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View Full Version : Nearly Ready to Fiberglass (Questions)



idiot
07-13-2004, 01:11 AM
I’m in the stage of gathering materials to build my first sub enclosure using fiberglass (well, an MDF/fiberglass hybrid, actually). Here’s what I have picked up (all from Home Depot). Please let me know if something I should have is missing from the list.

Fiberglass Resin (Bondo brand)
Extra tubes of Hardener
Fiberglass mat
Crappy paintbrushes, of various sizes
Latex gloves
Painter’s tape
Spray Adhesive
Some really heavy plastic sheeting to lay across the car

Firstly, Home Depot didn’t have any fiberglass cloth (only the mat). Am I correct in assuming that the only benefit of cloth is its ability (due to its reduced thickness) to mold to more delicate details? If so, it is not necessary in my application.

I’m going to be glassing a vertical surface. I’ve read recommendations to apply a thin coat of Vaseline to the painter’s tape before applying the first layer of fiberglass, so that the mold would be easier to remove from the vehicle once it has set. However, I’ve also read that I should use some sort of aerosol glue to stick the cloth to the vertical surfaces before dabbing on the resin, in order to hold them in place. These two ideas seems slightly incompatible to me; I don’t understand how I could spray down the glue for the first layer of mat, after I had already rubbed Vaseline on the painter’s tape. What is the best way to go about these two things (that is, ensuring that I can remove the mold after the first few layers without risking harm to the box, and holding the cloth on the vertical surfaces securely, before the resin is applied)?

This isn’t something that I’ll deal with until later, but how would I go about attaching a side of MDF to a partially made fiberglass enclosure? The front and top pieces for my box need to be MDF (as they are straight sides), while every other side needs to be contoured to some sort of curve (and therefore made with fiberglass). Would I simply use the resin/cloth mixture to make the connection between the two materials, or would I have to use screws or something like Liquid Nails in addition?

Acidburn
07-13-2004, 01:41 AM
i find the clothe is a lot easier to work with
you can put some vaseline or something down, i would use just a little resin to get it to stick to the side
the resin sticks to MDF

btnhfan
07-13-2004, 02:38 AM
your gonna wana put bondo or any body filler on the fiberglass afterwords

supa_c
07-13-2004, 02:40 AM
mask, do you want to get high?

ramos
07-13-2004, 08:09 AM
mask, do you want to get high?



Hell yeah, the fumes are the best part man :D :)

saywhat?
07-13-2004, 08:16 AM
one thing u need but cannot by, is common sense. as far as it holding to the part your attaching the mat to....just hold it with one hand and drop a little resin on and go at it, it wont move. and theres no "vertical surface" as u can always turn the box and make that side flat and u wont need anything to hold it.

idiot
07-13-2004, 08:20 AM
mask, do you want to get high?

I forgot to put that on the list. But yea, I've got one. ;)

ramos
07-13-2004, 08:22 AM
I’m in the stage of gathering materials to build my first sub enclosure using fiberglass (well, an MDF/fiberglass hybrid, actually). Here’s what I have picked up (all from Home Depot). Please let me know if something I should have is missing from the list.

Fiberglass Resin (Bondo brand)
Extra tubes of Hardener
Fiberglass mat
Crappy paintbrushes, of various sizes
Latex gloves
Painter’s tape
Spray Adhesive
Some really heavy plastic sheeting to lay across the car

Gonna need some body filler to add to your list. And a bunch of sandpaper.



Firstly, Home Depot didn’t have any fiberglass cloth (only the mat). Am I correct in assuming that the only benefit of cloth is its ability (due to its reduced thickness) to mold to more delicate details? If so, it is not necessary in my application.

