Dents on the body lines?

[BITESIZE]

My question is...How do you sand the bondo on a body line. I'm talking about the one that goes from the front of the car, clear to the rear. I've got quite a few dents right on that body line, and I haven't mastered sanding the bondo to get the body line back to straight. After sanding....when you look at it, it's flat not curved like it should be all down the car. Any tips? How do the body shops do it? I've searched the internet and can't find it? MARIOBURKE WHERE ARE YOU WHEN I NEED YOU! :rant:

http://memimage.cardomain.net/member_images/7/web/379000-379999/379742_181_full.jpg

[MessyHonda]

on my fender in autobody class we put a piece of masking tape to the body line and then filled the bottom with bondo....used 36 grit until it was good to go to 40 and then did the top part.....then used 80 grit.....we got it primed the same day....it was only the fender tho....it came out good.

tips...only go up to the line...using 45 degree angles

[BITESIZE]

You know, I was actually thinking about doing that with a piece of metal clamped to the body line and doing one side at a time. But the tape method sounds like common sense. Any other ideas?

[RamThis]

Tape to show you how far to sand, and use a "Longboard" sander. If you use those little hand held shorty sanding blocks, it tilts and follows the uneven surface too much because you dont have enough leverage to control it and keep it flat. Witht he long board, you have handles on each end, and can really make long, flat sanding strokes.

Also, to show low spots after you do your bondo work and spray on some heavy solids primer (Napa Tec-Prime is awesome) just use some rattle can flat black paint and dust the surface of the primer with the black paint. Now you can use the long board down your flat panels and sand off the black dusting. Any areas of black that remain are low spots that need to be built up with a thin layer finishing filler, the area re-long blocked out with some 120 grit, reshoot another layer of primer, black dust it, then run over the area again with the long block and 220 grit, and you should be able to get rid of any black low spots and it all sand off and just be gray primer.

If you get real good with eyeballing the body filler on the first pass, you will have alot less work with the primer and finishing fillers trying to keep bringing up low spots.

[BITESIZE]

I've been doing this bodywork since last summer and I'm starting to get the feel for it. The body lines are really hard though.

[RamThis]

Sharp body lines always are the hardest. The tape is the most common thing Ive seen used to guide you, and of course, the longboard sanding block.

Good thing about bondo and primer is, if it turns out looking like a turd, a DA with some 60 grit gets rid of the evidence real quick, and you can start right back over again :thumbup:

[BITESIZE]

Whats a DA?

[lostforawhile]

a da is a random orbit sander. it moves in an eccentric pattern to leave a super smooth surface. the best way to get the body lines straight is really going to be for you to learn how to do hammer and dolly work. the bondo will be ok,but it's never going to be quite right. you have to put the metal back in shape. filler is supposed to be for finishing up after REPAIRING the metal,not to repar the metal alone. I had dents all along both sides of my hatch,and that was the only way to properly fix them. the other thing you can use is to buy a stud welding tool kit. this welds small studs to the body,you use a slide hammer to pul each one,then you clip them off and grind them down. the trick with this is you want to pull the surface of the metal to just below where it was. if you try to make it flat again,you'll stretch the metal then it will be really hard to fix. you take almost all the dent out,then you use filler to finish it off. this relieves stress on the metal before you make the repair. the picture is of my wife using a variation on this tool,this one doesn't need studs to weld to the body. it welds itself to the body,you pull the dent,then you twist it to release. theres a lot of pictures on bodywork on the hatch,click on my signature and follow the image station link. use your back key to go back a page if needed on the main site,it's not navigating well right now.
http://www.imagestation.com/picture/sraid206/p63b41ac8d9ddc2124f58ca279e47404d/eecafe0e.jpg

[BITESIZE]

I have an orbital sander btw....wtf is it called a DA?

[lostforawhile]

crap I can't remember,I edited my post before with more info.

[MessyHonda]

I have an orbital sander btw....wtf is it called a DA?


