Fiberglassing questions

Telco · 07-26-2006, 06:00 PM

1987 GMC S15 ext cab 2WD auto 2.8L

I read Nick's long, long, freakishly long fiberglass page, and learned a lot, but his page doesn't address what I want to do.

I've removed my jump seats and now have a couple of holes in the interior. What I'd like to do is build a box in place of these holes. On the driver side I'd like an 8 - 10 inch single sub, on the passenger side I want a closable box where I can store the jack and 4 way lug (getting one of the foldable ones). I also don't want either side to extend out into the cab, I want to keep all the room behind the seats.

I've run through various ways to do this, and the one I keep coming back to is building a new trim piece out of fiberglass to completely replace the plastic piece where the seats were, up to the window. The other way would be to stretch spandex across the opening in the existing piece, fill in from the back to make it solid, then mold a box onto the back. Each one has its own challenges, and I don't know which would be easiest and strongest. I imagine using the factory trim and filling it in would be easiest but no idea how well it would last. Actual texture matching wouldn't be an issue, either way I go the trim pieces will be covered with vinyl. How well would fiberglass bond to the plastic? Would it be strong enough to handle a moderately powered (I don't crank it, I value what's left of my hearing) subwoofer? And how would I make a door work for the side where the jack goes?

Anyone have any advice on how to make this work the way I want it to? When I'm done I want it to look like the factory installed a sub and a jack storage area in the jump seat locations, and never even considered jump seats.

Once this is done, the jack box will go where the jump seats did, unless someone wants to buy it. The jump seats are in the dump, not too far from the factory center console. Thanks.

Telco · 08-09-2006, 11:47 AM

Anyone... anyone... Buuuuueeeeelllllllllllleeeerrrrrrr....

TwoWheelJay · 08-09-2006, 12:03 PM

your probably best off filling in the factory location. Set the frame for your sub, cover it with fleece or spandex and start layering. 3-4 layers should be enough to hold anything most 8" woofers would put out. Just take your time, bondo and sand and itll look wonderful. As far as the storage side goes, just disassemble your jump seat and use the stock panel. You can use the plastic panel that wass attached to the seat (the part with the handle that you pull on) as a door for the compartment, then just make a hinge or something.

bladehines · 08-09-2006, 12:10 PM

buy them on ebay

bladehines · 08-09-2006, 12:16 PM

http://www.s10forum.com/forum/showth...ight=jump+seat

JACKEL · 08-09-2006, 04:14 PM

Quote: Originally Posted by TwoWheelJay

your probably best off filling in the factory location. Set the frame for your sub, cover it with fleece or spandex and start layering. 3-4 layers should be enough to hold anything most 8" woofers would put out. Just take your time, bondo and sand and itll look wonderful. As far as the storage side goes, just disassemble your jump seat and use the stock panel. You can use the plastic panel that wass attached to the seat (the part with the handle that you pull on) as a door for the compartment, then just make a hinge or something.

ERRRRRRRRRRRRRRRRRt, guess again homie. Sub produce more pressure than you think. 1 10" sub is capable of 400psi of pressure for every excursion of the woofer. The rule of thumb is 5-7 layers of your heaviest weight fiberglass, then start your thread fill layers. In the end you should have a thickness larger the 1/8" thick fiberglass. This keeps the sub from sounding Boingy because of the box flexing. And, don't ever say fleece again.

As far as doing the project. Read the thread again. I don't need to address this particular type of install persay but I have laid out the ground rules and technique clearly for you to be able to accomplish most types of fiberglassed project varying in difficulty. Anyone of the techniques I've shown will work for such a project.

However, you will need to build the enclosure to the door panel. an 8" woofer isn't too heavy so it might bwe done, but what i would do would be to use mold release and mold the original door panel. Then, using the mold I would fill it with foam. Pop the foam out of the modl and now you have a solid replica of the door pabel and its curves. Then hog out of the foam and area needed to provide the required air space to the sub. Then proceed with mounting the woofer ring and fiberglass work. Lastly, cut the lower porting of the panel off and mate the upper portion to the foam replica lower portion. This way, the weight of the sub won't bonce with road vibration and yank the fiberglass from the door panel. It will also help aid in mounting it as it will reduce the likely hood of flexing the panel and cracking it during re-install.

and again, don't ever use the work fleece again. It provides false hope in strength which leads to less layers. It uses too much resin to get hard and it won't ever conform to curves like spandex will. The stretch fabric should never be relied on for strength and is not considered a layer. It actually gets brittle when the resin cures on it.

