Ghost Line In Bodywork!!!

[Mark A.]

I replaced the left rear portion of my 69 body with a piece from a donor car. I made the cuts so they were on top of original bonding seams. The only place I had to install a new bonding strip is on top of the deck lid where it goes over the top of the gas tank. I cut a strip from the donor car with the exact same contour of the panel and used it underneath for the bonding strip. I used Ecklers panel bonding adhesive. On top I veed the seam, and put 2 layers of mat on the seam. Over that is a small amount of filler, Dupont primer surfacer, and Dupont sealer, Dupont single stage urethane. My problem is that I have a ghost line where the seam is on the deck lid. I have ground the repair completely down 2 times and redid the whole process, only to have the same result. I don't understand how this can be with all the other materials on top. It is flat, without any detectable surface variation. I am stumped. Does anyone have an idea what is going on? Thanks, Mark

[Timothy B.]

Re: Ghost Line In Bodywork!!!

Mark,

I am not a body man but my experence with this is that you will never get rid of that ghost line. I think that's the reason all the panels are bonded on the side vertical surfaces. The fiberglass expands and contracts differently and no matter how flat you still see the repair line.

I do think you repair is correct with bonding, mat & resin on top and finished with body filler. Only other option is major surgery and you don't want to do that.

[Joe M.]

Re: Ghost Line In Bodywork!!!

Not sure what bonding strip you are refering to. If you mean the flange at the edge of the 'tub'/ underbody as opposed to a junction that is joined with a individual bonding strip, I would suggest the 'flange' of the tub which supports the upper deck lid is too narrow to act as a 'bonding strip". That portion of the deck has a lot of flex.

[Alan S.]

Re: Ghost Line In Bodywork!!!

Hi Mark,
I think Tim and Joe have a good take on your situation. The light on that horizontal surface allows your eyes to see a slight variation your hands and fingers can't feel.
Is this an example of a repair needing to be 'feathered' much further than normal to get to a truly flat surface and/or an edge?

I think hiding the holes from a luggage rack on the rear deck of a 68-72 is one of the most difficult jobs to do. The fellow who helped me said the repair sould be 5 or 6 times the side of the original hole, and use NO filler.

Does your feathered area need to be 5 or 6 times the size of the joint you made?

I'll be interested to hear what others have to say, too.
Regards,
Alan

Here's a picture of my rear deck holes in progress. Notice how large the repair is.

[Joe M.]

Re: Ghost Line In Bodywork!!! - one suggestion

For luggage rack holes I'll bet you a nickel even you can repair the holes and not see shrinkage.

Cut fiberglass discs from scrap about 2.5" - 3" in diameter, epoxy to the underside, dish the top and 'glass' with polyester fiberglass resin or epoxy and thin layers of matt....not cloth. Try to finish off as is, use Vette Bond if needed to superficially hide scratches. Prefer thickened epoxy and/ or finely cut matt to reach final finish. Shoot your favorite epoxy primer.

Pay attention to the resin to hardener ratio.

[Mark A.]

Re: Ghost Line In Bodywork!!!

The ghost line is under the bonding strip I cut to go under the seam from the rear of the car towards the front. I feathered the mat at least 6" on each side of the seam. Mark

[Bill W.]

Re: Ghost Line In Bodywork!!!

different rates of expansion due to different materials and material mix ratios . Caused by temp. change and the sun. your only chance of the repair not showing is 90 degree plus sunshine before prime & paint . Expand the repair out a few inches on each side. The darker the color the harder it is to hide ...Thats why most restorers wont repair panels. They will only replace them at the factory seams where they are supposed to show.....Bill

[Mark A.]

Re: Ghost Line In Bodywork!!!

Bill,
I replaced the left rear piece, because it had been hit in the left rear, and the repair job was horrible. What would have been the correct way to repair this? Are you saying that the whole rear clip should be replaced to avoid this problem? I would like to know so I know what to do if I run into this again in the future. Mark

[Wayne P.]

Re: Ghost Line In Bodywork!!!

You are correct. Replace the entire panel.

[Mike M.]

Re: Ghost Line In Bodywork!!!

Hi Mark
Did you apply daily heat and/or sunshine daily for about 6 months after the repair before final finishing?
HaND

[Mark A.]

Re: Ghost Line In Bodywork!!!

Wowee! 6 months of sunshine? That would take me about 4 years up here in Wi. What is the purpose of that? Thanks, Mark

[Mike M.]

Re: Ghost Line In Bodywork!!!

The resin needs time and heat to cure adequately. This process involves shrinkage, which in addition to what appears to be described as a very narrow seam could be what is presenting itself as the "Ghost Lines".
This consideration, a wider seam blend, creating the same density and composition in your repair as is in the surrounding original material, in addition to the good suggestions above should solve your dilemma.
HaND