I decided I wanted to try to make a fiberglass subbox. I was going to make it completely fiberglass, it is for underneath my rear seat. My roommate thinks he knows everything said that structure will not hold. I just wanted to get some opinions or suggestions on finishing it up. So far I took out the large section of the backseat and put down masking tap and built a form out of cardboard. I sprayed greatstuff in there. Everything is good so far we will what happens next.

 

What wouldnt hold? The seat will still sit on the brackets so any actual pressure on the box would be absolutely minimal. As long as the box is built right (drying time, layered, what not) then you shouldnt have any problem!

fyi I want to try this to but im not sure if i can do it!

 

Fiber glass is strong... you will need abotu 6-8 layers of the mat or cloth....

 

when curved, but flat it isnt that strong, and since i imagine it will be rather flat i would do 8 layers of mat, i was a strong believer of cloth but then after some experience i have learned to love mat, it is much thicker and stronger but can be a pain to work with if its your first time.

if you finish it and you cant stand on it then its not strong enough, you can add bracing inside made of mdf if you want...

 

Thanks for the replies. I don't know why he thinks that.. I am leaning towards using MDF on the outside where the feet would be so it is more durable and can take abuse of getting hit by heels. Should I make it downfiring? I haven't decided if I should expand it over to the passenger side or not.

 

You can certainly make fiberglass thick enough to be strong... but it takes time and effort compared to using MDF. You may only need 3/8 - 1/2" of fiberglass to be as strong as 3/4" MDF.... but consider how long it'll take you to lay all that fiberglass.

So IMHO, you should use MDF as much as possible, for example, on your baffle, any other flat surfaces and for bracing... and then where you cant, use the fiberglass. I did this on my box.... take a look at my console project build. If you notice, it's all MDF except the rear section that I needed to fiberglass to get the shape and fit it into place.

Either way, good luck.

 

kuruption you do great work. I would mdf on the sides and the top (under the seat) but I want to maximize the airspace.

 

Fiberglass is more resiliant than MDF. I prefer to work with glass over MDF. Just get your mixes right.

 

any tips for a first timer?