Composites: Difference between revisions
From GummyCarbs
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* Fenders and side plates are made of iso-flex or DCPD resins, no low grade ortho resins are used. | * Fenders and side plates are made of iso-flex or DCPD resins, no low grade ortho resins are used. | ||
* All parts are made with iso-flex gel coats to reduce cracking. | * All parts are made with iso-flex gel coats to reduce cracking. | ||
[http://www.redrockstore.com/resin.htm Epoxy Resin vs. Vinylesters and Polyesters] at Red Rock Store. This is an excellent layman's explanation of the different chemical properties of resins. | |||
* Epoxy resin | |||
** Strongest molecular bond | |||
** Will crack along a single line rather than splintering | |||
** Minimal shrinkage | |||
** Thin resin, easier to thoroughly wet-out fabric | |||
** Excellent repairability | |||
* Vinylester resin | |||
** Essentially polyester resin toughened with epoxy molecules | |||
** Weaker molecular bond than epoxy | |||
** Difficult to repair/patch | |||
* Polyester resin | |||
** Cheapest resin available | |||
** Highest water absorption | |||
** Highest shrinkage | |||
** Spider cracks when stressed | |||
** Difficult to repair/patch | |||
=Vacuum Bagging= | =Vacuum Bagging= | ||
* [http://volvospeed.com/Mods/vacuum_bagging.html Vacuum Bagging On $50] | * [http://volvospeed.com/~volvo/Mods/vacuum_bagging.html Vacuum Bagging On $50] | ||
** Glad ForceFlex trash bags are polyethylene and are suitable for vacuum bagging with epoxy. | ** Glad ForceFlex trash bags are polyethylene and are suitable for vacuum bagging with epoxy. | ||
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*** Uses a vacuum controller to switch the vacuum pump on only when additional vacuum is needed. | *** Uses a vacuum controller to switch the vacuum pump on only when additional vacuum is needed. | ||
*** Uses a "3-way Mac Valve" to relieve vacuum from the vacuum pump, which otherwise might prevent it from re-starting after cycling off. | *** Uses a "3-way Mac Valve" to relieve vacuum from the vacuum pump, which otherwise might prevent it from re-starting after cycling off. | ||
=Resources= | |||
* [http://www.bmeres.com/carbonframe1.htm How I Made My Carbon Frame At Home] at Brano Meres Engineering and Design. Demonstrates building a bicycle frame without vacuum bagging. | |||
* [http://www.badger.rchomepage.com/vacbag.html A Homemade Vacuum Bagging System] gives details on a low-cost vacuum bagging setup. | |||
Latest revision as of 06:24, 23 December 2015
Material Selection
Google's cache of the now-defunct www.pe.net/~rpm/about2.htm mentions:
- All gas tanks are made of vinyl ester resin for chemical resistance to gasoline.
- Fenders and side plates are made of iso-flex or DCPD resins, no low grade ortho resins are used.
- All parts are made with iso-flex gel coats to reduce cracking.
Epoxy Resin vs. Vinylesters and Polyesters at Red Rock Store. This is an excellent layman's explanation of the different chemical properties of resins.
- Epoxy resin
- Strongest molecular bond
- Will crack along a single line rather than splintering
- Minimal shrinkage
- Thin resin, easier to thoroughly wet-out fabric
- Excellent repairability
- Vinylester resin
- Essentially polyester resin toughened with epoxy molecules
- Weaker molecular bond than epoxy
- Difficult to repair/patch
- Polyester resin
- Cheapest resin available
- Highest water absorption
- Highest shrinkage
- Spider cracks when stressed
- Difficult to repair/patch
Vacuum Bagging
- Vacuum Bagging On $50
- Glad ForceFlex trash bags are polyethylene and are suitable for vacuum bagging with epoxy.
- Vacuum Bagging Basics is a good overview from a boating perspective.
- Simple Vacuum Bagging Systems recommends using a cheap hand-pump vacuum pump from an auto parts store. They have a built-in vacuum gauge.
- JoeWoodWorker.com has some excellent guides intended for applying veneers to woods.
- Project EVS is a how-to guide for building a very advanced vacuum system for a relatively low cost.
- Uses two vacuum reservoirs made of Schedule 40 or 80, solid-core PVC pipe. Just as an air tank prevents an air compressor from having to run continuously, a vacuum reservoir reduces the strain on a vacuum pump.
- Uses a vacuum controller to switch the vacuum pump on only when additional vacuum is needed.
- Uses a "3-way Mac Valve" to relieve vacuum from the vacuum pump, which otherwise might prevent it from re-starting after cycling off.
- Project EVS is a how-to guide for building a very advanced vacuum system for a relatively low cost.
Resources
- How I Made My Carbon Frame At Home at Brano Meres Engineering and Design. Demonstrates building a bicycle frame without vacuum bagging.
- A Homemade Vacuum Bagging System gives details on a low-cost vacuum bagging setup.