Dual action.....they have diferent types...they are like 4-6 inches in diameter....they also have the Killer....just a big ass 36 grit sand paper....its known to eat hondas fenders.

[gp02a0083]

lol yup and why r u using 36 grit i mean at most u should be using is 180

[BITESIZE]

I have been using 80 on the big spots, and then 180. 36 is going overboard.

[MessyHonda]

I have been using 80 on the big spots, and then 180. 36 is going overboard.

for bondo?.....well for puddy its 180 but that is for dings the size of dimes and the anything bigger you should go with bondo....i have no problem working with 36....maybe cuz it takes alot of material off.....i plan to take my autobody class again...it was fun as hell and the teachers knoe there shit.

[bobafett]

http://img.shopping.com/cctool/PrdImg/images/pr/177X150/00/01/8d/ef/4a/26079050.JPG

a dual action sander rotates, and orbits...
it slowly rotates around in a 360 degree motion, while doing miniature 'wax-on' style movements the whole time (i think this is the orbital motion, it makes sense, as that movement resembles the orbit of something)

[RamThis]

Yep, Dual Action, meaning the pad itself does not rotate under force, only friction. The pad is moved in a circular motion by an offset collet on the air motor itself, and the collet has a bearing on it that allows the pad to freely move. Most good DA's like mine have a lock to actually lock it solid so it works like a grinder, or unlock for DA action.

I have two Pneumatic DA's, a Porter Cable electric DA, and two longboard pneumatic sanders (noisy as hell). I need to get some good body hammers and dollies now, I gotta lot of body work to do on my Acura to get it looking like new again.

[lostforawhile]

for bondo?.....well for puddy its 180 but that is for dings the size of dimes and the anything bigger you should go with bondo....i have no problem working with 36....maybe cuz it takes alot of material off.....i plan to take my autobody class again...it was fun as hell and the teachers knoe there shit.
before you start slapping bondo in there,you need to bring the metal back as close as possible to it's original shape. if you just stick bondo in a dent,the metal is still under tension from the collision,the bondo will continue to crack because of this. you shouldn't have so much filler you need 36 grit paper to remove the excess. it should be a thin coat. there isn't any filler on my car deeper then about an eigth of an inch. it's filler by the way,not bondo,bondo brand sucks. try the Nappa ultralight filler.

[MessyHonda]

before you start slapping bondo in there,you need to bring the metal back as close as possible to it's original shape. if you just stick bondo in a dent,the metal is still under tension from the collision,the bondo will continue to crack because of this. you shouldn't have so much filler you need 36 grit paper to remove the excess. it should be a thin coat. there isn't any filler on my car deeper then about an eigth of an inch. it's filler by the way,not bondo,bondo brand sucks. try the Nappa ultralight filler.


yeah i knoe.....bondo on bear metal....and puddy on anything you just have to use 180 to scratch up the surface a bit.....i get free bondo...dont knoe the brand but it says Easy sanding....and it goes come out good....i just need one of thoes 50 buck paintjobs...lol

[BITESIZE]

$50 paintjob is the route I'm taking.

[MessyHonda]

$50 paintjob is the route I'm taking.

cool i did not feel like reading that whole thing you will have to do a short how to thread so i can paint my car...even tho i dont think my uncle will like it since he works at a body shop.

[BITESIZE]

I'm telling you to read the whole 80 page thread it's worth it.

[MessyHonda]

I'm telling you to read the whole 80 page thread it's worth it.

you are not going to give me my 3 hours back... would rather be with my girl...lol just make a how to for poor MessyHonda so he can paint his car and make it a PrettyHonda

[BITESIZE]

Don't do the paint job if you don't want to read the thread. Take the time to read, because if you don't have time to read it, you don't have time to paint the car. You have to read the whole thread if you want a good paint job. It will take a shit load of practice, knowledge, skill, and #1 patience.

In my own opinion. Good things come to those who wait.