I'm new to body work, and learning as I go. I've replaced the rear quarter panels on my 68 vert. I welded in the new panels with a seam about two inches below the top and floated it over with filler. I'm using a long board with 80 grit to shape and then smoothing with 180. The problem...I keep feeling waves. I get to where it seems good, but as I run my hand over it, I can feel slight waves and variations. it's subtle transitions from one curve to another. So I apply some more, and sand that out. Seems to be a vicious never ending cycle...over and over.

I'm wondering if there are any tricks to get this right, or possible a way to "wet" the panel so it shines and I get a glimpse of what it would look like with a coat of glossy paint?

any help is appreciated.
clay

Clay,
In your situation you definitely need to shoot a guide coat, probably several times to get straight panels.
Do a search on this as there is much posted here.

I've been using different colors of spray can primer specifically over the areas where I feel a low spot or a bad transition, then floating the whole thing over. I guess it seems the waves are bigger than what will show from a guide coat. I feel the transitions and curves, and some places it just feels too abrupt or out of place. Which leads me to want to see the gloss on it...to see a reflection and know whether that transition or wave is going to show weird, or not at all.

I've heard soapy water, when wet sanding, leaves a good shine and gives good indication? but i don't have a sealer primer on, so I'm not a fan of water on the car? right or wrong?

Bodywork is hard to teach, especially on a screen and keep insruction brief. It is mostly self taught with some guidance. You have to SEE w/ your HANDS. Some cannot and rely only on guide coats. I use a guide coat once or twice and I'm done. Sometimes never. If you can feel it it will show, depending upon the distance and depth between the crests. I've been doing it so long it is second nature and mindless. You apparently have the drive and desire to learn. Only with time and repetition will quality and speed be achieved. The latter being the least of your concerns. A crosshatch sanding pattern using the longest board in the area being repaired is best. Use long strokes with even pressure. (too much pressure and your pushing the panel down, defeating your objective) Be methodical, don't just sand on a gamble it will end up straight. Work as if you were only allotted a limited amount of filler. When a high spot in the metal appears--Stop. See it with your hand. High spots MAY have to be worked GENTLY with a body hammer. Filler edge transitions to metal must be smooth, tapered and not abrupt. When you are pleased that it is close apply a skim coat to the entire area. This should be your LAST coat. Spread filler smoothly making a final pass with the longest stroke you can. You can't get it right putting a little filler here and there. (this can be done after you gain experience, using evercoat or similar glazing products) You'll end up doing what so many novices do--Building filler WAAAY to thick and well beyond the repair area. Crosshatch methodically your last coat of filler. Now apply 2K primer and block that, with your guide coats, ultimately achieving a straight panel. Don't use different color guide coats as you were, You will only add confusion. Use guide coats ( sanding filler and primer ) as assistance, ultimately reaching a comfort level where constant reliance is unneccessary. Wiping slow evaporating wax and grease remover on the surface will help you inspect your work when you feel you are close to paint. You will get it, with PATIENCE. Many times I have had to finish someone's job only by removing their work and ending up with a repair 1/4 the size. Everyone has a variation. Veterans ultimately use the same principles.

It takes awhile in experience to get a feel for it. Even then, it seems there is times something will feel nice and straight and it ends up not being quite as straight as you thought, while other times it feels like waves on the ocean and it ends up looking straight. Have a hard time getting some semi fenders at work feeling perfectly straight, and don't have the luxury there of blocking the primer, its prime and sand, send her to paint. Yet I swear, had several that felt bumpy to me, but once painted it looks nice and straight, must be hard to pick up with the curvature of them, and the spots not being abrupt, but rode out over a distance.

You don't want to wet down you body filler, it will soak up water, and that could be bad news if you don't have epoxy primer down underneath it, and it reaches the metal. Epoxy is the only primer type also that is non porous.


Yes you will want to get it feeling good by hand. If you really do want to check what it might look like though, you could epoxy prime the area, and look down it while still wet. You can apply body filler over epoxy primer, it has a decent window time to do so without sanding or you can just rough it up with some 180 first. If it looks good enough for primer you could then apply a filler primer over the epoxy to block sand, if not, then do more bodyfiller work.

Once you are to the point of primer, you can block it, and to kind of get an idea how it looks, wet it down by wiping with some wax and grease remover and take a quick look down the side into the light before it has evaporated.