TwoWheelJay · 08-10-2006, 02:36 AM

nick, good call on the psi of the sub, didnt know that. We built some enclosures for my friends 6x9 and 6.5s for his doors, using 3 layers and worked out fine. I figured a shallow mount 8" couldnt produce that much pressure. If it were a 10 or 12 i would definately go with 5+ (were on layer 6 in my friends back seat enclosure right now, 2 alpine type r's...HEAVY)

TwoWheelJay · 08-10-2006, 02:41 AM

as far as the fleece goes, i never used it myself although i have seen writeups on other forums that specified a light grade fleece. guess i learn somethin new everyday. not to threadjack but is spandex like a specific thing, or does that refer to any of the stretchy rayon/polyester type fabrics? (weird question i know)

JACKEL · 08-10-2006, 07:52 AM

Quote: Originally Posted by TwoWheelJay

as far as the fleece goes, i never used it myself although i have seen writeups on other forums that specified a light grade fleece. guess i learn somethin new everyday. not to threadjack but is spandex like a specific thing, or does that refer to any of the stretchy rayon/polyester type fabrics? (weird question i know)

You're looking for true spandex, polyester. Its the stuff gymastic outfits are made of. It will stretch like you never imagined and gets the stretch fabric layer under the glass tight as a drum.

Telco · 08-11-2006, 10:45 AM

Thanks for the replies folks.

Nick, I was hoping you'd chime in on this. My main concern with just attaching it all to the factory pieces is making sure the fiberglass and plastic stay attached to each other because in the end, the entire trim piece and enclosure will be covered in vinyl so as to appear to be one piece. The subwoofer will be a flush mount with a screen over it, dyed to match the vinyl so as to appear to be a factory install. After re-reading my question I see I didn't specify exactly what my problem is, so I'll rephrase:

What would I use to make the fiberglass bond permanently to the interior plastic under the loads the piece will be under, in a vehicle that will most likely be subjected to rough roads?

I have a pretty good idea about how to make all this work thanks to your very detailed post, and will be rereading it again a few times to make sure I've got it down 100 percent. The only part I didn't see was how to make that permanent bond though. And will definitely be using the gymnast Spandex when I do this.

Also, the seats have been in the dump for well over a month, no way to recover, so I won't be able to use them for a mold.

JACKEL · 08-11-2006, 11:23 AM

Quote: Originally Posted by Telco

Thanks for the replies folks.

Nick, I was hoping you'd chime in on this. My main concern with just attaching it all to the factory pieces is making sure the fiberglass and plastic stay attached to each other because in the end, the entire trim piece and enclosure will be covered in vinyl so as to appear to be one piece. The subwoofer will be a flush mount with a screen over it, dyed to match the vinyl so as to appear to be a factory install. After re-reading my question I see I didn't specify exactly what my problem is, so I'll rephrase:

What would I use to make the fiberglass bond permanently to the interior plastic under the loads the piece will be under, in a vehicle that will most likely be subjected to rough roads?

I have a pretty good idea about how to make all this work thanks to your very detailed post, and will be rereading it again a few times to make sure I've got it down 100 percent. The only part I didn't see was how to make that permanent bond though. And will definitely be using the gymnast Spandex when I do this.

Also, the seats have been in the dump for well over a month, no way to recover, so I won't be able to use them for a mold.

Check my thread. I already answered this and provided videos on how to do it. Get CA glue and Kicker and attach the fabric to the plastic. Then I would in this case only use epoxy. Its is far stronger than polyester resins. Make sure you scuff the surface well with like 80 grit paper so the adhesive has tooth to bite on.

Telco · 08-16-2006, 01:28 PM

Good deal, thanks. I think that'll cover it then. When I finally get to do this, I'll post up some pics of the finished products, it'll be a few months.

07-26-2006, 06:00 PM	#1
Telco Registered User Join Date: Jun 2006 Posts: 98 Location: Tulsa area User is: OffLine	Fiberglassing questions 1987 GMC S15 ext cab 2WD auto 2.8L I read Nick's long, long, freakishly long fiberglass page, and learned a lot, but his page doesn't address what I want to do. I've removed my jump seats and now have a couple of holes in the interior. What I'd like to do is build a box in place of these holes. On the driver side I'd like an 8 - 10 inch single sub, on the passenger side I want a closable box where I can store the jack and 4 way lug (getting one of the foldable ones). I also don't want either side to extend out into the cab, I want to keep all the room behind the seats. I've run through various ways to do this, and the one I keep coming back to is building a new trim piece out of fiberglass to completely replace the plastic piece where the seats were, up to the window. The other way would be to stretch spandex across the opening in the existing piece, fill in from the back to make it solid, then mold a box onto the back. Each one has its own challenges, and I don't know which would be easiest and strongest. I imagine using the factory trim and filling it in would be easiest but no idea how well it would last. Actual texture matching wouldn't be an issue, either way I go the trim pieces will be covered with vinyl. How well would fiberglass bond to the plastic? Would it be strong enough to handle a moderately powered (I don't crank it, I value what's left of my hearing) subwoofer? And how would I make a door work for the side where the jack goes? Anyone have any advice on how to make this work the way I want it to? When I'm done I want it to look like the factory installed a sub and a jack storage area in the jump seat locations, and never even considered jump seats. Once this is done, the jack box will go where the jump seats did, unless someone wants to buy it. The jump seats are in the dump, not too far from the factory center console. Thanks. Last edited by Telco : 07-26-2006 at 06:03 PM.
	[Reply w/Quote]