Yeah you can do it with just mat. Although cloth does smooth around curves real nice :)



I’m going to be glassing a vertical surface. I’ve read recommendations to apply a thin coat of Vaseline to the painter’s tape before applying the first layer of fiberglass, so that the mold would be easier to remove from the vehicle once it has set. However, I’ve also read that I should use some sort of aerosol glue to stick the cloth to the vertical surfaces before dabbing on the resin, in order to hold them in place. These two ideas seems slightly incompatible to me; I don’t understand how I could spray down the glue for the first layer of mat, after I had already rubbed Vaseline on the painter’s tape. What is the best way to go about these two things (that is, ensuring that I can remove the mold after the first few layers without risking harm to the box, and holding the cloth on the vertical surfaces securely, before the resin is applied)?

When I'm doing vertical surfaces and need to use fleece. I put down a layer of tape. Then a layer of foil over the tape. Then I spray some adhesive down. I use elmers spray adhesive. It's crappy glue but holds long enough for this purpose :D Then put the fleece on. Then soak the fleece and add a couple layers of mat, Then boink out pops my panel :)




This isn’t something that I’ll deal with until later, but how would I go about attaching a side of MDF to a partially made fiberglass enclosure? The front and top pieces for my box need to be MDF (as they are straight sides), while every other side needs to be contoured to some sort of curve (and therefore made with fiberglass). Would I simply use the resin/cloth mixture to make the connection between the two materials, or would I have to use screws or something like Liquid Nails in addition?

Nope no liquid nails. Just resin and mat, it sticks real well to mdf by itself :)

idiot
07-13-2004, 08:29 AM
one thing u need but cannot by, is common sense. as far as it holding to the part your attaching the mat to....just hold it with one hand and drop a little resin on and go at it, it wont move. and theres no "vertical surface" as u can always turn the box and make that side flat and u wont need anything to hold it.

Many of the tutorials I've read say that it is better to stick all the cloth/mat to the area before applying resin, rather than sticking it piece by piece as one goes along, so that one can be sure that they will line up properly. So my intention was to first set up the pieces of mat over the area to be glassed, then mix the fiberglass and apply.

In case I haven't explained it well, here are a few pictures from one of the tutorials.

http://hem.passagen.se/gute/Corrado/byggbilder/Fram_gf.jpg

http://hem.passagen.se/gute/Corrado/byggbilder/Fram_plastat.jpg

ramos
07-13-2004, 10:42 AM
When I'm doing vertical surfaces and need to use fleece. I put down a layer of tape. Then a layer of foil over the tape. Then I spray some adhesive down. I use elmers spray adhesive. It's crappy glue but holds long enough for this purpose :D Then put the fleece on. Then soak the fleece and add a couple layers of mat, Then boink out pops my panel :)







This is the way I go about it. I do pretty much the same thing as your describing. I just don't use the vaseline. THe only time I use vaseline is when I'm copying a panel. I then use the vaseline directly on the panel. Then glass right on it. :)

idiot
07-13-2004, 05:59 PM
This is the way I go about it. I do pretty much the same thing as your describing. I just don't use the vaseline. THe only time I use vaseline is when I'm copying a panel. I then use the vaseline directly on the panel. Then glass right on it. :)

So you’ve never had a problem removing the mold from the car, even without using something like Vaseline or WD-40? And does the layer of foil you place over the tape do anything other than give added protection against leaks?

ramos
07-14-2004, 08:04 AM
So you’ve never had a problem removing the mold from the car, even without using something like Vaseline or WD-40? And does the layer of foil you place over the tape do anything other than give added protection against leaks?


Nope, the tape keeps the resin from gettting through to the car. And the foil keeps everything from sticking. The foil is actually the mold release. Some of the foil will stick to the glass. But the glass won't stick to anything else, and you will be able to remove the mold from the foil. :)

idiot
07-14-2004, 09:16 AM
Alright, I'll slap some foil down, in that case. Thanks. :)

Hondaluv
08-16-2004, 09:05 PM
If you have troubles laying cloth onto verticle parts you cannot tilt, slap a little resin on the part, stick the mat to it, and dab more resin in to soak, resin is relevently sticky, should be fine.