sandpaper grit for bondo

[konechiwa 10+ year member]

Alrighty so I'm making this sweet (if may say so myself) fiberglass amp rack, with a sub box to come. It's my absolute first fiberglass project ever, and personally I think I'm doing pretty good (sure i made some mistakes, but hey, nobodies perfect).

Anyway, I've put a few layers of bondo over the fiberglass, trying to get it smooth as a baby's ***, yet I'm having some problems, because no matter how smooth i try to get it, the sandpaper just won't take enough of it off (it's really smooth, but it looks more like a blasted wall tecture). I'm using 80 grit right now, but does anyone have a suggestion that would take the bondo right off? Electric sanders are out because of the small areas and curves.

the bondo i have is Evercoat Formula 27 Plastique Filler.

Somebody please help, I'm tired of listening to only rear fill. I need my front stage at least! I've put 300 dollars of second skin in, upgraded my amp (power acoustik to US Amps. Huge upgrade- also double the wattage) and I finally created something that doesn't look like shit (see MDF boxes gone wrong). Worst of all, i haven't gotten to listen to it yet! The suspense is KILLING ME!

Help!

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[IgnoreMe 5,000+ posts]

Alrighty so I'm making this sweet (if may say so myself) fiberglass amp rack, with a sub box to come. It's my absolute first fiberglass project ever, and personally I think I'm doing pretty good (sure i made some mistakes, but hey, nobodies perfect).
Anyway, I've put a few layers of bondo over the fiberglass, trying to get it smooth as a baby's ***, yet I'm having some problems, because no matter how smooth i try to get it, the sandpaper just won't take enough of it off (it's really smooth, but it looks more like a blasted wall tecture). I'm using 80 grit right now, but does anyone have a suggestion that would take the bondo right off? Electric sanders are out because of the small areas and curves.

the bondo i have is Evercoat Formula 27 Plastique Filler.

Somebody please help, I'm tired of listening to only rear fill. I need my front stage at least! I've put 300 dollars of second skin in, upgraded my amp (power acoustik to US Amps. Huge upgrade- also double the wattage) and I finally created something that doesn't look like shit (see MDF boxes gone wrong). Worst of all, i haven't gotten to listen to it yet! The suspense is KILLING ME!

Help!

im perfect //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[phyphoestilic 5,000+ posts]

NOT ALL BODY FILLER IS CALLED BONDO

Just had to get that outta the way. Try a cheese grater.

Than 40-80-160-320

By 320 it should be pretty smooth.

 

[davidfre21 5,000+ posts]

when workin with body filler, its a lot easier to attack it before it drys with 40grit. Once get the general shape, switch to evercoats metal glaze. Its a hell of a lot easier to sand and will give a final finish u can actually work with. Bondo or body filler will leave pin holes everywhere

 

[72 chevelle 10+ year member]

When I use filler on a car I start with 36 just to breaks down the heavy stuff. Move to 80, then 120.

 

[revrider1 5,000+ posts]

I use a cheesegrater to break it down then an Air file to smooth it out, or jitterbug...

 

[davidfre21 5,000+ posts]

NOT ALL BODY FILLER IS CALLED BONDO

Just had to get that outta the way. Try a cheese grater.

Than 40-80-160-320

By 320 it should be pretty smooth.

bondo brand does make a lot of those brands though

but same reason why i refered to it as body filler

 

[WantedIsHere]

for small projects one of my fav tools in the world is my drill press... just a cheap one from harbor freight that has lasted forever.... it was like 40 bucks and worth every penny... i use drum attachments on it and use it like an osolating drum sander.... gets in corners and breaks the filler down fast... after i get where i want to be i switch to an electric and break it down more then switch to hand... i use anywhere from 60 grit to as high as 2000 if im really looking for that pro smooth finish... all depends on how much you wanna spend on tools and supplies and what you want out of the project...

 

[jellyfish420 10+ year member]

NOT ALL BODY FILLER IS CALLED BONDO

Just had to get that outta the way. Try a cheese grater.

Than 40-80-160-320

By 320 it should be pretty smooth.

sounds about perfect. i go 40-80-120-200-primer-600-primer-800-paint-clear-1500-clear-2000-buff-buff-buff.

i HAVE to have a mirror finish. if your not going for a perfect finish, might as well carpet it:laugh:

 

[konechiwa 10+ year member]

thanks for the responses. I'll run out and get some 40 grit tommorow.

While i'm not going for MIRROR smooth, seeing how it is my first fiberglass project and I'm just not that skilled (trust me), but i don't want it to look like shit.

I'll try what you guys say and go on from there.

 

[phyphoestilic 5,000+ posts]

thanks for the responses. I'll run out and get some 40 grit tommorow.
While i'm not going for MIRROR smooth, seeing how it is my first fiberglass project and I'm just not that skilled (trust me), but i don't want it to look like shit.

I'll try what you guys say and go on from there.

If ur plannin on just carpet/vinyl covering it than u probably dont need to sand past 160

 

[ngsm13 5,000+ posts]

Cheese grater, then 36grit...

Pick up some Rage Gold or something equivalent...

nG

 

[billabongcr 5,000+ posts]

if your doing it by hand 40 is fine to start out with, but if your using anything pneumatic itll take the filler off ssssooooo quick youll have to refill and start over from scratch.

id start with 80 but thats me. (that i usually do while im sanding on cars)

80-120-240-320-400-600-800-1000-1500-2000 and if you want it perfect you can go to 3000 if you want.

in between the low grits..you should get some guide coating. you spray it on, sand it off. itll tell you if you have any high or low spots..save you alot of trouble later. do that up to about your 320 grit. after that..should be smooth.

 

[billabongcr 5,000+ posts]

Cheese grater, then 36grit...
Pick up some Rage Gold or something equivalent...

nG

rage is the best stuff out there in my opinion. its alittle more expensive..like $46/.8 gallon around here..but its worth it to me.

 

[jellyfish420 10+ year member]

def sand the filler while in the green stage. where you can barely dent it w/ your nail.

start sanding if it clumps, wait another couple minutes..