I know that bondo can't be used for like tears and splits like in the first pic. But what about scratches and gouges like in the second pic. Do you use plain bondo or gorilla hair or what?

you will have to use fiberglass. it's the best bet.
sorry that happened

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1987 Fiero Auto Base Coupe 56k Original Miles (SOLD;(
1988 FIERO Coupe "IRON DUKE" 5-Speed (the show car ;-)
1992 Firebird T-Tops V-8 24k original Florida miles(collectors car)

Personally, I would use fiberglass resin to impregnate the cracks, and fill in the chips/gouges with fiberglass. After that's done, I would sand it smooth and use filler putty to smooth out any minor imperfections.

The one thing to remember about filler putty (e.g. bondo putty) is that it has very little structural strength. It's not meant to hold things together, or reinforce damaged areas. It's only good for creating a surface finish.

[This message has been edited by Blacktree (edited 08-13-2009).]

You should use a product made specificly for SMC on the hoods & roofs. The bumpers are RIM, & you need another specific product for that.
SMC:
Fiberglass Evercoat Vette Panel Adhesive part # 870.
RIM:
SEM 39708 Flexible SEM-Weld.
Both available at your local autobody/paint supplier.
Grind any area you repair with 24 grit discs - SLOWLY on the RIM so as not to heat up & melt the material. Heating it will cause the pores to close & nothing will stick. Back up the damage first with the same product, & chop up some fiberglass mat with scissors to mix in for reinforcement. On the SMC if you have a scrap peice & have room on the back, make a "bonding strip" for reinforcement (with a bonding strip no mat is needed in the Vette Panel Adhesive). Make sure it's clamped tight untill fully setup (overnight is best). Once the back dries, "V" out the crack on the front side & fill it with the same product. Chopped mat dosen't hurt here, either.
You can use resin & mat on the hood if the resin is compatible with SMC. Regular polyester resin dosen't stick well.
~ Paul
aka "Tha Driver"

Why do they sterilize needles for lethal injection?

Don't do it any other way than what Tha Driver said... unless you want to be doing again and again and again...

quote Originally posted by Tha Driver: SMC: Fiberglass Evercoat Vette Panel Adhesive part # 870.

why would you use vette panel adhesive instead of evercoat kitty hair then finishing it out w/ a two part putty?

[This message has been edited by labbe001 (edited 08-13-2009).]

Never, Ever, use Bondo spot putty ! absolute garbage. Was 20 years ago, still is. I can't believe they even still bother to make it ! Use evercoat spot putty fot scratches & chips, followed by 2 part primer.

I would use a fiberglass and polyresin kit they got in every autoparts store. Could use the resin alone to skim coat a little for shallow stuff instead of Bondo. The real trick seems to be to work it from coarse to smooth with patience and attention. I would sand the entire panel damaged or not starting with about 400 wet sanding after taking the damaged bits up from 60 to 120ish and finally to 220 ish. I think the whole should be at a nice and even 600 before any painting. Wet sand between coats......Man! It's a lot of work but it's pretty cheap and totally worth it!

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

[This message has been edited by White 84 SE (edited 08-13-2009).]

quote Originally posted by labbe001: why would you use vette panel adhesive instead of evercoat kitty hair then finishing it out w/ a two part putty?

Kitty Hair is not made for SMC. SMC has a release agent in it to get it out of the molds. Anything not made specificly for SMC dosen't stick well. The panel adhesive is also a filler, so you can use it like bondo over a "dent" or imperfection.
EDIT: As I said, polyester resin is not made for SMC. Also, NEVER use resin alone for anything. It's not structural, & dosen't flex. You should always use MAT whenever you use resin.
~ Paul
aka "Tha Driver"

[This message has been edited by Tha Driver (edited 08-13-2009).]