08-09-2006, 11:47 AM	#2
Telco Registered User Join Date: Jun 2006 Posts: 98 Location: Tulsa area User is: OffLine	Re: Fiberglassing questions Anyone... anyone... Buuuuueeeeelllllllllllleeeerrrrrrr....
	[Reply w/Quote]

08-09-2006, 12:03 PM	#3
TwoWheelJay Registered User Age: 24 Join Date: Dec 2005 Posts: 867 Location: User is: OffLine	Re: Fiberglassing questions your probably best off filling in the factory location. Set the frame for your sub, cover it with fleece or spandex and start layering. 3-4 layers should be enough to hold anything most 8" woofers would put out. Just take your time, bondo and sand and itll look wonderful. As far as the storage side goes, just disassemble your jump seat and use the stock panel. You can use the plastic panel that wass attached to the seat (the part with the handle that you pull on) as a door for the compartment, then just make a hinge or something.
	[Reply w/Quote]

08-09-2006, 12:10 PM	#4
bladehines ASASN8 Age: 27 Join Date: Jan 2005 Posts: 7,616 Location: Bowling Green, KY User is: OffLine	Re: Fiberglassing questions buy them on ebay Last edited by bladehines : 08-09-2006 at 12:13 PM.
	[Reply w/Quote]

08-09-2006, 12:16 PM	#5
bladehines ASASN8 Age: 27 Join Date: Jan 2005 Posts: 7,616 Location: Bowling Green, KY User is: OffLine	Re: Fiberglassing questions http://www.s10forum.com/forum/showth...ight=jump+seat
	[Reply w/Quote]

08-09-2006, 04:14 PM	#6
JACKEL I Like Fire....HaHaHa Age: 79 Join Date: Jul 2005 Posts: 4,996 Location: God Damn Garage, STL User is: Online	Re: Fiberglassing questions Quote: Originally Posted by TwoWheelJay your probably best off filling in the factory location. Set the frame for your sub, cover it with fleece or spandex and start layering. 3-4 layers should be enough to hold anything most 8" woofers would put out. Just take your time, bondo and sand and itll look wonderful. As far as the storage side goes, just disassemble your jump seat and use the stock panel. You can use the plastic panel that wass attached to the seat (the part with the handle that you pull on) as a door for the compartment, then just make a hinge or something. ERRRRRRRRRRRRRRRRRt, guess again homie. Sub produce more pressure than you think. 1 10" sub is capable of 400psi of pressure for every excursion of the woofer. The rule of thumb is 5-7 layers of your heaviest weight fiberglass, then start your thread fill layers. In the end you should have a thickness larger the 1/8" thick fiberglass. This keeps the sub from sounding Boingy because of the box flexing. And, don't ever say fleece again. As far as doing the project. Read the thread again. I don't need to address this particular type of install persay but I have laid out the ground rules and technique clearly for you to be able to accomplish most types of fiberglassed project varying in difficulty. Anyone of the techniques I've shown will work for such a project. However, you will need to build the enclosure to the door panel. an 8" woofer isn't too heavy so it might bwe done, but what i would do would be to use mold release and mold the original door panel. Then, using the mold I would fill it with foam. Pop the foam out of the modl and now you have a solid replica of the door pabel and its curves. Then hog out of the foam and area needed to provide the required air space to the sub. Then proceed with mounting the woofer ring and fiberglass work. Lastly, cut the lower porting of the panel off and mate the upper portion to the foam replica lower portion. This way, the weight of the sub won't bonce with road vibration and yank the fiberglass from the door panel. It will also help aid in mounting it as it will reduce the likely hood of flexing the panel and cracking it during re-install. and again, don't ever use the work fleece again. It provides false hope in strength which leads to less layers. It uses too much resin to get hard and it won't ever conform to curves like spandex will. The stretch fabric should never be relied on for strength and is not considered a layer. It actually gets brittle when the resin cures on it.
	[Reply w/Quote]

