Fiberglass sub box.. do you have to use mat?

Methodical4u · Mar 4, 2007, 09:29 PM

Just wondering if you have to use fiberglass matting to build a box? I have some pretty thick woven stuff that I was going to cut into small pieces and use. I don't see how it would really matter though.. opinions?

TheShortBus · Mar 4, 2007, 09:58 PM

im guessing you just have fiberglass cloth.

i like it much better then mat because you dont have to deal with all the hairs.

badhabit90 · Mar 4, 2007, 10:07 PM

Quote:

Originally Posted by Methodical4u

Just wondering if you have to use fiberglass matting to build a box? I have some pretty thick woven stuff that I was going to cut into small pieces and use. I don't see how it would really matter though.. opinions?

no you dont have to. the woven stuff is usually more money that is why people use the matting. it does help however to use matting in corners and such to help strenghthen them up where the woven is thinner.

i used to use the woven stuff when i would make my kick panels for my competitions.

BillAce · Mar 5, 2007, 11:34 AM

Once I had a mold made I would use both cloth and mat so there was no resin buildup and weak spots.

The first layer would be mat, rip it apart, don't cut clean lines. Before it dries completely put down a layer of mat followed up with dry cloth to absorb any excess resin. Dpending on the shape and application, repeat as necessary.

Methodical4u · Mar 5, 2007, 01:54 PM

I had bought a whole gallon of boatyard resin sometime last year and I got my trunk all lined with tape and foil and had it ready and started putting down the resin and the cloth and then waited... and waited.... and waited... and it never would dry. I think from being in the garage and being so cold and hot it ruined it. I just got some new bondo resin now... it's drying fine now though. I guess i'll do 2 coats and then pull the form out and start reinforcing it with more cloth and such.

BillAce · Mar 5, 2007, 02:06 PM

You did put hardener in it right? Was the mix rate correct? Resin should be stored at room temp but I had plenty get cold in 55 gallon drums overnight without a problem.

Another clue: Go to a hobby store adn buy Rigid Wrap. It is the plaster cloth they use for making scenery in model train setups. It is water soluable, odor free and dries fast. Lay that in the car to make a firm mold in the shape you want. When it dries, remove it and glass the inside out of the car. no resin smell, mess an its easier to work on it and get even glass distribution.

Methodical4u · Mar 5, 2007, 02:19 PM

Quote:

Originally Posted by BillAce

You did put hardener in it right? Was the mix rate correct? Resin should be stored at room temp but I had plenty get cold in 55 gallon drums overnight without a problem.

Another clue: Go to a hobby store adn buy Rigid Wrap. It is the plaster cloth they use for making scenery in model train setups. It is water soluable, odor free and dries fast. Lay that in the car to make a firm mold in the shape you want. When it dries, remove it and glass the inside out of the car. no resin smell, mess an its easier to work on it and get even glass distribution.

that's awesome man... I will definitely check that stuff out... unfortunately i've already gotten a lot of the mold finished.. but I will probably do the other side too and I will have to use that stuff.

I'm pretty sure I put enough hardener in the stuff. Honestly it could have been off a bit... but now i'm scared to try it because I don't want to mess up my current mold job. I will have to try a correct ratio in a very small portion to make sure it is actually bad. I'd love it if it wasn't since that stuff isn't cheap!

BillAce · Mar 5, 2007, 02:38 PM

The mix rate is very important for curing and strength

MConsoliA4 · Mar 5, 2007, 09:22 PM

the different mats are for different points in a mold (most of the time) the thin "chop mat" is best used to get small contours since it can be torn into smaller pieces and the thicker "weave" when soaked right dries hard as concrete. If you were doing a section that is mostly flat, the weave would be best and the mat comes in different weights or thicknesses to build up quicker.

BillAce · Mar 6, 2007, 04:33 AM

The reason we always layer both was that the mat tends to hold more resin and the resin itself provides no strength. A layer of cloth will also give you a better surface to bond to for the next layer. If you set up the job properly the whole process will go pretty quickly if you hvae a good mold.