Perhaps they changed materials in various years but in my 84 factory manual the hood is described as being made of 2 panels of fiberglass (SMC). The nose and lower doors, etc "Enduroflex". It specifies using 3M product # 05900 or equivalent with the Enduroflex. I looked up the 3M product and it is actually an Epoxy based product which adheres well and has other desirable qualities for the soft panels. The polyester based resin is said to adhere only fairly well. I have seen those little carded "bumper repair" kits which SEEM like the #05900 equivalent. I have assumed it would be fine to use the polyester resin based products designed for fiberglass on the SMC. So there it is. The epoxy based resin on the softer parts and the polyester resins on the harder parts....

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

quote Originally posted by White 84 SE: Perhaps they changed materials in various years but in my 84 factory manual the hood is described as being made of 2 panels of fiberglass (SMC). The nose and lower doors, etc "Enduroflex". It specifies using 3M product # 05900 or equivalent with the Enduroflex. I looked up the 3M product and it is actually an Epoxy based product which adheres well and has other desirable qualities for the soft panels. The polyester based resin is said to adhere only fairly well. I have seen those little carded "bumper repair" kits which SEEM like the #05900 equivalent. I have assumed it would be fine to use the polyester resin based products designed for fiberglass on the SMC. So there it is. The epoxy based resin on the softer parts and the polyester resins on the harder parts....

"Enduroflex" is GM's name for RIM. You can't use any kind of resin on it & expect it to stay. It's not flexible enough. So there it ain't. No resin on the RIM & only resin made for SMC (not polyester) on the SMC.
I've been doing body/fiberglass work, mold work, & Vette repair since 1971, in case you're interested...
~ Paul
aka "Tha Driver"

If you can't take the heat, get out of the nuclear reactor.

driver, so as not to steal this thread, PM sent

So you seem to be sayin SMC is not fiberglass. GM said so in 1984. That stuff I got at the parts store with the polyester resin and the glass matting is for fiberglass. Dynatron/Bondo says it is. Perhaps you say it is inferior or something? If so please explain as I am not speaking from decades of experience just reading stuff and brushing up for a future project.

[This message has been edited by White 84 SE (edited 08-14-2009).]

Well thanks to everyone who posted, What ever is used it looks like I have my work cut out for me

quote Originally posted by White 84 SE: So you seem to be sayin SMC is not fiberglass. GM said so in 1984. That stuff I got at the parts store with the polyester resin and the glass matting is for fiberglass. Dynatron/Bondo says it is. Perhaps you say it is inferior or something? If so please explain as I am not speaking from decades of experience just reading stuff and brushing up for a future project.

No, it's fiberglass, it's just different from other fiberglass. When they first started using it on 'vettes, no one knew the difference & we still used polyester resin. Found out the hard way it dosen't stick very well long term.
~ Paul
aka "Tha Driver"

It's been so long since I've had sex, I can't remember who gets tied up.

pm sent to "the driver"

quote Originally posted by Tha Driver: No, it's fiberglass, it's just different from other fiberglass. When they first started using it on 'vettes, no one knew the difference & we still used polyester resin. Found out the hard way it dosen't stick very well long term. ~ Paul aka "Tha Driver" It's been so long since I've had sex, I can't remember who gets tied up.

Ahh, Thanks! I noticed when I was drilling out part of the trunk to omit the bike rack thingy that it seemed different than I expected. Almost seemed chalky and not as much fibrous material.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

Blacktree has a desertation on fibreglass at central florida fiero,,just google it,,if you would like to know more about fibreglass check this out ,,easy to read and understand ..

centralfloridafieros.com

go to == interior and exterior cosmetics

[This message has been edited by uhlanstan (edited 08-16-2009).]

paul aka tha driver,
you have a pm.
al aka......al

ps i have no idea how or why that pissed off red face thing is on the top bar of this post!!

[This message has been edited by ace5514 (edited 08-17-2009).]

quote Originally posted by ace5514: paul aka tha driver, you have a pm. al aka......al ps i have no idea how or why that pissed off red face thing is on the top bar of this post!!

Al aka "ace5514" -
PM returned.
The red face is the result of clicking on the "button" above the input field. Open a "Reply" page & you'll see.
~ Paul
aka "Tha Driver"