how to prevent shrinkage

You  really can't prevent this.  Just take it into accound when setting your  FG.  Polyester and tooling resins will shrink differently - you can stick to one, or learn both.

my first response to reading the topic title was "dont go in the pool" lol but obviously that isnt audio related. I dont have to much problem with resin shrinking. I make sure to leave whatever is being glassed in place for atleast 24 hours so it doesnt lose shape.

i too dont have a problem with this just slow down you dry times. the farset it drys the hotter it gets the mor it shrinks and a good solid frame will hepl a lotbring back the rotary phone so i dont have to press 1 to proceed in english

killer sonata wrote: my first response to reading the topic title was "dont go in the pool" lol but obviously that isnt audio related. I dont have to much problem with resin shrinking. I make sure to leave whatever is being glassed in place for atleast 24 hours so it doesnt lose shape.

lol Yea, moving it, you are just asking for trouble.I have not failed. I've just found 10,000 ways that won't work.

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The biggest issue with shrinkage is the quality of resin you are using and your drying time. You want to make sure that you are buying a good quality of resin that is designed for what your doing. Alot of places end up buying the left over crap from their supplier and thru a "General Purpose" sticker on it and call it a day. If you have access to actual fiberglass wholesalers, tell them what your doing, how your using it and your preferred setup times etc and they should be able to suggest the proper resin (at not a whole lot more $$$ then your paying now). The drying time is a huge part of it, you should try and stick with the regular drying time recommendations (MAX 5%, should stick with about 2%) cause if you rush it, your job will suffer. You should try and let it set for 24 hours once done before sanding so it has dried all inside the resin as the outside and bottom will dry first, if you start sanding right away you can shift your work and make a mess. STAY away from Resin sold at Autoparts store and Home hardware stores, it's the bottom of the grade CRAP !Tim Baillie

Installer/Designer/Fabricator

Certified Autosound & Security

select products offers a resin that wont shrink - so they say - ive had shrinkage with some resins before but nothing that freaked me out......quality frame work is usually the best answer to this problem though

hzemall wrote: The biggest issue with shrinkage is the quality of resin you are using and your drying time. You want to make sure that you are buying a good quality of resin that is designed for what your doing. Alot of places end up buying the left over crap from their supplier and thru a "General Purpose" sticker on it and call it a day. If you have access to actual fiberglass wholesalers, tell them what your doing, how your using it and your preferred setup times etc and they should be able to suggest the proper resin (at not a whole lot more $$$ then your paying now). The drying time is a huge part of it, you should try and stick with the regular drying time recommendations (MAX 5%, should stick with about 2%) cause if you rush it, your job will suffer. You should try and let it set for 24 hours once done before sanding so it has dried all inside the resin as the outside and bottom will dry first, if you start sanding right away you can shift your work and make a mess. STAY away from Resin sold at Autoparts store and Home hardware stores, it's the bottom of the grade CRAP !

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killer sonata wrote: my first response to reading the topic title was "dont go in the pool" lol but obviously that isnt audio related. I dont have to much problem with resin shrinking. I make sure to leave whatever is being glassed in place for atleast 24 hours so it doesnt lose shape.

:: groans ::

>.>

<.<

^_^*         LOL...

Making sure you have a solid frame is a good start. Even the best resins will shrink slightly, but if you have a solid frame, then you shouldn't have a big issue with it unless your mix is too "hot".

Good Luck!

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