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View Full Version : fiberglass - how many layers of matt usualy go down ?



brian84corvette
01-29-2014, 03:59 AM
hey guys - my trunk floor has a 2" lump in it that i have built my box around by cutting out that part on the box so it sits flat on the trunk floor now.
im glassing over the hump part - and have done 3 layers of mat on the inside of the box today
and was planing on doing 1 or 2 layers of mat on the outside tomorow

i left shop before it was dry so i didnt get to test its streingth yet
but was wondering how many layers of glass mat yall usualy do when making custom fibergalss enclosures ?

mklett33
01-29-2014, 02:26 PM
Theres no magic number, people will try saying, oh 3 or whatever but thats not the way it works. First it changes based on the weight of the mat you are using. Second it changes based on if the surface is curved or flat. I can make something with 3 layers of 1.5 oz mat that would snap if flat but be ungodly strong if curved.

Best bet is to wait for it to dry and try flexing it, if you can flex it by pushing on it, you need more layers.

redrider
01-29-2014, 03:26 PM
Theres no magic number, people will try saying, oh 3 or whatever but thats not the way it works. First it changes based on the weight of the mat you are using. Second it changes based on if the surface is curved or flat. I can make something with 3 layers of 1.5 oz mat that would snap if flat but be ungodly strong if curved.

Best bet is to wait for it to dry and try flexing it, if you can flex it by pushing on it, you need more layers.

this guy knows his stuff.... wish i had his skills.

i typically get my projects to where they seem strong enough(no flex etc) and i do like 1 or 2 more layers just for extra members. i was told once you can never have too many layers.....

brian84corvette
01-29-2014, 11:45 PM
cool i ended up doing another few layers on the inside of the box today at work.. its curing over night again - and then will do 2 layers on the outside as well.
when i got in today i tried flexing it - and it had a tiny amount of give to it still - so thats why i went ahead and did more inside layers. inside can be as thick as it needs to be - but the outside cant have a bunch of build up or it might not fit so well over the lump in the trunk floor.

thanks guys

mklett33
01-31-2014, 02:10 PM
No problem, good luck!