View Full Version : Vaccume baggin advice


BSR001
09-23-2008, 09:33 PM
Im building freestyle jetski hulls and im looking into vaccume bagging.however i have a few questions.right now my layup scheadule is where im happy with it.my question is if i do the same layup and bag it im gonna loose some of my thickness.does that mean i also loose the rigidity of the part do to it being thinner or will it not be enough to notice.
Also is polyester or vinylester resing baggable.thanks
here is a few pics of my hulls
http://i227.photobucket.com/albums/dd294/lpsracers1/kx250003.jpg
http://i227.photobucket.com/albums/dd294/lpsracers1/kx250002.jpg
http://i227.photobucket.com/albums/dd294/lpsracers1/newskikittensroastersdogsggma97b-4.jpg
http://i227.photobucket.com/albums/dd294/lpsracers1/pumpshoe.jpg
http://i227.photobucket.com/albums/dd294/lpsracers1/hull101.jpg

TeddyDiver
09-24-2008, 01:59 PM
my question is if i do the same layup and bag it im gonna loose some of my thickness.does that mean i also loose the rigidity of the part do to it being thinner or will it not be enough to notice.

Basicly getting rid of excess resin increases strength. About rigidity not sure..

Rick Willoughby
09-24-2008, 05:50 PM
Panel rigidity is a function of the elastic modulus of the glass used and the thickness to the third power. So thickness is extremely important for gaining rigidity. If you are effectively using excess resin as a filler to increase thickness then you gain in rigidity for the amount of glass used.

This is not the most effective way to gain rigidity because there are much lower density fillers but making a cored panel is a more complicated layup particularly if it is a complex shape.

If you vacuum bag to reduce excess resin in the same glass schedule you should expect that the strength will be the same, the weight a little less and the panels considerably more flexible. The latter may be undesirable.

Rick W

View Full Version : Vaccume baggin advice