How do I build this body line

[rod7515]

Working on my 66 Dart. I have the front fenders off the car. This was a 270 model and I am eliminating the body trim that went from front to back. This left many holes where the clips would go thru the body to hold them on. I have welded these holes shut and now I am working on trying to finish so I can primer and put back on car. At the front of the fender there is a 1 - 1 1/2" wide metal strip that the trim sat on. When welding then sanding some of this line was removed so I need to rebuild that body line. I am adding pics of what I am talking about and I'm hoping some of you members can give me a good procedure for rebuilding this line so I can make it straight and the right height to blend into the fender.
Here are the pics:

Thanks for your help,
Rod

 

[Dicer]

Hi Rod, I will bump this thread for you with the procedure I did. Maybe you will get some more replies. I started out using a metal straight edge and visually check the low and high spots to concentrate on first. Adding small amounts and checking as I sanded, using a long as possible sanding board, you do not have to cover the whole board with sand paper. Start with the highest ridge first, making sure it is straight and flat. Using a radius sanding broad next, as you can see in the photo I just use a wooden dowel rod. Broom stick, ridged PVC pipe, gas line, radiator hose, something that will come close to the radius, and a course the longer the better, and then again you don not have to cover the whole board of your choosing with sand paper. I have usually switch colors of hardener for the bondo, the cream hardener usually comes in red or blue colors. I do this to let me know where I left off so not to sand over the spots that are already I know that are low. You can use the straight edge on the radius length ways, use the straight edge lightly scuff the area, you will feel the areas where it is indeed low. If you wish now, to check your work, buy a rattle can of sand-able primer, spray the area of concern, let dry and sand with a scot brite pad until glossy smooth. Kill the shop lights, get the trouble light out and have a look at the fender, the glare and shadows will let you now where the trouble spots are located. Pretty much after this I would use some body filler cream and spread pretty much the whole area and work it the same way again, but with fine sand paper. Hope this gets you a start.

View attachment 1715028522

 

[rod7515]

Thanks dicer, on the larger areas i was doing as you recommened with red and blue hardener for the reason you stated. Im just stuck on the lines. I guess its attack them slowly with patience. I have different size dowels and many sanding blocks big and small. I remember seeing a video or something once that showed using masking tape as well to help make and preserve the line but couldnt find that again. I'll attack it more tonight and hopefully more will chime in here as well.
Thanks Rod

 

[GeorgeH]

Guide coat the bondo, lay masking tape down following one side of the line, block the other side to the tape, pull tape up you'll see the line on the still guide coated side, and lay a masking line down on the side you just sanded, then block guide coated side to the tape. Alternate back and forth with each coat of plastic. it can make for a very sharp line. Get it built up, then you go back and soften/round the edge. Hope that makes sense. I like to work the upper surfaces flat mask it out then work the recesses. I also work an area as one piece. Each coat goes over the whole area. Hard to get them nice if you go back dab a little bondo here and there. You'll waffle up the rest of the area working it that way. Little blocks, cut down Paint sticks, sandpaper wrapped around a cardboard tube etc. Use stuff similar to the contours your trying to match.

 

[rod7515]

Thanks George, Going to give it a try and see how it comes out. I have a few body lines that need done. I am using short strand fiberglass then top off with glaze. Is this a good method?
Rod

 

[1968FormulaS340]

Thanks George, Going to give it a try and see how it comes out. I have a few body lines that need done. I am using short strand fiberglass then top off with glaze. Is this a good method?
Rod

I would use a quality, regular body filler and change your paper often. You want sharp paper. As your paper dulls, you have a natural tendency to press harder. The paper should be doing the work. Pressing hard while blocking makes waves.

Your body filler looks undercut, judging by the obvious edge between the filler and the metal. Your body filler edge should gradually fade away as the repair area becomes level with the metal surrounding it.

 

[GeorgeH]

I don't use a whole lot of fiber reinforced filler other then over a weld seam sometimes. Regular filler is a little easier and faster to work. FormulaS340 makes a good point about removing too much material.