Make sure you are sanding (block sanding) at a 45* angle on each pass. Wet the area with a wax and grease remover to see where you are.

Clay , there are some very good tips and methods in the above posts , especially Scott's , his part about seeing with your hands is the hardest acquired talent . One method that may help with this is using a soft cotton rag between your hand and the metal , it seems to let your hand slide over the area with less resistance allowing you to feel the small irregularities in the surface easier . One other thing (don't laugh) , close your eyes when running your hand across it , seems to block out any distractions and lets you "see" what your feeling . You may also be sanding too far , as in , man that feels good just a little more and it's going to be perfect , then , Too far !

Clay, I would shape the bondo with 40 grit then come back with 80 grit to remove the sanding marks, then 180 to eliminate more of the sanding marks, then spray area with about three coats of primer surfacer, let dry then use guide coat, sand with 180 on long board to see if you have any high or low spots, repair high or low spots and repeat this process. When area is good and straight use 500 grit wet sand to remove all sanding marks and prep for paint. It is not a bad idea to use guide coat on the final sanding to ensure that you do not miss any areas or bad spots. How did you weld the panel on? Did you warp the panel?

I truly appreciate all the advice. I'll keep working it, and incorporate these tips...

The seams were spot welded...meaning I kept the welds as short as possible and jumped around in fear of warping the metal. And I don't think it turned out bad...looked good on the surface...but once I started floating and sanding, there are places where it's definitely higher or lower. Some I gently tap down...some I float over and sand smooth.

The concern is more in the curves...and keeping the curves even through the length of the quarter panel. It all flows well, but I can feel some areas are flatter than others. So I keep working it, trying to find the balance between going insane over something that might never be noticeable and accepting the mistakes of first time body work. I have the same issues with some areas on the repop fenders I bought. They look straight, but I can feel waves as I walk along. How much it's worth to try to work those out I haven't decided yet.

thanks again for all the advice.
clay

Another thing that might help, make sure you get a good brand of sandpaper, and change it out a little more frequently, good sharp sandpaper without a lot of pressure will level it.

I use one of those cheap brown cotton gloves to feel the waves, if you stand facing the car then extend your arm all the way out, then kind of walk down the side of it with your arm straight out, instead of rubbing your hand across it right in front of you.
I don't know if anybody mentioned it, but make sure your sanding block is straight on the bottom, put a couple of sheets of sand paper on a flat surface, and go over it with your sanding block to take off the high spots.

I have used 2 and 4 foot levels for sanding blocks, you wrap the sandpaper around it, and duct tape it in the center, it will stay on pretty good, and levels are nice and light. You can preform it by bending it over the edge of the level, then lay it down on the table and put a good crease in it and tape it on.

Once you do it a couple times you can change it out pretty quick.

I go through a lot of paper...I can't stand when it gets dull and slows me down. I'm using an 18 inch longboard, but it's the padded kind, so that might be part of the problem. However, I can't see the need for a longer board. with the curves of the quarter, it's a very small section of the board that is ever in contact. the long board helps me steady it out, but it's only sanding in the specific spot in the center...or to an end if I lean it that way. I can see the need on a flat panel, like the hood or trunk lid, but not in this area?

first forget the 180 grit. you should be able to load on the bondo with flat enough to start with 180 for shape and then go to 220. the flat needs to be at least 6 inches long. put spray paint on the panel when you think you re done and lightly go over. the imprefections will appear. when i started i would always take off too much. put on take off put on take off, etc. finally i had a body shop buddy tell me to put on and leave it alone then use 220, that way i could never take off too much. you learn that way and then you can go with another grit. hope this helps, pick a panel that is flat like the hood and practice. curves take a little more practice. good luck

I'm using an 18 inch longboard, but it's the padded kind, so that might be part of the problem. I think you've got it! Go to the paint store or Lowe's, Home Depot and get a hard rubber sanding block and use guide coats as these men suggested.

Lots of good advice.

Yep, lots of good advice. Most everyone has problems doing bodywork in the begining but you learn as ya go. I used to hate it 'cause it's alot of work and seems I never was satisfied. My main problem was I'd put the filler on in a confined area where I thought it needed to be but I've since learned not to be afraid to spread it out much farther than where you THINK the repair area is. Don't be skimpy.....the vast majority is sanded off and the outer region will be so thin you can see through it but atleast ya get it where it needs to be;)