08-10-2006, 02:36 AM	#7
TwoWheelJay Registered User Age: 24 Join Date: Dec 2005 Posts: 867 Location: User is: OffLine	Re: Fiberglassing questions nick, good call on the psi of the sub, didnt know that. We built some enclosures for my friends 6x9 and 6.5s for his doors, using 3 layers and worked out fine. I figured a shallow mount 8" couldnt produce that much pressure. If it were a 10 or 12 i would definately go with 5+ (were on layer 6 in my friends back seat enclosure right now, 2 alpine type r's...HEAVY)
	[Reply w/Quote]

08-10-2006, 02:41 AM	#8
TwoWheelJay Registered User Age: 24 Join Date: Dec 2005 Posts: 867 Location: User is: OffLine	Re: Fiberglassing questions as far as the fleece goes, i never used it myself although i have seen writeups on other forums that specified a light grade fleece. guess i learn somethin new everyday. not to threadjack but is spandex like a specific thing, or does that refer to any of the stretchy rayon/polyester type fabrics? (weird question i know)
	[Reply w/Quote]

08-10-2006, 07:52 AM	#9
JACKEL I Like Fire....HaHaHa Age: 79 Join Date: Jul 2005 Posts: 4,996 Location: God Damn Garage, STL User is: Online	Re: Fiberglassing questions Quote: Originally Posted by TwoWheelJay as far as the fleece goes, i never used it myself although i have seen writeups on other forums that specified a light grade fleece. guess i learn somethin new everyday. not to threadjack but is spandex like a specific thing, or does that refer to any of the stretchy rayon/polyester type fabrics? (weird question i know) You're looking for true spandex, polyester. Its the stuff gymastic outfits are made of. It will stretch like you never imagined and gets the stretch fabric layer under the glass tight as a drum.
	[Reply w/Quote]

08-11-2006, 10:45 AM	#10
Telco Registered User Join Date: Jun 2006 Posts: 98 Location: Tulsa area User is: OffLine	Re: Fiberglassing questions Thanks for the replies folks. Nick, I was hoping you'd chime in on this. My main concern with just attaching it all to the factory pieces is making sure the fiberglass and plastic stay attached to each other because in the end, the entire trim piece and enclosure will be covered in vinyl so as to appear to be one piece. The subwoofer will be a flush mount with a screen over it, dyed to match the vinyl so as to appear to be a factory install. After re-reading my question I see I didn't specify exactly what my problem is, so I'll rephrase: What would I use to make the fiberglass bond permanently to the interior plastic under the loads the piece will be under, in a vehicle that will most likely be subjected to rough roads? I have a pretty good idea about how to make all this work thanks to your very detailed post, and will be rereading it again a few times to make sure I've got it down 100 percent. The only part I didn't see was how to make that permanent bond though. And will definitely be using the gymnast Spandex when I do this. Also, the seats have been in the dump for well over a month, no way to recover, so I won't be able to use them for a mold.
	[Reply w/Quote]

08-11-2006, 11:23 AM	#11
JACKEL I Like Fire....HaHaHa Age: 79 Join Date: Jul 2005 Posts: 4,996 Location: God Damn Garage, STL User is: Online	Re: Fiberglassing questions Quote: Originally Posted by Telco Thanks for the replies folks. Nick, I was hoping you'd chime in on this. My main concern with just attaching it all to the factory pieces is making sure the fiberglass and plastic stay attached to each other because in the end, the entire trim piece and enclosure will be covered in vinyl so as to appear to be one piece. The subwoofer will be a flush mount with a screen over it, dyed to match the vinyl so as to appear to be a factory install. After re-reading my question I see I didn't specify exactly what my problem is, so I'll rephrase: What would I use to make the fiberglass bond permanently to the interior plastic under the loads the piece will be under, in a vehicle that will most likely be subjected to rough roads? I have a pretty good idea about how to make all this work thanks to your very detailed post, and will be rereading it again a few times to make sure I've got it down 100 percent. The only part I didn't see was how to make that permanent bond though. And will definitely be using the gymnast Spandex when I do this. Also, the seats have been in the dump for well over a month, no way to recover, so I won't be able to use them for a mold. Check my thread. I already answered this and provided videos on how to do it. Get CA glue and Kicker and attach the fabric to the plastic. Then I would in this case only use epoxy. Its is far stronger than polyester resins. Make sure you scuff the surface well with like 80 grit paper so the adhesive has tooth to bite on.
	[Reply w/Quote]

08-16-2006, 01:28 PM	#12
Telco Registered User Join Date: Jun 2006 Posts: 98 Location: Tulsa area User is: OffLine	Re: Fiberglassing questions Good deal, thanks. I think that'll cover it then. When I finally get to do this, I'll post up some pics of the finished products, it'll be a few months.
	[Reply w/Quote]