I'd love to hear it!! cuz I have info to exactly the contrairy ! there productucts come highly recommended .. as can be atested to by lots of people on other boards .. yotatech to name one .
speak up !
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Ok here goes:
What it seems that they are doing here is a classic way to form fiberglass. They are lamanating the glass with plywood.
Glass has imesurable tensile strength. Fiber glass is in fact glass just like you would find in a window pane so if you could imagane trying to break a window not by smashing it but by pulling it lengthwise.
When we get our glass at the shop it comes in 300 lb rolls 4 ft wide, and if you drop it you will in fact shatter the glass and it will be a waste of about 1200$ (this sucks big time as im the one chucking this stuff around the shop all day)
But its compression strength is the week point. You can get around this by just laying up an enormous amount of glass, or you can lamanate it with other materials. Similar to the concept of using a 3 inch square tube vs a 3 inch block of steel.
The important factor in this style of beam in the end is the thikness. If you lamanate one course of 1/16 inch glass on either side of a 1 inch peice of something or other you gain nearly the same amount of strength as if you were just to lay up a crap load of glass till it was 1 1/8th thick.
The inherent problem is that the bond between the glass and the lamination needs to stay intact for you to retain this type of strength.
Wood in its propertys has comparitivly a lot of moisture in it. Eveyone knows that wood swells and contracts through the seasons. You see it all the time in door frames and windows on houses.
The same is true for even plywood, and other processed wood products. Although its not nearly to the extent as you will find in a 2x4, but its still true.
So you get this situation where your glass that has cured to the matrix youve used is very rigid, but the wood that you have laminated it to is not. And to make matters worse when the wood expands and contracts it releases the bond it has made to your glass or carbon.
(hopefully the matrix is some high grade epoxy although usually not the case, most everybody uses polyester resins ((similar to bondo)) wich are just flat out a cheap crappy product)
Now after the lamination has separated itself you loose the capability for an outside force to distribute pressure from one side of the lay up to the other. And at this point you have lost so much integrity the only strength you've got really is that of which the ply wood itself has, the glass is doing little to nothing other than keeping your ply wood in place. In extreme cases I have even seen ply wood separate 100% internally to its glass and then chafed the glass as it moved around to the point where the ply wood carved a hole in the glass and started to fall out entirely.
For the past 70 years people have been trying to find ways to keep wood and glass from delaminating, but nothing has really been effective.
A number of other tecniques have been implimented to prevent this situation. Rigid foam is the usual that you see being used to lamanate fiberglass and carbon fiber due to its propertys of being porus thus able to soak up more of the matrix, light weight, and able to disperse load efectivly.
There are also other products such as Nida-Core a lamination of fiberglass and a plastic honeycomb coring. These products are even lighter than foam glass lay ups and if you punch a hole through the middle of it, the honeycomb coring segregates the rest of the coring material to contamination preventing delimitation of the rest of the material that has not been effected by the damage. (this is not a cheap solution like foam is, one 4 x 8 sheet of 1 1/8 with 18 oz skins costs upwards of 300$)
Nida-Core Lightweight Composite Honeycomb Core Materials and Structures
Composite Panels - Balsalite 090CSM - Honeycomb Core Sandwich Panels - Bonded Panels - Architectural Panels - (couple photos of the stuff on this page)
Back at the shop I work at we have even tried on a couple occasions to try to laminate pressure treated wood to glass on a vacuum table with an epoxy resin that boeing uses for ballistic missile cones, and the results still are not anywhere near to ideal.
The just of it is you can do this, and it will look good. And even work good, for a while, but as time passes it will deteriorate and eventually get to a point where you will have to replace things just to keep structural integrity.
If I were to start up a home built shop building truck beds out of composites I would probably set up a few vac tables to make foam coring slabs of glass large enough to be used for the major components of the bed, and then tab it all together with a biaxial weave glass somewhere around 32 oz.
Then again this is a lot of work and probably not cost effective.
But thats why I wouldn't buy one of those myself. And probably why even though I work with composites all day long I prefer to keep a big smashed up tin can on the back of my truck instead of fabing something sleek outa carbon fiber.
p.s. cudos to all who actually read all this rambling malarky
