:
A good material for making the "buck" is the Styrofoam mentioned above. Blue seems to be denser. The buck would be a perfect replica of what the finished speaker would look like. So, it needs to be perfectly smooth. Unfortunately, auto body filler has the same solvent as this foam (styrene) therefore it will dissolve it.
Priming the the smoothed foam with a couple of coats of water based paint will protect it.
Maybe Mr. Colani gives you some hints for prototyping if you show him some freehand drawings and some nicely rendered graphics.
http://www.colani.de
http://www.colani.de
OK I've found some really nice photo's of a construction using what I think is plaster and filler on a plywood frame.
The pictures and descriptions were taken from http://www.mundohi-fi.com and I'd highly recommend looking at the whole project because its a real stunner.
Could some kind person please translate the text below each image please and I'll go back and edit in the english translation.
I plotted the plan and attached it to a piece of wood to cut it with a carpenter's saber saw.
The spines of the two snail shells after cutting
With a compass and the saw I proceeded with the cutting and gluing of the ribs which will form the skeleton of the snail shell.
First side of the snail shell finished
Pieces of stainless steel to be placed inside the shells for attaching the stands. Their curved shape fits the interior shape of the shells.
I fille the interior with polyester fiber cloth and hardened it with resin to ensure the best connection of the ribs with best accuracy.
Exterior of the snail after the interior is covered with polyester fiber
The ribs are aligned with a square to get them as perfect as possible
Here you can see the fiber before and after application of the resin and in the rear the stainless steel support
Adding resin to the side except where the hoop for the woofer goes.
I turned a custom wood "crown " where the woofer will fit and glued it to the front.
Testing how the two halves fit. The lower has fiber the upper without fiber.
Overall view of the mounting of the "snails"
Glueing the hoop where the woofer goes.
The pictures and descriptions were taken from http://www.mundohi-fi.com and I'd highly recommend looking at the whole project because its a real stunner.
Could some kind person please translate the text below each image please and I'll go back and edit in the english translation.
I plotted the plan and attached it to a piece of wood to cut it with a carpenter's saber saw.
The spines of the two snail shells after cutting
With a compass and the saw I proceeded with the cutting and gluing of the ribs which will form the skeleton of the snail shell.
First side of the snail shell finished
Pieces of stainless steel to be placed inside the shells for attaching the stands. Their curved shape fits the interior shape of the shells.
I fille the interior with polyester fiber cloth and hardened it with resin to ensure the best connection of the ribs with best accuracy.
Exterior of the snail after the interior is covered with polyester fiber
The ribs are aligned with a square to get them as perfect as possible
Here you can see the fiber before and after application of the resin and in the rear the stainless steel support
Adding resin to the side except where the hoop for the woofer goes.
I turned a custom wood "crown " where the woofer will fit and glued it to the front.
Testing how the two halves fit. The lower has fiber the upper without fiber.
Overall view of the mounting of the "snails"
Glueing the hoop where the woofer goes.
I was tempted to put my head in the snail to listen to how it resonated, and of course... I did.
Here we can now see the project taking shape.
Before gluing the two sides, I meticulously polished their interiors with an air polisher. They were brushed with resin so that they would end up with the finest possible finish when they were finished.
Beginning to fill the ribs that form the snail shell with a paste of polyester/fiber, and smoothed...????
On the sides you can see the wood ribs
here, one of the most difficult operations, is putting the polyester/fiber paste in the interior of the snail shell.
Here I'm testing the driver to make sure it fits well it's opening to control any shrinkage and expansion. The blue paste is the finishing paste (filler?) These are the first tests of the final finish.
This is a test of the final assembly to see how things were going. Now the final finishing begins..
Snail shell finished and filled with the polyester paste.
Maybe you know that....
...11 pages,step by step.
http://www.mundohi-fi.com/portal/index.php?module=pagesetter&func=viewpub&tid=8&pid=8
...11 pages,step by step.
http://www.mundohi-fi.com/portal/index.php?module=pagesetter&func=viewpub&tid=8&pid=8
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