hey i'm going to paint my first car. i have a question about spreading filler / sanding across the body gaps. Any tricks to it? Thanks.
its alway been my impression that panels are treated individually for filler. working across body gaps would require a long sanding board to keep everything flat. a friend of mine used a 3 foot sanding block on his fury to keep everything straight.
Nope just sand across them and sand the filler later .Just dont get alot of filler in gaps and if you do Take a utility knife and cut it out....
i've never spread filler before, but i'm assuming it's best to spread the filler across all body gaps then sand across those body gaps so the panels all line up perfectly. Would i just use something like a butter knife to run down the gaps to remove excess filler?
Hey man, we need pix of what kinda gaps you are referring to. If it is the gap between the hood and the fenders, or the trunk lid and the rear quarter panels, those parts are to be aligned and set with rubber bumpers, hinges or whatever the manufacturer used.
The fenders are adjustable, the doors are adjustable. Align the panels mechanically first. You'll have to skim coat the entire side of the vehicle and use a longboard to align the panels by your method.
If you are talking about losing gaps (like a fender connection) then you have to weld and grind them, and then filler to clean them up.
hey Cerberus, I'm referring to all the gaps on the car: hood to fenders, trunk to quarters, doors to quarters, etc. Yes, i've already got all the gaps aligned properly in bare metal. Now i'm going to spread the filler, block sand, then primer. So it sounds like I just spread the filler across those fitted gaps, then block across them.
If you are talking about making it "straight" from one panel to the other, then you will need to make POSITIVE that the panels are aligned EXACTLY where they are going to be and then you will want to tape the very inside edges of each side of the gap with some fine line tape or something to prevent your filler from getting down in the cracks. Then, assuming that you have a good mechanical etch on your panels like 40 grit or something, you can skim coat them both and block them as one panel to get that laser straight look. You will need a VERY LONG block to do this, DURA BLOCK makes some the are 2 or 3 feet long that are awesome for this type of work. Be sure to go back and clean up the edges before you prime though because you dont want filler running all the way to the edges of your panels or it will chip off. Make sure to keep your block strokes at about a 30 degree angle at all times to prevent cutting grooves into your work.
Don't spread filler across gap lines. If you must use body filler to square up a part at a door or trunk lid gap apply only to the body side. Filler along door edges and trunk lid edges don't last long. Some of the "show car" paint and body men back tape the seams then apply filler across the gaps and sculpt perfect gaps this way, but if you are here and asking for our advice, then you ain't developed enough skill to do this trick. Sorry Ted, but some skills take long practice and can't be perfected by reading about it.
the trick is NOT spreading filler across gaps. if you're using filler to gap your panels, you're not doing it right. filler is for small imperfections on the broad section of a panel. if anything, the panel edge should be the high point. if it is a low point, your panel is tweaked and requires fixing.
take some pictures of what the gaps look like now so we can get an idea of whether you still need to metal work the gaps or if you're ready to apply filler. a good trick i saw was using a plastic sign( it has the correct thickness 3-4 mm) and applying filler on either side . when the filler is dry itll just pop off and you have a perfect gap. just make sure you're not trying to use filler to make the edge or else youre asking for trouble.
got it. thanks. in my head i was thinking that if there's an 1/16" or 1/8" of filler on the panel and none around the gaps then the gap area would naturally be a low spot. I'm a beginner but i know that filler should never be used to form or correct a gap. I just want to make sure the gap area is the same height as the panels.
Do whatever works for you, it's not rocket science, or fine jewelry, but if you build up filler at a door/fender gap, one is going to have to clear the other when the door opens so you don't want them rubbing when you open the door, after it's got the paint buildup on it too. That's why a lot of cars with stainless side trim have tapers at the jambs so the doors clear the fender. Lots of people will claim "I don't have any filler at all on this car!" but they shot 1/4" thickness of catalyzed primer/surfacer (sprayable bondo) on it instead and blocked that down.
Panel alignment is critical. I always have a metal edge showing after sanding on the adjacent panels. A thick door edge, say, i so ugly and unnatural looking . Like the older vettes
Be sure to have your new weather strips in place before you start blocking it down. Back tape the gaps so you're not filling them with mud. Lots of good advice so far.
Ted I know what you're asking, I think, and yes you do want to block over your gaps so that the car is perfectly straight down the side. A common mistake I see alot on cars is when guys body work, block, and prime panels individually and after the car is painted you see the "dips" at the gaps when you look down the side of the car. So yes, when doing a complete it is important to align all your panels and then body work and prime as a whole, not piece by piece. I hope that made sense...
This is what I do, but I'm sure the pro's will cringe; after aligning the panels as well as possible using shims, hinge adjustments, etc, I run masking tape along the gaps on the INSIDE of the mating panels. Then spread on the skim coat including over the gaps. Then sand it all flat with a long board. When that's done, hopefully there is VERY little filler across the gap. Slice along the gap, open the doors/trunk lid/whatever, then sand the gaps perpendicular to the panel to create a nice crisp edge. I keep the filler to a minimum to avoid chip-outs.
Hey Ted, Another method is to not worry about how much filler you cover the gaps with so long as before the filler kicks off you run the spreader thru it to about 1/4''-1/2''. With this gap in the filler you can finish the gap with an ''idiot stick'' a paint stirring stick wrapped in 40 grit production paper. Be sure to keep the idiot stick to a right angle to the panel you've filled, and semi finish the gap before you finish sand the filled panel. The above method will yield clean & uniform panel gaps, but is no answer for properly bumped and straightened metalwork " Humpty Dumpty was pushed "
Royalscadillac is correct that most customs have three separate compumd curves instead of one that goes from the front to the back. They spread a quarter inch of filler then round it off at the gaps. Filler should be used to fill low spots only. Highs need to be worked down. Most guys say the a cheese grater cuts right down to the metal. That is exactly what it should do. Then you don't have to worry about filler in the gaps.
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